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Sample records for absolute dynamic topography

  1. An estimate of global absolute dynamic topography

    NASA Technical Reports Server (NTRS)

    Tai, C.-K.; Wunsch, C.

    1984-01-01

    The absolute dynamic topography of the world ocean is estimated from the largest scales to a short-wavelength cutoff of about 6700 km for the period July through September, 1978. The data base consisted of the time-averaged sea-surface topography determined by Seasat and geoid estimates made at the Goddard Space Flight Center. The issues are those of accuracy and resolution. Use of the altimetric surface as a geoid estimate beyond the short-wavelength cutoff reduces the spectral leakage in the estimated dynamic topography from erroneous small-scale geoid estimates without contaminating the low wavenumbers. Comparison of the result with a similarly filtered version of Levitus' (1982) historical average dynamic topography shows good qualitative agreement. There is quantitative disagreement, but it is within the estimated errors of both methods of calculation.

  2. Evaluation of Absolute Dynamic Ocean Topography Profiles along the Brazilian Coast

    NASA Astrophysics Data System (ADS)

    Luz, R. T.; Bosch, W.; Freitas, S. R. C.; Heck, B.

    2009-04-01

    Based on a new approach, which consistently filters GRACE-based geoid undulations and altimetry-derived sea surface heights along the tracks of altimeter satellites, absolute dynamic ocean topography (DOT) profiles are estimated along the Brazilian coast. Such DOT profiles can be used to perform levelling over the sea. Connecting these profiles with Brazilian Geodetic Tide Gauge Network (RMPG) stations it would be possible to validate the current studies on the modernization of the Brazilian height system, extended over many thousand kilometers on land. The link with coastal reference sites would also allow to connect isolated height systems, e.g. north of the Amazonas River mouth. We perform long-term mean DOT-profiles of cross-calibrated altimeter satellites which operated for many years over repeated ground tracks (TOPEX, Jason-1, ERS-2). Moreover, we analyze the consistency among crossing profiles (single- and dual-satellite) in particular in areas with strong mesoscale currents. The extrapolation of DOT profiles towards selected RMPG stations is investigated. For this connection strategies are considered to overcome the degradation of coastal altimetry due to errors in ocean tide models and the land contamination of the radiometer observations.

  3. Dynamic Topography Revisited

    NASA Astrophysics Data System (ADS)

    Moresi, Louis

    2015-04-01

    Dynamic Topography Revisited Dynamic topography is usually considered to be one of the trinity of contributing causes to the Earth's non-hydrostatic topography along with the long-term elastic strength of the lithosphere and isostatic responses to density anomalies within the lithosphere. Dynamic topography, thought of this way, is what is left over when other sources of support have been eliminated. An alternate and explicit definition of dynamic topography is that deflection of the surface which is attributable to creeping viscous flow. The problem with the first definition of dynamic topography is 1) that the lithosphere is almost certainly a visco-elastic / brittle layer with no absolute boundary between flowing and static regions, and 2) the lithosphere is, a thermal / compositional boundary layer in which some buoyancy is attributable to immutable, intrinsic density variations and some is due to thermal anomalies which are coupled to the flow. In each case, it is difficult to draw a sharp line between each contribution to the overall topography. The second definition of dynamic topography does seem cleaner / more precise but it suffers from the problem that it is not measurable in practice. On the other hand, this approach has resulted in a rich literature concerning the analysis of large scale geoid and topography and the relation to buoyancy and mechanical properties of the Earth [e.g. refs 1,2,3] In convection models with viscous, elastic, brittle rheology and compositional buoyancy, however, it is possible to examine how the surface topography (and geoid) are supported and how different ways of interpreting the "observable" fields introduce different biases. This is what we will do. References (a.k.a. homework) [1] Hager, B. H., R. W. Clayton, M. A. Richards, R. P. Comer, and A. M. Dziewonski (1985), Lower mantle heterogeneity, dynamic topography and the geoid, Nature, 313(6003), 541-545, doi:10.1038/313541a0. [2] Parsons, B., and S. Daly (1983), The relationship between surface topography, gravity anomalies, and temperature structure of convection, Journal of Geophysical Research: Solid Earth (1978-2012), 88(B2), 1129-1144, doi:10.1029/JB088iB02p01129. [3] Robinson, E. M., B. Parsons, and S. F. Daly (1987), The effect of a shallow low viscosity zone on the apparent compensation of mid-plate swells, Earth and Planetary Science Letters, 82(3-4), 335-348, doi:10.1016/0012-821X(87)90207-X.

  4. Inferring Cetacean Population Densities from the Absolute Dynamic Topography of the Ocean in a Hierarchical Bayesian Framework

    PubMed Central

    Pardo, Mario A.; Gerrodette, Tim; Beier, Emilio; Gendron, Diane; Forney, Karin A.; Chivers, Susan J.; Barlow, Jay; Palacios, Daniel M.

    2015-01-01

    We inferred the population densities of blue whales (Balaenoptera musculus) and short-beaked common dolphins (Delphinus delphis) in the Northeast Pacific Ocean as functions of the water-column’s physical structure by implementing hierarchical models in a Bayesian framework. This approach allowed us to propagate the uncertainty of the field observations into the inference of species-habitat relationships and to generate spatially explicit population density predictions with reduced effects of sampling heterogeneity. Our hypothesis was that the large-scale spatial distributions of these two cetacean species respond primarily to ecological processes resulting from shoaling and outcropping of the pycnocline in regions of wind-forced upwelling and eddy-like circulation. Physically, these processes affect the thermodynamic balance of the water column, decreasing its volume and thus the height of the absolute dynamic topography (ADT). Biologically, they lead to elevated primary productivity and persistent aggregation of low-trophic-level prey. Unlike other remotely sensed variables, ADT provides information about the structure of the entire water column and it is also routinely measured at high spatial-temporal resolution by satellite altimeters with uniform global coverage. Our models provide spatially explicit population density predictions for both species, even in areas where the pycnocline shoals but does not outcrop (e.g. the Costa Rica Dome and the North Equatorial Countercurrent thermocline ridge). Interannual variations in distribution during El Niño anomalies suggest that the population density of both species decreases dramatically in the Equatorial Cold Tongue and the Costa Rica Dome, and that their distributions retract to particular areas that remain productive, such as the more oceanic waters in the central California Current System, the northern Gulf of California, the North Equatorial Countercurrent thermocline ridge, and the more southern portion of the Humboldt Current System. We posit that such reductions in available foraging habitats during climatic disturbances could incur high energetic costs on these populations, ultimately affecting individual fitness and survival. PMID:25785692

  5. Inferring cetacean population densities from the absolute dynamic topography of the ocean in a hierarchical Bayesian framework.

    PubMed

    Pardo, Mario A; Gerrodette, Tim; Beier, Emilio; Gendron, Diane; Forney, Karin A; Chivers, Susan J; Barlow, Jay; Palacios, Daniel M

    2015-01-01

    We inferred the population densities of blue whales (Balaenoptera musculus) and short-beaked common dolphins (Delphinus delphis) in the Northeast Pacific Ocean as functions of the water-column's physical structure by implementing hierarchical models in a Bayesian framework. This approach allowed us to propagate the uncertainty of the field observations into the inference of species-habitat relationships and to generate spatially explicit population density predictions with reduced effects of sampling heterogeneity. Our hypothesis was that the large-scale spatial distributions of these two cetacean species respond primarily to ecological processes resulting from shoaling and outcropping of the pycnocline in regions of wind-forced upwelling and eddy-like circulation. Physically, these processes affect the thermodynamic balance of the water column, decreasing its volume and thus the height of the absolute dynamic topography (ADT). Biologically, they lead to elevated primary productivity and persistent aggregation of low-trophic-level prey. Unlike other remotely sensed variables, ADT provides information about the structure of the entire water column and it is also routinely measured at high spatial-temporal resolution by satellite altimeters with uniform global coverage. Our models provide spatially explicit population density predictions for both species, even in areas where the pycnocline shoals but does not outcrop (e.g. the Costa Rica Dome and the North Equatorial Countercurrent thermocline ridge). Interannual variations in distribution during El Niño anomalies suggest that the population density of both species decreases dramatically in the Equatorial Cold Tongue and the Costa Rica Dome, and that their distributions retract to particular areas that remain productive, such as the more oceanic waters in the central California Current System, the northern Gulf of California, the North Equatorial Countercurrent thermocline ridge, and the more southern portion of the Humboldt Current System. We posit that such reductions in available foraging habitats during climatic disturbances could incur high energetic costs on these populations, ultimately affecting individual fitness and survival. PMID:25785692

  6. Eroding dynamic topography (Invited)

    NASA Astrophysics Data System (ADS)

    Braun, J.; Moucha, R.; Forte, A. M.

    2009-12-01

    We have investigated the feedback that the erosion of surface dynamic topography may have on the vigor of the driving mantle flow. Dynamic topography generates stresses that exactly balance the stresses originating from the divergence of the mantle flow in the vicinity of the quasi-rigid upper boundary. We show that, in the hypothetical situation where erosion is efficient enough to completely remove the dynamic topography, the amplitude of the underlying mantle flow is nearly doubled. We use the simple case of an anomalously light/hot spherical body rising through an isoviscous mantle to illustrate this point. We show that the rising velocity of the light sphere is doubled when erosion actively removes any surface topography at a rate that is similar to the sphere ascent velocity. We demonstrate that the effect of erosion on mantle dynamics is thus limited by the rate at which erosion is able to remove surface topography, and, consequently, strongly depends on the width and height of the dynamic topography. Using predictions of a self-consistent model of present-day mantle flow, driven by mantle heterogeneity derived from a high resolution joint seismic-geodynamic tomography model (Simmons et al. 2009), we analyze the spectral character of the predicted dynamic topography to conclude whether erosion is an important direct control on the vigor of mantle flow. To further constrain this feedback, we use a well-calibrated global model of surface erosion, sediment transport and sedimentation to predict the distribution and amplitude of present-day erosion and deposition, coupled to a 3d convection model of the present-day mantle. Results show that the feedback is not negligible but is most efficient at small wavelengths, i.e. less than a few hundred kilometers.

  7. Interferometer for measuring dynamic corneal topography

    NASA Astrophysics Data System (ADS)

    Micali, Jason Daniel

    The cornea is the anterior most surface of the eye and plays a critical role in vision. A thin fluid layer, the tear film, coats the outer surface of the cornea and serves to protect, nourish, and lubricate the cornea. At the same time, the tear film is responsible for creating a smooth continuous surface where the majority of refraction takes place in the eye. A significant component of vision quality is determined by the shape of the cornea and stability of the tear film. It is desirable to possess an instrument that can measure the corneal shape and tear film surface with the same accuracy and resolution that is currently performed on common optical elements. A dual interferometer system for measuring the dynamic corneal topography is designed, built, and verified. The completed system is validated by testing on human subjects. The system consists of two co-aligned polarization splitting Twyman-Green interferometers designed to measure phase instantaneously. The primary interferometer measures the surface of the tear film while the secondary interferometer simultaneously tracks the absolute position of the cornea. Eye motion, ocular variation, and a dynamic tear film surface will result in a non-null configuration of the surface with respect to the interferometer system. A non-null test results in significant interferometer induced errors that add to the measured phase. New algorithms are developed to recover the absolute surface topography of the tear film and corneal surface from the simultaneous interferometer measurements. The results are high-resolution and high-accuracy surface topography measurements of the in vivo cornea that are captured at standard camera frame rates. This dissertation will cover the development and construction of an interferometer system for measuring the dynamic corneal topography of the human eye. The discussion starts with the completion of an interferometer for measuring the tear film. The tear film interferometer is part of an ongoing research project that has spanned multiple dissertations. For this research, the instrument was tested on human subjects and resulted in refinements to the interferometer design. The final configuration of the tear film interferometer and results from human subjects testing are presented. Feedback from this instrument was used to support the development and construction of the interferometric corneal topographer system. A calibration is performed on the instrument, and then verified against simulated eye surfaces. Finally, the instrument is validated by testing on human subjects. The result is an interferometer system that can non-invasively measure the dynamic corneal topography with greater accuracy and resolution than existing technologies.

  8. Flat Subduction and Dynamic Topography

    NASA Astrophysics Data System (ADS)

    Lithgow-Bertelloni, C. R.; Dávila, F. M.; Eakin, C. M.; Crameri, F.

    2014-12-01

    Mantle dynamics manifests at the surface via the horizontal motions of plates and the vertical deflections that influence topography and the non-hydrostatic geoid. The pioneering work of Mitrovica et al. (1989) and Gurnis (1990) on this dynamic topography revolutionized our understanding of sedimentary basin formation, sea level changes and continental flooding. The temporal evolution of subduction can explain the migration of basins and even the drainage reversal of the Amazon (Shephard et al., 2012; Eakin et al., 2014). Until recently, flat subduction has been seen as enhancing downward deflection of the overriding plate and increasing flooding. However, this interpretation depends crucially on the details of the morphology and density structure of the slab, which controls the loci and amplitude of the deflection. We tend to ignore morphological details in mantle dynamics because flow can smooth out short wavelength variations. We have shown instead that details matter! Using South America as a natural laboratory because of the large changes in morphology of the Nazca slab along strike, we show that downward deflection of the overriding plate and hence basin formation, do not occur over flat segments but at the leading edge, where slabs plunge back into the mantle. This is true in both Argentina and Peru. The temporal evolution from a 'normally' dipplng slab to a flat slab leads to uplift over flat segments rather than enhanced subsidence. Critical for this result is the use of a detailed morphological model of the present-day Nazca slab with a spatial resolution of 50-100 km and based on relocated seismicity and magnetotelluric results. The density structure of the slab, due to age and the presence of overthickened crust from aseismic ridge subduction is essential. Overthickened crust leads to buoyant slabs. We reproduce formation and deposition of the Acres-Solimoes basin and the evolution of the Amazon drainage basin in Peru as well as the Mar Chiquita depression in Argentina. We explain the uplift of the paleosols of the los Llanos formation and the Fitzcarrald Arch. We show the effects of strong viscosity variations and slab dip on the extent of continental flooding.

  9. Predicting dynamic topography from mantle circulation models

    NASA Astrophysics Data System (ADS)

    Webb, Peter; Davies, J. Huw

    2013-04-01

    Dynamic topography is anomalous vertical motions of Earth's surface associated with viscous flow in the mantle. Deformable boundaries, such as the surface, CMB and phase transition boundaries, within a fluid (Earth's mantle) are deflected by viscous flow. Denser than average, sinking mantle creates inward deflections of Earth's surface. Equally, upwelling flow creates bulges in the surface; large plumes are commonly thought to produce superswells, such as the anomalously high elevation of Southern Africa. Dynamic topography appears to operate on a number of length scales. Mantle density anomalies estimated from seismic tomography indicate long wavelength dynamic topography at present day of around 2 km amplitude (e.g. Conrand & Husson, 2009) whilst continental scale studies suggest vertical motions of a few hundred metres. Furthermore, time scales must be an important factor to consider when assessing dynamic topography. Stable, dense lower mantle 'piles' may contribute to dynamic surface topography; as they appear stable over reasonably long time scales, long wavelength dynamic topography may be a fairly constant feature over the recent geological past. Shorter wavelength, smaller amplitude dynamic topography may be due to more transient features of mantle convection. Studies on a continental scale reveal shorter term changes in dynamic topography of the order of a few hundred metres (e.g. Roberts & White, 2010; Heine et al., 2010). Understanding dynamic topography is complicated by the fact it is difficult to observe as the signal is often masked by isostatic effects. We use forward mantle convection models with 300 million years of recent plate motion history as the surface boundary condition to generate a present day distribution of density anomalies associated with subducted lithosphere. From the modelled temperature and density fields we calculate the normal stress at or near the surface of the model. As the models generally have a free slip surface where no vertical motion is allowed, an excess or deficit of stress exists near the surface. A pointwise force balance between this stress excess and the weight of rock above is used to calculate the anomalous elevation associated with the stress. Here we present some of the results obtained from mantle circulation models. We look at different ways of predicting dynamic topography, including the depth at which the stress field is calculated and by removing lithospheric density anomalies from the calculation. We also assess the impact of crustal thickness and isostasy on the predictions of dynamic topography.

  10. Dynamic topography over the Antarctic continent

    NASA Astrophysics Data System (ADS)

    Anderson, L.; Ferraccioli, F.; Eagles, G.; Steinberger, B. M.; Ritsema, J. E.

    2012-12-01

    Our knowledge of dynamic topography in Antarctica remains in an infancy stage compared to other continents. We assess the space-time variability in dynamic topography in Antarctica by analysing grids of global dynamic topography from present-day to 80 Ma based on the tomographic model S40RTS. Our model reveals that the Gamburtsev Province and Dronning Maud Land, two of the major nucleation sites for the East Antarctic Ice Sheet (EAIS) were ~500 m higher 60 Ma ago. The increased elevation may have facilitated ephemeral ice cap development in the early Cenozoic. Between ca 25 and 50 Ma the northern Wilkes Subglacial Basin was ca 200 m higher than today and a major increase in regional elevation (>600 m) occurred over the last 20-15 Ma over the northern and southern Victoria Land in the Transantarctic Mountains (TAM). The most prominent signal is observed over the Ross Sea Rift (RSR) where predicted Neogene dynamic topography exceeds 1,000 m. The flow of warm mantle from the West Antarctic Rift System (WARS) may have driven these dynamic topography effects over the TAM and RSR. However, we found that these effects are comparatively less significant over the Marie Byrd Land Dome and the interior of the WARS. If these contrasting dynamic topography effects are included, then the predicted elevations of the Ross Sea Embayment ca 20 Ma ago are more similar to the interior of the WARS, with significant implications for the early development of the West Antarctic Ice Sheet

  11. Absolute 3D reconstruction of thin films topography in microfluidic channels by interference reflection microscopy.

    PubMed

    Huerre, A; Jullien, M-C; Theodoly, O; Valignat, M-P

    2016-02-23

    The travel of droplets, bubbles, vesicles, capsules, living cells or small organisms in microchannels is a hallmark in microfluidics applications. A full description of the dynamics of such objects requires a quantitative understanding of the complex hydrodynamic and interfacial interactions between objects and channel walls. In this paper, we present an interferometric method that allows absolute topographic reconstruction of the interspace between an object and channel walls for objects confined in microfluidic channels. Wide field microscopic imaging in reflection interference contrast mode (RICM) is directly performed at the bottom wall of microfluidic chips. Importantly, we show that the reflections at both the lower and upper surface of the microchannel have to be considered in the quantitative analysis of the optical signal. More precisely, the contribution of the reflection at the upper surface is weighted depending on the light coherence length and channel height. Using several wavelengths and illumination apertures, our method allows reconstructing the topography of thin films on channel walls in a range of 0-500 nm, with a precision as accurate as 2 nm for the thinnest films. A complete description of the protocol is exemplified for oil in water droplets travelling in channels of height 10-400 μm at a speed up to 5 mm s(-1). PMID:26830018

  12. Absolute stability of dynamic cavities

    NASA Astrophysics Data System (ADS)

    Rosanov, N. N.

    2015-07-01

    The field structure in a cavity composed of an oscillating plane mirror and an immobile spherical mirror has been analyzed within the paraxial approximation. Relations between the radius of curvature of the spherical mirror and the distance between the mirrors at which the initially paraxial beam remains paraxial after multiple propagations through the cavity have been determined. It is shown that the stability is absolute, in contrast to the case of a static cavity (with immobile mirrors); i.e., deviations from the axial direction decrease exponentially with time.

  13. Renormalisation of Global Mantle Dynamic Topography Predictions using Residual Topography Measurements for "Normal" Ocean Crust

    NASA Astrophysics Data System (ADS)

    Cowie, Fergus; Kusznir, Nick; Cowie, Leanne

    2015-04-01

    The best constraint on model predictions of present day mantle dynamic topography are measurements of residual topography. Residual topography is calculated by removing the isostatic effects of bathymetry, sediments, ice, crustal thickness variation and lithosphere thermal anomalies from the observed topography. Comparison of global model predictions of mantle dynamic topography with global compilations of residual topography, while showing a broadly similar pattern at long wavelengths, differ substantially in amplitude. A strong contribution to the present day surface topographic signal arises from crustal thickness variation. As a consequence it is difficult to accurately determine residual topography for continental crust and for oceanic regions with substantially thicker than average oceanic crust (e.g. oceanic crust adjacent to volcanic rifted margins, oceanic plume tracks, volcanic plateaux, micro-continents). Residual topography is best measured on ocean crust of "normal" oceanic thickness. We use global mapping of crustal thickness using gravity inversion to identify crust with thicknesses greater than that of "normal" oceanic crust in order than we can eliminate the less accurate measurements of residual topography for these thicker crustal regions. Comparison of model predicted mantle dynamic topography with residual topography measurements for the remaining regions of thinner "normal" oceanic crust shows an improved correlation but with a dynamic topography showing a positive bias with respect to residual topography and a greater amplitude. We use residual topography measurements for "normal" oceanic crust to downward shift (by approximately 600 m) and rescale (by 0.6) predicted global mantle dynamic topography. We present maps of the renormalised model predictions of global mantle topography from Steinberger (2007) and Flament et al. (2013). One consequence of renormalization is to reduce the amplitude of predicted mantle dynamic topographic uplift in the Pacific. The gravity inversion methodology includes a correction for the elevated geothermal gradient of oceanic and rifted continental margin lithosphere and sediment thickness. Caveats on this methodology are (i) that the gravity inversion methodology used to determine crustal thickness for screening out thick crust is itself dependent on mantle dynamic topography (but fortunately only weakly so) and (ii) that the renormalization procedure is biased towards oceanic regions.

  14. Mean dynamic topography of the Arctic Ocean

    NASA Astrophysics Data System (ADS)

    Farrell, Sinéad Louise; McAdoo, David C.; Laxon, Seymour W.; Zwally, H. Jay; Yi, Donghui; Ridout, Andy; Giles, Katharine

    2012-01-01

    ICESat and Envisat altimetry data provide measurements of the instantaneous sea surface height (SSH) across the Arctic Ocean, using lead and open water elevation within the sea ice pack. First, these data were used to derive two independent mean sea surface (MSS) models by stacking and averaging along-track SSH profiles gathered between 2003 and 2009. The ICESat and Envisat MSS data were combined to construct the high-resolution ICEn MSS. Second, we estimate the 5.5-year mean dynamic topography (MDT) of the Arctic Ocean by differencing the ICEn MSS with the new GOCO02S geoid model, derived from GRACE and GOCE gravity. Using these satellite-only data we map the major features of Arctic Ocean dynamical height that are consistent with in situ observations, including the topographical highs and lows of the Beaufort and Greenland Gyres, respectively. Smaller-scale MDT structures remain largely unresolved due to uncertainties in the geoid at short wavelengths.

  15. Mean Dynamic Topography of the Arctic Ocean

    NASA Technical Reports Server (NTRS)

    Farrell, Sinead Louise; Mcadoo, David C.; Laxon, Seymour W.; Zwally, H. Jay; Yi, Donghui; Ridout, Andy; Giles, Katherine

    2012-01-01

    ICESat and Envisat altimetry data provide measurements of the instantaneous sea surface height (SSH) across the Arctic Ocean, using lead and open water elevation within the sea ice pack. First, these data were used to derive two independent mean sea surface (MSS) models by stacking and averaging along-track SSH profiles gathered between 2003 and 2009. The ICESat and Envisat MSS data were combined to construct the high-resolution ICEn MSS. Second, we estimate the 5.5-year mean dynamic topography (MDT) of the Arctic Ocean by differencing the ICEn MSS with the new GOCO02S geoid model, derived from GRACE and GOCE gravity. Using these satellite-only data we map the major features of Arctic Ocean dynamical height that are consistent with in situ observations, including the topographical highs and lows of the Beaufort and Greenland Gyres, respectively. Smaller-scale MDT structures remain largely unresolved due to uncertainties in the geoid at short wavelengths.

  16. Mean dynamic topography: inter-comparisons and errors.

    PubMed

    Bingham, Rory J; Haines, Keith

    2006-04-15

    Knowledge of the ocean dynamic topography, defined as the height of the sea surface above its rest-state (the geoid), would allow oceanographers to study the absolute circulation of the ocean and determine the associated geostrophic surface currents that help to regulate the Earth's climate. Here a novel approach to computing a mean dynamic topography (MDT), together with an error field, is presented for the northern North Atlantic. The method uses an ensemble of MDTs, each of which has been produced by the assimilation of hydrographic data into a numerical ocean model, to form a composite MDT, and uses the spread within the ensemble as a measure of the error on this MDT. The r.m.s. error for the composite MDT is 3.2 cm, and for the associated geostrophic currents the r.m.s. error is 2.5 cms(-1). Taylor diagrams are used to compare the composite MDT with several MDTs produced by a variety of alternative methods. Of these, the composite MDT is found to agree remarkably well with an MDT based on the GRACE geoid GGM01C. It is shown how the composite MDT and its error field are useful validation products against which other MDTs and their error fields can be compared. PMID:16537147

  17. Global dynamic topography: geoscience communities requirements

    NASA Astrophysics Data System (ADS)

    Dewez, T.; Costeraste, J.

    2012-04-01

    The advent of free-of-charge global topographic data sets SRTM and Aster GDEM have enabled testing a host of geoscience hypotheses. This is because they first revealed the relief of previously unavailable earth landscapes, enabled quantitative geomorphometric analyses across entire landscapes and improved the resolution of measurements. Availability of such data is now considered standard, and though resolved at 30-m to 90-m pixel, which is amazing seeing where we come from, they are now regarded as mostly obsolete given the sub-meter imagery coming through web services like Google Earth. Geoscientists now appear to desire two additional features: field-scale-compatible elevation datasets (i.e. meter-scale digital models and sub-meter elevation precision) and dispose of regularly updated topography to retrieve earth surface changes, while retaining the key for success: data availability at no charge. A new satellite instrument is currently under phase 0 study at CNES, the French space agency, to fulfil these aims. The scientific community backing this demand is that of natural hazards, glaciology and to a lesser extent the biomass community. The system under study combines a native stereo imager and a lidar profiler. This combination provides spatially resolved elevation swaths together with absolute along-track elevation control point profiles. Data generated through this system, designed for revisit time better than a year, is intended to produce not only single acquisition digital surface models, colour orthoimages and small footprint full-wave-form lidar profiles to update existing topographic coverages, but also time series of them. This enables 3D change detection with centimetre-scale planimetric precision and metric vertical precision, in complement of classical spectral change appoaches. The purpose of this contribution, on behalf of the science team, is to present the mission concepts and philosophy and the scientific needs for such instrument including foreseen societal benefits.

  18. Evolution of Neogene Dynamic Topography in Madagascar

    NASA Astrophysics Data System (ADS)

    Paul, J. D.; Roberts, G.; White, N. J.

    2012-12-01

    Madagascar is located on the fringes of the African superswell. Its position and the existence of a +30 mGal long wavelength free-air gravity anomaly suggest that its present-day topography is maintained by convective circulation of the sub-lithospheric mantle. Residual depth anomalies of oceanic crust encompassing the island imply that Madagascar straddles a dynamic topographic gradient. In June-July 2012, we examined geologic evidence for Neogene uplift around the Malagasy coastline. Uplifted coral reef deposits, fossil beach rock, and terraces demonstrate that the northern and southern coasts are probably being uplifted at a rate of ~0.2 mm/yr. Rates of uplift clearly vary around the coastline. Inland, extensive peneplains occur at elevations of 1 - 2 km. These peneplains are underlain by 10 - 20 m thick laterite deposits, and there is abundant evidence for rapid erosion (e.g. lavaka). Basaltic volcanism also occurred during Neogene times. These field observations can be combined with an analysis of drainage networks to determine the spatial and temporal pattern of convectively driven uplift. ~100 longitudinal river profiles were extracted from a digital elevation model of Madagascar. An inverse model is then used to minimize the misfit between observed and calculated river profiles as a function of uplift rate history. During inversion, the residual misfit decreases from ~20 to ~4. Our results suggest that youthful and rapid uplift of 1-2 km occurred at rates of 0.2-0.4 mm/yr during the last ˜15 Myr. The algorithm resolves distinct phases of uplift which generate localized swells of high topography and relief (e.g. the Hauts Plateaux). Our field observations and modeling indicate that the evolution of drainage networks may contain useful information about mantle convective processes.

  19. Curvature sensor for the measurement of the static corneal topography and the dynamic tear film topography in the human eye.

    PubMed

    Gruppetta, Steve; Koechlin, Laurent; Lacombe, François; Puget, Pascal

    2005-10-15

    A system to measure the topography of the first optical surface of the human eye noninvasively by using a curvature sensor is described. The static corneal topography and the dynamic topography of the tear film can both be measured, and the topographies obtained are presented. The system makes possible the study of the dynamic aberrations introduced by the tear film to determine their contribution to the overall ocular aberrations in healthy eyes, eyes with corneal pathologies, and eyes wearing contact lenses. PMID:16252765

  20. Lower mantle heterogeneity, dynamic topography and the geoid

    NASA Technical Reports Server (NTRS)

    Hager, B. H.; Clayton, R. W.; Richards, M. A.; Comer, R. P.; Dziewonski, A. M.

    1984-01-01

    Density contrasts in the lower mantle, recently imaged using seismic tomography, drive convective flow which results in kilometers of dynamically maintained topography at the core-mantle boundary and at the Earth's surface. The total gravity field due to interior density contrasts and boundary topography predicts the largest wavelength components of the geoid remarkably well. Neglecting dynamic surface deformation leads to geoid anomalies of opposite sign than are observed.

  1. Mercury's Thermal Evolution, Dynamical Topography and Geoid

    NASA Astrophysics Data System (ADS)

    Ziethe, Ruth; Benkhoff, Johannes

    Among the terrestrial planets Mercury is not only the smallest, but also the densest (after correction for self-compression). To explain Mercury's high density it is considered likely that the planet's mantle was removed during a giant impact event, when proto-Mercury was already differentiated into an iron core and a silicate mantle. Beside the damage to the planet's mantle the vaporization would cause a significant loss of volatile elements, leaving the remaining planet molten and dominated by extremely refractory material.Since the arrival of a spacecraft at the enigmatic planet is not to be expected before 2011 (Messenger) or 2019 (BepiColombo) we might already prepare ourselves for the upcoming results and perform tests that allow some anticipation of the measured data. The hermean mantle is modelled as an internally and bottom heated, isochemical fluid in a spherical shell. The principle of this convection model is widely accepted and is used for various models of thermal evolution of terrestrial planets, e.g., the Earth, Mars or the Moon. We are solving the hydrodynamical equations, derived from the conservation of mass, momentum and energy. A program originally written by S. Zhang is used to solve the temperature field which employs a combination of a spectral and a finite difference method. Beside the large core as a heat source 'from below' the decay of radioactive isotopes provides internal heating of the hermean mantle. The viscosity of the mantel material depends exponentially on the inverse temperature. The model results show the typical behaviour of a one-plate-planet, meaning the surface is not broken into several tectonic plates but the outside is a single rigid shell. The thermal evolution is generally charaterized by the growth of a massive lithosphere on top of the convecting mantle. The lower mantle and core cool comparatively little and stay at temperatures between 1900K and 2000K until about 2.0Ga after the simulation was started. The stagnant lid comprises roughly half the mantle after only 0.5Ga. Since the rigid lithosphere does not take part in the convection anymore, the heat coming from the interior (due to the cooling of the large core) can only be transported through the lithosphere by thermal conduction. This is a significantly less effective mechanism of heat transport than convection and hence the lithosphere forms an insulating layer. As a result, the interior is kept relatively warm.Because the mantle is relatively shallow compared to the planet's radius, and additionally the thick stagnant lid is formed relatively rapid, the convection is confined to a layer of only about 200km to 300km. Convection structures are therefore relatively small structured. The flow patterns in the early evolution show that mantle convection is characterized by numerous upwelling plumes, which are fed by the heat flow from the cooling core. These upwellings are relatively stable regarding their spatial position. As the core cools down the temperature anomalies become colder and less pronounced but not less numerous. In our calculations, a region of partial melt in the mantle forms immediately after the start of the model at a depths of roughly 220km. While in the entire lower mantle the temperature exceeds the solidus, the highest melt degrees can be found in the upwelling plumes. The partial molten region persists a significant time (up to 2.5Ga). How long the partial molten zone actually survives depends strongly on the initial conditions of the model. For instance, an outer layer with a reduced thermal conductivity would keep the lower mantle significantly warmer and a molten layer survives longer. The hot upwellings cause a surface deformation (dynamical topography) which itself causes a gravity anomaly. Due to the weak constraints of important parameters (e.g. sulfur content of the core, mantle rheology, amount and distribution of radiogenic heat sources, planetary contraction, thermal conductivity, etc) numerous models are required to understand the importance and influence of the mentioned variables. The models variety is huge and more investigations of the results on initial parameters are yet to be performed. The special interior structure of Mercury compared to the other terrestrial planets makes his thermal history very unique. Future work will cope with the thorough investigation of several parameters and their influence on the model outcome. Eventually observables like topography can be measured with spacecrafts in orbit (e.g. BepiColombo) and then allow conclusions on the interior dynamics of Mercury.

  2. Evolution of Neogene Dynamic Topography in Africa

    NASA Astrophysics Data System (ADS)

    Paul, Jonathan; Roberts, Gareth; White, Nicky

    2013-04-01

    The characteristic basins and swells of Africa's surface topography probably reflect patterns of convective circulation in the sub-lithospheric mantle. We have interrogated drainage networks to determine the spatial and temporal pattern of convectively driven uplift. ~560 longitudinal river profiles were extracted from a digital elevation model of Africa. An inverse model is then used to minimise the misfit between observed and calculated river profiles as a function of uplift rate history. During inversion, the residual misfit decreases from ~22 to ~5. Our results suggest that Africa's topography began to grow most rapidly after ~30 Ma at peak uplift rates of 0.1-0.15 mm/yr. The algorithm resolves distinct phases of uplift which generate localized swells of high topography and relief (e.g. the Angolan Dome). Uplift rate histories are shown to vary significantly from swell to swell. The calculated magnitudes, timing, and location of uplift agree well with local independent geological constraints, such as intense volcanism at Hoggar (42-39 Ma) and Afar (31-29 Ma), uplifted marine terraces, and warped peneplains. We have also calculated solid sediment flux histories for major African deltas which have persisted through time. This onshore record provides an important indirect constraint on the history of vertical motions at the surface, and agrees well with the offshore flux record, obtained from mapping isopachs of deltaic sediments. Our modelling and reconstructed sedimentary flux histories indicate that the evolution of drainage networks may contain useful information about mantle convective processes.

  3. Zooplankton patch dynamics: daily gap formation over abrupt topography

    NASA Astrophysics Data System (ADS)

    Genin, Amatzia; Greene, Charles; Haury, Loren; Wiebe, Peter; Gal, Gideon; Kaartvedt, Stein; Meir, Eli; Fey, Connie; Dawson, Jim

    1994-05-01

    Net tow and acoustic surveys of zooplankton distributions were made over and around Sixtymile Bank (110 km southwest of San Diego, California). Gaps devoid of vertically migrating zooplankton were formed every evening above the summit of the bank. Interactions between the migrating animals, their predators, physical advection and the local topography appear to determine the gap formation and dynamics. Gaps were transported downstream during the night and appeared to disintegrate slowly through vertical swimming behavior, current shear and mixing processes. Patch dynamics following gap formation, mediated by both ocean currents and animal behavior, should augment the spatial heterogeneity of zooplankton and affect marine food webs in areas where abrupt topography features are common.

  4. Static and dynamic support of western United States topography

    NASA Astrophysics Data System (ADS)

    Becker, Thorsten W.; Faccenna, Claudio; Humphreys, Eugene D.; Lowry, Anthony R.; Miller, Meghan S.

    2014-09-01

    Isostatic and dynamic models of Earth's surface topography can provide important insights into the driving processes of tectonic deformation. We analyze these two estimates for the tectonically-active western United States using refined structural models derived from EarthScope USArray. For the crust, use of recent Moho depth measurements and crustal density anomalies inferred from passive source seismology improve isostatic models. However, seismically determined lithospheric thickness variations from “lithosphere-asthenosphere boundary” (LAB) maps, and lithospheric and mantle density anomalies derived from heat flow or uppermost mantle tomography, do not improve isostatic models substantially. Perhaps this is a consequence of compositional heterogeneity, a mismatch between thermal and seismological LAB, and structural complexity caused by smaller-scale dynamics. The remaining, non-isostatic (“dynamic”) component of topography is large. Topography anomalies include negative residuals likely due to active subduction of the Juan de Fuca plate, and perhaps remnants of formerly active convergence further south along the margin. Our finding of broad-scale, positive residual topography in the Basin and Range substantiates previous results, implying the presence of anomalous buoyancy there which we cannot fully explain. The Colorado Plateau does not appear dynamically anomalous at present, except at its edges. Many of the residual topography features are consistent with predictions from mantle flow computations. This suggests a convective origin, and important interactions between vigorous upper mantle convection and intraplate deformation.

  5. Dynamic topography in subduction zones: insights from laboratory models

    NASA Astrophysics Data System (ADS)

    Bajolet, Flora; Faccenna, Claudio; Funiciello, Francesca

    2014-05-01

    The topography in subduction zones can exhibit very complex patterns due to the variety of forces operating this setting. If we can deduce the theoretical isostatic value from density structure of the lithosphere, the effect of flexural bending and the dynamic component of topography are difficult to quantify. In this work, we attempt to measure and analyze the topography of the overriding plate during subduction compared to a pure shortening setting. We use analog models where the lithospheres are modeled by thin-sheet layers of silicone putty lying on low-viscosity syrup (asthenosphere). The model is shorten by a piston pushing an oceanic plate while a continental plate including a weak zone to localize the deformation is fixed. In one type of experiments, the oceanic plate bends and subducts underneath the continental one; in a second type the two plates are in contact without any trench, and thus simply shorten. The topography evolution is monitored with a laser-scanner. In the shortening model, the elevation increases progressively, especially in the weak zone, and is consistent with expected isostatic values. In the subduction model, the topography is characterized, from the piston to the back-wall, by a low elevation of the dense oceanic plate, a flexural bulge, the trench forming a deep depression, the highly elevated weak zone, and the continental upper plate of intermediate elevation. The topography of the upper plate is consistent with isostatic values for very early stages, but exhibits lower elevations than expected for later stages. For a same amount of shortening of the continental plate, the thickening is the same and the plate should have the same elevation in both types of models. However, comparing the topography at 20, 29 and 39% of shortening, we found that the weak zone is 0.4 to 0.6 mm lower when there is an active subduction. Theses values correspond to 2.6 to 4 km in nature. Although theses values are high, there are of the same order as dynamic topography and could represent the dynamic effect of the slab sinking into the asthenosphere and lowering the elevation of the upper plate.

  6. The effects of abrupt topography on plankton dynamics.

    PubMed

    Zavala Sansón, L; Provenzale, A

    2009-12-01

    Plankton population dynamics in the upper layer of the ocean depends on upwelling processes that bring nutrients from deeper waters. In turn, these depend on the structure of the vertical velocity field. In coastal areas and in oceanic regions characterized by the presence of strong submarine topographic features, the variable bottom topography induces significant effects on vertical velocities and upwelling/downwelling patterns. As a consequence, large plankton and fish abundances are frequently observed above seamounts, canyons and steep continental shelves. In this work, the dynamics of an NPZ (nutrient-phytoplankton-zooplankton) system is numerically studied by coupling the ecosystem model with a quasi two-dimensional (2D) fluid model with topography. At variance with classical 2D approaches, this formulation allows for an explicit expression of the vertical motions produced when fluid columns are squeezed and stretched as they experience changes of depth. Thus, input or output of nutrients at the surface are associated with fluid motion over the bottom topography. We examine the dynamics of a cyclonic vortex over two basic topographies: a steep escarpment and a submarine mountain. We show that plankton abundance over the escarpment is modulated by the passing of topographic Rossby waves, generated by the vortex-topography interaction. In such configuration, advection effects driven by the flow over the escarpment are of limited relevance for the dynamics of biological fields. By contrast, we find that the flow resulting from the interaction of a vortex with a seamount is sufficiently strong and persistent to allow for a remarkable increase of nutrients, and a corresponding enhancement of phytoplankton and zooplankton concentrations. Over the seamount, advection effects associated with trapped flow perturbations around the summit play an essential role. PMID:19737575

  7. The Relationship between Dynamic Topography and Sequence Stratigraphy

    NASA Astrophysics Data System (ADS)

    White, N. J.

    2014-12-01

    An evolving pattern of convective circulation within the mantle generates and maintains dynamic topography which is some fraction of observed topography. Spatial variations of dynamic topography are easy to measure within the oceanic realm and it is possible to exploit inventories of seismic reflection and wide-angle data to determine the dynamic topography of the oldest oceanic lithosphere that abuts passive continental margins. Results show that oceanic lithosphere has dynamic topographic anomalies of +/- 1 km with wavelengths of 500-1000 km. These substantial anomalies intersect coastal shelves and so it is expected that the development of these anomalies has affected sequence stratigraphic architecture in important ways. A series of examples will be used to illustrate how sequence stratigraphy can be profoundly influenced by changing patterns of dynamic topography. First, along the West African margin a set of dynamic topographic domes intersect the shelf edge. Onshore, the Neogene growth of these domes is recorded by emergent terraces and by drainage patterns. Offshore, an Oligo-Miocene switch from aggradation to progradation together with a series of younger disconformities have modified stratigraphic architecture along the shelf. Secondly, along the Northwest Shelf of Australia there is evidence for 700 m of dynamic drawdown of the oldest oceanic floor. Regional mapping and backstripping of clinoformal geometries within a Miocene carbonate reef complex shows that there is a dramatic switch from progradation to aggradation which cannot be attributed to glacio-eustatic variations. Instead, this switch appears to reflect growth of dynamic drawdown within the mantle. Finally, the Icelandic plume has controlled vertical motions along fringing North Atlantic margins over the last 60 Ma. Thanks to the intersecting mid-oceanic ridge, there is independent evidence that the temperature structure of this plume has fluctuated through time. These fluctuations are recorded within the detailed sequence stratigraphy of the margins where a series of ephemeral terrestrial landscapes have been mapped. Stratigraphic architecture appears to be an important repository of details about transient convective circulation which are otherwise difficult to obtain.

  8. Dynamic evaluation of facial palsy by moire topography video

    NASA Astrophysics Data System (ADS)

    Yuen, Koji; Inokuchi, Ikuo; Maeta, Manabu; Kawakami, Shinichiro; Masuda, Yu

    1994-02-01

    Several visual assessment methods have been proposed for evaluating facial nerve function. They are of value clinically, but they have drawbacks when objective, quantitative, and reproducible assessment is required. To solve these problems, we used moire topography, which helps visualize information in three dimensions. We previously reported that one could evaluate the severity of facial palsy by observing characteristic patterns of the moire strips produced by facial movement. Accordingly, we developed a new form of the dynamic evaluation by recording the dynamic changes in moire strip patterns on the face on a videotape.

  9. A new Mean Dynamic Topography of the Mediterranean Sea based on model outputs, drifter data, hydrological profiles and altimeter measurements

    NASA Astrophysics Data System (ADS)

    rio, marie-helene; pascual, ananda; poulain, pierre-marie; menna, milena; adani, mario; balbin, rosa; aparicio, alberto; López Jurado, José Luis; Barceló, Bàrbara; Tintoré, Joaquin

    2013-04-01

    A new estimate of the Mediterranean Mean Dynamic Topography has been computed. The methodology used is similar to the previous work by (Rio et al, 2007). A first guess solution based on the Mediterranean Forecasting System 7 years (1993-1999) model mean is improved using information from oceanographic in-situ measurements and altimeter anomalies. Altimeter data used are the Level Anomalies computed specifically for the Mediterranean Sea by the SSALTO-DUACS center and distributed by AVISO. In addition, two types of in-situ measurements are used: on one hand, dynamic heights relative to 350m are computed from T/S profiles measured by CTD (IBAMar database covering the period 1993-2010), gliders (Socib-Imedea database for 2011) and different other casts, including ARGO floats from the EN3 database for the period ranging from 1993 to 2012. The missing barotropic and deep baroclinic components were estimated and added to the dynamic heights relative to 350m in order to compute the absolute dynamic topography. On the other hand, surface currents were deduced from drifting buoy trajectories and processed to extract the geostrophic component. Altimeter sea level (resp. velocity) anomalies were then subtracted from the instantaneous in-situ measurements of the absolute dynamic topography (resp. ocean surface geostrophic current) to obtain estimates of the mean dynamic topography (resp. mean geostrophic currents). These estimates were then used to improve the model first guess through a multivariate objective analysis and map the Mediterranean Mean Dynamic Topography on a 1/8° regular grid. The obtained MDT was validated against independent in-situ observations. A specific validation was carried out in the Balearic Sea.

  10. Dynamic Topography in the Oceanic Realm of West Africa, India, and the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Hoggard, M. J.; Roberts, G.; White, N. J.

    2012-12-01

    It is generally agreed that convection in the mantle can generate vertical motions at the Earth's surface. Consequently, the recorded history of subsidence and uplift holds important clues about mantle convection. We use the well-established relationship between seafloor subsidence and age to map present-day residual depth anomalies in the oceanic realm. This map yields estimates of the spatial variation of dynamic topography, providing care is taken to rule out other potential causes of subsidence or uplift such as flexure adjacent to seamounts and subduction zones. Global analysis indicates that anomalies typically vary between 1 km, over wavelengths of ~1000 km. This analysis of residual topography is concentrated on the oldest oceanic crust that abuts continental margins in order to provide a leg up onto the continents, where measuring absolute values of dynamic topography is considerably more complicated. Here we begin by looking at three areas in more detail - the west coast of Africa, India and the Gulf of Mexico. Residual depths along the west coast of Africa capture two full wavelengths of dynamic topography, which correlate well with the long-wavelength free air gravity anomaly. To constrain the temporal evolution of dynamic topography, we focus on regions such as the Gulf of Mexico which is currently drawn-down by ~2 km at its centre. Backstripping stratigraphic data from wells implies the majority of the anomalous subsidence has occurred in the last ~15 Ma. The east coast of India shows a drawdown of 2 km beneath the Bengal fan and the development of this anomaly is clearly recorded in the transition from progradational to aggradational behaviour within the margin's clinoform architecture. Analysis of adjacent river profiles indicates recent onshore uplift has provided high quantities of clastic detritus that have been deposited on the margin. Oceanic residual depths along the west African margin overlain by the long wavelength filtered free air gravity anomaly in contours of 10 mGal. The filigree corresponds to estimates calculated from published global grid datasets of water and sediment thickness. The points are based on primary data such as reflection seismic profiles. Circles are our most accurate residual depth measurements where crustal thickness is known. Downwards pointing triangles are maximum estimates and upwards pointing triangles are minimum.

  11. Absolute stability and dynamical stabilisation in predator-prey systems.

    PubMed

    Dagbovie, Ayawoa S; Sherratt, Jonathan A

    2014-05-01

    Many ecological systems exhibit multi-year cycles. In such systems, invasions have a complicated spatiotemporal structure. In particular, it is common for unstable steady states to exist as long-term transients behind the invasion front, a phenomenon known as dynamical stabilisation. We combine absolute stability theory and computation to predict how the width of the stabilised region depends on parameter values. We develop our calculations in the context of a model for a cyclic predator-prey system, in which the invasion front and spatiotemporal oscillations of predators and prey are separated by a region in which the coexistence steady state is dynamically stabilised. PMID:23571604

  12. Impacts of mean dynamic topography on a regional ocean assimilation system

    NASA Astrophysics Data System (ADS)

    Yan, C.; Zhu, J.; Tanajura, C. A. S.

    2015-10-01

    An ocean data assimilation system was developed for the Pacific-Indian oceans with the aim of assimilating altimetry data, sea surface temperature, and in situ measurements from Argo (Array for Real-time Geostrophic Oceanography), XBT (expendable bathythermographs), CTD (conductivity temperature depth), and TAO (Tropical Atmosphere Ocean). The altimetry data assimilation requires the addition of the mean dynamic topography to the altimetric sea level anomaly to match the model sea surface height. The mean dynamic topography is usually computed from the model long-term mean sea surface height, and is also available from gravimetric satellite data. In this study, the impact of different mean dynamic topographies on the sea level anomaly assimilation is examined. Results show that impacts of the mean dynamic topography cannot be neglected. The mean dynamic topography from the model long-term mean sea surface height without assimilating in situ observations results in worsened subsurface temperature and salinity estimates. Even if all available observations including in situ measurements, sea surface temperature measurements, and altimetry data are assimilated, the estimates are still not improved. This proves the significant impact of the MDT (mean dynamic topography) on the analysis system, as the other types of observations do not compensate for the shortcoming due to the altimetry data assimilation. The gravimeter-based mean dynamic topography results in a good estimate compared with that of the experiment without assimilation. The mean dynamic topography computed from the model long-term mean sea surface height after assimilating in situ observations presents better results.

  13. Mantle flow and dynamic topography associated with slab window opening

    NASA Astrophysics Data System (ADS)

    Guillaume, Benjamin; Moroni, Monica; Funiciello, Francesca; Martinod, Joseph; Faccenna, Claudio

    2010-05-01

    A slab window is defined as an 'hole' in the subducting lithosphere. In the classical view, slab windows develop where a spreading ridge intersects a subduction zone. The main consequences of this phenomenon are the modifications of the physical, chemical and thermal conditions in the backarc mantle that in turn affect the tectonic and magmatic evolution of the overriding plate. In this work, we perform dynamically self-consistent mantle-scale laboratory models, to evaluate how the opening of a window in the subducting panel influences the geometry and the kinematics of the slab, the mantle circulation pattern and, finally, the overriding plate dynamic topography. The adopted setup consists in a two-layer linearly viscous system simulating the roll-back of a fixed subducting plate (simulated using silicone putty) into the upper mantle (simulated using glucose syrup). Our experimental setting is also characterized by a constant-width rectangular window located at the center of a laterally confined slab, modeling the case of the interaction of a trench-parallel spreading ridge with a wide subduction zone. We find that the geometry and the kinematics of the slab are only minorly affected by the opening of a slab window. On the contrary, slab induced mantle circulation, quantified using Feature Tracking image analysis technique, is strongly modified and produces a peculiar non-isostatic topographic signal on the overriding plate. Assuming that our modeling results can be representative of the natural behavior of subduction zones, we compare them to the Patagonian subduction zone finding that anomalous backarc volcanism that developed since middle Miocene could result from the lateral flowage of subslab mantle, and that part of the Patagonian uplift could be dynamically supported.

  14. Assessing Gravity Estimates to Improve Dynamic Ocean Topography

    NASA Astrophysics Data System (ADS)

    Gille, S. T.; Krzemien, T.; Mazloff, M. R.; Cornuelle, B. D.

    2013-12-01

    Dynamic ocean topography (DOT), which defines the streamlines of ocean circulation, can be computed from the difference between mean sea surface (MSS) measurements (e.g. from satellite altimetry) and the Earth's geoid (from gravity observations). Uncertainties in the geoid translate into uncertainties in DOT, and this is particularly an issue for smaller length-scales. We estimate these uncertainties at various length-scales by comparing GRACE and GOCE-based geoid products with MSS and DOT products. Geoid and mean sea surface height fields are then combined to constrain the DOT in an assimilating ocean model, the Southern Ocean State Estimate (SOSE). Uncertainties in the small-scale geoid are accounted for with a prescribed error variance. The large-scale geoid errors are accounted for by solving for a smooth error field representing misfit to geoid model estimates. This error field minimizes the impact of correlated errors in the geoid on the optimization, while providing a metric for evaluating the consistency estimate of SOSE relative to the geoid products. For the EGM08 and TIMR3 geoid fields, our analysis for the Southern Ocean shows that error variances tend to be largest in small-scale regions associated with large topographic features. Error covariance magnitudes imply regional differences between the two products.

  15. Freeboard, sea level and dynamic topography during aggregation of a supercontinent

    NASA Astrophysics Data System (ADS)

    Guillaume, B.; Husson, L.; Choblet, G.

    2012-04-01

    The long-term evolution of sea level is a combination of eustatic mechanisms (tectono-eustatism, distribution of continental masses through orogenesis and sedimentation) and non-uniform processes (dynamic topography, geoid, wander of the Earth rotation pole). Given the potentially similar amplitude of both factors, there is a bias in the observation of absolute sea level. Moreover, over large time-scales, and more specifically over the Wilson cycle time-scale, plate aggregation and separation are associated both with (i) variations of the flow pattern and (ii) thermal state in the mantle, which in turn may induce specific vertical motions of the surface. By changing the size of the oceanic and continental water reservoirs, large-scale dynamic topography associated with subduction or the presence of mantle plumes controls rises or drops of sea level, which in turn controls part of the stratigraphic record. The Earth has known periods of continental aggregation and fragmentation that redistribute the location of plate boundaries, especially the location and the length of subduction zones, that could potentially affect sea level. The distribution of mass anomalies in the mantle with respect to continents may therefore have a significant impact. To test the possible correlation between sea level changes and the Wilson cycle, we decide to first focus on the Pangea, which is known to be a period during which most subductions took place beneath continents. We run a set of Earth-like instantaneous flow model using the OEDIPUS (Origin, Evolution and Dynamics of the Interiors of Planets Using Simulation) tool, which allows spherical geometries with lateral viscosity variations. In these models, Pangea is modeled by a spherical continental cap, covering 29% of the planet surface, and floating above a two-layered viscous mantle. We vary parameters such as the dip of the subducting panel, the depth reached by the slab, the viscosity structure and the plate thickness within reasonable ranges to evaluate the volume of water reservoirs created by dynamic topography and its impact on the variations of sea level. In addition, we evaluate analytically the effect of an increase in temperature at the base of the lithosphere, as can be produced by thermal insulation above the convecting mantle during supercontinent aggregation, on the isostatic response of the continent, which modifies the continental reservoir shape and can produce sea level variations.

  16. A magmatic probe of dynamic topography beneath western North America

    NASA Astrophysics Data System (ADS)

    Klöcking, M.; White, N. J.; Maclennan, J.

    2014-12-01

    A region centered on the Yellowstone hotspot and encompassing the Colorado Plateau sits at an elevation 2 km higher than the cratonic North America. This difference broadly coincides with tomographically observed variations in lithospheric thickness: ~120 km beneath western North America, ~240 km beneath the craton. Thermochronology of the Grand Canyon area, sedimentary flux to the Gulf of Mexico, and river profile inversion all suggest that regional uplift occurred in at least two separate stages. High resolution seismic tomographic models, using USArray data, have identified a ring of low velocity material beneath the edges of the Colorado Plateau. Magmatism coincides with these low velocity zones and shows distinct phases: an overall increase in volume around 40 Ma and a change from lithospheric to asthenospheric signatures around 5 Ma. Volcanism is also observed to migrate north-east with time. Here, we attempt to integrate these different observations with lithospheric thickness. A dynamic topography model of progressive lithospheric erosion over a hot mantle plume might account for uplift as well as the temporal and spatial distribution of magmatism across western North America. Thinning of the lithosphere around the edges of the Colorado Plateau in combination with the hotter mantle potential temperature of a plume could create isostatic and dynamic uplift as well as allowing for melt production. To test this model, we have analysed around 100 samples from volcanic centers across western North America by ICP-MS for rare earth elements (REE). Most of the samples are younger than 5 Ma, and all of them have previously been analysed by XRF. Using trace element ratios such as La/Yb and Nb/Y we assess depth of melting and melt fraction, respectively. In addition, we use REE inversion modelling to estimate melt fractions as a function of depth and temperature of melting. The results are compared to existing constraints on lithospheric thickness and mantle potential temperature.

  17. Impacts of mean dynamic topography on a regional ocean assimilation system

    NASA Astrophysics Data System (ADS)

    Yan, C.; Zhu, J.; Tanajura, C. A. S.

    2015-06-01

    An ocean assimilation system was developed for the Pacific-Indian oceans with the aim of assimilating altimetry data, sea surface temperature, and in-situ measurements from ARGO, XBT, CTD, and TAO. The altimetry data assimilation requires the addition of the mean dynamic topography to the altimetric sea level anomaly to match the model sea surface height. The mean dynamic topography is usually computed from the model long-term mean sea surface height, and is also available from gravimeteric satellite data. In this study, different mean dynamic topographies are used to examine their impacts on the sea level anomaly assimilation. Results show that impacts of the mean dynamic topography cannot be neglected. The mean dynamic topography from the model long-term mean sea surface height without assimilating in-situ observations results in worsened subsurface temperature and salinity estimates. The gravimeter-based mean dynamic topography results in an even worse estimate. Even if all available observations including in-situ measurements, sea surface temperature measurements, and altimetry data are assimilated, the estimates are still not improved. This further indicates that the other types of observations do not compensate for the shortcoming due to the altimetry data assimilation. The mean dynamic topography computed from the model's long-term mean sea surface height after assimilating in-situ observations presents better results.

  18. Assessment of optimally filtered recent geodetic mean dynamic topographies

    NASA Astrophysics Data System (ADS)

    Siegismund, F.

    2013-01-01

    AbstractRecent geoids from the Gravity Recovery and Climate Experiment (GRACE) and the Gravity field and steady state Ocean Circulation Explorer satellite mission (GOCE) contain useful short-scale information for the construction of a geodetic ocean mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> (MDT). The geodetic MDT is obtained from subtracting the geoid from a mean sea surface (MSS) as measured by satellite altimetry. A gainful use of the MDT and an adequate assessment needs an optimal filtering. This is accomplished here by defining a cutoff length scale dmax for the geoid and applying a Gaussian filter with half-width radius r on the MDT. A series of MDTs (GRACE, GOCE, and combined satellite-only (GOCO) solutions) is tested, using different sets of filter parameters dmax and r. Optimal global and regional dependent filter parameters are estimated. To find optimal parameters and to assess the resulting MDTs, the geostrophic surface currents induced by the filtered geodetic MDT are compared to corrected near-surface currents obtained from the Global Drifter Program (GDP). The global optimal cutoff degree and order (d/o) dmax (half-width radius r of the spatial Gaussian filter) is 160 (1.1°) for GRACE; 180 (1.1-1.2°) for 1st releases of GOCE (time- and space-wise methods) and GOCO models; and 210 (1.0 degree) for 2nd and 3rd releases of GOCE and GOCO models. The cutoff d/o is generally larger (smaller) and the filter length smaller (larger) for regions with strong, small-scale (slow, broad scale) currents. The smallest deviations from the drifter data are obtained with the GOCO03s geoid model, although deviations of other models are only slightly higher.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014E%26PSL.407..163F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014E%26PSL.407..163F"><span id="translatedtitle">Isostasy, <span class="hlt">dynamic</span> <span class="hlt">topography</span>, and the elevation of the Apennines of Italy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Faccenna, Claudio; Becker, Thorsten W.; Miller, Meghan S.; Serpelloni, Enrico; Willett, Sean D.</p> <p>2014-12-01</p> <p>The elevation of an orogenic belt is commonly related to crustal/lithosphere thickening. Here, we discuss the Apennines as an example to show that <span class="hlt">topography</span> at a plate margin may be controlled not only by isostatic adjustment but also by <span class="hlt">dynamic</span>, mantle-driven processes. Using recent structural constraints for the crust and mantle we find that the expected crustal isostatic component explains only a fraction of the <span class="hlt">topography</span> of the belt, indicating positive residual <span class="hlt">topography</span> in the central Apennines and negative residual <span class="hlt">topography</span> in the northern Apennines and Calabria. The trend of the residual <span class="hlt">topography</span> matches the mantle flow induced <span class="hlt">dynamic</span> <span class="hlt">topography</span> estimated from regional tomography models. We infer that a large fraction of the Apennines <span class="hlt">topography</span> is related to mantle <span class="hlt">dynamics</span>, producing relative upwellings in the central Apennines and downwellings in the northern Apennines and Calabria where subduction is still ongoing. Comparison between geodetic and geological data on vertical motions indicates that this <span class="hlt">dynamic</span> process started in the early Pleistocene and the resulting uplift appears related to the formation and enlargement of a slab window below the central Apennines. The case of the Apennines shows that at convergent margins the elevation of a mountain belt may be significantly different from that predicted solely by crustal isostasy and that a large fraction of the elevation and its rate of change are <span class="hlt">dynamically</span> controlled by mantle convection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1615334B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1615334B"><span id="translatedtitle">Integrated approach to estimate the ocean's time variable <span class="hlt">dynamic</span> <span class="hlt">topography</span> including its covariance matrix</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Becker, Silvia; Brockmann, Jan Martin; Schuh, Wolf-Dieter</p> <p>2014-05-01</p> <p>The ocean's mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> as the difference between the sea surface and the geoid reflects many characteristics of the general ocean circulation. Consequently, it provides valuable information for evaluating or tuning ocean circulation models. However, the determination of the mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> from satellite based gravity field and altimetric observations is not straightforward. For the integration of the <span class="hlt">dynamic</span> <span class="hlt">topography</span> into ocean circulation models not only the <span class="hlt">dynamic</span> <span class="hlt">topography</span> itself but also its inverse covariance matrix on the ocean model grid is required. We developed a rigorous combination method where both instrumental errors and omission errors are accounted for, including the determination of optimal relative weights between the observation groups. The altimetric mean sea surface is expressed as a sum of geoid heights represented in terms of spherical harmonics and the mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> parameterized by a finite element method which can be directly related to the particular ocean model grid. The different observation groups are combined in terms of normal equations. This allows the direct determination of the normal equations of the mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> which contain the appropriate weights for model-data misfits in least-squares ocean model inversions. The developed integrated approach can be extended by modeling the time variable component of the <span class="hlt">dynamic</span> <span class="hlt">topography</span> to provide estimates not only at a mean state but also at arbitrary points in time including a rigorously computed covariance matrix. The focus of this study is on the North Atlantic Ocean. We will present the conceptual design and <span class="hlt">dynamic</span> <span class="hlt">topography</span> estimates based on time variable data from several satellite altimeter missions in combination with GOCE and GRACE gravity field models.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li class="active"><span>2</span></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_2 --> <div id="page_3" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="41"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1512898A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1512898A"><span id="translatedtitle">Spatial patterns in the evolution of Cenozoic <span class="hlt">dynamic</span> <span class="hlt">topography</span> and its influence on the Antarctic continent</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anderson, Lester; Ferraccioli, Fausto; Eagles, Graeme; Steinberger, Bernhard; Ritsema, Jeroen</p> <p>2013-04-01</p> <p>Our knowledge of <span class="hlt">dynamic</span> <span class="hlt">topography</span> in Antarctica remains in an infancy stage compared to other continents. We assess the space-time variability in <span class="hlt">dynamic</span> <span class="hlt">topography</span> in Antarctica by analysing grids of global <span class="hlt">dynamic</span> <span class="hlt">topography</span> in the Cenozoic (and late Cretaceous) based on the tomographic model S40RTS. Our model reveals that the Gamburtsev Province and Dronning Maud Land, two of the major nucleation sites for the East Antarctic Ice Sheet (EAIS) were ~500 m higher 60 Ma ago. The increased elevation may have facilitated ephemeral ice cap development in the early Cenozoic. Between ca 25 and 50 Ma the northern Wilkes Subglacial Basin was ca 200 m higher than today and a major increase in regional elevation (>600 m) occurred over the last 20-15 Ma over the northern and southern Victoria Land in the Transantarctic Mountains (TAM). The most prominent signal is observed over the Ross Sea Rift (RSR) where predicted Neogene <span class="hlt">dynamic</span> <span class="hlt">topography</span> exceeds 1,000 m. The flow of warm mantle from the West Antarctic Rift System (WARS)may have driven these <span class="hlt">dynamic</span> <span class="hlt">topography</span> effects over the TAM and RSR. However, we found that these effects are comparatively less significant over the Marie Byrd Land Dome and the interior of the WARS. If these contrasting <span class="hlt">dynamic</span> <span class="hlt">topography</span> effects are included, then the predicted elevations of the Ross Sea Embayment ca 20 Ma ago are more similar to the interior of the WARS, with significant implications for the early development of the West Antarctic Ice Sheet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SGeo...35.1507B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SGeo...35.1507B"><span id="translatedtitle">A Tailored Computation of the Mean <span class="hlt">Dynamic</span> <span class="hlt">Topography</span> for a Consistent Integration into Ocean Circulation Models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Becker, S.; Losch, M.; Brockmann, J. M.; Freiwald, G.; Schuh, W.-D.</p> <p>2014-11-01</p> <p>Geostrophic surface velocities can be derived from the gradients of the mean <span class="hlt">dynamic</span> topography—the difference between the mean sea surface and the geoid. Therefore, independently observed mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> data are valuable input parameters and constraints for ocean circulation models. For a successful fit to observational <span class="hlt">dynamic</span> <span class="hlt">topography</span> data, not only the mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> on the particular ocean model grid is required, but also information about its inverse covariance matrix. The calculation of the mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> from satellite-based gravity field models and altimetric sea surface height measurements, however, is not straightforward. For this purpose, we previously developed an integrated approach to combining these two different observation groups in a consistent way without using the common filter approaches (Becker et al. in J Geodyn 59(60):99-110, 2012; Becker in Konsistente Kombination von Schwerefeld, Altimetrie und hydrographischen Daten zur Modellierung der dynamischen Ozeantopographie 2012). Within this combination method, the full spectral range of the observations is considered. Further, it allows the direct determination of the normal equations (i.e., the inverse of the error covariance matrix) of the mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> on arbitrary grids, which is one of the requirements for ocean data assimilation. In this paper, we report progress through selection and improved processing of altimetric data sets. We focus on the preprocessing steps of along-track altimetry data from Jason-1 and Envisat to obtain a mean sea surface profile. During this procedure, a rigorous variance propagation is accomplished, so that, for the first time, the full covariance matrix of the mean sea surface is available. The combination of the mean profile and a combined GRACE/GOCE gravity field model yields a mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> model for the North Atlantic Ocean that is characterized by a defined set of assumptions. We show that including the geodetically derived mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> with the full error structure in a 3D stationary inverse ocean model improves modeled oceanographic features over previous estimates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.4450M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.4450M"><span id="translatedtitle">Integrated approach to estimate the ocean's time variable <span class="hlt">dynamic</span> <span class="hlt">topography</span> including its covariance matrix</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Müller, Silvia; Brockmann, Jan Martin; Schuh, Wolf-Dieter</p> <p>2015-04-01</p> <p>The ocean's <span class="hlt">dynamic</span> <span class="hlt">topography</span> as the difference between the sea surface and the geoid reflects many characteristics of the general ocean circulation. Consequently, it provides valuable information for evaluating or tuning ocean circulation models. The sea surface is directly observed by satellite radar altimetry while the geoid cannot be observed directly. The satellite-based gravity field determination requires different measurement principles (satellite-to-satellite tracking (e.g. GRACE), satellite-gravity-gradiometry (GOCE)). In addition, hydrographic measurements (salinity, temperature and pressure; near-surface velocities) provide information on the <span class="hlt">dynamic</span> <span class="hlt">topography</span>. The observation types have different representations and spatial as well as temporal resolutions. Therefore, the determination of the <span class="hlt">dynamic</span> <span class="hlt">topography</span> is not straightforward. Furthermore, the integration of the <span class="hlt">dynamic</span> <span class="hlt">topography</span> into ocean circulation models requires not only the <span class="hlt">dynamic</span> <span class="hlt">topography</span> itself but also its inverse covariance matrix on the ocean model grid. We developed a rigorous combination method in which the <span class="hlt">dynamic</span> <span class="hlt">topography</span> is parameterized in space as well as in time. The altimetric sea surface heights are expressed as a sum of geoid heights represented in terms of spherical harmonics and the <span class="hlt">dynamic</span> <span class="hlt">topography</span> parameterized by a finite element method which can be directly related to the particular ocean model grid. Besides the difficult task of combining altimetry data with a gravity field model, a major aspect is the consistent combination of satellite data and in-situ observations. The particular characteristics and the signal content of the different observations must be adequately considered requiring the introduction of auxiliary parameters. Within our model the individual observation groups are combined in terms of normal equations considering their full covariance information; i.e. a rigorous variance/covariance propagation from the original measurements to the final product is accomplished. In conclusion, the developed integrated approach allows for estimating the <span class="hlt">dynamic</span> <span class="hlt">topography</span> and its inverse covariance matrix on arbitrary grids in space and time. The inverse covariance matrix contains the appropriate weights for model-data misfits in least-squares ocean model inversions. The focus of this study is on the North Atlantic Ocean. We will present the conceptual design and <span class="hlt">dynamic</span> <span class="hlt">topography</span> estimates based on time variable data from seven satellite altimeter missions (Jason-1, Jason-2, Topex/Poseidon, Envisat, ERS-2, GFO, Cryosat2) in combination with the latest GOCE gravity field model and in-situ data from the Argo floats and near-surface drifting buoys.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoJI.203.1909A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoJI.203.1909A"><span id="translatedtitle">Calculating gravitationally self-consistent sea level changes driven by <span class="hlt">dynamic</span> <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Austermann, J.; Mitrovica, J. X.</p> <p>2015-12-01</p> <p>We present a generalized formalism for computing gravitationally self-consistent sea level changes driven by the combined effects of <span class="hlt">dynamic</span> <span class="hlt">topography</span>, geoid perturbations due to mantle convection, ice mass fluctuations and sediment redistribution on a deforming Earth. Our mathematical treatment conserves mass of the surface (ice plus ocean) load and the solid Earth. Moreover, it takes precise account of shoreline migration and the associated ocean loading. The new formalism avoids a variety of approximations adopted in previous models of sea level change driven by <span class="hlt">dynamic</span> <span class="hlt">topography</span>, including the assumption that a spatially fixed isostatic amplification of `air-loaded' <span class="hlt">dynamic</span> <span class="hlt">topography</span> accurately accounts for ocean loading effects. While our approach is valid for Earth models of arbitrary complexity, we present numerical results for a set of simple cases in which a pattern of <span class="hlt">dynamic</span> <span class="hlt">topography</span> is imposed, the response to surface mass loading assumes that Earth structure varies only with depth and that isostatic equilibrium is maintained at all times. These calculations, involving fluid Love number theory, indicate that the largest errors in previous predictions of sea level change driven by <span class="hlt">dynamic</span> <span class="hlt">topography</span> occur in regions of shoreline migration, and thus in the vicinity of most geological markers of ancient sea level. We conclude that a gravitationally self-consistent treatment of long-term sea level change is necessary in any effort to use such geological markers to estimate ancient ice volumes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SuTMP...4a4001M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SuTMP...4a4001M"><span id="translatedtitle">Effect of surface <span class="hlt">topography</span> upon micro-impact <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mohammadpour, M.; Morris, N. J.; Leighton, M.; Rahnejat, H.</p> <p>2016-03-01</p> <p>Often the effect of interactions at nano-scale determines the tribological performance of load bearing contacts. This is particularly the case for lightly loaded conjunctions where a plethora of short range kinetic interactions occur. It is also true of larger load bearing conjunctions where boundary interactions become dominant. At the diminutive scale of fairly smooth surface <span class="hlt">topography</span> the cumulative discrete interactions give rise to the dominance of boundary effects rather than the bulk micro-scale phenomena, based on continuum mechanics. The integration of the manifold localized discrete interactions into a continuum is the pre-requisite to the understanding of characteristic boundary effects, which transcend the physical length scales and affect the key observed system attributes. These are energy efficiency and vibration refinement. This paper strives to present such an approach. It is shown that boundary and near boundary interactions can be adequately described by surface topographical measures, as well the thermodynamic conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeoRL..41.8944M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeoRL..41.8944M"><span id="translatedtitle">Improving the geoid: Combining altimetry and mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> in the California coastal ocean</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mazloff, Matthew R.; Gille, Sarah T.; Cornuelle, Bruce</p> <p>2014-12-01</p> <p>Satellite gravity mapping missions, altimeters, and other platforms have allowed the Earth's geoid to be mapped over the ocean to a horizontal resolution of approximately 100 km with an uncertainty of less than 10 cm. At finer resolution this uncertainty increases to greater than 10 cm. Achieving greater accuracy requires accurate estimates of the <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span> (DOT). In this study two DOT estimates for the California Current System with uncertainties less than 10 cm are used to solve for a geoid correction field. The derived field increases the consistency between the DOTs and along-track altimetric observations, suggesting it is a useful correction to the gravitational field. The correction is large compared to the <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span>, with a magnitude of 15 cm and significant structure, especially near the coast. The results are evidence that modern high-resolution <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span> products can be used to improve estimates of the geoid.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4542339','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4542339"><span id="translatedtitle"><span class="hlt">Dynamic</span> scalp <span class="hlt">topography</span> reveals neural signs just before performance errors</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ora, Hiroki; Sekiguchi, Tatsuhiko; Miyake, Yoshihiro</p> <p>2015-01-01</p> <p>Performance errors may cause serious consequences. It has been reported that ongoing activity of the frontal control regions across trials associates with the occurrence of performance errors. However, neural mechanisms that cause performance errors remain largely unknown. In this study, we hypothesized that some neural functions required for correct outcomes are lacking just before performance errors, and to determine this lack of neural function we applied a spatiotemporal analysis to high-density electroencephalogram signals recorded during a visual discrimination task, a d2 test of attention. To our knowledge, this is the first report of a difference in the temporal development of scalp ERP between trials with error, and correct outcomes as seen by <span class="hlt">topography</span> during the d2 test of attention. We observed differences in the signal potential in the frontal region and then the occipital region between reaction times matched with correct and error outcomes. Our observations suggest that lapses of top-down signals from frontal control regions cause performance errors just after the lapses. PMID:26289925</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23292960','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23292960"><span id="translatedtitle">Bioinspired surfaces with <span class="hlt">dynamic</span> <span class="hlt">topography</span> for active control of biofouling.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shivapooja, Phanindhar; Wang, Qiming; Orihuela, Beatriz; Rittschof, Daniel; López, Gabriel P; Zhao, Xuanhe</p> <p>2013-03-13</p> <p><span class="hlt">Dynamic</span> change of the surface area and topology of elastomers is used as a general, environmentally friendly approach for effectively detaching micro- and macro-fouling organisms adhered on the elastomer surfaces. Deformation of elastomer surfaces under electrical or pneumatic actuation can debond various biofilms and barnacles. The bio-inspired <span class="hlt">dynamic</span> surfaces can be fabricated over large areas through simple and practical processes. This new mechanism is complementary with existing materials and methods for biofouling control. PMID:23292960</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19990109139&hterms=mantle+hotspot&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmantle%2Bhotspot','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19990109139&hterms=mantle+hotspot&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dmantle%2Bhotspot"><span id="translatedtitle">Geoid Anomalies and <span class="hlt">Dynamic</span> <span class="hlt">Topography</span> from Time Dependent, Spherical Axisymmetric Mantle Convection</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kiefer, Walter S.; Kellogg, Louise H.</p> <p>1998-01-01</p> <p>Geoid anomalies and <span class="hlt">dynamic</span> <span class="hlt">topography</span> are two important diagnostics of mantle convection. We present geoid and <span class="hlt">topography</span> results for several time-dependent convection models in spherical axisymmetric geometry for Rayleigh numbers between 10(exp 6) and 10(exp 7) with depth-dependent viscosity and mixtures of bottom and internal heating. The models are strongly chaotic, with boundary layer instabilities erupting out of both thermal boundary layers. In some instances, instabilities from one boundary layer influence the development of instabilities in the other boundary layer. Such coupling between events at the top and bottom of the mantle has been suggested to play a role in a mid-Cretaceous episode of enhanced volcanism in the Pacific. These boundary layer instabilities produce large temporal variations in the geoid anomalies and <span class="hlt">dynamic</span> nd to the <span class="hlt">topography</span> associated with the convection. The amplitudes of these fluctuations depend on the detailed model parameter,.% it of this but fluctuations of 30-50% relative to the time-averaged geoid and <span class="hlt">topography</span> are common. The convective planform is strongly sensitive to the specific initial conditions. Convection cells with larger aspect ratio tend to have larger fractional fluctuations in their geoid and <span class="hlt">topography</span> amplitudes, because boundary layer instabilities have more time to develop in long cells. In some instances, we observe low-amplitude topographic highs adjacent to the topographic lows produced by cold downwellings. We discuss applications of these results to several situations, including the temporal variability of m basis. hotspots such as Hawaii, the <span class="hlt">topography</span> of subduction zone outer rises, and the <span class="hlt">topography</span> of coronae on Venus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.5114D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.5114D"><span id="translatedtitle">How to approximate viscoelastic <span class="hlt">dynamic</span> <span class="hlt">topographies</span> of stagnant lid planetary bodies?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dumoulin, Caroline; Čadek, Ondřej; Choblet, Gaël</p> <p>2013-04-01</p> <p>Planetary mantles are viscoelastic media. However, since numerical models of thermal convection in a viscoelastic spherical shell are still very challenging, most of the studies concerning <span class="hlt">dynamic</span> <span class="hlt">topography</span> of planetary surfaces generated by mantle convection use one of the following simplified rheological set-up: i) IVF (instantaneous viscous flow), ii) viscous body with a free surface, or iii) hybrid methods combining viscous deformation and elastic filtering of the <span class="hlt">topography</span>. Justifications for the use of such approximations instead of a fully viscoelastic rheology have been made on the basis of simple tests with step-like viscosity structures, with small to moderate viscosity contrasts. However, because the rheology of planetary materials is thermally activated, the radial stratification of viscosity is more likely to be a continuous function of depth, and global viscosity contrasts might be very large. In our study, we systematically compare viscoelastic <span class="hlt">dynamic</span> <span class="hlt">topography</span> induced by an internal load to <span class="hlt">topographies</span> generated by the three different simplified approaches listed above using a realistic viscosity profile for a stagnant lid associated to the lithosphere of a one plate planete. To this purpose, we compute response functions of surface <span class="hlt">topography</span> and geoid using three different semi-spectral models that all include self-gravitation: a) a linear Maxwell body with a pseudo free upper surface, b) a viscous body with a pseudo free upper surface, and c) a viscous body with a free-slip condition at the surface. Results obtained with this last model (IVF) can then be filtered using the elastic thin shell approximation: the effective elastic thickness then corresponds to the elastic thickness that is needed to fit the viscoelastic <span class="hlt">topography</span> with an elastic filtering of the IVF <span class="hlt">topography</span>. We show that the effective elastic thickness varies strongly with the degree of the load, with the depth of the load, and with the duration of the loading. These results naturally depend on the ratio between the mantle and the lithospheric thicknesses. We show that, in the case of Mars, it is not possible to approximate viscoelastic <span class="hlt">topographies</span> generated by a stable plume using the elastic filtering of viscous <span class="hlt">dynamic</span> <span class="hlt">topographies</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870063001&hterms=asthenosphere&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dasthenosphere','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870063001&hterms=asthenosphere&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dasthenosphere"><span id="translatedtitle"><span class="hlt">Dynamic</span> <span class="hlt">topography</span> and gravity anomalies for fluid layers whose viscosity varies exponentially with depth</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Revenaugh, Justin; Parsons, Barry</p> <p>1987-01-01</p> <p>Adopting the formalism of Parsons and Daly (1983), analytical integral equations (Green's function integrals) are derived which relate gravity anomalies and <span class="hlt">dynamic</span> boundary <span class="hlt">topography</span> with temperature as a function of wavenumber for a fluid layer whose viscosity varies exponentially with depth. In the earth, such a viscosity profile may be found in the asthenosphere, where the large thermal gradient leads to exponential decrease of viscosity with depth, the effects of a pressure increase being small in comparison. It is shown that, when viscosity varies rapidly, <span class="hlt">topography</span> kernels for both the surface and bottom boundaries (and hence the gravity kernel) are strongly affected at all wavelengths.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoJI.203..384O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoJI.203..384O"><span id="translatedtitle">Effect of the Earth's surface <span class="hlt">topography</span> on quasi-<span class="hlt">dynamic</span> earthquake cycles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ohtani, Makiko; Hirahara, Kazuro</p> <p>2015-10-01</p> <p>We take account of the effect of Earth's surface <span class="hlt">topography</span> in quasi-<span class="hlt">dynamic</span> earthquake cycle simulations using a boundary integral equation method. While we have so far assumed a homogeneous elastic half-space medium with a flat free surface, Earth's actual surface <span class="hlt">topography</span> is complicated. Here, we constructed new slip response functions in half-space with an arbitrarily shaped surface <span class="hlt">topography</span> in which we used slip response functions in full-space by introducing imaginary free surface cells in addition to embedded fault ones. By comparing analytical slip response functions in the case of a flat surface overlying half-space with the new ones, we developed a computationally efficient method for setting the Earth's surface region, which was divided into cells with the appropriate sizes depending on the fault source cell depth to maintain the computational accuracy. With these new slip response functions, we simulated simple interplate earthquake cycles in the region close to the Japan Trench, off Miyagi, Tohoku, in northeast Japan, which has the amplitude of 7 km in depth. Compared with the case where the flat surface level was set at the trench depth, the slip response functions for the case where actual seafloor <span class="hlt">topography</span> was used had smaller amplitudes. Hence, the actual <span class="hlt">topography</span> produces smaller recurrence times for earthquake cycles than that for the flat surface case. These effects of the actual Earth's surface <span class="hlt">topography</span> mainly come from changes in the distance between the surface and the fault compared with the flat surface case. Changes in the slip response function also represent changes in the fault stiffness of the system. Considering the actual <span class="hlt">topography</span> of the Earth's surface to be convex upwards as opposed to the flat, the fault stiffness becomes larger compared to the case of the flat Earth's surface. This leads to a change in the frictional instability, and sometime leads to the change in the way of rupture.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoRL..42.8021V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoRL..42.8021V"><span id="translatedtitle">Noise-driven cooperative <span class="hlt">dynamics</span> between vegetation and <span class="hlt">topography</span> in riparian zones</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vesipa, R.; Camporeale, C.; Ridolfi, L.</p> <p>2015-10-01</p> <p>Riparian ecosystems exhibit complex biotic and abiotic <span class="hlt">dynamics</span>, where the triad vegetation-sediments-stream determines the ecogeomorphological features of the river landscape. Random fluctuations of the water stage are a key trait of this triad, and a number of behaviors of the fluvial environment can be understood only taking into consideration the role of noise. In order to elucidate how randomness shape riparian transects, a stochastic model that takes into account the main links between vegetation, sediments, and the stream is adopted, emphasizing the capability of vegetation to alter the plot <span class="hlt">topography</span>. A minimalistic approach is pursued, and the probability density function of vegetation biomass is analytically evaluated in any transect plot. This probability density function strongly depends on the vegetation-<span class="hlt">topography</span> feedback. We demonstrate how the vegetation-induced modifications of the bed <span class="hlt">topography</span> create more suitable conditions for the survival of vegetation in a stochastically dominated environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23686342','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23686342"><span id="translatedtitle"><span class="hlt">Dynamic</span> <span class="hlt">topography</span> change of the eastern United States since 3 million years ago.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rowley, David B; Forte, Alessandro M; Moucha, Robert; Mitrovica, Jerry X; Simmons, Nathan A; Grand, Stephen P</p> <p>2013-06-28</p> <p>Sedimentary rocks from Virginia through Florida record marine flooding during the mid-Pliocene. Several wave-cut scarps that at the time of deposition would have been horizontal are now draped over a warped surface with a maximum variation of 60 meters. We modeled <span class="hlt">dynamic</span> <span class="hlt">topography</span> by using mantle convection simulations that predict the amplitude and broad spatial distribution of this distortion. The results imply that <span class="hlt">dynamic</span> <span class="hlt">topography</span> and, to a lesser extent, glacial isostatic adjustment account for the current architecture of the coastal plain and proximal shelf. This confounds attempts to use regional stratigraphic relations as references for longer-term sea-level determinations. Inferences of Pliocene global sea-level heights or stability of Antarctic ice sheets therefore cannot be deciphered in the absence of an appropriate mantle <span class="hlt">dynamic</span> reference frame. PMID:23686342</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.6454L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.6454L"><span id="translatedtitle">Infrasound wavefield modeled by coupling conduit <span class="hlt">dynamics</span> and <span class="hlt">topography</span> by 3D-FDTD</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>lacanna, giorgio; ripepe, maurizio</p> <p>2014-05-01</p> <p>Infrasound signal on active volcanoes has become an important tool for monitoring and understanding the explosive source <span class="hlt">dynamics</span>. Volcano infrasound is the direct measure of pressure oscillations near open-vent and it can provide important constraints on the intensity of the eruption as well as on the source parameters including the variations of volumetric flux and exit velocity. At present, infrasonic signals recorded close to the volcano (<5 Km) have been used to model the acoustic source of volcanic explosions considering that at this distance the acoustic wavefield is relatively less affected by atmospheric structure. On the contrary, recent 2D finite-difference time-domain (FDTD) numerical modelling of infrasound propagation indicates a strong effect on the wavefield induced by the diffraction of the crater rim [Kim and Lees 2011] and by the near-source <span class="hlt">topography</span> [Lacanna and Ripepe 2013]. However, the full three-dimensional interaction of acoustic source with conduit geometry and the <span class="hlt">topography</span> of the volcano edifice have not been fully investigated. In order to evaluate these effects, we have developed a 3D-FDTD modelling to simulate infrasound propagation taking in account conduit <span class="hlt">dynamics</span> and <span class="hlt">topography</span> of the volcano. In linear acoustics, the pressure perturbations in a duct propagates as a plane wave front, which become spherical outside the vent. The radiation impedance at the vent depends on the pressure wavelength and the vent radius. In addition, the diffraction and reflection of <span class="hlt">topography</span> contaminate the acoustic wave field and have a strong effect in reducing the amplitude and changing the waveform of the infrasonic signal also at short (<2 km) distances. Besides, the 3D numerical model allows to define in terms of Green's function the scattering effects on the acoustic wavefield caused by <span class="hlt">topography</span> along the source-receiver path. Only by removing topographic effects from the infrasonic record and by considering the propagation inside the conduit we can quantify the source parameters with a strong impact on our understanding of the explosive <span class="hlt">dynamics</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.6110F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.6110F"><span id="translatedtitle">Isostasy, <span class="hlt">dynamic</span> <span class="hlt">topography</span>, and the elevation of the Apennines of Italy: insights into deformation of subducting lithosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Faccenna, Claudio; Becker, Thorsten; Miller, Meghan; Serpelloni, Enrico; Willett, Sean</p> <p>2015-04-01</p> <p>The elevation of an orogenic belt is commonly related to crustal/lithosphere thickening. Here, we discuss the Apennines as an example to show that <span class="hlt">topography</span> at a plate margin may be controlled not only by isostatic adjustment but also by <span class="hlt">dynamic</span>, mantle-driven processes. Using recent structural constraints for the crust and mantle we find that the expected crustal isostatic component explains only a fraction of the <span class="hlt">topography</span> of the belt, indicating positive residual <span class="hlt">topography</span> in the central Apennines and negative residual <span class="hlt">topography</span> in the northern Apennines and Calabria. The trend of the residual <span class="hlt">topography</span> matches the mantle flow induced <span class="hlt">dynamic</span> <span class="hlt">topography</span> estimated from regional tomography models. We infer that a large fraction of the Apennines <span class="hlt">topography</span> is related to mantle <span class="hlt">dynamics</span>, producing relative upwellings in the central Apennines and downwellings in the northern Apennines and Calabria where subduction is still ongoing. Comparison between geodetic and geological data on vertical motions indicates that this <span class="hlt">dynamic</span> process started in the early Pleistocene and the resulting uplift appears related to the formation and enlargement of a slab window below the central Apennines. The case of the Apennines shows that the <span class="hlt">topography</span> of mountain can be used to infer rate and evolution of processes <span class="hlt">dynamically</span> controlled by mantle convection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010cosp...38..256J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010cosp...38..256J"><span id="translatedtitle">Assimilation of geodetic <span class="hlt">dynamical</span> ocean <span class="hlt">topography</span> data into ocean circulation model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Janjic, Tijana; Schroeter, Jens; Albertella, Alberta; Bosch, Wolfgang; Rummel, Reiner; Savcenko, Roman</p> <p></p> <p>Estimation of ocean circulation via assimilation of satellite measurements of <span class="hlt">dynamical</span> ocean <span class="hlt">topography</span> (DOT) into the global finite-element ocean model (FEOM) is investigated. The DOT was obtained by means of geodetic approach from carefully cross-calibrated multi-mission-altimeter data and GRACE gravity fields. The spectral consistency was achieved by means of the filtering applied on sea surface and geoid. Since the <span class="hlt">dynamical</span> ocean <span class="hlt">topography</span> is obtained from data types coming from different sources, different techniques can be employed for their assimilation into ocean circulation models. For example, the data can be combined and interpolated onto the model grid before they are used in assimilation. In this case special care needs to be taken concerning the specification of observational error statistics. The assimilation is performed by employing the local SEIK filter and various functions for observations error covariance are used. Finally we consider the effects of assimilation on potential temperature field and on steric height changes. Analysed potential temperature is compared with ARGO data. We also compared the standard deviation of the observations and standard deviation of the steric height calculated from the analysis. In many regions of the world ocean there is a good correspondence between these two fields. However also structures that are not present in the observations appear in the steric height standard deviations. Keywords: <span class="hlt">dynamical</span> ocean <span class="hlt">topography</span>, data assimilation Session: A2.6</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.T43E..03G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.T43E..03G"><span id="translatedtitle">Spatial Patterns of Channel Steepness in the Central Rockies: Do River Profiles Record Landscape Evolution Forcing By Yellowstone <span class="hlt">Dynamic</span> <span class="hlt">Topography</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guerrero, E. F.; Meigs, A.; Kirby, E.; Gregg, P. M.</p> <p>2014-12-01</p> <p>Numerous investigations demonstrate that mantle convective processes affect the surface <span class="hlt">topography</span> of the overriding plate. 'Positive <span class="hlt">dynamic</span> <span class="hlt">topography</span>' refers to the surface expression of mantle upwelling. An advecting wave of <span class="hlt">dynamic</span> topographic surface uplift plate is thought to result from migration of North America relative to the Yellowstone hotspot. Advection of positive <span class="hlt">dynamic</span> <span class="hlt">topography</span> through an overriding plate disturbs the landscape by a combination of a change in surface uplift rate and tilting. Identification of <span class="hlt">dynamic</span> <span class="hlt">topography</span>'s contribution to evolution of the greater Yellowstone region's landscape, however, is complicated by the polygenetic regional <span class="hlt">topography</span> that results from glaciation, bimodal volcanism, Basin and Range extension, early Cenozoic arc volcanism, and Laramide contraction. Our model, which is parameterized to Yellowstone but doesn't include climate variations, suggests contribution of the <span class="hlt">dynamic</span> <span class="hlt">topography</span> erosional signal should decrease from 0.1mm/yr to 0.5 mm/yr at a 100km radius from the hotspot uplift source. The cosmogenic chronology that we are building to constrain spatial patterns of incision in the Bighorn Basin indicates that there is differential incision occurring in the Bighorn basin. Rates vary from 2.8mm/yr in the western basin, which is closer to Yellowstone to 1.1mm/yr in the eastern basin. Global cooling and its effects at the Plio-Pleistocene transition is thought to be the dominant control on the region's erosional regime. However, the magnitude of the contribution from Yellowstone <span class="hlt">dynamic</span> <span class="hlt">topography</span> to the regional landscape evolution is still unknown because published incision rates lack the resolution to differentiate between incision forcing mechanisms. Bedrock stream profile analysis is powerful tool for determining spatial patterns of surface deformation. We compare results for normalized channel steepness indices across various basins in the Central Rockies and Greater Yellowstone area with existing datasets to determine whether regional steepness patterns are associated with the proposed spatial distribution of <span class="hlt">dynamic</span> <span class="hlt">topography</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.C21A0305A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.C21A0305A"><span id="translatedtitle">Enhanced Arctic Mean Sea Surface and Mean <span class="hlt">Dynamic</span> <span class="hlt">Topography</span> including retracked CryoSat-2 Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Andersen, O. B.; Jain, M.; Stenseng, L.; Knudsen, P.</p> <p>2014-12-01</p> <p>A reliable mean sea surface (MSS) is essential to derive a good mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> (MDT) and for the estimation of short and long-term changes in the sea surface. The lack of satellite radar altimetry observations above 82 degrees latitude means that existing mean sea surface models have been unreliable in the Arctic Ocean. We here present the latest DTU mean sea surface and mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> models combining conventional altimetry with retracked CryoSat-2 data to improve the reliability in the Arctic Ocean. For the derivation of a mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> the ESA GOCE derived geoid model have been used to constrain the longer wavelength. We present the retracking of C2 SAR data using various retrackes and how we have been able to combine data from various retrackers under various sea ice conditions. DTU13MSS and DTU13MDT are the newest state of the art global high-resolution models including CryoSat-2 data to extend the satellite radar altimetry coverage up to 88 degrees latitude and through combination with a GOCE geoid model completes coverage all the way to the North Pole. Furthermore the SAR and SARin capability of CryoSat-2 dramatically increases the amount of useable sea surface returns in sea-ice covered areas compared to conventional radar altimeters like ENVISAT and ERS-1/2. With the inclusion of CryoSat-2 data the new mean sea surface is improved by more than 20 cm above 82 degrees latitude compared with the previous generation of mean sea surfaces.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMEP41C0811R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMEP41C0811R"><span id="translatedtitle">The emergence of topographic steady-state in perpetually <span class="hlt">dynamic</span> <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reinhardt, L.; Ellis, M. A.</p> <p>2012-12-01</p> <p>We report here the results of a series of analog experiments of landscape evolution in which the evolving <span class="hlt">topography</span> and sediment flux is observed as a function of the rate of base-level fall (equivalent to rock uplift) under a constant model-climate. The experimental apparatus comprises a 50 cm x 50 cm box that contains up to 30 cm of ~20 micron silicon paste. Climate is simulated as a constant and spatially uniform rate of precipitation derived from an overhead suite of fine misters. <span class="hlt">Topography</span> was measured via a laser scanner to a precision of less than 1mm and imaged digitally at 5 min intervals. Base-level fall is achieved through the slow sliding of two opposing sides of the box at rates between 9 to 60 mm/hr. Erosion occurs as both hillslope (mass movements) and channel processes; our slope-area data show that we are simulating reasonably realistic landscapes. Our results show that in a flux-steady-state landscape, the non-linear highly <span class="hlt">dynamic</span> behavior of ridge-valley <span class="hlt">topography</span> leads to the emergence of stable catchment geometries. We further demonstrate that this stability is a fundamental characteristic of internal system <span class="hlt">dynamics</span>, is independent of climate and uplift rate and is instead linked to the exhumation of mountain relief: both scale-dependence and scale-invariance in topographic <span class="hlt">dynamics</span> emerges after 1.2 relief-depths of erosion. We also show that the temporal evolution of sediment flux follows a classic growth curve in which flux decreases as a reflection of limited resources as propagating headwaters run out of new uneroded landscape. In response to changes in uplift rate, sediment flux also provides a measure of an intrinsic time-response within the system, which could be used to transform model time to real time.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_3 --> <div id="page_4" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="61"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1998RScI...69..457K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1998RScI...69..457K"><span id="translatedtitle">Broad band and <span class="hlt">absolute</span> measurement of transient <span class="hlt">dynamic</span> normal velocity of surface</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Byoung-Geuk; Enoki, Manabu; Kishi, Teruo</p> <p>1998-02-01</p> <p>Broad band direct sensing of the transient <span class="hlt">dynamic</span> normal velocity of an object surface and evaluating its <span class="hlt">absolute</span> value were realized by using a sensor fabricated with a piezoelectric polyvinylidene fluoride film and a polyvinyl chloride (PVC) back load and a PVC wear plate. The transient output signal from the sensor obtained by a test employing a well-defined steplike force, at the epicenter of a steel plate, showed very good agreement with the <span class="hlt">dynamic</span> normal velocity calculated by using a Green's function and a simulated source function. The output was proportional to the <span class="hlt">dynamic</span> normal velocity of the surface, and the frequency-dependent sensitivity for the velocity was flat within a deviation of ±3.8 dB for the average in the frequency range up to 2 MHz. The transient <span class="hlt">dynamic</span> normal velocity of the surface could be <span class="hlt">absolutely</span> determined by using a sensor calibrated by theoretical one.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.8034M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.8034M"><span id="translatedtitle">Interplay between <span class="hlt">dynamic</span> <span class="hlt">topography</span> and flexure along the U.S. Atlantic passive margin: Insights from landscape evolution modeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moucha, Robert; Ruetenik, Gregory A.; Hoke, Gregory D.; Rovere, Alessio</p> <p>2015-04-01</p> <p>Recent global backwards-in time models of mantle convection have resulted in vastly different interpretations of the transient state of <span class="hlt">dynamic</span> <span class="hlt">topography</span> on the U.S. Atlantic passive margin over the past 30 Myr (Moucha et al., 2008; Spacejovic et al., 2008; Rowley et al., 2013; Liu, 2014). A promising way of benchmarking these geodynamic models is by reconciling them with the observed offshore sedimentary record. However, it is difficult to deconvolve the erosional response produced by changes in <span class="hlt">dynamic</span> <span class="hlt">topography</span> from other sources of landscape change because the erosional response is a convolution of <span class="hlt">dynamic</span> <span class="hlt">topography</span> changes, tectonic uplift/subsidence, flexural response to erosional unloading and depositional loading, rock properties, and climate. Herein, we present results from a new landscape evolution model that is capable of producing simulations that are required at the scale and resolution necessary to quantify the landscape response to various models of <span class="hlt">dynamic</span> topographic change on the U.S. Atlantic passive margin in the presence of flexural unloading and loading due to erosion and deposition. We focus here on the deformation of the Orangeburg scarp, a well-documented mid-Pliocene shoreline, and demonstrate that flexural effects along this margin may be comparable to changes in <span class="hlt">dynamic</span> <span class="hlt">topography</span>. We conclude by exploring the parameter space to find an acceptable fit to the observed warping of the Orangeburg scarp by combining <span class="hlt">dynamic</span> <span class="hlt">topography</span> and flexural effects changes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.4343A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.4343A"><span id="translatedtitle">The impact of <span class="hlt">dynamic</span> <span class="hlt">topography</span> on the bedrock elevation and volume of the Pliocene Antarctic Ice Sheet</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Austermann, Jacqueline; Pollard, David; Mitrovica, Jerry X.; Moucha, Robert; Forte, Alessandro M.; DeConto, Robert M.</p> <p>2015-04-01</p> <p>Reconstructions of the Antarctic ice sheet over long timescales (i.e. Myrs) require estimates of bedrock elevation through time. Ice sheet models have accounted, with varying levels of sophistication, for changes in the bedrock elevation due to glacial isostatic adjustment (GIA), but they have neglected other processes that may perturb <span class="hlt">topography</span>. One notable example is <span class="hlt">dynamic</span> <span class="hlt">topography</span>, the deflection of the solid surface of the Earth due to convective flow within the mantle. Numerically predicted changes in <span class="hlt">dynamic</span> <span class="hlt">topography</span> have been used to correct paleo shorelines for this departure from eustasy, but the effect of such changes on ice sheet stability is unknown. In this study we use numerical predictions of time-varying <span class="hlt">dynamic</span> <span class="hlt">topography</span> to reconstruct bedrock elevation below the Antarctic ice sheet during the mid Pliocene warm period (~3 Ma). Moreover, we couple this reconstruction to a three-dimensional ice sheet model to explore the impact of <span class="hlt">dynamic</span> <span class="hlt">topography</span> on the evolution of the Antarctic ice sheet since the Pliocene. Our modeling indicates significant uplift in the area of the Transantarctic Mountains (TAM) and the adjacent Wilkes basin. This predicted uplift, which is at the lower end of geological inferences of uplift of the TAM, implies a lower elevation of the basin in the Pliocene. Relative to simulations that do not include <span class="hlt">dynamic</span> <span class="hlt">topography</span>, the lower elevation leads to a smaller Antarctic Ice Sheet volume and a more significant retreat of the grounding line in the Wilkes basin, both of which are consistent with offshore sediment core data. We conclude that reconstructions of the Antarctic Ice Sheet during the mid-Pliocene warm period should be based on bedrock elevation models that include the impact of both GIA and <span class="hlt">dynamic</span> <span class="hlt">topography</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920004856','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920004856"><span id="translatedtitle">Flight <span class="hlt">dynamics</span> facility operational orbit determination support for the ocean <span class="hlt">topography</span> experiment</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bolvin, D. T.; Schanzle, A. F.; Samii, M. V.; Doll, C. E.</p> <p>1991-01-01</p> <p>The Ocean <span class="hlt">Topography</span> Experiment (TOPEX/POSEIDON) mission is designed to determine the <span class="hlt">topography</span> of the Earth's sea surface across a 3 yr period, beginning with launch in June 1992. The Goddard Space Flight Center <span class="hlt">Dynamics</span> Facility has the capability to operationally receive and process Tracking and Data Relay Satellite System (TDRSS) tracking data. Because these data will be used to support orbit determination (OD) aspects of the TOPEX mission, the <span class="hlt">Dynamics</span> Facility was designated to perform TOPEX operational OD. The scientific data require stringent OD accuracy in navigating the TOPEX spacecraft. The OD accuracy requirements fall into two categories: (1) on orbit free flight; and (2) maneuver. The maneuver OD accuracy requirements are of two types; premaneuver planning and postmaneuver evaluation. Analysis using the Orbit Determination Error Analysis System (ODEAS) covariance software has shown that, during the first postlaunch mission phase of the TOPEX mission, some postmaneuver evaluation OD accuracy requirements cannot be met. ODEAS results also show that the most difficult requirements to meet are those that determine the change in the components of velocity for postmaneuver evaluation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.T14B..04E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.T14B..04E"><span id="translatedtitle"><span class="hlt">Dynamic</span> Passage of <span class="hlt">Topography</span> Beneath the Southern Costa Rica Forearc seen with Seismic Stratigraphy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Edwards, J. H.; Kluesner, J. W.; Silver, E. A.</p> <p>2014-12-01</p> <p>3D seismic reflection data (CRISP) collected across the southern Costa Rica margin reveals that a thick, deforming sedimentary wedge underlies the younger slope sediments (Silver et al., this meeting). The older wedge material and younger slope sediments are separated by a high-amplitude regional unconformity. Seismic stratigraphy of the sedimentary strata overlying this regional unconformity reflects a <span class="hlt">dynamic</span> deformation history of the margin. The younger slope sediments contain series of more localized unconformities, separating sedimentary units as thick as 1 km that reveal a <span class="hlt">dynamically</span> changing set of inverted, overlapping basins. The geometry of these overlapping, inverted basins indicate sequential uplift events. The direction of basin thickening varies upsection, and these basins are cut by both thrust and normal faults and are deformed by folding. Structural development appears to be controlled by relief on the subducting plate interface, which induces uplift and subsidence and thereby controls the pattern of erosion and deposition. We interpret the evolution of these inverted stratigraphic packages as forming from subducting <span class="hlt">topography</span>. Correlating these seismic-stratigraphic packages to recent drilling based on preliminary magnetostratigraphy from IODP site U1413 (Expedition 344 Scientists, 2013), allows us to date the passage of the subducting plate <span class="hlt">topography</span> beginning ~2 Ma.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20000004592&hterms=implied+term&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dimplied%2Bterm','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20000004592&hterms=implied+term&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dimplied%2Bterm"><span id="translatedtitle">Modelling and Estimation of <span class="hlt">Dynamic</span> Ocean <span class="hlt">Topography</span> Within Global Geopotential Solutions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lemoine, Frank G.; Pavlis, Nikolaos; Wang, Y. M.; Cox, C. M.</p> <p>1998-01-01</p> <p>In this poster, we will present a report on the ongoing investigation "Improved Gravitational and <span class="hlt">Dynamic</span> Height Models Through the use of Oceanographic Data." we have used a two year mean (1993-1994) of the <span class="hlt">Dynamic</span> ocean <span class="hlt">Topography</span> (DOT) field implied by the Semtner and Chervin POCM_4B model, and developed normal equations in surface spherical harmonics to degree and order 30. These normal equations, were combined with normal equations derived from TOPEX and ERS-1 altimeter data over the same time period. Combination solutions (based on satellite tracking data, altimeter data, surface gravity data and OCM data) were were developed Test solutions were obtained estimating the DOT field to 2Ox2O and 3ox3O. These solutions were tested with independent DOT values computed over 38 WOCE hydrographic sections, which contained a total of 3072 stations and represented 216000 km of travelled lines. The weighted standard deviation of the differences between the DOT obtained from the hydrographic data and and the field estimated from the joint combination solutions was computed for each of the test models, the weighted standard deviation for the baseline combination solution excluding the POCM4_B data was 9.7 cm for a DOT solution to 30x30, where introducing the POCM4_B data into the combination model reduced the standard deviation to 9.2 cm, indicating the the introduction of oceanographic information benefits the solution for the <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span>. We will discuss the weighting schemes applied and the method of solution. Another aspect of our investigation involves testing alternate parametric representations of the <span class="hlt">dynamic</span> height field. We looked at the alternative representations in terms of the Proudman functions (PF), and compared these to the use of spherical harmonics (SH) to represent the <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span>, using once again the 1993 and 1994 output of the POCM4_B OCM as the reference model. A significant advantage of PF's over SH's is that the former require no "fill-in" values over areas where the DOT is undefined. We show that the PF and SH results using equal number of parameters agree quite well in overall content. In addition, PFs appear better suited for representation of high frequency signals close to the signal boundary. The development of the PF solutions for the DOT will be described and the statistics of the comparisons will be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25430103','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25430103"><span id="translatedtitle"><span class="hlt">Dynamic</span> frequency-domain interferometer for <span class="hlt">absolute</span> distance measurements with high resolution.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Weng, Jidong; Liu, Shenggang; Ma, Heli; Tao, Tianjiong; Wang, Xiang; Liu, Cangli; Tan, Hua</p> <p>2014-11-01</p> <p>A unique <span class="hlt">dynamic</span> frequency-domain interferometer for <span class="hlt">absolute</span> distance measurement has been developed recently. This paper presents the working principle of the new interferometric system, which uses a photonic crystal fiber to transmit the wide-spectrum light beams and a high-speed streak camera or frame camera to record the interference stripes. Preliminary measurements of harmonic vibrations of a speaker, driven by a radio, and the changes in the tip clearance of a rotating gear wheel show that this new type of interferometer has the ability to perform <span class="hlt">absolute</span> distance measurements both with high time- and distance-resolution. PMID:25430103</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22392223','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22392223"><span id="translatedtitle"><span class="hlt">Dynamic</span> frequency-domain interferometer for <span class="hlt">absolute</span> distance measurements with high resolution</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Weng, Jidong; Liu, Shenggang; Ma, Heli; Tao, Tianjiong; Wang, Xiang; Liu, Cangli; Tan, Hua</p> <p>2014-11-15</p> <p>A unique <span class="hlt">dynamic</span> frequency-domain interferometer for <span class="hlt">absolute</span> distance measurement has been developed recently. This paper presents the working principle of the new interferometric system, which uses a photonic crystal fiber to transmit the wide-spectrum light beams and a high-speed streak camera or frame camera to record the interference stripes. Preliminary measurements of harmonic vibrations of a speaker, driven by a radio, and the changes in the tip clearance of a rotating gear wheel show that this new type of interferometer has the ability to perform <span class="hlt">absolute</span> distance measurements both with high time- and distance-resolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014RScI...85k3112W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014RScI...85k3112W"><span id="translatedtitle"><span class="hlt">Dynamic</span> frequency-domain interferometer for <span class="hlt">absolute</span> distance measurements with high resolution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weng, Jidong; Liu, Shenggang; Ma, Heli; Tao, Tianjiong; Wang, Xiang; Liu, Cangli; Tan, Hua</p> <p>2014-11-01</p> <p>A unique <span class="hlt">dynamic</span> frequency-domain interferometer for <span class="hlt">absolute</span> distance measurement has been developed recently. This paper presents the working principle of the new interferometric system, which uses a photonic crystal fiber to transmit the wide-spectrum light beams and a high-speed streak camera or frame camera to record the interference stripes. Preliminary measurements of harmonic vibrations of a speaker, driven by a radio, and the changes in the tip clearance of a rotating gear wheel show that this new type of interferometer has the ability to perform <span class="hlt">absolute</span> distance measurements both with high time- and distance-resolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.P41D1963Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.P41D1963Y"><span id="translatedtitle">Separation of <span class="hlt">dynamic</span> and isostatic components for Venusian gravity and <span class="hlt">topography</span> and its influence in crustal thickness calculation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, A.; Huang, J.; Wei, D.</p> <p>2013-12-01</p> <p>The crustal thickness of Venus can give us important information about the extent of melting and the tectonics of Venus's surface. With no seismological observation on Venus, the knowledge of Venusian crustal thickness can only be obtained from gravity and <span class="hlt">topography</span> observations via satellites. However, analyses on the gravity and <span class="hlt">topography</span> shown that on Venus the gravity and <span class="hlt">topography</span> are strongly influenced by internal <span class="hlt">dynamical</span> processes, especially the long-wavelength components or low-degree spherical harmonics. In many regions on Venus, gravity and <span class="hlt">topography</span> are highly correlated and with high gravity <span class="hlt">topography</span> ratio (GTR) and large apparent depth of compensation (ADC). All these led to the hypotheses that there are mantle plumes under these areas. In these cases, the <span class="hlt">dynamical</span> influences need to be excluded from gravity and <span class="hlt">topography</span> data in order to obtain a reasonable crustal thickness. In this study, we set up a method to separate the <span class="hlt">dynamic</span> component of the gravity and <span class="hlt">topography</span> from the observations by supposing that the Venusian crust is in a state of Airy isostasy if taking off the <span class="hlt">dynamic</span> influences. After doing so, the Venusian global crustal thickness has been calculated and the results shown that (1) the gravity and <span class="hlt">topography</span> are strongly correlated with the Venusian mantle convection and the Venusian crust has a significant influence on the observed <span class="hlt">topography</span>;(2) the Venusian crustal thickness varies from 28 km to 70 km if an average thickness of 35 km is adopted; (3) Ishtar Terra, Ovda Regio and Thetis Regio in western Aphrodite Terra have the most largest crustal thickness (larger than 50 km). The high <span class="hlt">topography</span> of these areas is thought to be supported by crustal compensation and our results are consistent with the hypothesis that these areas are remnants of ancient continents; (4) the crustal thickness in the Beta, Themis, Dione, Eistla, Bell, and Lada regiones is thin and shows less correlation with the <span class="hlt">topography</span>, especially in the Atla and Imdr regiones in the eastern part of Aphrodite Terra. This is consistent with the hypothesis that these highlands are mainly supported by mantle plumes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.T43F2729D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.T43F2729D"><span id="translatedtitle">The Time Dependance of <span class="hlt">Dynamic</span> <span class="hlt">Topography</span>: Mantle <span class="hlt">Dynamic</span> Contributions to Local and Global Sea-Level Histories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Durbin, C. J.; Shahnas, M.; Peltier, W. R.</p> <p>2012-12-01</p> <p>Earth's <span class="hlt">topography</span> plays an important role in many surface processes, particularly through its influence on the water cycle and erosional processes. Our ability to predict weather patterns and surface/subsurface hydrological processes depends upon our knowledge of this field. Similarly, understanding the evolution of <span class="hlt">topography</span> through time (paleo-<span class="hlt">topography</span>) is critically important for the accurate modeling of past climate states such as that of the last glacial maximum. Whilst the present day topographic field can be accurately inferred over the entire globe using satellite based sensors and geodetic techniques, no equivalently comprehensive tools exist that enable access to paleo-<span class="hlt">topography</span>. The rock record allows for limited, local estimations of deposition elevation with respect to sea level using appropriate fossils combined with sedimentological analyses. However, this method is not available in most locations as a consequence of poor-preservation of the requisite sea level indicators and in any event the accuracy of the relative sea level record is often compromised. Furthermore, just as <span class="hlt">topography</span> itself consists of distinct <span class="hlt">dynamic</span> and isostatic contributions, relatives sea level also consists of two contributions, respectively that due to the vertical motion of the surface of the solid Earth and that due to the changing volume of water in the global oceans. In this paper we study the time dependence of Earth's <span class="hlt">dynamic</span> <span class="hlt">topography</span> that has occurred over the recent past due to the action of the mantle convection process. We use a modern model of mantle mixing, an extension to three dimensions of the recently published control volume based convection model of Shahnas and Peltier (2010, JGR, vol 115, B11408). This is initialized using a mantle temperature field inferred on the basis of modern seismic tomographic imaging analysis, which enables the model to simulate the present day <span class="hlt">dynamical</span> state of Earth's mantle. The use of this methodology enables the model to be employed to study the present state of the mantle and its evolution in the recent geological past. The predictions of the model that interest us are those of the rate of uplift and depression of the crust that contribute to records of relative sea level history over timescales sufficiently long to encompass several Late Quaternary glacial cycles. We employ a number of available local records of the time dependence of <span class="hlt">dynamical</span> <span class="hlt">topography</span> such as the coral based Barbados record of Peltier and Fairbanks (2006, QSR 25, pp. 3322-3337) to first demonstrate the accuracy with which the convection model is able to reconcile such observational constraints. Although several of the best available constraint data sets derive from regions in the near vicinity of active subduction zones, we proceed to apply the model's predictions to a number of (assumed to be) passive continental margins from which data have been derived that have been assumed to represent variations in eustatic sea level due to the variation of continental land ice volume such as those recently discussed by Miller et al. (2012, Geology 20, pp. 407-410). We assess the extent to which the passive continental margin assumption may have led to significant errors in the inference of global sea level rise for the mid-Pliocene interval of time centered upon 3 Ma.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890016168','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890016168"><span id="translatedtitle"><span class="hlt">Dynamic</span> sea surface <span class="hlt">topography</span>, gravity and improved orbit accuracies from the direct evaluation of SEASAT altimeter data</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Marsh, J. G.; Lerch, F.; Koblinsky, C. J.; Klosko, S. M.; Robbins, J. W.; Williamson, R. G.; Patel, G. B.</p> <p>1989-01-01</p> <p>A method for the simultaneous solution of <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span>, gravity and orbits using satellite altimeter data is described. A GEM-T1 based gravitational model called PGS-3337 that incorporates Seasat altimetry, surface gravimetry and satellite tracking data has been determined complete to degree and order 50. The altimeter data is utilized as a <span class="hlt">dynamic</span> observation of the satellite's height above the sea surface with a degree 10 model of <span class="hlt">dynamic</span> <span class="hlt">topography</span> being recovered simultaneously with the orbit parameters, gravity and tidal terms in this model. PGS-3337 has a geoid uncertainty of 60 cm root-mean-square (RMS) globally, with the uncertainty over the altimeter tracked ocean being in the 25 cm range. Doppler determined orbits for Seasat, show large improvements, with the sub-30 cm radial accuracies being achieved. When altimeter data is used in orbit determination, radial orbital accuracies of 20 cm are achieved. The RMS of fit to the altimeter data directly gives 30 cm fits for Seasat when using PGS-3337 and its geoid and <span class="hlt">dynamic</span> <span class="hlt">topography</span> model. This performance level is two to three times better than that achieved with earlier Goddard earth models (GEM) using the <span class="hlt">dynamic</span> <span class="hlt">topography</span> from long-term oceanographic averages. The recovered <span class="hlt">dynamic</span> <span class="hlt">topography</span> reveals the global long wavelength circulation of the oceans with a resolution of 1500 km. The power in the <span class="hlt">dynamic</span> <span class="hlt">topography</span> recovery is now found to be closer to that of oceanographic studies than for previous satellite solutions. This is attributed primarily to the improved modeling of the geoid which has occurred. Study of the altimeter residuals reveals regions where tidal models are poor and sea state effects are major limitations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013APS..MARM45006K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013APS..MARM45006K"><span id="translatedtitle">Effect of surface <span class="hlt">topography</span> on actin <span class="hlt">dynamics</span> and receptor clustering in B cells</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ketchum, Christina; Sun, Xiaoyu; Song, Wenxia; Fourkas, John; Upadhyaya, Arpita</p> <p>2013-03-01</p> <p>B cells are activated upon binding of the B cell receptor (BCR) with antigen on the surface of antigen presenting cells (APC). Activated B cells deform and spread on the surface of APCs which may comprise of complex membrane topologies. In order to model the diverse range of <span class="hlt">topographies</span> that B cells may encounter, substrates fabricated with vertical ridges separated by gaps ranging from hundreds of nm to microns were coated with activating antigen to enable B cell spreading. Simultaneous imaging of actin and BCR shows that the organization of both depends profoundly on the ridge spacing. On smaller ridge spacing (<2 microns), actin forms long filopodial structures that explore the substrate parallel to ridges while the BCR clusters accumulate linearly along the direction of the ridges with limited ability to escape these channels. Cells on larger ridge spacing (>2 microns) exhibit central actin patches and peripheral actin waves and form semi-stable polymerization zones at ridges, while BCR distribution is more homogeneous. Our results indicate that surface <span class="hlt">topography</span> may be a critical determinant of cytoskeletal <span class="hlt">dynamics</span> and the spatiotemporal organization of signaling clusters. Biophysics Program</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.2288K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.2288K"><span id="translatedtitle">Mean <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span> determination from recent GOCE/GRACE geopotential models and satellite altimetry data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Katsadourou, Afroditi; Vergos, Georgios S.; Tziavos, Ilias N.</p> <p>2013-04-01</p> <p>The mean <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span> (MDOT) is a fundamental reference surface for both geodesy and physical oceanography. Geodesy focuses on studying and understanding of the Earth's <span class="hlt">dynamic</span> system and the determination of the Earth's gravity field, within which MDOT plays a crucial role to separate the mean sea surface from the geoid. The evolution of space geodesy led to the establishment of modern satellite missions and new methods of determining and tracking homogeneously the Earth's gravity field, thus providing a unique outlook of its spectrum, both over continental and marine areas, with increased accuracy. The study of sea level variations and the determination of the sea surface <span class="hlt">topography</span> outline the interrelation of geodesy and oceanography. In this work two data sets were used in order to estimate the MDOT and consequently the ocean circulation of two study areas located in North Atlantic Ocean and the Mediterranean Sea. To this respect, the DTU10 Mean Sea Surface model and geoid heights from the GOCE/GRACE global geopotential model GOCO02S have been employed. After proper data pre-processing for the determination of the MDOT for both areas under study, in order to evaluate the initial results and subsequently fine-tune the solution, statistical tests (2σ and 3σ tests) as well as linear filtering have been applied. The latter are needed to account for blunders and the geoid omission and commission errors, respectively. Three different types of filters were used namely boxcar, cosine arch and Gaussian ones, employing various cut-off frequencies in order to reduce geoid and MSS errors as well as white noise. The results are validated against the DTU10 Mean <span class="hlt">Dynamic</span> <span class="hlt">Topography</span> model. The solutions presented refer to filters with spatial wavelengths set to 400km and 550km (200km and 275km half wavelength, respectively) for the North Atlantic and 600km and 780km (300km and 390km half wavelength, respectively) for the Mediterranean Sea. From the so-determined MDOT models the surface geostrophic current velocities and the ocean circulation are studied for both areas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1711649H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1711649H"><span id="translatedtitle">Improvements in the oceanic mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> as determined using GOCE gravimetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hughes, Christopher W.; Wilson, Chris; Gruber, Thomas</p> <p>2015-04-01</p> <p>Data from GOCE have pushed the accuracy of the satellite-derived geoid out to shorter length scales than have previously been accessible. This is clear particularly over land regions where the match with levelling is improved, especially in regions which are poor in situ gravity measurement coverage. In principle, this should mean that it is possible to improve the resolution of ocean currents from a combination of geoid and mean sea surface, but handling of omission errors over the ocean is a subtle matter which can make any gains difficult to see. Here, we show that the combination of a combined GOCE-GRACE-altimetry-in situ gravity geoid (TUM2013c) with a compatible mean sea surface, and an adaptive filtering algorithm, provides clear improvements in the mean <span class="hlt">dynamic</span> <span class="hlt">topography</span>, especially over the Southern Ocean. The improvement is verified by comparison with mean sea surface temperature fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=23210','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=23210"><span id="translatedtitle">Linking <span class="hlt">topography</span> of its potential surface with the <span class="hlt">dynamics</span> of folding of a protein model</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Berry, R. Stephen; Elmaci, Nuran; Rose, John P.; Vekhter, Benjamin</p> <p>1997-01-01</p> <p>The “3-color, 46-bead” model of a folding polypeptide is the vehicle for adapting to proteins a mode of analysis used heretofore for atomic clusters, to relate the <span class="hlt">topography</span> of the potential surface to the <span class="hlt">dynamics</span> that lead to formation of selected structures. The analysis is based on sequences of stationary points—successive minima, joined by saddles—that rise monotonically in energy from basin bottoms. Like structure-seeking clusters, the potential surface of the model studied here is staircase-like, rather than sawtooth-like, with highly collective motions required for passage from one minimum to the next. The surface has several deep basins whose minima correspond to very similar structures, but which are separated by high energy barriers. PMID:9275155</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012GeoJI.190..922A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012GeoJI.190..922A"><span id="translatedtitle">High resolution <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span> in the Southern Ocean from GOCE</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Albertella, A.; Savcenko, R.; Janjić, T.; Rummel, R.; Bosch, W.; Schröter, J.</p> <p>2012-08-01</p> <p>A mean <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span> (MDT) has been computed using a high resolution GOCE (Gravity field and steady-state Ocean Circulation Explorer) gravity model and a new mean sea surface obtained from a combination of satellite altimetry covering the period 1992 October till 2010 April. The considered gravity model is GO-CONS-GCF-2-TIM-R3, which computes geoid using 12 months of GOCE gravity field data. The GOCE gravity data allow for more detailed and accurate estimates of MDT. This is illustrated in the Southern Ocean where the commission error is reduced from 20 to 5 cm compared to the MDT computed using the GRACE gravity field model ITG-Grace2010. As a result of the more detailed and accurate MDT, the calculation of geostrophic velocities from the MDT is now possible with higher accuracy and spatial resolution, and the error estimate is about 7 cm s-1 for the Southern Ocean.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040031692','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040031692"><span id="translatedtitle">The Effect of Surface <span class="hlt">Topography</span> on the Nonlinear <span class="hlt">Dynamics</span> of Rossby Waves</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Abarzhi, S. I.; Desjardins, O.; Pitsch, H.</p> <p>2003-01-01</p> <p>Boussinesq convection in rotating systems attracts a sustained attention of the fluid <span class="hlt">dynamics</span> community, because it has intricate non-linear <span class="hlt">dynamics</span> (Cross & Hohenberg 1993) and plays an important role in geophysical and astrophysical applications, such as the motion of the liquid outer core of Earth, the Red Spot in Jupiter, the giant cells in the Sun etc. (Alridge et al. 1990). A fundamental distinction between the real geo- and astrophysical problems and the idealized laboratory studies is that natural systems are inhomogeneous (Alridge et al. 1990). Heterogeneities modulate the flow and influence significantly the <span class="hlt">dynamics</span> of convective patterns (Alridge et al. 1990; Hide 1971). The effect of modulations on pattern formation and transition to turbulence in Boussinesq convection is far from being completely understood (Cross & Hohenberg 1993; Aranson & Kramer 2002). It is generally accepted that in the liquid outer core of the Earth the transport of the angular momentum and internal heat occurs via thermal Rossby waves (Zhang et al. 2001; Kuang & Bloxham 1999). These waves been visualized in laboratory experiments in rotating liquid-filled spheres and concentric spherical shells (Zhang et al. 2001; Kuang & Bloxham 1999). The basic <span class="hlt">dynamical</span> features of Rossby waves have been reproduced in a cylindrical annulus, a system much simpler than the spherical ones (Busse & Or 1986; Or & Busse 1987). For convection in a cylindrical annulus, the fluid motion is two-dimensional, and gravity is replaced by a centrifugal force, (Busse & Or 1986; Or & Busse 1987). Hide (1971) has suggested that the momentum and heat transport in the core might be influenced significantly by so-called bumps, which are heterogeneities on the mantle-core boundary. To model the effect of surface <span class="hlt">topography</span> on the transport of momentum and energy in the liquid outer core of the Earth, Bell & Soward (1996), Herrmann & Busse (1998) and Westerburg & Busse (2001) have studied the nonlinear <span class="hlt">dynamics</span> of thermal Rossby waves in a cylindrical annulus with azimuthally modulated height.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060029916&hterms=topography&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dtopography','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060029916&hterms=topography&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dtopography"><span id="translatedtitle">Advances in large-scale ocean <span class="hlt">dynamics</span> from a decade of satellite altimetric measurement of ocean surface <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fu, L. L.; Menard, Y.</p> <p>2002-01-01</p> <p>The past decade has seen the most intensive observations of the global ocean surface <span class="hlt">topography</span> from satellite altimeters. The Joint U.S./France TOPEX/Poseidon (T/P) Mission has become the longest radar mission ever flown in space, providing the most accurate measurements for the study of ocean <span class="hlt">dynamics</span> since October 1992.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25061442','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25061442"><span id="translatedtitle">Multiscale Reactive Molecular <span class="hlt">Dynamics</span> for <span class="hlt">Absolute</span> pK a Predictions and Amino Acid Deprotonation.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nelson, J Gard; Peng, Yuxing; Silverstein, Daniel W; Swanson, Jessica M J</p> <p>2014-07-01</p> <p>Accurately calculating a weak acid's pK a from simulations remains a challenging task. We report a multiscale theoretical approach to calculate the free energy profile for acid ionization, resulting in accurate <span class="hlt">absolute</span> pK a values in addition to insights into the underlying mechanism. Importantly, our approach minimizes empiricism by mapping electronic structure data (QM/MM forces) into a reactive molecular <span class="hlt">dynamics</span> model capable of extensive sampling. Consequently, the bulk property of interest (the <span class="hlt">absolute</span> pK a) is the natural consequence of the model, not a parameter used to fit it. This approach is applied to create reactive models of aspartic and glutamic acids. We show that these models predict the correct pK a values and provide ample statistics to probe the molecular mechanism of dissociation. This analysis shows changes in the solvation structure and Zundel-dominated transitions between the protonated acid, contact ion pair, and bulk solvated excess proton. PMID:25061442</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_4 --> <div id="page_5" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="81"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.B33I0577T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.B33I0577T"><span id="translatedtitle">Impacts of <span class="hlt">topography</span> on aspen and black spruce successional <span class="hlt">dynamics</span> in the boreal forest</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Trugman, A. T.; Medvigy, D.</p> <p>2013-12-01</p> <p>The boreal forest contains over 30 percent of Earth's terrestrial carbon, stored mainly as organic matter in soils underlain by discontinuous permafrost. In interior Alaska, black spruce trees dominate these nutrient-depleted soils where the combination of cold temperatures and nutrient-poor black spruce detritus results in an accumulation of a thick layer of organic matter that is not easily decomposed. However, warming temperatures have decreased fire return intervals and resulted in permafrost recession, opening more boreal forest space to early-successional hardwoods such aspen. Because aspen and black spruce stands have a much different capacity for near-surface carbon storage, shifts in vegetation type have important implications for carbon storage in boreal forests. Yet, existing global climate models that run at resolutions of 50-100 square kilometers cannot capture vegetation <span class="hlt">dynamics</span> that result from fire and topographic variation, where significant heterogeneity is present on scales of 1 square kilometer or less. In this study we use the Ecosystem Demography model version 2 to examine the growth and mortality <span class="hlt">dynamics</span> of black spruce and aspen trees. Employing meteorological forcing data from the Bonanza Creek Long Term Ecological Research (BNZ-LTER) weather station (64.70°N, 148.25°W) we investigate the interdependence of permafrost depth, soil temperature, soil moisture content and plant functional type on <span class="hlt">topography</span>. Modeled plant densities are corroborated with observed aspen and black spruce distributions at the BNZ-LTER and nearby Delta Junction, AK. We then show how an accurate spatial parameterization of aspen and black spruce trees can be used to better simulate boreal zone carbon <span class="hlt">dynamics</span> with receding permafrost and increased fire frequency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMEP41B0778T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMEP41B0778T"><span id="translatedtitle">Simulating Turbidity Current <span class="hlt">Dynamics</span> Using Natural <span class="hlt">Topographies</span> With and Without Clear-Water Entrainment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Traer, M. M.; Hilley, G. E.; Fildani, A.; McHargue, T.</p> <p>2012-12-01</p> <p>This study uses a modified version of Parker et al. (1986)'s one-dimensional turbidity current model to simulate the <span class="hlt">dynamics</span> of currents that traverse natural submarine <span class="hlt">topographies</span>, in an effort to determine if such flows might plausibly traverse channel forms currently observed at the seafloor or in shallow seismic datasets. To accomplish this, we calculated flow <span class="hlt">dynamics</span> based on 50000 sets of initial conditions that were drawn randomly between prescribed bounds, and identified those starting conditions that allowed flows to traverse the naturally observed systems. In addition to examining the along-channel runout lengths of these flows, we used flow height and maximum velocity to rule out initial conditions that created flows that would be broadly accepted as unphysical. We found that when the clear-water entrainment rules of Parker et al. (1987) were used, a small percentage of flows (2.3-9.7%) traversed the measured portion of these natural systems and maintained physically plausible peak depth-averaged velocities. However, flows meeting these criteria nonetheless reach peak heights that were many times that of the channel-bottom to levee-crest relief. Often the height of the simulated turbidity current exceeded this channel relief by as much as an order of magnitude. When clear-water entrainment was removed from the model, a larger percentage of flows traversed the measured channel geometries, and maintained more physically plausible ranges of peak depth-averaged velocities and heights. We speculate that the unphysical flows produced using clear-water entrainment may arise due to the model's neglect of flow loss through flow stripping and/or overbank collapse, or scaling problems associated with extrapolating laboratory-measured clear-water entrainment rules to the field. Future studies that aim to account for fluid mass loss by lateral collapse and extract the clear-water entrainment relationship independently of laboratory experiments may be necessary to accurately model turbidity current <span class="hlt">dynamics</span> at the field-scale.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ESASP.722E..27R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ESASP.722E..27R"><span id="translatedtitle">New Global Mean <span class="hlt">Dynamic</span> <span class="hlt">Topography</span> From A GOCE Geoid Model, Altimer Measurements And Oceanographic In-Situ Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rio, M.-H.; Mulet, S.; Picot, N.</p> <p>2013-12-01</p> <p>The use of recent GOCE geoid models together with an altimeter Mean Sea Surface significantly improves the estimate of the ocean Mean <span class="hlt">Dynamic</span> <span class="hlt">Topography</span> at 100 km resolution compared to the use of previous GRACE geoid models. However, at scales shorter than 100km, the combined effect of geoid omission and commission errors prevents from directly using such models to estimate the ocean MDT and additional information is needed. In this study, the methodology used by [1] to estimate the CNES-CLS09 MDT is applied to include the shortest scales provided by in-situ measurements of current velocities and <span class="hlt">dynamic</span> heights and compute a new, high resolution Mean <span class="hlt">Dynamic</span> <span class="hlt">Topography</span> for the global ocean. Improvements over the previous CNES-CLS09 MDT are quantified through comparison to independent in- situ velocities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6055997','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6055997"><span id="translatedtitle"><span class="hlt">Dynamic</span> sea surface <span class="hlt">topography</span>, gravity, and improved orbit accuracies from the direct evaluation of Seasat altimeter data</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Marsh, J.G.; Koblinsky, C.J.; Lerch, F. ); Klosko, S.M.; Robbins, J.W.; Williamson, R.G.; Patel, G.B. )</p> <p>1990-08-15</p> <p>A gravitational model incorporating Seasat altimetry, surface gravimetry, and satellite tracking data has been determined in terms of global spherical harmonics complete to degree and order 50. This model, PGS-3337, uses altimeter data as a <span class="hlt">dynamic</span> observation of the satellite's height above the sea surface. A solution for the ocean's <span class="hlt">dynamic</span> <span class="hlt">topography</span> is recovered simultaneously with the orbit parameters, gravity, and ocean tidal terms. The recovered <span class="hlt">dynamic</span> <span class="hlt">topography</span> reveals the global long wavelength circulation of the oceans with a resolution of 2,000 km and is very similar to the mean upper ocean <span class="hlt">dynamic</span> height derived from historical ship observations. The PGS-3337 geoid has an uncertainty of 60 cm rms globally but only 25 cm rms over the ocean because of the altimeter measurements. Seasat orbits determined in this solution have an estimated accuracy for the radial position of 20 cm rms. The difference between the altimeter observed sea height and the geoid plus <span class="hlt">dynamic</span> <span class="hlt">topography</span> model is 30 cm rms. Contained in these residuals are the sea height variability, as well as errors from the geoid, orbits, tidal models, and altimeter range measurements. This performance level is 2 to 3 times better than that achieved with previous Goddard gravitational models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRC..120.7807O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRC..120.7807O"><span id="translatedtitle">A comparative assessment of coastal mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> in Norway by geodetic and ocean approaches</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ophaug, Vegard; Breili, Kristian; Gerlach, Christian</p> <p>2015-12-01</p> <p>The ocean's mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> (MDT) is the surface representation of ocean circulation. It may be determined by the ocean approach, using numerical ocean circulation models, or by the geodetic approach, where MDT is the height of the mean sea surface (MSS), or mean sea level (MSL), above the geoid. Using new geoid models, geodetic MDT profiles based on tide gauges, dedicated coastal altimetry products, and conventional altimetry are compared with six ocean MDT estimates independent of geodetic data. Emphasis is put on the determination of high-resolution geoid models, combining ESA's fifth release (R5) of GOCE satellite-only global gravity models (GGMs) with a regional geoid model for Norway by a filtering technique. Differences between MDT profiles along the Norwegian coast together with Taylor diagrams confirm that geodetic and ocean MDTs agree on the ˜3-7 cm level at the tide gauges, and on the ˜5-11 cm level at the altimetry sites. Some geodetic MDTs correlate more with the best-performing ocean MDT than do other ocean MDTs, suggesting a convergence of the methods. While the GOCE R5 geoids are shown to be more accurate over land, they do not necessarily show the best agreement over the ocean. Pointwise monomission altimetry products give results comparable with the multimission DTU13MSS grid on the ˜5 cm level. However, dedicated coastal altimetry products generally do not offer an improvement over conventional altimetry along the Norwegian coast.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGeod..89..811W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGeod..89..811W"><span id="translatedtitle">The status of measurement of the Mediterranean mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> by geodetic techniques</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Woodworth, Philip L.; Gravelle, Médéric; Marcos, Marta; Wöppelmann, Guy; Hughes, Chris W.</p> <p>2015-08-01</p> <p>We review the measurement of the mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> (MDT) of the Mediterranean using ellipsoidal heights of sea level at discrete tide gauge locations, and across the entire basin using satellite altimetry, subtracting estimates of the geoid obtained from recent models. This `geodetic approach' to the determination of the MDT can be compared to the independent `ocean approach' that involves the use of in situ oceanographic measurements and ocean modelling. We demonstrate that with modern geoid and ocean models there is an encouraging level of consistency between the two sets of MDTs. In addition, we show how important geodetic MDT information can be in judging between existing global ocean circulation models, and in providing insight for the development of new ones. The review makes clear the major limitations in Mediterranean data sets that prevent a more complete validation, including the need for improved geoid models of high spatial resolution and accuracy. Suggestions are made on how a greater amount of reliable geo-located tide gauge information can be obtained in the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.9337P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.9337P"><span id="translatedtitle">GOCE studies of mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> and ocean circulation in the Nordic Seas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pripp, Trond; Johannessen, Johnny; Eldevik, Tor</p> <p>2013-04-01</p> <p>By combining the GOCE (Gravity field and steady-state Ocean Circulation Explorer) derived Mean <span class="hlt">Dynamic</span> <span class="hlt">Topography</span> (MDT) and altimetric sea level anomalies (SLA) with hydrographic data an estimate of the mean and variables transport of Atlantic Water entering the Nordic seas is obtained for the period 1993 - 2010 at a spatial resolution of 100 km. The mean inflow of Atlantic Water (Salinity >35) through the Faroe-Shetland Channel is estimated to approximately 4.1 Sv (1 Sv = 106 m^3s^-1). Across the Iceland Faroe Ridge the mean volume transport of Atlantic Water is 3.5 Sv. In comparison, the mean transport of the two branches of Atlantic Water crossing the Svinøy section the Norwegian Atlantic Slope Current and the Norwegian Atlantic Front Current is respectively 3.8 Sv and 3.0 Sv. This is in close agreement with previous estimates. Taking benefit of the temporal variability observed in the SLA and hydrography data the seasonal cycle in the transport of the inflowing Atlantic Water reveals a consistent pattern with a maximum of 9.3 Sv during the winter months (Des - Feb), and a minimum of 5.4 Sv during the summer months (Jun - Aug). The winter maximum was almost twice as large as the summer minimum, and a preliminary analysis suggests that the strength of Atlantic flow toward the Arctic reflect the strength of the regional wind forcing (NAO).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.8216G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.8216G"><span id="translatedtitle">Global mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> based on GOCE data and Wiener filters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gilardoni, Maddalena; Reguzzoni, Mirko; Albertella, Alberta</p> <p>2015-04-01</p> <p>A mean <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span> (MDT) has been computed by using a GOCE-only gravity model and a given mean sea surface (MSS) obtained from satellite altimetry. Since the used gravity model, i.e. the fifth release of the time-wise solution covering the full mission lifetime, is truncated at a maximum harmonic degree of 280, the obtained MDT has to be consistently filtered. This has been done globally by using the spherical harmonic representation and following a Wiener minimization principle. This global filtering approach is convenient from the computational point of view but requires to have MDT values all over the Earth surface and therefore to fill the continents with fictitious data. The main improvements with respect to the already presented results are in the MDT filling procedure (to guarantee that the global signal has the same covariance of the one over the oceans), in the error modelling of the input MSS and in the error estimation of the filtered MDT and of the corresponding geostrophic velocities. The impact of GOCE data in the ocean circulation global modelling has been assessed by comparing the pattern of the obtained geostrophic currents with those computed by using EGM2008. Comparisons with independent circulation data based on drifters and other MDT models have been also performed with the aim of evaluating the accuracy of the obtained results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20010016297&hterms=implied+term&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dimplied%2Bterm','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20010016297&hterms=implied+term&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dimplied%2Bterm"><span id="translatedtitle">Geopotential Model Improvement Using POCM_4B <span class="hlt">Dynamic</span> Ocean <span class="hlt">Topography</span> Information: PGM2000A</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pavlis, N. K.; Chinn, D. S.; Cox, C. M.; Lemoine, Frank G.; Smith, David E. (Technical Monitor)</p> <p>2000-01-01</p> <p>The two-year mean (1993-1994) <span class="hlt">Dynamic</span> Ocean <span class="hlt">Topography</span> (DOT) field implied by the POCM_4B circulation model was used to develop normal equations for DOT, in a surface spherical harmonic representation. These normal equations were combined with normal equations from satellite tracking data, surface gravity data, and altimeter data from TOPEX/Poseidon and ERS-1. Several least-squares combination solutions were developed in this fashion, by varying parameters such as the maximum degree of the estimated DOT and the relative weights of the different data. The solutions were evaluated in terms of orbit fit residuals, GPS/Leveling-derived undulations, and independent DOT information from in situ WOCE hydrographic data. An optimal solution was developed in this fashion which was originally presented at the 1998 EGS meeting in Nice, France. This model, designated here PGM2000A, maintains the orbit and land geoid modeling performance of EGM96, while improving its marine geoid modeling capability. In addition, PGM2000A's error spectrum is considerably more realistic than those of other contemporary gravitational models and agrees well with the error spectrum of EGM96. We will present the development and evaluation of PGM2000A, with particular emphasis on the weighting of the DOT information implied by POCM_4B. We will also present an inter-comparison of PGM2000A with the GRIM5-C1 and TEG-4 models. Directions for future work and problematic areas will be identified.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013PEPI..224...21B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013PEPI..224...21B"><span id="translatedtitle"><span class="hlt">Dynamics</span> of plumes in a compressible mantle with phase changes: Implications for phase boundary <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bossmann, Andrea B.; van Keken, Peter E.</p> <p>2013-11-01</p> <p>While plumes rising from the deep mantle may be responsible for hotspot volcanism, their existence has not yet been unambiguously confirmed by seismological studies. Several seismic studies reported that the <span class="hlt">topography</span> of the 670-km discontinuity is flat below hotspots, which disagrees with the elevation expected due to its negative Clapeyron slope and plume excess temperature. An improved numerical method that includes compressibility and consistently implemented phase transitions is used to study plume evolution in the Earth’s mantle. The influence of latent heat on plume behavior for varying convective vigor and Clapeyron slope of the endothermic phase change at 670 km depth is studied in axisymmetric spherical shell geometry. Minor differences in plume <span class="hlt">dynamics</span> are found for models considering and neglecting latent heat. Three regimes of plume behavior at the endothermic phase boundary are observed: besides complete plume inhibition and penetration along the symmetry axis an intermediate regime in which the plume forms a ring around the symmetry axis is found. These models also predict that the 670-km discontinuity is flat below hotspots due to a large plume head in the lower mantle of about 1000 km diameter that significantly thins as it rises into the upper mantle. This is explained by the lower viscosity in the upper mantle and the spreading of the temporarily inhibited plume below the endothermic phase boundary, which reconciles the flat 670-km discontinuity with a deep mantle plume origin.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060039468&hterms=sales&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dsales','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060039468&hterms=sales&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dsales"><span id="translatedtitle">Video Animation of Ocean <span class="hlt">Topography</span> From TOPEX/POSEIDON</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fu, Lee-Lueng; Leconte, Denis; Pihos, Greg; Davidson, Roger; Kruizinga, Gerhard; Tapley, Byron</p> <p>1993-01-01</p> <p>Three video loops showing various aspects of the <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span> obtained from the TOPEX/POSEIDON radar altimetry data will be presented. The first shows the temporal change of the global ocean <span class="hlt">topography</span> during the first year of the mission. The time-averaged mean is removed to reveal the temporal variabilities. Temporal interpolation is performed to create daily maps for the animation. A spatial smoothing is also performed to retain only the large-sale features. Gyre-scale seasonal changes are the main features. The second shows the temporal evolution of the Gulf Stream. The high resolution gravimetric geoid of Rapp is used to obtain the <span class="hlt">absolute</span> ocean <span class="hlt">topography</span>. Simulated drifters are used to visualize the flow pattern of the current. Meanders and rings of the current are the main features. The third is an animation of the global ocean <span class="hlt">topography</span> on a spherical earth. The JGM-2 geoid is used to obtain the ocean <span class="hlt">topography</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.T43E..01B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.T43E..01B"><span id="translatedtitle">Recognising the Different Roles and Expressions of <span class="hlt">Dynamic</span> Mantle Flow and Plate Kinematics in the Evolution of Africa's <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brown, R. W.; Wildman, M.; Beucher, R.; Chardon, D.; Rouby, D.; Stuart, F. M.; Persano, C.</p> <p>2014-12-01</p> <p>Continental elevation can be partitioned into contributions from intrinsic isostatic buoyancy forces arising from thermal, compositional and thickness variations within the crust or lithosphere and external geodynamic forces. External forces include horizontal in-plane stress and vertical forces arising from convection within the deep mantle giving rise to <span class="hlt">dynamic</span> uplift of Earth's surface. In essence both of these are ultimately expressions of the energy driving and/or contained within the convecting lithosphere-mantle system, and so are not really separate, but their expression in the <span class="hlt">topography</span> at the surface is often quite different. The term <span class="hlt">dynamic</span> uplift refers to <span class="hlt">topography</span> that is supported by the vertical stresses arising from the upward viscous flow of mantle impinging on the base of the lithosphere, and it is typically regional in extent. In recent years the importance of <span class="hlt">dynamic</span> uplift as a major control on continental <span class="hlt">topography</span> has been emphasised by the advances in seismology and progress in understanding the structure of the shallow as well as deep mantle. However, the difficulty of quantifying surface uplift within non-orogenic regions has hampered progress in understanding how continental <span class="hlt">topography</span> reacts to the competing interaction between mantle process creating the <span class="hlt">topography</span> and surface processes that destroy it. Any geomorphic response, and the resulting erosion or sedimentary signal related to these uplift events, is strongly filtered through the response times of surface processes that are responding to relatively small changes in surface gradient. But with care, the erosional history, measured over large areas, can monitor the evolution of continental scale <span class="hlt">topography</span> and this can be very effectively measured at appropriate temporal and spatial scales using low temperature thermochronometry. This approach, combined with analysis of the offshore sedimentary record around southern Africa, has proved to be very effective at documenting the topographic evolution of the sub-continent and has identified the expression of 'conventional' plate tectonic processes of rifting and rift flank uplift as well as discrete responses to significant plate kinematic changes and the more regional expression of <span class="hlt">dynamic</span> uplift likely arising from flow within the deep mantle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRF..120.1485T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRF..120.1485T"><span id="translatedtitle">Simulating depth-averaged, one-dimensional turbidity current <span class="hlt">dynamics</span> using natural <span class="hlt">topographies</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Traer, M. M.; Fildani, A.; McHargue, T.; Hilley, G. E.</p> <p>2015-08-01</p> <p>This study simulates turbidity currents through natural submarine <span class="hlt">topographies</span> using a steady, one-dimensional, depth-averaged model to determine if modeled flows might traverse the length of channel forms observed at the seafloor or in shallow seismic data sets. To accomplish this, we calculated flow <span class="hlt">dynamics</span> based on 50,000 sets of initial conditions drawn randomly between prescribed bounds and identified those conditions that allowed flows to traverse the naturally observed systems. We also used flow height and velocity to rule out initial conditions that produced flows that would be broadly accepted as unrealistic. We found that a small percentage (2.3-9.7%) of flows traversed the measured portion of these natural systems and maintained plausible peak depth-averaged velocities when laboratory-derived clear-water entrainment rules were used. However, even these flows reached peak heights that were many times (10-200) greater than that of the channel bottom to levee crest relief. When clear-water entrainment was removed from the model, a larger percentage of flows (34.5-41.6%) traversed the measured channel geometries, maintained lower ranges of flow height, and typically had higher flow velocities. Alternate entrainment relationships allowed flows to maintain realistic flow heights and velocities. We speculate that the unrealistic flows produced using clear-water entrainment rules arise because flow loss through stripping and/or overbank collapse is neglected in this one-dimensional model, or extrapolating laboratory-measured clear-water entrainment rules to the field is problematic.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AcMSn.tmp..117W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AcMSn.tmp..117W"><span id="translatedtitle">Contact <span class="hlt">dynamics</span> of elasto-plastic thin beams simulated via <span class="hlt">absolute</span> nodal coordinate formulation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Qing-Tao; Tian, Qiang; Hu, Hai-Yan</p> <p>2015-12-01</p> <p>Under the frame of multibody <span class="hlt">dynamics</span>, the contact <span class="hlt">dynamics</span> of elasto-plastic spatial thin beams is numerically studied by using the spatial thin beam elements of <span class="hlt">absolute</span> nodal coordinate formulation (ANCF). The internal force of the elasto-plastic spatial thin beam element is derived under the assumption that the plastic strain of the beam element depends only on its longitudinal deformation. A new body-fixed local coordinate system is introduced into the spatial thin beam element of ANCF for efficient contact detection in the contact <span class="hlt">dynamics</span> simulation. The linear isotropic hardening constitutive law is used to describe the elasto-plastic deformation of beam material, and the classical return mapping algorithm is adopted to evaluate the plastic strains. A multi-zone contact approach of thin beams previously proposed by the authors is also introduced to detect the multiple contact zones of beams accurately, and the penalty method is used to compute the normal contact force of thin beams in contact. Four numerical examples are given to demonstrate the applicability and effectiveness of the proposed elasto-plastic spatial thin beam element of ANCF for flexible multibody system <span class="hlt">dynamics</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16483197','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16483197"><span id="translatedtitle">On the calculation of <span class="hlt">absolute</span> free energies from molecular-<span class="hlt">dynamics</span> or Monte Carlo data.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Huang, Lei; Makarov, Dmitrii E</p> <p>2006-02-14</p> <p>We propose a method for calculating <span class="hlt">absolute</span> free energies from Monte Carlo or molecular-<span class="hlt">dynamics</span> data. The method is based on the identity that expresses the partition function Q as a Boltzmann average: 1Q=w(p,x)exp[betaH(p,x)], where w(p,x) is an arbitrary weight function such that its integral over the phase space is equal to 1. In practice, to minimize statistical errors the weight function is chosen such that the regions of the phase space where sampling statistics are poor are excluded from the average. The "ideal" weight function would be the equilibrium phase-space density exp[-betaH(p,x)]Q itself. We consider two methods for constructing the weight function based on different estimates of the equilibrium phase-space density from simulation data. In the first method, it is chosen to be a Gaussian function, whose parameters are obtained from the covariance matrix of the atomic coordinates. In the second, a clustering algorithm is used to attempt partitioning the data into clusters corresponding to different basins of attraction visited by the system. The weight function is then constructed as a superposition of Gaussians calculated for each cluster separately. We show that these strategies can be used to improve upon previous methods of estimating <span class="hlt">absolute</span> entropies from covariance matrices. PMID:16483197</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.6310D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.6310D"><span id="translatedtitle"><span class="hlt">Dynamics</span> of thermo-chemical mantle plumes and their influence on surface <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dannberg, J.; Sobolev, S. V.</p> <p>2012-04-01</p> <p>According to widely recognised models, large igneous provinces (LIPs) develop as a result of plumes ascending from the core-mantle boundary and the associated massive melting when the plume head reaches the base of the lithosphere. Most of these models include kilometer-scale topographic uplift before and during the eruption of flood basalts. On the contrary several paleogeographic and paleotectonic field studies indicate significantly smaller surface uplift during the development of many LIPs. Recent geodynamic models show that the interaction of thermo-chemical, rather than purely thermal, plumes with the lithosphere explains observations for LIPs much better. This includes small premagmatic uplift and enormous magmatic activity even at thick cratonic lithosphere. Such thermo-chemical plumes are formed by the entrainment of dense material derived from recycled oceanic crust while the plume ascends from the D''-layer. Presence of this material reduces plume buoyancy and thus generates smaller surface uplift. However, previous studies considered neither the interaction of the thermo-chemical plume with transition zone phase boundaries nor its motion in the lower mantle. They also assume a constant density difference between peridotite and eclogite, or neglect phase transformations. In this work we present a systematic study of the <span class="hlt">dynamics</span> of thermo-chemical plumes in the whole mantle and their influence on <span class="hlt">dynamic</span> <span class="hlt">topography</span>. For that we use a two-dimensional axisymmetric finite-element model that includes 410 km and 660 km phase boundaries as well as depth-dependent density difference between pyrolite and the MORB material. We employ a modified version of the Citcom code that includes mantle compressibility, a tracer-ratio method to incorporate the two chemical components and strongly temperature- and depth-dependent viscosity. Our study shows that thermo-chemical plumes cause a surface uplift on a scale of 150 - 1000 m during their ascent and spreading below the lithosphere. This is significantly smaller than predicted for purely thermal plumes. We show that a plume containing a too high fraction of recycled oceanic crust to rise to the lithosphere more likely ponds at a depth of 300 - 400 km than at the 660-km phase boundary. This barrier is caused by the high density contrast between eclogite and pyrolite in this region. In addition, we show that neglecting phase transformations and the depth-dependence of MORB density leads to substantial different results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMDI51A4347R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMDI51A4347R"><span id="translatedtitle">Combining Mantle Convection Modeling With Gravity and <span class="hlt">Topography</span> Spectra to Constrain the <span class="hlt">Dynamic</span> Evolution of the Terrestrial Planets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rolf, T.; Werner, S. C.; Steinberger, B. M.</p> <p>2014-12-01</p> <p>From some perspective the terrestrial planets of our Solar System appear very similar, for instance in their bulk composition and the differentiation in core, silicate mantle and crust. However, from other perspectives they appear significantly different, perhaps most strikingly in their current tectonic mode: while Earth is the only planet with currently ongoing plate tectonics, Venus is likely to be in a regime of episodic resurfacing. Mars features the stagnant lid mode and so might Mercury, if its mantle is still undergoing large-scale convection at all. Understanding the similarities and differences in the <span class="hlt">dynamic</span> evolution of the different planets can thus provide important information about the conditions needed to initialize and maintain plate tectonics and shed light on the question why Earth is unique in this respect. Reliable constraints for planets other than Earth are difficult to make and are mostly limited to the planetary surface. However, measuring a planet's gravity field provides one, though not unique, way to constrain the internal structure of a planet. Additionally, the planet's moment of inertia factor and surface <span class="hlt">topography</span> may help to limit the number of possible structures. All of these, moment of inertia, gravity and <span class="hlt">topography</span> are reasonably well known for the terrestrial planets from various satellite missions. Here, we use such measurements to constrain the radial structure of the planetary mantles. <span class="hlt">Dynamic</span> forward modeling is then used to analyze the different evolutions and <span class="hlt">dynamic</span> features that cause the inferred structures and the resulting geoid and <span class="hlt">topography</span> spectra to evolve. Using <span class="hlt">dynamic</span> models also enables us to estimate the role of lateral variations, particularly in viscosity. In this first step, we focus on a comparison between the Earth and Venus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1578458','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1578458"><span id="translatedtitle"><span class="hlt">Absolute</span> Binding Free Energy Calculations Using Molecular <span class="hlt">Dynamics</span> Simulations with Restraining Potentials</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wang, Jiyao; Deng, Yuqing; Roux, Benoît</p> <p>2006-01-01</p> <p>The <span class="hlt">absolute</span> (standard) binding free energy of eight FK506-related ligands to FKBP12 is calculated using free energy perturbation molecular <span class="hlt">dynamics</span> (FEP/MD) simulations with explicit solvent. A number of features are implemented to improve the accuracy and enhance the convergence of the calculations. First, the <span class="hlt">absolute</span> binding free energy is decomposed into sequential steps during which the ligand-surrounding interactions as well as various biasing potentials restraining the translation, orientation, and conformation of the ligand are turned “on” and “off.” Second, sampling of the ligand conformation is enforced by a restraining potential based on the root mean-square deviation relative to the bound state conformation. The effect of all the restraining potentials is rigorously unbiased, and it is shown explicitly that the final results are independent of all artificial restraints. Third, the repulsive and dispersive free energy contribution arising from the Lennard-Jones interactions of the ligand with its surrounding (protein and solvent) is calculated using the Weeks-Chandler-Andersen separation. This separation also improves convergence of the FEP/MD calculations. Fourth, to decrease the computational cost, only a small number of atoms in the vicinity of the binding site are simulated explicitly, while all the influence of the remaining atoms is incorporated implicitly using the generalized solvent boundary potential (GSBP) method. With GSBP, the size of the simulated FKBP12/ligand systems is significantly reduced, from ∼25,000 to 2500. The computations are very efficient and the statistical error is small (∼1 kcal/mol). The calculated binding free energies are generally in good agreement with available experimental data and previous calculations (within ∼2 kcal/mol). The present results indicate that a strategy based on FEP/MD simulations of a reduced GSBP atomic model sampled with conformational, translational, and orientational restraining potentials can be computationally inexpensive and accurate. PMID:16844742</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19794240','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19794240"><span id="translatedtitle">A quantitative assessment of the depth sensitivity of an optical <span class="hlt">topography</span> system using a solid <span class="hlt">dynamic</span> tissue-phantom.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Correia, Teresa; Banga, Anil; Everdell, N L; Gibson, Adam P; Hebden, Jeremy C</p> <p>2009-10-21</p> <p>A solid <span class="hlt">dynamic</span> phantom with tissue-like optical properties is presented, which contains seven discrete targets impregnated with thermochromic pigment located at different depths from the surface. Changes in absorption are obtained in response to localized heating of the targets, simulating haemodynamic changes occurring in the brain and other tissues. The depth sensitivity of a continuous wave optical <span class="hlt">topography</span> system was assessed successfully using the phantom. Images of the targets have been reconstructed using a spatially variant regularization, and the determined spatial localization in the depth direction is shown to be accurate within an uncertainty of about 3 mm down to a depth of about 30 mm. PMID:19794240</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PMB....54.6277C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PMB....54.6277C"><span id="translatedtitle">A quantitative assessment of the depth sensitivity of an optical <span class="hlt">topography</span> system using a solid <span class="hlt">dynamic</span> tissue-phantom</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Correia, Teresa; Banga, Anil; Everdell, N. L.; Gibson, Adam P.; Hebden, Jeremy C.</p> <p>2009-10-01</p> <p>A solid <span class="hlt">dynamic</span> phantom with tissue-like optical properties is presented, which contains seven discrete targets impregnated with thermochromic pigment located at different depths from the surface. Changes in absorption are obtained in response to localized heating of the targets, simulating haemodynamic changes occurring in the brain and other tissues. The depth sensitivity of a continuous wave optical <span class="hlt">topography</span> system was assessed successfully using the phantom. Images of the targets have been reconstructed using a spatially variant regularization, and the determined spatial localization in the depth direction is shown to be accurate within an uncertainty of about 3 mm down to a depth of about 30 mm.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_5 --> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980223942','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980223942"><span id="translatedtitle">The Development of a Degree 360 Expansion of the <span class="hlt">Dynamic</span> Ocean <span class="hlt">Topography</span> of the POCM_4B Global Circulation Model</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rapp, Richard H.</p> <p>1998-01-01</p> <p>This paper documents the development of a degree 360 expansion of the <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span> (DOT) of the POCM_4B ocean circulation model. The principles and software used that led to the final model are described. A key principle was the development of interpolated DOT values into land areas to avoid discontinuities at or near the land/ocean interface. The power spectrum of the POCM_4B is also presented with comparisons made between orthonormal (ON) and spherical harmonic magnitudes to degree 24. A merged file of ON and SH computed degree variances is proposed for applications where the DOT power spectrum from low to high (360) degrees is needed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.T51B4637C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.T51B4637C"><span id="translatedtitle">Physical Parameters Controlling Subduction <span class="hlt">Dynamics</span> and Surface <span class="hlt">Topography</span> in Self-consistent Global Models of Mantle Convection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crameri, F.; Pears, M. I.; Lithgow-Bertelloni, C. R.; Tackley, P. J.</p> <p>2014-12-01</p> <p>Recent advances in numerical modelling allow global models of mantle convection to realistically reproduce the behaviour at convergent plate boundaries (Crameri et al., 2012a). This allows for a more extensive study of subduction that, in contrast to the numerous regional models, incorporates the complete framework of mantle convection. Here, we focus on different aspects of mantle convection including (i) slab dip variations, (ii) variations in radial mantle viscosity, and (iii) the presence of localised mantle upwellings and discuss their control on the <span class="hlt">dynamics</span> of Earth-like plate tectonics. Additionally, we present the effect these parameter variations have on measurable quantities like <span class="hlt">dynamic</span> <span class="hlt">topography</span> and plate velocity. The models are calculated by the finite-volume code Stag-YY (e.g., Tackley 2008) using a multi-grid method on a fully staggered grid. Second, the sticky-air method (Matsumoto and Tomoda 1983; Schmeling et al, 2008) is applied and thus approximates a free surface when the sticky-air parameters are chosen carefully (Crameri et al., 2012b). Overall, this study demonstrates the ability of various parameters to significantly influence both subduction <span class="hlt">dynamics</span> and surface <span class="hlt">topography</span>. REFERENCES Crameri, F., et al. (2012a), Geophys. Res. Lett., 39(3). Crameri, F., et al. (2012b), Geophys. J. Int., 189(1). Matsumoto, T., and Y. Tomoda (1983), J. Phys. Earth, 31(3). Schmeling, H., et al. (2008), Phys. Earth Planet. Int., 171(1-4). Tackley, P. J. (2008), Phys. Earth Planet. Int., 171(1-4).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.9353B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.9353B"><span id="translatedtitle">Validating geostrophic currents of a <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span> estimate with data of ARGO floats and surface drifters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bosch, Wolfgang; Müller, Felix; Dettmering, Denise</p> <p>2015-04-01</p> <p>Improvements in both, satellite altimetry and Earth gravity field modelling allows today to significantly estimate the deviations between the sea surface and a geopotential reference surface, known as <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span> (DOT). The DOT estimate used in the present investigation is based on the "profile-approach" developed and documented by Bosch & Savcenko (2010) and Bosch et al. (2012). While other geodetic methods use a long-term mean sea surface and estimate a mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> the profile approach provides DOT estimates on individual altimeter ground tracks and allows to study the temporal variation of the DOT on spatial scales, close to meso-scale structures. In the present study we validate the time-variable DOT by gridding the DOT-profiles, computing the associated geostrophic velocity field and comparing this with gridded surface currents observed by ARGO floats and surface drifters, both corrected for wind and Ekman drift. It can be shown that both velocity fields agree quit well on a quaterly basis, choosen in order to have a sufficient density of the in-situ data. In order to avoid any unneccessary smoothing we also perform a pointwise comparison, where the geodetic DOT and the geostrophic velocity components are interpolated to individual observations of ARGO floats and surface drifters. Results are presented for a number of study areas covering above all the strong western boundary currents.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20010002520&hterms=Dynamics+Structures&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DDynamics%2BStructures','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20010002520&hterms=Dynamics+Structures&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DDynamics%2BStructures"><span id="translatedtitle">Structure and <span class="hlt">Dynamics</span> of the Polar Regions of Mars from MGS <span class="hlt">Topography</span> and Gravity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zuber, Maria T.; Smith, David E.; Neumann, Gregory A.; Lemoine, Frank G.</p> <p>2000-01-01</p> <p>The Mars Global Surveyor (MGS) spacecraft has been engaged in systematic mapping of Mars since insertion into Mars orbit in September, 1997. The objectives of the MGS mission are to globally map Mars as well as to quantify seasonal changes on the planet. MGS geophysical/geodetic observations of <span class="hlt">topography</span> from the Mars Orbiter Laser Altimeter (MOLA) and gravity from the Radio Science investigation are providing significant new insights on both static and time-varying aspects of the polar regions of Mars. These observations have implications for polar processes on diurnal seasonal and climatic timescales. Thus far, MOLA has collected over 300 million precise measurements of Martian <span class="hlt">topography</span> and cloud heights. The instrument has also provided measurements of the width of the backscattered optical pulse and of the 1064 nm reflectivity of the Martian surface and atmosphere. The along-track resolution of MOLA ground shots is approx. 300 m and the across-track spacing in the polar regions is a maximum of about four kilometers. The vertical accuracy of the <span class="hlt">topography</span> is determined by the precision recovery of spacecraft orbits from the Radio Science investigation, which includes MOLA altimetry in the form of crossovers. This accuracy is currently approx. one meter. The gravity field is derived from X-band Doppler tracking with typical accuracy of 0.03 to 0.05 mm/s averaged over ten seconds. Current Mars gravity fields are to approximately degree and order 80 but are interpretable to the approximate degree and order 60 (spatial resolution < 180 km), which represents an estimate of the approximate coefficient limit of a field that can be produced without a power law constraint on the gravitational field inversion, which is commonly imposed for solution stability. Additional information is contained in the original extended abstract.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/20188188','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/20188188"><span id="translatedtitle">BOLD correlates of EEG <span class="hlt">topography</span> reveal rapid resting-state network <span class="hlt">dynamics</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Britz, Juliane; Van De Ville, Dimitri; Michel, Christoph M</p> <p>2010-10-01</p> <p>Resting-state functional connectivity studies with fMRI showed that the brain is intrinsically organized into large-scale functional networks for which the hemodynamic signature is stable for about 10s. Spatial analyses of the <span class="hlt">topography</span> of the spontaneous EEG also show discrete epochs of stable global brain states (so-called microstates), but they remain quasi-stationary for only about 100 ms. In order to test the relationship between the rapidly fluctuating EEG-defined microstates and the slowly oscillating fMRI-defined resting states, we recorded 64-channel EEG in the scanner while subjects were at rest with their eyes closed. Conventional EEG-microstate analysis determined the typical four EEG <span class="hlt">topographies</span> that dominated across all subjects. The convolution of the time course of these maps with the hemodynamic response function allowed to fit a linear model to the fMRI BOLD responses and revealed four distinct distributed networks. These networks were spatially correlated with four of the resting-state networks (RSNs) that were found by the conventional fMRI group-level independent component analysis (ICA). These RSNs have previously been attributed to phonological processing, visual imagery, attention reorientation, and subjective interoceptive-autonomic processing. We found no EEG-correlate of the default mode network. Thus, the four typical microstates of the spontaneous EEG seem to represent the neurophysiological correlate of four of the RSNs and show that they are fluctuating much more rapidly than fMRI alone suggests. PMID:20188188</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27192396','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27192396"><span id="translatedtitle"><span class="hlt">Absolute</span> dosimetry on a <span class="hlt">dynamically</span> scanned sample for synchrotron radiotherapy using graphite calorimetry and ionization chambers.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lye, J E; Harty, P D; Butler, D J; Crosbie, J C; Livingstone, J; Poole, C M; Ramanathan, G; Wright, T; Stevenson, A W</p> <p>2016-06-01</p> <p>The <span class="hlt">absolute</span> dose delivered to a <span class="hlt">dynamically</span> scanned sample in the Imaging and Medical Beamline (IMBL) on the Australian Synchrotron was measured with a graphite calorimeter anticipated to be established as a primary standard for synchrotron dosimetry. The calorimetry was compared to measurements using a free-air chamber (FAC), a PTW 31 014 Pinpoint ionization chamber, and a PTW 34 001 Roos ionization chamber. The IMBL beam height is limited to approximately 2 mm. To produce clinically useful beams of a few centimetres the beam must be scanned in the vertical direction. In practice it is the patient/detector that is scanned and the scanning velocity defines the dose that is delivered. The calorimeter, FAC, and Roos chamber measure the dose area product which is then converted to central axis dose with the scanned beam area derived from Monte Carlo (MC) simulations and film measurements. The Pinpoint chamber measures the central axis dose directly and does not require beam area measurements. The calorimeter and FAC measure dose from first principles. The calorimetry requires conversion of the measured absorbed dose to graphite to absorbed dose to water using MC calculations with the EGSnrc code. Air kerma measurements from the free air chamber were converted to absorbed dose to water using the AAPM TG-61 protocol. The two ionization chambers are secondary standards requiring calibration with kilovoltage x-ray tubes. The Roos and Pinpoint chambers were calibrated against the Australian primary standard for air kerma at the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA). Agreement of order 2% or better was obtained between the calorimetry and ionization chambers. The FAC measured a dose 3-5% higher than the calorimetry, within the stated uncertainties. PMID:27192396</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996JGR...10122583R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996JGR...10122583R"><span id="translatedtitle">Analysis of <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span> using TOPEX data and orthonormal functions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rapp, Richard H.; Zhang, Changyou; Yi, Yuchan</p> <p>1996-10-01</p> <p>The representation of <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span> (ζ) through spherical harmonic (SH) and orthonormal (ON) expansions was studied using TOPEX altimeter data, three potential coefficient models used to define geoid undulations, and three estimates of ζ from oceanographic data and global circulation models (GCMs). The ON expansions are desirable when one wishes to study the spectral characteristics of a function in a defined domain such as the ocean. The potential coefficient models tested were JGM-2, JGM-3, and GRIM4_C4b. Each model was augmented with the OSU91A potential coefficients from degree 71 to 360. The ζ models were those of Levitus [1982] and values implied by the POCM_4B (Semtner/Chervin) model and a Los Alamos National Laboratory Model POP(96) (Malone, Smith, Dukowicz). The latter two models were defined over a 2-year time period. Values of ζ were computed from 2 years of TOPEX data using the three potential coefficient models. The ON expansions of ζ from the TOPEX data were then compared to the estimates from the oceanographic data. The differences, to ON degree 14, with the POCM_4B model and the TOPEX results were ±14.0 cm (JGM-2), ±12.4 cm (JGM-3), and ±14.4 cm (GRIM4_C4b). A comparison with the other ζ estimates using TOPEX/JGM-3 gives differences of ±14.3 cm (Levitus) and ±13.3 cm (POP (96)). The comparisons were made only to degree 14 because (1) the correlation between the ζ coefficients from TOPEX data and POCM_4B fell off beyond degree 14 and (2) the geoid undulation accuracy, in the ocean region, was equal to the ζ signal near degree 14. These results suggest ζ estimates made above degree 14 may be contaminated by geoid undulation errors. Also suggested from the comparisons was that the TOPEX/JGM-3 estimates of ζ were more reliable than those from oceanographic data to degree 8 (2500-km resolution). The ζ estimates from the POCM_4B and POP(96) models, 2-year averages, agreed well north of 40°S. Below this the differences could reach 40 cm in the Antarctic Circumpolar Current (60°S, 215°). The differences between the TOPEX/JGM-3 and POCM_4B ζ estimates exceeded 20 cm in a number of places (e.g., (20°N, 140°), (5°S, 130°), (60°S, 220°), (45°N, 320°)). The largest differences (-62 cm) occurred in the Banda Sea. The ζ representations were used to calculate upper ocean geostrophic velocities in the east/west and north/south directions. Excluding a 10° band on either side of the equator, the difference (TOPEX versus POCM_4B) was ±2.5 cm/s with the magnitude of the total velocity being 4.8 cm/s. The difference was consistent with the error estimates of the velocities implied by the errors in the JGM-3 coefficients to degree 14. The ζ estimates were also determined from four recent mean sea surface grids and the results compared to the POCM_4B model through the ON representation. The MSS grids used were the OSUMSS95, the UTCSRMSS95, the GFZ/D-PAF MSS95A, and the CNES/GRGS MSS95. The best agreement, to degree 14, was found with the OSUMSS95 (±11.1 cm) and the CSRMSS95 (±11.5 cm). The comparisons were poorer (±15 cm) when a mean sea surface was used where no mean inverted barometer correction had been applied to the gridded data. Although substantial progress has been made in the past 10 years in the determination of the Earth's gravitational potential, the accuracy limitations of geoid undulation determination still hinder the comparison and assimilation of altimeter data and oceanographic data. The need for a dedicated gravity satellite mission, to yield improved geoid undulation determinations, is clearly seen.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=computation&pg=3&id=EJ1070880','ERIC'); return false;" href="http://eric.ed.gov/?q=computation&pg=3&id=EJ1070880"><span id="translatedtitle">Easy <span class="hlt">Absolute</span> Values? <span class="hlt">Absolutely</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Taylor, Sharon E.; Mittag, Kathleen Cage</p> <p>2015-01-01</p> <p>The authors teach a problem-solving course for preservice middle-grades education majors that includes concepts dealing with <span class="hlt">absolute</span>-value computations, equations, and inequalities. Many of these students like mathematics and plan to teach it, so they are adept at symbolic manipulations. Getting them to think differently about a concept that they…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=inequality&pg=2&id=EJ1070880','ERIC'); return false;" href="http://eric.ed.gov/?q=inequality&pg=2&id=EJ1070880"><span id="translatedtitle">Easy <span class="hlt">Absolute</span> Values? <span class="hlt">Absolutely</span></span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Taylor, Sharon E.; Mittag, Kathleen Cage</p> <p>2015-01-01</p> <p>The authors teach a problem-solving course for preservice middle-grades education majors that includes concepts dealing with <span class="hlt">absolute</span>-value computations, equations, and inequalities. Many of these students like mathematics and plan to teach it, so they are adept at symbolic manipulations. Getting them to think differently about a concept that they</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015RvGeo..53.1022L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015RvGeo..53.1022L"><span id="translatedtitle">The ups and downs of North America: Evaluating the role of mantle <span class="hlt">dynamic</span> <span class="hlt">topography</span> since the Mesozoic</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Lijun</p> <p>2015-09-01</p> <p>The driving force for transient vertical motions of Earth's surface remains an outstanding question. A main difficulty lies in the uncertain role of the underlying mantle, especially during the geological past. Here I review previous studies on both observational constraints and physical mechanisms of North American topographic evolution since the Mesozoic. I first summarize the North American vertical motion history using proxies from structural geology, geochronology, sedimentary stratigraphy, and geomorphology, based on which I then discuss the published physical models. Overall, there is a progressive consensus on the contribution of mantle <span class="hlt">dynamic</span> <span class="hlt">topography</span> due to buoyancy structures associated with the past subduction. At the continental scale, a largely west-to-east migrating deformation pattern suggests an eastward translation of mantle <span class="hlt">dynamic</span> effects, consistent with models involving an eastward subduction and sinking of former Farallon slabs since the Cretaceous. Among the existing models, the inverse model based on an adjoint algorithm and time-dependent data constraints provides the most extensive explanations for the temporal changes of North American <span class="hlt">topography</span> since the Mesozoic. At regional scales, debates still exist on the predicted surface subsidence and uplift within both the western and eastern United States, where discrepancies are likely due to differences in model setup (e.g., mantle <span class="hlt">dynamic</span> properties and boundary conditions) and the amount of time-dependent observational constraints. Toward the development of the next-generation predictive geodynamic models, new research directions may include (1) development of enhanced data assimilation capabilities, (2) exploration of multiscale and multiphysics processes, and (3) cross-disciplinary code coupling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9677E..2FL','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9677E..2FL"><span id="translatedtitle">The correction of vibration in frequency scanning interferometry based <span class="hlt">absolute</span> distance measurement system for <span class="hlt">dynamic</span> measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, Cheng; Liu, Guodong; Liu, Bingguo; Chen, Fengdong; Zhuang, Zhitao; Xu, Xinke; Gan, Yu</p> <p>2015-10-01</p> <p><span class="hlt">Absolute</span> distance measurement systems are of significant interest in the field of metrology, which could improve the manufacturing efficiency and accuracy of large assemblies in fields such as aircraft construction, automotive engineering, and the production of modern windmill blades. Frequency scanning interferometry demonstrates noticeable advantages as an <span class="hlt">absolute</span> distance measurement system which has a high precision and doesn't depend on a cooperative target. In this paper , the influence of inevitable vibration in the frequency scanning interferometry based <span class="hlt">absolute</span> distance measurement system is analyzed. The distance spectrum is broadened as the existence of Doppler effect caused by vibration, which will bring in a measurement error more than 103 times bigger than the changes of optical path difference. In order to decrease the influence of vibration, the changes of the optical path difference are monitored by a frequency stabilized laser, which runs parallel to the frequency scanning interferometry. The experiment has verified the effectiveness of this method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011JGRC..116.6029S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011JGRC..116.6029S"><span id="translatedtitle">The <span class="hlt">dynamics</span> of the Mississippi River plume: Impact of <span class="hlt">topography</span>, wind and offshore forcing on the fate of plume waters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schiller, R. V.; Kourafalou, V. H.; Hogan, P.; Walker, N. D.</p> <p>2011-06-01</p> <p>High-resolution numerical simulations of the northern Gulf of Mexico region using the Hybrid Coordinate Ocean Model (HYCOM) were employed to investigate the <span class="hlt">dynamical</span> processes controlling the fate of the Mississippi River plume, in particular the conditions that favor cross-marginal transport. The study focuses on the effects of <span class="hlt">topography</span>, wind-driven and eddy-driven circulation on the offshore removal of plume waters. A realistically forced simulation (nested in a data-assimilative regional Gulf of Mexico HYCOM model) reveals that the offshore removal is a frequent plume pathway. Eastward wind-driven currents promote large freshwater transport toward the shelf break and the DeSoto Canyon, where eddies with diameters ranging from 50 to 130 km interact with the buoyant plume and effectively entrain the riverine waters. Our estimates show that the offshore removal by eddies can be as large as the wind-driven shelf transport. The proximity of eddies to the shelf break is a sufficient condition for offshore removal, and shelf-to-offshore interaction is facilitated by the steep bottom <span class="hlt">topography</span> near the delta. Strong eddy-plume interactions were observed when the Loop Current System impinged against the shelf break, causing the formation of coherent, narrow low-salinity bands that extended toward the gulf interior. The offshore pathways depend on the position of the eddies near the shelf edge, their life span and the formation of eddy pairs that generate coherent cross-shelf flows. This study elucidates the <span class="hlt">dynamics</span> that initiate a unique cross-marginal removal mechanism of riverine low-salinity, nutrient-rich waters, allowing their export along connectivity pathways, induced by a large-scale current system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1616351A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1616351A"><span id="translatedtitle">Future Antarctic bed <span class="hlt">topography</span> and its implications for ice sheet <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Adhikari, Surendra; Ivins, Erik; Larour, Eric; Seroussi, Helene; Morlighem, Mathieu; Nowicki, Sophie</p> <p>2014-05-01</p> <p>A recently improved ice loading history suggests that the Antarctic Ice Sheet (AIS) has been generally losing its mass since the last glacial maximum. In a sustained warming climate, the AIS is predicted to retreat at a greater pace primarily via melting beneath the ice shelves. We employ the glacial isostatic adjustment (GIA) capability of the Ice Sheet System Model (ISSM) to combine these past and future ice loadings and provide the new solid Earth computations for the AIS. We find that the past loading is relatively less important than future loading on the evolution of the future bed <span class="hlt">topography</span>. Our computations predict that the West Antarctic Ice Sheet (WAIS) may uplift by a few meters and a few tens of meters at years 2100 and 2500 AD, respectively, and that the East Antarctic Ice Sheet (EAIS) is likely to remain unchanged or subside minimally except around the Amery Ice Shelf. The Amundsen Sea Sector of WAIS in particular is predicted to rise at the greatest rate; one hundred years of ice evolution in this region, for example, predicts that the coastline of Pine Island Bay approaches roughly 45 mm/yr in viscoelastic vertical motion. Of particular importance, we systematically demonstrate that the effect of a pervasive and large GIA uplift in the WAIS is associated with the flattening of reverse bed, reduction of local sea depth, and thus the extension of grounding line (GL) towards the continental shelf. Using the 3-D higher-order ice flow capability of ISSM, such a migration of GL is shown to inhibit the ice flow. This negative feedback between the ice sheet and the solid Earth may promote the stability to marine portions of the ice sheet in the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SolE....5..569A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SolE....5..569A"><span id="translatedtitle">Future Antarctic bed <span class="hlt">topography</span> and its implications for ice sheet <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Adhikari, S.; Ivins, E. R.; Larour, E.; Seroussi, H.; Morlighem, M.; Nowicki, S.</p> <p>2014-06-01</p> <p>The Antarctic bedrock is evolving as the solid Earth responds to the past and ongoing evolution of the ice sheet. A recently improved ice loading history suggests that the Antarctic Ice Sheet (AIS) has generally been losing its mass since the Last Glacial Maximum. In a sustained warming climate, the AIS is predicted to retreat at a greater pace, primarily via melting beneath the ice shelves. We employ the glacial isostatic adjustment (GIA) capability of the Ice Sheet System Model (ISSM) to combine these past and future ice loadings and provide the new solid Earth computations for the AIS. We find that past loading is relatively less important than future loading for the evolution of the future bed <span class="hlt">topography</span>. Our computations predict that the West Antarctic Ice Sheet (WAIS) may uplift by a few meters and a few tens of meters at years AD 2100 and 2500, respectively, and that the East Antarctic Ice Sheet is likely to remain unchanged or subside minimally except around the Amery Ice Shelf. The Amundsen Sea Sector in particular is predicted to rise at the greatest rate; one hundred years of ice evolution in this region, for example, predicts that the coastline of Pine Island Bay will approach roughly 45 mm yr-1 in viscoelastic vertical motion. Of particular importance, we systematically demonstrate that the effect of a pervasive and large GIA uplift in the WAIS is generally associated with the flattening of reverse bed slope, reduction of local sea depth, and thus the extension of grounding line (GL) towards the continental shelf. Using the 3-D higher-order ice flow capability of ISSM, such a migration of GL is shown to inhibit the ice flow. This negative feedback between the ice sheet and the solid Earth may promote stability in marine portions of the ice sheet in the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SolED...6..191A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SolED...6..191A"><span id="translatedtitle">Future Antarctic bed <span class="hlt">topography</span> and its implications for ice sheet <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Adhikari, S.; Ivins, E.; Larour, E.; Seroussi, H.; Morlighem, M.; Nowicki, S.</p> <p>2014-01-01</p> <p>The Antarctic bedrock is evolving as the solid Earth responds to the past and ongoing evolution of the ice sheet. A~recently improved ice loading history suggests that the Antarctic Ice Sheet (AIS) is generally losing its mass since the last glacial maximum (LGM). In a sustained warming climate, the AIS is predicted to retreat at a greater pace primarily via melting beneath the ice shelves. We employ the glacial isostatic adjustment (GIA) capability of the Ice Sheet System Model (ISSM) to combine these past and future ice loadings and provide the new solid Earth computations for the AIS. We find that the past loading is relatively less important than future loading on the evolution of the future bed <span class="hlt">topography</span>. Our computations predict that the West Antarctic Ice Sheet (WAIS) may uplift by a few meters and a few tens of meters at years 2100 and 2500 AD, respectively, and that the East Antarctic Ice Sheet (EAIS) is likely to remain unchanged or subside minimally except around the Amery Ice Shelf. The Amundsen Sea Sector in particular is predicted to rise at the greatest rate; one hundred years of ice evolution in this region, for example, predicts that the coastline of Pine Island Bay approaches roughly 45 mm yr-1 in viscoelastic vertical motion. Of particular importance, we systematically demonstrate that the effect of a pervasive and large GIA uplift in the WAIS is associated with the flattening of reverse bed, reduction of local sea depth, and thus the extension of grounding line (GL) towards the continental shelf. Using the 3-D higher-order ice flow capability of ISSM, such a migration of GL is shown to inhibit the ice flow. This negative feedback between the ice sheet and the solid Earth may promote the stability to marine portions of the ice sheet in future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140017427','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140017427"><span id="translatedtitle">Future Antarctic Bed <span class="hlt">Topography</span> and Its Implications for Ice Sheet <span class="hlt">Dynamics</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Adhikari, Surendra; Ivins, Erik R.; Larour, Eric Y.; Seroussi, Helene L.; Morlighem, Mathieu; Nowicki, S.</p> <p>2014-01-01</p> <p>The Antarctic bedrock is evolving as the solid Earth responds to the past and ongoing evolution of the ice sheet. A recently improved ice loading history suggests that the Antarctic Ice Sheet (AIS) has generally been losing its mass since the Last Glacial Maximum. In a sustained warming climate, the AIS is predicted to retreat at a greater pace, primarily via melting beneath the ice shelves.We employ the glacial isostatic adjustment (GIA) capability of the Ice Sheet System Model (ISSM) to combine these past and future ice loadings and provide the new solid Earth computations for the AIS.We find that past loading is relatively less important than future loading for the evolution of the future bed <span class="hlt">topography</span>. Our computations predict that the West Antarctic Ice Sheet (WAIS) may uplift by a few meters and a few tens of meters at years AD 2100 and 2500, respectively, and that the East Antarctic Ice Sheet is likely to remain unchanged or subside minimally except around the Amery Ice Shelf. The Amundsen Sea Sector in particular is predicted to rise at the greatest rate; one hundred years of ice evolution in this region, for example, predicts that the coastline of Pine Island Bay will approach roughly 45mmyr-1 in viscoelastic vertical motion. Of particular importance, we systematically demonstrate that the effect of a pervasive and large GIA uplift in the WAIS is generally associated with the flattening of reverse bed slope, reduction of local sea depth, and thus the extension of grounding line (GL) towards the continental shelf. Using the 3-D higher-order ice flow capability of ISSM, such a migration of GL is shown to inhibit the ice flow. This negative feedback between the ice sheet and the solid Earth may promote stability in marine portions of the ice sheet in the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.C53B0313F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.C53B0313F"><span id="translatedtitle">Geological Influences on Bedrock <span class="hlt">Topography</span> and East Antarctic Ice Sheet <span class="hlt">Dynamics</span> in the Wilkes Subglacial Basin</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ferraccioli, F.; Armadillo, E.; Young, D. A.; Blankenship, D. D.; Jordan, T. A.; Balbi, P.; Bozzo, E.; Siegert, M. J.</p> <p>2014-12-01</p> <p>The Wilkes Subglacial Basin (WSB) extends for 1,400 km from George V Land into the interior of East Antarctica and hosts several major glaciers that drain a large sector of the East Antarctic Ice Sheet (EAIS). This region is of key significance for the long-term stability of the ice sheet in East Antarctica, as it lies well below sea level and its bedrock deepens inland, making it potentially prone to marine ice sheet instability, much like areas of the West Antarctic Ice Sheet (WAIS) that are presently experiencing significant mass loss. We present new enhanced potential field images of the WSB combined with existing radar imaging to study geological controls on bedrock <span class="hlt">topography</span> and ice flow regimes in this key sector of the ice sheet. These images reveal mayor Precambrian and Paleozoic basement faults that exert tectonic controls both on the margins of the basin and its sub-basins. Several major sub-basins can be recognised: the Eastern Basin, the Central Basins and the Western Basins. Using ICECAP aerogeophysical data we show that these tectonically controlled interior basins connect to newly identified basins underlying the Cook Ice Shelf region. This connection implies that any ocean-induced changes at the margin of the EAIS could potentially propagate rapidly further into the interior. With the aid of simple magnetic and gravity models we show that the WSB does not presently include major post Jurassic sedimentary infill. Its bedrock geology is highly variable and includes Proterozoic basement, Neoproterozoic and Cambrian sediments, intruded by Cambrian arc rocks, and cover rocks formed by Beacon sediments intruded by Jurassic Ferrar sills. Enhanced ice flow in this part of the EAIS occurs therefore in a area of mixed and spatially variable bedrock geology. This contrasts with some regions of the WAIS where more extensive sedimentary basins may represent a geological template for the onset and maintenance of fast glacial flow.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.H14B..05J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.H14B..05J"><span id="translatedtitle">Linking catchment structure to hydrologic function: Implications of catchment <span class="hlt">topography</span> for patterns of landscape hydrologic connectivity and stream flow <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jencso, K. G.; McGlynn, B. L.; Marshall, L. A.</p> <p>2010-12-01</p> <p>The relationship between catchment structure (<span class="hlt">topography</span> and topology), stream network hydrologic connectivity, and runoff response remains poorly understood. Hillslope-riparian-stream (HRS) water table connectivity serves as the hydrologic linkage between a catchment’s uplands and the channel network and facilitates the transmission of water and solutes to streams. While there has been tremendous interest in the concept of hydrological connectivity to characterize catchments, there are relatively few studies that have quantified hydrologic connectivity at the stream network and catchment scales. Here, we examine how catchment <span class="hlt">topography</span> influenced patterns of stream network HRS connectivity and resultant runoff <span class="hlt">dynamics</span> across 11 nested headwater catchments in the Tenderfoot Creek Experimental Forest (TCEF), MT. This study extends the empirical findings of Jencso et al. (2009) who found a strong linear relationship (r2 = 0.92) between the upslope accumulated area (UAA) and annual duration of shallow ground water table connectivity observed across 24 HRS transects (146 groundwater recording wells) within the TCEF. We applied this relationship to the entire stream network to quantify the frequency distribution of stream network connectivity through time (as a function of UAA) and ascertain its relationship to catchment-scale runoff <span class="hlt">dynamics</span>. Each catchment’s estimated connectivity duration curve (CDC) was highly related to its flow duration curve (FDC); albeit the rate of change of runoff with respect to stream network connectedness varied significantly across catchments. To ascertain potential reasons for these differences we compared the slope of each catchment’s CDC-FDC relationship (annual, peak, transition and baseflow periods) in multiple linear models against median values of common terrain indices and land cover-vegetation characteristics. Significant predictors (p<0.05) included the flow path distance to the creek (DFC), the flow path gradient to the creek (GTC), and their ratios DFC/GTC. Our results suggest that spatio-temporal distributions of upland-riparian-stream hydrologic connectivity can provide insight into runoff source area <span class="hlt">dynamics</span>, runoff implications of catchment morphology and topology, and a direct and quantifiable link between catchment structure and hydrologic <span class="hlt">dynamics</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014OcSci..10..863K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014OcSci..10..863K"><span id="translatedtitle">Effects of bottom <span class="hlt">topography</span> on <span class="hlt">dynamics</span> of river discharges in tidal regions: case study of twin plumes in Taiwan Strait</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Korotenko, K. A.; Osadchiev, A. A.; Zavialov, P. O.; Kao, R.-C.; Ding, C.-F.</p> <p>2014-10-01</p> <p>The Princeton Ocean Model (POM) is used to investigate the intratidal variability of currents and turbulent mixing and their impact on the characteristics and evolution of the plumes of two neighbouring rivers, the Zhuoshui River and the Wu River, at the central eastern coast of Taiwan Strait. The two estuaries are located close to each other and their conditions are similar in many respects, and yet the two plumes exhibit significantly different behaviour. We explain this through differences of the bottom <span class="hlt">topography</span> in the areas adjacent to the two river mouths. The Zhuoshui River runs into a shallow area that is permanently exposed to strong tidal mixing, while the Wu River mouth is located in a deeper, stratified area outside the region of intense mixing. This destruction of the plume by tidal mixing is confirmed by the results of numerical modeling with POM. The spatial and temporal variability of turbulent kinetic energy, the rates of its production by shear and destruction rate by buoyancy in the study, as well as the horizontal diffusivity, are analysed with the emphasis given to the dependence of the turbulence parameters on the bottom <span class="hlt">topography</span> on the one hand and their influence on the river plumes on the other. The results of the study support the central hypothesis of this paper: the <span class="hlt">dynamic</span> behaviours of the Zhuoshui and Wu plumes are different because their evolution occurs under different regimes of bottom-generated turbulent mixing. Further, we use a Lagrangian particle tracking model in combination with POM to investigate the effect of the tidal wetting-and-drying (WAD) near the Zhuoshui River estuary, and demonstrate that WAD leads to significant reduction of the plume extent and surface salinity deficit near the river mouth. We use observational data from a short field campaign in the study area to tune and validate the model experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22402907','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22402907"><span id="translatedtitle">Particle visualization in high-power impulse magnetron sputtering. II. <span class="hlt">Absolute</span> density <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Britun, Nikolay Palmucci, Maria; Konstantinidis, Stephanos; Snyders, Rony</p> <p>2015-04-28</p> <p>Time-resolved characterization of an Ar-Ti high-power impulse magnetron sputtering discharge has been performed. The present, second, paper of the study is related to the discharge characterization in terms of the <span class="hlt">absolute</span> density of species using resonant absorption spectroscopy. The results on the time-resolved density evolution of the neutral and singly-ionized Ti ground state atoms as well as the metastable Ti and Ar atoms during the discharge on- and off-time are presented. Among the others, the questions related to the inversion of population of the Ti energy sublevels, as well as to re-normalization of the two-dimensional density maps in terms of the <span class="hlt">absolute</span> density of species, are stressed.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16..147A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16..147A"><span id="translatedtitle">Sea level change since the Pliocene - a new formalism for predicting sea level in the presence of <span class="hlt">dynamic</span> <span class="hlt">topography</span> and isostasy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Austermann, Jacqueline; Rovere, Alessio; Moucha, Robert; Mitrovica, Jerry X.; Rowley, David B.; Forte, Alessandro M.; Raymo, Maureen E.</p> <p>2014-05-01</p> <p><span class="hlt">Dynamic</span> <span class="hlt">topography</span> (DT), as reflected in local sea level change, provides a unique lens for studying the imprint of deep Earth <span class="hlt">dynamics</span> on the Earth's surface. The elevation of paleo-shorelines over long time scales is, however, not only perturbed by DT but also by glacial isostatic adjustment (GIA) and eustatic changes in sea level. Isolating these contributions is essential for efforts to constrain past changes in ice volume or mantle convection models. Previous studies have performed this separation by modeling <span class="hlt">dynamic</span> <span class="hlt">topography</span> and superimposing the signal on the elevation of a GIA-corrected paleo-shoreline. However, this approach neglects deformation of the Earth in response to changes in the ocean load and geometry driven by DT. We describe a generalized, gravitationally self-consistent framework for computing sea-level changes that incorporates DT and GIA. The formalism is based on a sea-level theory developed within the GIA community that takes accurate account of viscoelastic deformation of the solid Earth, perturbations in the gravity field, migration of shorelines and the feedback into sea-level of contemporaneous (load-induced) changes in Earth rotation. Specifically, <span class="hlt">dynamic</span> <span class="hlt">topography</span> is introduced as a perturbation to the elevation of the solid surface that does not load the Earth because it is <span class="hlt">dynamically</span> supported. However, water that is displaced by DT is allowed to redistribute, perturb the gravitational field and load (or unload) the ocean floor wherever the water column is increased (or decreased). The problem is complicated by plate tectonics, which (in a tectonic reference frame) leaves changes in <span class="hlt">topography</span> and DT undefined in areas of the ocean floor where plates have been subducted. We interpolate these regions by imposing mass conservation of both the solid Earth and water on the reconstructed <span class="hlt">topography</span>. We use the new formalism to calculate sea level change since the mid-Pliocene (3 Ma) using recent global simulations of <span class="hlt">dynamic</span> <span class="hlt">topography</span> that are constrained to fit a large suite of modern geophysical observables. We demonstrate that the results differ significantly from calculations in which <span class="hlt">dynamic</span> <span class="hlt">topography</span> is simply added to the elevation of GIA-corrected paleo-shorelines. Moreover, we apply these results to new paleo-shoreline data of Pliocene age from the US east coast, South Africa and southwest Australia to estimate peak eustatic sea level (and, thus, minimum ice volume) during the Mid Pliocene Warm Period.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016APS..MAR.G1327P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016APS..MAR.G1327P"><span id="translatedtitle"><span class="hlt">Absolute</span> Summ</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Phillips, Alfred, Jr.</p> <p></p> <p>Summ means the entirety of the multiverse. It seems clear, from the inflation theories of A. Guth and others, that the creation of many universes is plausible. We argue that <span class="hlt">Absolute</span> cosmological ideas, not unlike those of I. Newton, may be consistent with <span class="hlt">dynamic</span> multiverse creations. As suggested in W. Heisenberg's uncertainty principle, and with the Anthropic Principle defended by S. Hawking, et al., human consciousness, buttressed by findings of neuroscience, may have to be considered in our models. Predictability, as A. Einstein realized with Invariants and General Relativity, may be required for new ideas to be part of physics. We present here a two postulate model geared to an <span class="hlt">Absolute</span> Summ. The seedbed of this work is part of Akhnaton's philosophy (see S. Freud, Moses and Monotheism). Most important, however, is that the structure of human consciousness, manifest in Kenya's Rift Valley 200,000 years ago as Homo sapiens, who were the culmination of the six million year co-creation process of Hominins and Nature in Africa, allows us to do the physics that we do. .</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.H31A1130Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.H31A1130Z"><span id="translatedtitle">Forecasting spatial plant <span class="hlt">dynamics</span> under future climate change in a semiarid savanna ecosystem with complex <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, X.; Fatichi, S.; Istanbulluoglu, E.; Vivoni, E. R.</p> <p>2011-12-01</p> <p>The space and time <span class="hlt">dynamics</span> of savanna ecosystems in semiarid regions is tightly related to fluctuations and changes in the climate, and the competition strategies of individual plants for resources. In most parts of the southwest U.S., various General Circulation Models (GCMs) predict general warming trends with reduced annual precipitation amounts, and increased frequency of extreme droughts and wet periods in the 21st century. Despite the potential risks posed by climate change on vegetation patterns and hydrology, our ability to predict such changes at the catchment and regional scales is limited. In this study, we used a recently developed spatially explicit Cellular Automata Tree-Grass-Shrub Simulator (CATGraSS) to investigate the impacts of climate change on plant <span class="hlt">dynamics</span> in a semiarid catchment (>3km2) located in the Sevilleta National Wildlife Refuge (SNWR) in central New Mexico, USA. In the catchment north-facing slopes are characterized by a juniper-grass savanna, and south-facing slopes by creosote bush and grass species. Initialized by LIDAR-derived tree locations and simulated grass and shrub patterns obtained from model calibration, CATGraSS is forced by a weather generator, AWE-GEN, used to downscale an ensemble of eight different GCM outputs at the study basin, producing multiple stochastic realizations of a transient climate scenario for the next hundred years. The ensemble simulations are used to examine the uncertainty in vegetation response and develop probabilistic plant distribution maps in relation to landscape morphology. This study highlights the importance of understanding local scale plant-to-plant interactions and the role of climate variability in determining climate change impacts on vegetation <span class="hlt">dynamics</span> at varying spatial scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930005791&hterms=ocean+surface+topography&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Docean%2Bsurface%2Btopography','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930005791&hterms=ocean+surface+topography&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Docean%2Bsurface%2Btopography"><span id="translatedtitle">Studies of tropical ocean <span class="hlt">dynamics</span> using the TOPEX/Poseidon altimeter-derived sea surface <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lukas, Roger; Busalacchi, A. J., Jr.; Mitchum, G. T.; Wyrtki, K.</p> <p>1991-01-01</p> <p>Our primary objective is to carry out studies of tropical ocean <span class="hlt">dynamics</span> using the TOPEX/POSEIDON altimeter-derived sea level data set in conjunction with the large in situ sea level data set available at the Tropical Ocean Global Atmosphere (TOGA) Sea Level Center. These studies will be supported by an interaction with numerical model simulations of tropical ocean variability. Five specific objectives can be identified: (1) research products; (2) short-term climate variations; (3) tropical-current variations; (4) synoptic-scale variability; and (5) model simulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19750050989&hterms=gravitation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dgravitation','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19750050989&hterms=gravitation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dgravitation"><span id="translatedtitle">Mariner 9 - An instrument of <span class="hlt">dynamical</span> science. [for Mars gravitation and <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jordan, J. F.; Lorell, J.</p> <p>1975-01-01</p> <p>We review and evaluate the contributions of Mariner 9 in improving our knowledge of the <span class="hlt">dynamical</span> characteristics of Mars and its two satellites, Phobos and Deimos. Primary results include the discovery of the large gravitational and topographical bulge in the Tharsis region, the development of a detailed gravity model representable as coefficients in a spherical harmonic expansion, the development of a topographic model exhibiting a three kilometer displacement of the center of figure from the center of mass, and the determination of the size, shape and motion of Phobos and Deimos.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMOS43E..10Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMOS43E..10Z"><span id="translatedtitle">Interaction Between the Basin-Scale and Mesoscale <span class="hlt">Dynamics</span> of the Black Sea: Impacts of Wind Forcing and Bottom <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zatsepin, A. G.; Kremenetskiy, V. V.; Ratner, Y. B.; Stanichny, S. V.</p> <p>2008-12-01</p> <p>The general element of the classical theory of the Black Sea basin-scale circulation is the Rim current (RC) flowing cyclonically along the continental slope. Broad oceanographic application of the satellite data during the past decades has also revealed energetic mesoscale eddy-like structures that provide an effective cross- basin exchange. The aim of this report is to describe and discuss physical mechanisms of interaction between the RC and mesoscale eddies and their dependences on wind forcing and bottom <span class="hlt">topography</span>. The study was based on the analysis of field observations and results of laboratory modeling. It was revealed by observations that in the northeastern Black Sea, having a very narrow continental slope, the topographic control of RC is weaker. The position and stability of RC is governed by the Ekman pumping. Under the strong (positive) Ekman pumping, which is more typical for the winter period, RC is a coherent and strong jet located over the continental slope. In this case, the lateral, cross-jet, exchange is relatively weak as the coastal and deep waters are separated by the <span class="hlt">dynamical</span> front. In the alternative case of weak Ekman pumping, which is more typical for the Spring-Summer time, RC becomes unstable, meanders and breaks up into eddies producing strong lateral exchange. The effects of the wind forcing and bottom <span class="hlt">topography</span> on the along-shore current, <span class="hlt">dynamically</span> similar to RC, were studied in the laboratory experiment with the two-layer fluid in circular tank placed on the rotating table. It was shown that in case, when the width L of the continental slope is smaller or equal to the baroclinic Rossby deformation radius R, the influence of the bottom <span class="hlt">topography</span> on the stability and structure of the along-shore current was negligible. After the decline or termination of the wind forcing, the along-shore current shifted in the off-shore direction, became unstable and disintegrated into eddies, providing an intensive water exchange between the near-shore zone and deep regions. The timescale of the disintegration process was approximately 15-30 laboratory days - similar to that observed in natural conditions. In the case when L was equal to or larger than 2R, the instability was rather weak and had a wave-like nature. No energetic eddies were formed in this regime, and exchange between the near-shore and deep regions was reduced. The results of this study allow us to conclude that in the northeastern Black Sea, having a very narrow continental slope, the topographic control of RC is weak. The position and stability of the along-shore current are controlled by the Ekman pumping. The general mechanism of the mesoscale eddy formation is the instability of RC after the decrease of the Ekman pumping. In the northwestern Black sea, where the slope is wide (L is close to 4R), both the RC and mesoscale eddies are topographically controlled. Acknowledgements. The work was supported by the Program 17 "World Ocean" of the Russian Academy of Sciences, the grants of Russian Foundation for Basic Research and by the project MK-1220.2008.5 of the President of Russian Federation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.G13C..08P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.G13C..08P"><span id="translatedtitle"><span class="hlt">Dynamic</span> Ocean <span class="hlt">Topography</span> Solutions Based on a new Mean sea Surface Model and a GRACE-Based Geoid Model</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pavlis, N. K.; Holmes, S. A.; Andersen, O. B.</p> <p>2006-12-01</p> <p>A new Mean Sea Surface (MSS) model has been compiled recently at the Danish National Space Center (DNSC). This MSS model incorporates data from several altimeter missions (Geosat GM, ERS-1 and ERS-2, TOPEX/Poseidon and Jason-1, GFO, Envisat, and ICESat). In parallel, as part of an activity sponsored by the USA National Geospatial-Intelligence Agency, a new Preliminary Gravitational Model (PGM) has been developed recently. This model is an intermediate solution leading to a new Earth Gravitational Model complete to degree and order 2160. We have used the new MSS from DNSC and the latest PGM to estimate the mean <span class="hlt">Dynamic</span> Ocean <span class="hlt">Topography</span> (DOT), represented both as an ocean-wide grid and in terms of surface spherical harmonics. Of particular interest to these analyses is the treatment of systematic errors in GRACE-based gravitational solutions that manifest themselves as "stripes", predominantly in the North-South direction. We will present our DOT solutions and compare them against DOT estimates obtained from Ocean Circulation Models. We will also present comparisons with hydrographic data that are independent from our solutions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20000121260','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20000121260"><span id="translatedtitle">A New Clinical Instrument for The Early Detection of Cataract Using <span class="hlt">Dynamic</span> Light Scattering and Corneal <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ansari, Rafat R.; Datiles, Manuel B., III; King, James F.</p> <p>2000-01-01</p> <p>A growing cataract can be detected at the molecular level using the technique of <span class="hlt">dynamic</span> light scattering (DLS). However, the success of this method in clinical use depends upon the precise control of the scattering volume inside a patient's eye and especially during patient's repeat visits. This is important because the scattering volume (cross-over region between the scattered fight and incident light) inside the eye in a high-quality DLS set-up is very small (few microns in dimension). This precise control holds the key for success in the longitudinal studies of cataract and during anti-cataract drug screening. We have circumvented these problems by fabricating a new DLS fiber optic probe with a working distance of 40 mm and by mounting it inside a cone of a corneal analyzer. This analyzer is frequently used in mapping the corneal <span class="hlt">topography</span> during PRK (photorefractive keratectomy) and LASIK (laser in situ keratomileusis) procedures in shaping of the cornea to correct myopia. This new instrument and some preliminary clinical tests on one of us (RRA) showing the data reproducibility are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PApGe.tmp...47S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PApGe.tmp...47S"><span id="translatedtitle">Improving Surface Geostrophic Current from a GOCE-Derived Mean <span class="hlt">Dynamic</span> <span class="hlt">Topography</span> Using Edge-Enhancing Diffusion Filtering</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sánchez-Reales, J. M.; Andersen, O. B.; Vigo, M. I.</p> <p>2015-02-01</p> <p>With increased geoid resolution provided by the gravity and steady-state ocean circulation explorer (GOCE) mission, the ocean's mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> (MDT) can be now estimated with an accuracy not available prior to using geodetic methods. However, an altimetric-derived MDT still needs filtering in order to remove short wavelength noise unless integrated methods are used in which the three quantities are determined simultaneously using appropriate covariance functions. We studied nonlinear anisotropic diffusive filtering applied to the oceańs MDT and a new approach based on edge-enhancing diffusion (EED) filtering is presented. EED filters enable controlling the direction and magnitude of the filtering, with subsequent enhancement of computations of the associated surface geostrophic currents (SGCs). Applying this method to a smooth MDT and to a noisy MDT, both for a region in the Northwestern Pacific Ocean, we found that EED filtering provides similar estimation of the current velocities in both cases, whereas a non-linear isotropic filter (the Perona and Malik filter) returns results influenced by local residual noise when a difficult case is tested. We found that EED filtering preserves all the advantages that the Perona and Malik filter have over the standard linear isotropic Gaussian filters. Moreover, EED is shown to be more stable and less influenced by outliers. This suggests that the EED filtering strategy would be preferred given its capabilities in controlling/preserving the SGCs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1612905K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1612905K"><span id="translatedtitle">Combining a Global GOCE Derived MDT with In-situ Observation for Regional Enhancement of the Mean <span class="hlt">Dynamic</span> <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Knudsen, Per; Andersen, Ole</p> <p>2014-05-01</p> <p>The Gravity and steady state Ocean Circulation Explorer (GOCE) satellite mission measures Earth's gravity field with an unprecedented accuracy at short spatial scales. Previous results have demonstrated a significant advance in our ability to determine the ocean's general circulation. The improved gravity models provided by the GOCE mission have enhanced the resolution and sharpened the boundaries of those features and the associated geostrophic surface currents reveal improvements for all of the ocean's major current systems. Furthermore, finer scale features, such as meanders and branches of the current system have become visible. In this study, a global mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> (MDT) derived using a gravity models from GOCE combined with the DTU13MSS mean sea surface is used as a reference model. Then regional analyses are carried out using in-situ observations of the gravity field as well as of the geostrophic surface currents. The aim of those analyses is to evaluate the GOCE derived MDT in detail at regional scales. Subsequently, the in-situ observations are used in a regional enhancement of the estimated MDT and its associated currents. The data are combined using an optimal estimation technique such as least squares collocation, that is based on the functional relationship between the gravity field and the MDT as well as their a-priori statistical characteristics. The methodology and preliminary results will be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.4105K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.4105K"><span id="translatedtitle">Combining a Global GOCE Derived MDT with In-situ Current Observation for Regional Enhancement of the Mean <span class="hlt">Dynamic</span> <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Knudsen, Per; Andersen, Ole; Maximenko, Nikolai</p> <p>2015-04-01</p> <p>The Gravity and steady state Ocean Circulation Explorer (GOCE) satellite mission measures Earth's gravity field with an unprecedented accuracy at short spatial scales. Previous results have demonstrated a significant advance in our ability to determine the ocean's general circulation. The improved gravity models provided by the GOCE mission have enhanced the resolution and sharpened the boundaries of those features and the associated geostrophic surface currents reveal improvements for all of the ocean's major current systems. Furthermore, finer scale features, such as meanders and branches of the current system have become visible. In this study, models of the mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> (MDT) derived using a series of gravity models from GOCE combined with the DTU13MSS mean sea surface are used as a reference model. Then regional analyses are carried out using in-situ observations of the geostrophic surface currents obtained from drifters. The aim of those analyses is to evaluate the GOCE derived MDT in detail at regional scales. Subsequently, the in-situ observations are used in a regional enhancement of the estimated MDT and its associated currents. The data are combined using an optimal estimation technique such as least squares collocation, that is based on the functional relationship between the gravity field and the MDT as well as their a-priori statistical characteristics. The methodology and preliminary results will be presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016PApGe.173..871S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016PApGe.173..871S"><span id="translatedtitle">Improving Surface Geostrophic Current from a GOCE-Derived Mean <span class="hlt">Dynamic</span> <span class="hlt">Topography</span> Using Edge-Enhancing Diffusion Filtering</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sánchez-Reales, J. M.; Andersen, O. B.; Vigo, M. I.</p> <p>2016-03-01</p> <p>With increased geoid resolution provided by the gravity and steady-state ocean circulation explorer (GOCE) mission, the ocean's mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> (MDT) can be now estimated with an accuracy not available prior to using geodetic methods. However, an altimetric-derived MDT still needs filtering in order to remove short wavelength noise unless integrated methods are used in which the three quantities are determined simultaneously using appropriate covariance functions. We studied nonlinear anisotropic diffusive filtering applied to the oceańs MDT and a new approach based on edge-enhancing diffusion (EED) filtering is presented. EED filters enable controlling the direction and magnitude of the filtering, with subsequent enhancement of computations of the associated surface geostrophic currents (SGCs). Applying this method to a smooth MDT and to a noisy MDT, both for a region in the Northwestern Pacific Ocean, we found that EED filtering provides similar estimation of the current velocities in both cases, whereas a non-linear isotropic filter (the Perona and Malik filter) returns results influenced by local residual noise when a difficult case is tested. We found that EED filtering preserves all the advantages that the Perona and Malik filter have over the standard linear isotropic Gaussian filters. Moreover, EED is shown to be more stable and less influenced by outliers. This suggests that the EED filtering strategy would be preferred given its capabilities in controlling/preserving the SGCs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19780019781','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19780019781"><span id="translatedtitle">Determination of some dominant parameters of the global <span class="hlt">dynamic</span> sea surface <span class="hlt">topography</span> from GEOS-3 altimetry</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mather, R. S.; Lerch, F. J.; Rizos, C.; Masters, E. G.; Hirsch, B.</p> <p>1978-01-01</p> <p>The 1977 altimetry data bank is analyzed for the geometrical shape of the sea surface expressed as surface spherical harmonics after referral to the higher reference model defined by GEM 9. The resulting determination is expressed as quasi-stationary <span class="hlt">dynamic</span> SST. Solutions are obtained from different sets of long arcs in the GEOS-3 altimeter data bank as well as from sub-sets related to the September 1975 and March 1976 equinoxes assembled with a view to minimizing seasonal effects. The results are compared with equivalent parameters obtained from the hydrostatic analysis of sporadic temperature, pressure and salinity measurements of the oceans and the known major steady state current systems with comparable wavelengths. The most clearly defined parameter (the zonal harmonic of degree 2) is obtained with an uncertainty of + or - 6 cm. The preferred numerical value is smaller than the oceanographic value due to the effect of the correction for the permanent earth tide. Similar precision is achieved for the zonal harmonic of degree 3. The precision obtained for the fourth degree zonal harmonic reflects more closely the accuracy expected from the level of noise in the orbital solutions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/165368','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/165368"><span id="translatedtitle">Poincare maps define <span class="hlt">topography</span> of Vlasov distribution functions consistent with stochastic <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bailey, A.D. III; Bellan, P.M.; Stern, R.A.</p> <p>1995-08-01</p> <p>In a recent paper [A. D. Bailey {ital et} {ital al}., Phys. Rev. Lett. {bold 34}, 3124 (1993)], the authors presented direct planar laser induced fluorescence measurements of the oscillatory ion fluid velocity field in the presence of a large amplitude drift-Alfven wave. Surprisingly, the measured speeds were an order of magnitude lower than predicted by standard fluid theory, yet the flow pattern was consistent with the fluid theory. A new model, based on the connection between stochasticity and bulk behavior, is presented which gives insights into the cause of this behavior. It is shown that when particle motion is stochastic, invariant sets of a `Poincare map` define a flat-topped particle distribution function consistent with both the electromagnetic field driving the Vlasov equation {ital and} the fine-scale single particle <span class="hlt">dynamics</span>. The approach is described for the general case and explored for a slab model of the observed drift wave. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRC..121..674K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRC..121..674K"><span id="translatedtitle">Sea surface height and <span class="hlt">dynamic</span> <span class="hlt">topography</span> of the ice-covered oceans from CryoSat-2: 2011-2014</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kwok, Ron; Morison, James</p> <p>2016-01-01</p> <p>We examine 4 years (2011-2014) of sea surface heights (SSH) from CryoSat-2 (CS-2) over the ice-covered Arctic and Southern Oceans. Results are from a procedure that identifies and determines the heights of sea surface returns. Along 25 km segments of satellite ground tracks, variability in the retrieved SSHs is between ˜2 and 3 cm (standard deviation) in the Arctic and is slightly higher (˜3 cm) in the summer and the Southern Ocean. Average sea surface tilts (along these 25 km segments) are 0.01 ± 3.8 cm/10 km in the Arctic, and slightly lower (0.01 ± 2.0 cm/10 km) in the Southern Ocean. Intra-seasonal variability of CS-2 <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span> (DOT) in the ice-covered Arctic is nearly twice as high as that of the Southern Ocean. In the Arctic, we find a correlation of 0.92 between 3 years of DOT and <span class="hlt">dynamic</span> heights (DH) from hydrographic stations. Further, correlation of 4 years of area-averaged CS-2 DOT near the North Pole with time-variable ocean-bottom pressure from a pressure gauge and from GRACE, yields coefficients of 0.83 and 0.77, with corresponding differences of <3 cm (RMS). These comparisons contrast the length scale of baroclinic and barotropic features and reveal the smaller amplitude barotropic signals in the Arctic Ocean. Broadly, the mean DOT from CS-2 for both poles compares well with those from the ICESat campaigns and the DOT2008A and DTU13MDT fields. Short length scale topographic variations, due to oceanographic signals and geoid residuals, are especially prominent in the Arctic Basin but less so in the Southern Ocean.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Tectp.663...95P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Tectp.663...95P"><span id="translatedtitle">Extracting <span class="hlt">dynamic</span> <span class="hlt">topography</span> from river profiles and cosmogenic nuclide geochronology in the Middle Atlas and the High Plateaus of Morocco</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pastor, Alvar; Babault, Julien; Owen, Lewis A.; Teixell, Antonio; Arboleya, María-Luisa</p> <p>2015-11-01</p> <p>The Moulouya river system has intensely eroded the Arhbalou, Missour, and Guercif Neogene foreland basins in northeastern Morocco, having changed from net aggradation during the Miocene-early Pliocene to net incision punctuated by alluvial fan deposition at late Pliocene or early Quaternary time. This region as a whole has experienced mantle-driven, surface uplift (<span class="hlt">dynamic</span> <span class="hlt">topography</span>) since the late Cenozoic, being locally affected by uplift due to crustal shortening and thickening of the Middle Atlas too. Knickpoints located along the major streams of the Moulouya fluvial network, appear on both the undeformed margins of the Missour and Guercif foreland basins (High Plateaus), as well as along the thrust mountain front of the southern Middle Atlas, where they reach heights of 800-1000 m. 500-550 m of the knickpoint vertical incision might be explained by long-wavelength mantle-driven <span class="hlt">dynamic</span> surface uplift, whereas the remaining 450-500 m in the southern Middle Atlas front and 200-300 m in the northeastern Middle Atlas front seem to be thrust-related uplift of the Jebel Bou Naceur. Be-10 terrestrial cosmogenic nuclides have been used to date two Quaternary river terraces in the Chegg Ard valley at 62 ± 14 ka and 411 ± 55 ka. The dated terraces allow the incision rates associated with the frontal structures of the Middle Atlas to be estimated at ~ 0.3 mm yr- 1. Furthermore, these ages have served to evaluate mantle-driven regional surface uplift since the middle Pleistocene in the central Missour basin, yielding values of ~ 0.1-0.2 mm yr- 1.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GMD.....7..407S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GMD.....7..407S"><span id="translatedtitle">Inherently mass-conservative version of the semi-Lagrangian <span class="hlt">absolute</span> vorticity (SL-AV) atmospheric model <span class="hlt">dynamical</span> core</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shashkin, V. V.; Tolstykh, M. A.</p> <p>2014-02-01</p> <p>The semi-Lagrangian <span class="hlt">absolute</span> vorticity (SL-AV) atmospheric model is the global semi-Lagrangian hydrostatic model used for operational medium-range and seasonal forecasts at the Hydrometeorological Centre of Russia. The distinct feature of the SL-AV <span class="hlt">dynamical</span> core is the semi-implicit, semi-Lagrangian vorticity-divergence formulation on the unstaggered grid. A semi-implicit, semi-Lagrangian approach allows for long time steps but violates the global and local mass conservation. In particular, the total mass in simulations with semi-Lagrangian models can drift significantly if no a posteriori mass-fixing algorithm is applied. However, the global mass-fixing algorithms degrade the local mass conservation. The new inherently mass-conservative version of the SL-AV model <span class="hlt">dynamical</span> core presented here ensures global and local mass conservation without mass-fixing algorithms. The mass conservation is achieved with the introduction of the finite-volume, semi-Lagrangian discretization for a continuity equation based on the 3-D extension of the conservative cascade semi-Lagrangian transport scheme (CCS). Numerical experiments show that the new version of the SL-AV <span class="hlt">dynamical</span> core presented combines the accuracy and stability of the standard SL-AV <span class="hlt">dynamical</span> core with the mass-conservation properties. The results of the mountain-induced Rossby-wave test and baroclinic instability test for the mass-conservative <span class="hlt">dynamical</span> core are found to be in agreement with the results available in the literature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.6544S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.6544S"><span id="translatedtitle">On the effect of the Post-perovskite phase change on global mantle flow, geoid and <span class="hlt">dynamic</span> <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shahraki, Meysam; Schmeling, Harro; Kaban, Mikhail; Petrunin, Alexei</p> <p>2014-05-01</p> <p>In the lowermost parts of mantle, the D" layer is a profoundly important layer as it involves the process of heat and mass transfer between core and mantle. However, the physical nature of this layer is an issue of active debate. The seismic data represent a rapid increase and decrease of the shear velocity, especially beneath Circum-Pacific margins, in the D" layer. Indeed, such abrupt velocity discontinuity is not expected for this hot layer. The discovery of the perovskite (pv) to Post-perovskite (pPv) phase transformation has led to dramatic increase in our understanding of the structure of the D" layer, since it is thought to produce such seismic discontinuity. Here, we have investigate the influence of the phase transformation of pv to pPv on the geoid undulation as one of the most important geophysical observable, using 3D spherical shell mantle circulation models based on a seismic tomography model (S40RTS) and strongly lateral viscosity variations in the D" layer and the mantle above. We demonstrate that the geoid anomalies are strongly affected by the presence of pPv in the lowermost mantle. While the geoid heights over subduction zones are increased by considering a strong pPv compared to then surrounding mantle, a weak pPv reduces the geoid height, and a better fit to the observed geoid is obtained. We show that, applying a weak pPv viscosity of at least three orders of magnitude any higher viscosity contrast does not affect the geoid any further. We also investigate the effects of weak pPv combined with a different tomography model, a different pPv density contrast, the presence or absence of a global thermal-boundary-layer (TBL) and the presence or absence of lateral viscosity variations in the lower mantle. Keywords: Post-perovskite, phase transitions, geoid, <span class="hlt">dynamic</span> <span class="hlt">topography</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1614170B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1614170B"><span id="translatedtitle">Who is in control? Competing influences of geology, land use and <span class="hlt">topography</span> on soil moisture and soil temperature <span class="hlt">dynamics</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Blume, Theresa; Hassler, Sibylle; Weiler, Markus</p> <p>2014-05-01</p> <p>Can we identify distinct signatures of landscape elements in the event response of soil moisture and soil temperature? Moisture and temperature <span class="hlt">dynamics</span> in soils are largely controlled by the climatic boundary conditions of rainfall, evapotranspiration and radiation. However, certain landscape features also leave characteristic finger prints on soil moisture and soil temperature time series. The extent of these influences and their time variable relative importance are important in a number of contexts, such as landscape scale prediction of soil moisture patterns or runoff generation, process predictions in ungauged basins or the improvement of hydrological model structures for the mesoscale. The competing influences of geology, land use and <span class="hlt">topography</span> on temperature and moisture characteristics in the vadose zone are explored at the CAOS hydrological observatory in Luxemburg (http://www.caos-project.de/) with a unique experimental setup of 45 sensor clusters. These sensor clusters cover three different geologies (schist, sandstone, marls), two land use classes (forest and grassland), five different landscape positions (plateau, top-, mid- and lower hillslope as well as near stream/floodplain locations), and contrasting expositions. At each of these sensor clusters three soil moisture profiles with sensors at depths from 10 to 70 cm, four soil temperature profiles as well as air temperature, relative humidity, global radiation, rainfall/throughfall, sapflow and shallow groundwater and stream water levels were measured continuously. Time series of up to 2 years for the schist region and up to 6 months for the complete set of sites allow for a first intercomparison of characteristic event response behavior.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPSJ...85d4701O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPSJ...85d4701O"><span id="translatedtitle">Equilibrium and <span class="hlt">Dynamic</span> Vortex States near <span class="hlt">Absolute</span> Zero in a Weak Pinning Amorphous Film</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ochi, Aguri; Sohara, Naoya; Kaneko, Shin-ichi; Kokubo, Nobuhito; Okuma, Satoshi</p> <p>2016-04-01</p> <p>By developing and employing a mode-locking measurement with pulsed currents, we successfully determine the <span class="hlt">dynamic</span> melting field B{c,dyn}∞ (T) for a driven vortex lattice of an amorphous MoxGe1-x film in the limit of zero temperature (T → 0) and complete a <span class="hlt">dynamic</span> as well as a static vortex phase diagram. At T = 0, the mixed state in the absence of pinning comprises vortex-lattice and quantum-vortex-liquid (QVL) phases, and the melting field separating the two phases is identified as B{c,dyn}∞ (0). Comparison of the <span class="hlt">dynamic</span> and static phase diagrams reveals that, when the weak pinning is introduced into the pin-free system, a disordered phase emerges just above the vortex-lattice phase and a threshold field separating the two phases is slightly suppressed from B{c,dyn}∞ (0), indicative of defect-induced disordering of the lattice. By contrast, a melting field into QVL is much enhanced from B{c,dyn}∞ (0) up to a point near the upper critical field, resulting in a significant suppression of the QVL phase. This is attributed to the stronger effective pinning at lower T, which survives quantum fluctuations.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.6088P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.6088P"><span id="translatedtitle">Comparing the effects of rheology on the <span class="hlt">dynamics</span> and <span class="hlt">topography</span> of 3D subduction-collision models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pusok, Adina E.; Kaus, Boris; Popov, Anton</p> <p>2015-04-01</p> <p>Most of the major mountain belts and orogenic plateaus are found within the overlying plate of active or fossil subduction and/or collision zones. It is well known that they evolve differently from one another as the result of specific combinations of surface and mantle processes. The differences among the structures and evolutions of mountain belts arise for several reasons, such as different strengths of materials, different amounts of regional isostatic compensation, and different mechanisms by which forces are applied to the convergence plates. All these possible controlling factors can change with space and time. Of all the mountain belts and orogenic plateaus, the most striking example is the India-Asia collision zone, which gave rise to the Himalayas and the Tibetan Plateau, the largest region of elevated <span class="hlt">topography</span> and anomalously thick crust on Earth. Understanding the formation and evolution of such a highly elevated region has been the focus of many tectonic and numerical models. While some of these models (i.e. thin sheet model) have successfully illustrated some of the basic physics of continental collision, none can simultaneously represent active processes such as subduction, underthrusting, channel flow or extrusion, for which fully 3D models are required. Here, we employed the 3D code LaMEM to investigate the role that subduction, continental collision and indentation play on lithosphere <span class="hlt">dynamics</span> at convergent margins, and the implications they have for the Asian tectonics. Our model setup resembles a simplified tectonic map of the India-Asia collision zone and we performed long-term 3D simulations to analyse the <span class="hlt">dynamics</span> and the conditions under which large topographic plateaus, such as the Tibetan Plateau can form in an integrated lithospheric and upper-mantle scale model. Results of models with linear viscous rheologies show different modes between the oceanic subduction side (continuous subduction, trench retreat and slab roll-back) and the continental collision side (trench advance, slab detachment, topographic uplift and lateral extrusion of material). Moreover, different topographic regimes can be identified in the upper plate during continental subduction/collision, which can be determined using the Argand number and an initial buoyancy ratio of the upper plate. Next, we investigate the effect of using more complex (powerlaw viscous and plastic) rheologies and compare the results with linear viscous models. Acknowledgements: Funding was provided by the European Research Council under the European Community's Seventh Framework Program (FP7/2007-2013) / ERC Grant agreement #258830. Numerical computations have been performed on MOGON (ZDV Mainz computing center) and JUQUEEN (Jülich high-performance computing center).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70020807','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70020807"><span id="translatedtitle">Coseismic temporal changes of slip direction: the effect of <span class="hlt">absolute</span> stress on <span class="hlt">dynamic</span> rupture</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Guatteri, Mariagiovanna; Spudich, P.</p> <p>1998-01-01</p> <p>We investigate the <span class="hlt">dynamics</span> of rupture at low-stress level. We show that one main difference between the <span class="hlt">dynamics</span> of high- and low-stress events is the amount of coseismic temporal rake rotation occurring at given points on the fault. Curved stations on exposed fault surfaces and earthquake dislocation models derived from ground-motion inversion indicate that the slip direction may change with time at a pointon the fault during <span class="hlt">dynamic</span> rupture. We use a 3D boundary integral method to model temporal rake variations during <span class="hlt">dynamic</span> rupture propagation assuming a slip-weakening friction law and isotropic friction. The points at which the slip rotates most are characterized by an initial shear stress direction substantially different from the average stress direction over the fault plane. We show that for a given value of stress drop, the level of initial shear stress (i.e., the fractional stress drop) determines the amount of rotation in slip direction. We infer that seismic events that show evidence of temporal rake rorations are characterized by a low initial shear-stress level with spatially variable direction on the fault (possibly due to changes in fault surface geometry) and an almost complete stress drop. Our models motivate a new interpretation of curved and cross-cutting striations and put new constraints on their analysis. The initial rake is in general collinear with the initial stress at the hypocenter zone, supporting the assumptions made in stress-tensor inversion from first-motion analysis. At other points on the fualt, especially away from the hypocenter, the initial slip rake may not be collinear with the initial shear stress, contradicting a common assumption of structural geology. On the other hand, the later part of slip in our models is systematically more aligned withi the average stress direction than the early slip. Our modeling suggests that the length of the straight part of curved striations is usually an upper bound of the slip-weakening distance is this parameter is uniform over the fault plane, and the direction of the late part of slip of curved striations should have more weight in the estimate of initial stress direction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.1914Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.1914Z"><span id="translatedtitle">Influence of bottom <span class="hlt">topography</span> on <span class="hlt">dynamics</span> of river plumes in semi-enclosed domains: Case study in Taiwan Strait</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zavialov, Peter; Korotenko, Konstantin; Osadchiev, Alexander; Kao, Ruei-Chi; Ding, Chung-Feng</p> <p>2014-05-01</p> <p>This paper summarizes the results of a Russian-Taiwan research project focused on the role of continental discharges into the Taiwan Strait, an important channel in the western Pacific Ocean transporting water between the South China Sea and the East China Sea. Another critically important hydrographic feature in the area is the discharge of freshwater from multiple rivers of the western coast of Taiwan. With its long-term average discharge rate of 210 m3/s, the Zhuoshui River is the biggest of the rivers bringing a large amount of pollutants and nutrients into the Strait. The northern extremity of Zhuoshui River's plume often merges with that of the Wu River (also known as Dudu River) whose average discharge rate is about 120 m3/s. Oceanic waters in the area experience significant anthropogenic pressures, traceable to the distance of a few km offshore and tens of km along the shore. This is manifested, in particular, in strongly elevated concentrations of copper, iron, and other trace metals. The corresponding quantitative estimates are obtained. The newly obtained in situ data from a field campaign were also used to implement 2 numerical models aimed at simulating the pathways of the continental waters in the study region. One of them, based on the Princeton Ocean Model, was coupled with a regional barotropic tidal model for the Taiwan Strait. The other one, a fully Lagrangian model STRiPE is based on applying a complete set of momentum equations to individual "particles" of river water released into the ocean. Both models demonstrated reasonable good agreement with the in situ data and each other. The bathymetry, tides and winds significantly affect the <span class="hlt">dynamics</span> of the Wu and Zhuoshui river plumes, acting together in a complex interactive manner. The Zhuoshui River plume stretches in a narrow alongshore belt both to the south and north from the river mouth while the larger, round-shaped Wu River's plume elongates mostly north of its mouth. The difference is explained through the bottom <span class="hlt">topography</span>: while near the Zhuoshui mouth the bottom is very flat and shallow, the terrain adjacent to the Wu mouth is much steeper and deeper. Bottom <span class="hlt">topography</span> and tidal inundation also play an important role in the plume dissipation: due to enhanced mixing in shallow areas subject to tidal drying/flooding of the bottom, such as the area north of the Zhoushui mouth, the salinity anomaly is generally smaller and the plume is narrower and dissipates faster than in the deeper near-mouth areas like that of Wu River. Under the NE wind conditions, the Wu and Zhuoshui plume almost merge and form a unified low salinity belt. In contrast, action of SW wind causes effective separation of river plumes. In the case of NW winds, the plumes are pressed towards the shore and trapped at the mouths, while in the case of SE wind they stretch towards the ocean. The daily mean area of the plumes under the SE wind conditions is about 6 times larger than that under the NW wind.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008SPIE.7155E..13P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008SPIE.7155E..13P"><span id="translatedtitle"><span class="hlt">Absolute</span> and <span class="hlt">dynamic</span> position and shape measurement of fast moving objects employing novel laser Doppler techniques</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pfister, Thorsten; Günther, Philipp; Büttner, Lars; Czarske, Jürgen</p> <p>2008-09-01</p> <p>In this contribution a novel laser Doppler distance (LDD) sensor is presented, which allows simultaneous measurement of axial position and tangential velocity and, thus, determination of the shape of moving and especially rotating objects with one single sensor. Conventional laser Doppler velocimeters measure only velocities. A concurrent position measurement can be realized by generating two fan-shaped interference fringe systems with contrary fringe spacing gradients and evaluating the quotient of the two resulting Doppler frequencies. Alternatively, two tilted fringe systems in combination with phase evaluation can be employed. It will be shown that, in contrast to conventional distance sensors, high temporal resolution below 3 μs and high position resolution of about 1 μm can be achieved simultaneously, because the position uncertainty of the LDD sensor is in principle independent of the object velocity. This is advantageous especially for monitoring highly <span class="hlt">dynamic</span> processes e.g. at turbo machines, where in-process measurements of tip clearance and rotor vibrations are reported for up to 600 m/s blade tip velocity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1018895','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1018895"><span id="translatedtitle">Free Energy Perturbation Hamiltonian Replica-Exchange Molecular <span class="hlt">Dynamics</span> (FEP\\H-REMD) for <span class="hlt">absolute</span> ligand binding free energy calculations.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jiang, W.; Roux, B.</p> <p>2010-09-01</p> <p>Free Energy Perturbation with Replica Exchange Molecular <span class="hlt">Dynamics</span> (FEP/REMD) offers a powerful strategy to improve the convergence of free energy computations. In particular, it has been shown previously that a FEP/REMD scheme allowing random moves within an extended replica ensemble of thermodynamic coupling parameters '{lambda}' can improve the statistical convergence in calculations of <span class="hlt">absolute</span> binding free energy of ligands to proteins [J. Chem. Theory Comput. 2009, 5, 2583]. In the present study, FEP/REMD is extended and combined with an accelerated MD simulations method based on Hamiltonian replica-exchange MD (H-REMD) to overcome the additional problems arising from the existence of kinetically trapped conformations within the protein receptor. In the combined strategy, each system with a given thermodynamic coupling factor {lambda} in the extended ensemble is further coupled with a set of replicas evolving on a biased energy surface with boosting potentials used to accelerate the interconversion among different rotameric states of the side chains in the neighborhood of the binding site. Exchanges are allowed to occur alternatively along the axes corresponding to the thermodynamic coupling parameter {lambda} and the boosting potential, in an extended dual array of coupled {lambda}- and H-REMD simulations. The method is implemented on the basis of new extensions to the REPDSTR module of the biomolecular simulation program CHARMM. As an illustrative example, the <span class="hlt">absolute</span> binding free energy of p-xylene to the nonpolar cavity of the L99A mutant of the T4 lysozyme was calculated. The tests demonstrate that the dual {lambda}-REMD and H-REMD simulation scheme greatly accelerates the configurational sampling of the rotameric states of the side chains around the binding pocket, thereby improving the convergence of the FEP computations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26235749','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26235749"><span id="translatedtitle">Nuclear depolarization and <span class="hlt">absolute</span> sensitivity in magic-angle spinning cross effect <span class="hlt">dynamic</span> nuclear polarization.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mentink-Vigier, Frédéric; Paul, Subhradip; Lee, Daniel; Feintuch, Akiva; Hediger, Sabine; Vega, Shimon; De Paëpe, Gaël</p> <p>2015-09-14</p> <p>Over the last two decades solid state Nuclear Magnetic Resonance has witnessed a breakthrough in increasing the nuclear polarization, and thus experimental sensitivity, with the advent of Magic Angle Spinning <span class="hlt">Dynamic</span> Nuclear Polarization (MAS-DNP). To enhance the nuclear polarization of protons, exogenous nitroxide biradicals such as TOTAPOL or AMUPOL are routinely used. Their efficiency is usually assessed as the ratio between the NMR signal intensity in the presence and the absence of microwave irradiation εon/off. While TOTAPOL delivers an enhancement εon/off of about 60 on a model sample, the more recent AMUPOL is more efficient: >200 at 100 K. Such a comparison is valid as long as the signal measured in the absence of microwaves is merely the Boltzmann polarization and is not affected by the spinning of the sample. However, recent MAS-DNP studies at 25 K by Thurber and Tycko (2014) have demonstrated that the presence of nitroxide biradicals combined with sample spinning can lead to a depolarized nuclear state, below the Boltzmann polarization. In this work we demonstrate that TOTAPOL and AMUPOL both lead to observable depolarization at ≈110 K, and that the magnitude of this depolarization is radical dependent. Compared to the static sample, TOTAPOL and AMUPOL lead, respectively, to nuclear polarization losses of up to 20% and 60% at a 10 kHz MAS frequency, while Trityl OX63 does not depolarize at all. This experimental work is analyzed using a theoretical model that explains how the depolarization process works under MAS and gives new insights into the DNP mechanism and into the spin parameters, which are relevant for the efficiency of a biradical. In light of these results, the outstanding performance of AMUPOL must be revised and we propose a new method to assess the polarization gain for future radicals. PMID:26235749</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014DyAtO..66...10T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014DyAtO..66...10T"><span id="translatedtitle">Introducing variable-step <span class="hlt">topography</span> (VST) coordinates within <span class="hlt">dynamically</span> constrained nonhydrostatic modeling system (NMS). Part 2: VST performance on orthodox obstacle flows</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tripoli, Gregory J.; Smith, Eric A.</p> <p>2014-06-01</p> <p>In this second part of a two-part sequence of papers, the performance metrics and quantitative advantages of a new VST surface coordinate system, implemented within a <span class="hlt">dynamically</span> constrained, nonhydrostatic, cloud mesoscale atmospheric model, are evaluated in conjunction with seven orthodox obstacle flow problems. [The first part presented a full formulation of the VST model, prefaced by a description of the framework of the newly re-tooled nonhydrostatic modeling system (NMS) operating within integral constraints based on the conservation of the foremost quantities of mass, energy and circulation.] The intent behind VST is to create a vertical surface coordinate system boundary underpinning a nonhydrostatic atmosphere capable of reliable simulations of flows over both smooth and steep terrain without sacrificing <span class="hlt">dynamical</span> integrity over either type of surface. Model simulation results are analyzed for six classical fluid <span class="hlt">dynamics</span> problems involving flows relative to obstacles with known analytical or laboratory-simulated solutions, as well as for a seventh noteworthy mountain wave breaking problem that has well-studied numerical solutions. For cases when <span class="hlt">topography</span> becomes excessively severe or poorly resolved numerically, atmospheric models using transform (terrain-following) coordinates produce noteworthy errors rendering a stable integration only if the <span class="hlt">topography</span> is smoothed. For cases when <span class="hlt">topography</span> is slowly varying (smooth or subtle), models using discrete-step coordinates also produce noteworthy errors relative to known solutions. Alternatively, the VST model demonstrates that both limitations of the two conventional approaches, for the entire range of slope severities, can be overcome. This means that VST is ideally suited for a scalable, nonhydrostatic atmospheric model, safeguarded with physically realistic <span class="hlt">dynamical</span> constraints.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ESASP.722E.205J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ESASP.722E.205J"><span id="translatedtitle">Towards Improved Estimation Of The <span class="hlt">Dynamic</span> <span class="hlt">Topography</span> And Ocean Circulation In The High Latitude And Arctic Ocean: The Importance Of GOCE</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Johannessen, J. A.; Raj, R. P.; Nilsen, J. E. Ø.; Pripp, T.; Knudsen, P.; Counillon, F.; Stammer, D.; Bertino, L.; Andersen, O. B.; Serra, N.; Koldunov, N.</p> <p>2013-12-01</p> <p>The Arctic plays a fundamental role in the climate system and shows significant sensitivity to anthropogenic climate forcing and the ongoing climate change. Evidently changes in the Arctic and surrounding seas have far reaching influences on regional and global environment and climate variability. In this respect this study combines in-situ hydrographical data, surface drifter data and direct current meter measurements, with coupled sea ice - ocean models, radar altimeter data and the latest GOCE- based geoid in order to estimate and assess the quality, usefulness and validity of the new GOCE derived mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> for studies of the ocean circulation and transport estimates in the Nordic Seas and Arctic Ocean.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014OcSci..10..731R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014OcSci..10..731R"><span id="translatedtitle">Computation of a new mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> for the Mediterranean Sea from model outputs, altimeter measurements and oceanographic in situ data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rio, M.-H.; Pascual, A.; Poulain, P.-M.; Menna, M.; Barceló, B.; Tintoré, J.</p> <p>2014-08-01</p> <p>The accurate knowledge of the ocean's mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> (MDT) is a crucial issue for a number of oceanographic applications and, in some areas of the Mediterranean Sea, important limitations have been found pointing to the need of an upgrade. We present a new MDT that was computed for the Mediterranean Sea. It profits from improvements made possible by the use of extended data sets and refined processing. The updated data set spans the 1993-2012 period and consists of drifter velocities, altimetry data, hydrological profiles and model data. The methodology is similar to the previous MDT by Rio et al. (2007). However, in Rio et al. (2007) no hydrological profiles had been taken into account. This required the development of dedicated processing. A number of sensitivity studies have been carried out to obtain the most accurate MDT as possible. The main results from these sensitivity studies are the following: moderate impact to the choice of correlation scales but almost negligible sensitivity to the choice of the first guess (model solution). A systematic external validation to independent data has been made to evaluate the performance of the new MDT. Compared to previous versions, SMDT-MED-2014 (Synthetic Mean <span class="hlt">Dynamic</span> <span class="hlt">Topography</span> of the MEDiterranean sea) features shorter-scale structures, which results in an altimeter velocity variance closer to the observed velocity variance and, at the same time, gives better Taylor skills.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110023549','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110023549"><span id="translatedtitle">Constraining the <span class="hlt">Absolute</span> Orientation of eta Carinae's Binary Orbit: A 3-D <span class="hlt">Dynamical</span> Model for the Broad [Fe III] Emission</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Madura, T. I.; Gull, T. R.; Owocki, S. P.; Groh, J. H.; Okazaki, A. T.; Russell, C. M. P.</p> <p>2011-01-01</p> <p>We present a three-dimensional (3-D) <span class="hlt">dynamical</span> model for the broad [Fe III] emission observed in Eta Carinae using the Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS). This model is based on full 3-D Smoothed Particle Hydrodynamics (SPH) simulations of Eta Car's binary colliding winds. Radiative transfer codes are used to generate synthetic spectro-images of [Fe III] emission line structures at various observed orbital phases and STIS slit position angles (PAs). Through a parameter study that varies the orbital inclination i, the PA(theta) that the orbital plane projection of the line-of-sight makes with the apastron side of the semi-major axis, and the PA on the sky of the orbital axis, we are able, for the first time, to tightly constrain the <span class="hlt">absolute</span> 3-D orientation of the binary orbit. To simultaneously reproduce the blue-shifted emission arcs observed at orbital phase 0.976, STIS slit PA = +38deg, and the temporal variations in emission seen at negative slit PAs, the binary needs to have an i approx. = 130deg to 145deg, Theta approx. = -15deg to +30deg, and an orbital axis projected on the sky at a P A approx. = 302deg to 327deg east of north. This represents a system with an orbital axis that is closely aligned with the inferred polar axis of the Homunculus nebula, in 3-D. The companion star, Eta(sub B), thus orbits clockwise on the sky and is on the observer's side of the system at apastron. This orientation has important implications for theories for the formation of the Homunculus and helps lay the groundwork for orbital modeling to determine the stellar masses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140001041','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140001041"><span id="translatedtitle">Does <span class="hlt">Dynamical</span> Downscaling Introduce Novel Information in Climate Model Simulations of Recipitation Change over a Complex <span class="hlt">Topography</span> Region?</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Tselioudis, George; Douvis, Costas; Zerefos, Christos</p> <p>2012-01-01</p> <p>Current climate and future climate-warming runs with the RegCM Regional Climate Model (RCM) at 50 and 11 km-resolutions forced by the ECHAM GCM are used to examine whether the increased resolution of the RCM introduces novel information in the precipitation field when the models are run for the mountainous region of the Hellenic peninsula. The model results are inter-compared with the resolution of the RCM output degraded to match that of the GCM, and it is found that in both the present and future climate runs the regional models produce more precipitation than the forcing GCM. At the same time, the RCM runs produce increases in precipitation with climate warming even though they are forced with a GCM that shows no precipitation change in the region. The additional precipitation is mostly concentrated over the mountain ranges, where orographic precipitation formation is expected to be a dominant mechanism. It is found that, when examined at the same resolution, the elevation heights of the GCM are lower than those of the averaged RCM in the areas of the main mountain ranges. It is also found that the majority of the difference in precipitation between the RCM and the GCM can be explained by their difference in topographic height. The study results indicate that, in complex <span class="hlt">topography</span> regions, GCM predictions of precipitation change with climate warming may be dry biased due to the GCM smoothing of the regional <span class="hlt">topography</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JChPh.137x4507P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JChPh.137x4507P"><span id="translatedtitle">On the <span class="hlt">absolute</span> thermodynamics of water from computer simulations: A comparison of first-principles molecular <span class="hlt">dynamics</span>, reactive and empirical force fields</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pascal, Tod A.; Schärf, Daniel; Jung, Yousung; Kühne, Thomas D.</p> <p>2012-12-01</p> <p>We present the <span class="hlt">absolute</span> enthalpy, entropy, heat capacity, and free energy of liquid water at ambient conditions calculated by the two-phase thermodynamic method applied to ab initio, reactive and classical molecular <span class="hlt">dynamics</span> simulations. We find that the <span class="hlt">absolute</span> entropy and heat capacity of liquid water from ab initio molecular <span class="hlt">dynamics</span> (AIMD) is underestimated, but falls within the range of the flexible empirical as well as the reactive force fields. The origin of the low <span class="hlt">absolute</span> entropy of liquid water from AIMD simulations is due to an underestimation of the translational entropy by 20% and the rotational entropy by 40% compared to the TIP3P classical water model, consistent with previous studies that reports low diffusivity and increased ordering of liquid water from AIMD simulations. Classical MD simulations with rigid water models tend to be in better agreement with experiment (in particular TIP3P yielding the best agreement), although the TIP4P-ice water model, the only empirical force field that reproduces the experimental melting temperature, has the lowest entropy, perhaps expectedly. This reiterates the limitations of existing empirical water models in simultaneously capturing the thermodynamics of solid and liquid phases. We find that the quantum corrections to heat capacity of water can be as large as 60%. Although certain water models are computed to yield good <span class="hlt">absolute</span> free energies of water compared to experiments, they are often due to the fortuitous enthalpy-entropy cancellation, but not necessarily due to the correct descriptions of enthalpy and entropy separately.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/8451339','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/8451339"><span id="translatedtitle"><span class="hlt">Absolute</span> pitch.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Takeuchi, A H; Hulse, S H</p> <p>1993-03-01</p> <p><span class="hlt">Absolute</span> pitch (AP) is the ability to identify a tone's pitch or to produce a tone at a particular pitch without the use of an external reference pitch. AP exists in varying degrees among people generally described as AP possessors. AP possessors vary not only in the accuracy with which they can identify pitches but also in their ability to produce pitches <span class="hlt">absolutely</span> and in their ability to identify tones of various timbers and in various pitch registers. AP possessors' memory for pitches is mediated by verbal pitch names; they do not have superior memory for pitches per se. Although the etiology of AP is not yet completely understood, evidence points toward the early-learning theory. This theory states that AP can be learned by anyone during a limited period early in development, up to about age 6, after which a general developmental shift from perceiving individual features to perceiving relations among features makes AP difficult or impossible to acquire. PMID:8451339</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AAS...20912001D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AAS...20912001D"><span id="translatedtitle"><span class="hlt">Absolute</span> Zero</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Donnelly, Russell J.; Sheibley, D.; Belloni, M.; Stamper-Kurn, D.; Vinen, W. F.</p> <p>2006-12-01</p> <p><span class="hlt">Absolute</span> Zero is a two hour PBS special attempting to bring to the general public some of the advances made in 400 years of thermodynamics. It is based on the book “<span class="hlt">Absolute</span> Zero and the Conquest of Cold” by Tom Shachtman. <span class="hlt">Absolute</span> Zero will call long-overdue attention to the remarkable strides that have been made in low-temperature physics, a field that has produced 27 Nobel Prizes. It will explore the ongoing interplay between science and technology through historical examples including refrigerators, ice machines, frozen foods, liquid oxygen and nitrogen as well as much colder fluids such as liquid hydrogen and liquid helium. A website has been established to promote the series: www.absolutezerocampaign.org. It contains information on the series, aimed primarily at students at the middle school level. There is a wealth of material here and we hope interested teachers will draw their student’s attention to this website and its substantial contents, which have been carefully vetted for accuracy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19920037750&hterms=asthenosphere&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dasthenosphere','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19920037750&hterms=asthenosphere&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dasthenosphere"><span id="translatedtitle">Geoid anomalies and <span class="hlt">dynamic</span> <span class="hlt">topography</span> from convection in cylindrical geometry - Applications to mantle plumes on earth and Venus</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kiefer, Walter S.; Hager, Bradford H.</p> <p>1992-01-01</p> <p>A variety of evidence suggests that at least some hotspots are formed by quasi-cylindrical mantle plumes upwelling from deep in the mantle. Such plumes are modeled in cylindrical, axisymmetric geometry with depth-dependent, Newtonian viscosity. Cylindrical and sheet-like, Cartesian upwellings have significantly different geoid and <span class="hlt">topography</span> signatures. However, Rayleigh number-Nusselt number systematics in the two geometries are quite similar. The geoid anomaly and topographic uplift over a plume are insensitive to the viscosity of the surface layer, provided that it is at least 1000 times the interior viscosity. Increasing the Rayleigh number or including a low-viscosity asthenosphere decreases the geoid anomaly and the topographic uplift associated with an upwelling plume.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.T13B2380N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.T13B2380N"><span id="translatedtitle"><span class="hlt">Dynamic</span> <span class="hlt">topography</span> of the western Great Plains: landscape evidence for mantle-driven uplift associated with the Jemez lineament of NE New Mexico and SE Colorado</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nereson, A. L.; Karlstrom, K. E.; McIntosh, W. C.; Heizler, M. T.; Kelley, S. A.; Brown, S. W.</p> <p>2011-12-01</p> <p><span class="hlt">Dynamic</span> <span class="hlt">topography</span> results when viscous stresses created by flow within the mantle are transmitted through the lithosphere and interact with, and deform, the Earth's surface. Because <span class="hlt">dynamic</span> <span class="hlt">topography</span> is characterized by low amplitudes and long wavelengths, its subtle effects may be best recorded in low-relief areas such as the Great Plains of the USA where they can be readily observed and measured. We apply this concept to a unique region of the western Great Plains in New Mexico and Colorado where basalt flows of the Jemez lineament (Raton-Clayton and Ocate fields) form mesas (inverted <span class="hlt">topography</span>) that record the evolution of the Great Plains surface through time. This study uses multiple datasets to evaluate the mechanisms which have driven the evolution of this landscape. Normalized channel steepness index (ksn) analysis identifies anomalously steep river gradients across broad (50-100 km) convexities within a NE- trending zone of differential river incision where higher downstream incision rates in the last 1.5 Ma suggest headwater uplift. At 2-8 Ma timescales, 40Ar/39Ar ages of basalt-capped paleosurfaces in the Raton-Clayton and Ocate volcanic fields indicate that rates of denudation increase systematically towards the NW from a NE-trending zone of approximately zero denudation (that approximately coincides with the high ksn zone), also suggestive of regional warping above the Jemez lineament. Onset of more rapid denudation is observed in the Raton-Clayton field beginning at ca. 3.6 Ma. Furthermore, two 300-400-m-high NE-trending erosional escarpments impart a staircase-like topographic profile to the region. Tomographic images from the EarthScope experiment show that NE-trending topographic features of this region correspond to an ~8 % P-wave velocity gradient of similar trend at the margin of the low-velocity Jemez mantle anomaly. We propose that the erosional landscapes of this unique area are, in large part, the surface expression of <span class="hlt">dynamic</span> mantle-driven uplift along the Jemez anomaly in the last 3.6 Ma. Apatite fission-track ages indicate a tilted 30 Ma 110C isotherm, however, suggesting that Jemez mantle-driven uplift is superimposed on earlier Rocky Mountain uplift that was initiated in the mid-Tertiary.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014GeoJI.198...55C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014GeoJI.198...55C"><span id="translatedtitle">Seismic waveform inversion for core-mantle boundary <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Colombi, Andrea; Nissen-Meyer, Tarje; Boschi, Lapo; Giardini, Domenico</p> <p>2014-07-01</p> <p>The <span class="hlt">topography</span> of the core-mantle boundary (CMB) is directly linked to the <span class="hlt">dynamics</span> of both the mantle and the outer core, although it is poorly constrained and understood. Recent studies have produced <span class="hlt">topography</span> models with mutual agreement up to degree 2. A broad-band waveform inversion strategy is introduced and applied here, with relatively low computational cost and based on a first-order Born approximation. Its performance is validated using synthetic waveforms calculated in theoretical earth models that include different <span class="hlt">topography</span> patterns with varying lateral wavelengths, from 600 to 2500 km, and magnitudes (˜10 km peak-to-peak). The source-receiver geometry focuses mainly on the Pdiff, PKP, PcP and ScS phases. The results show that PKP branches, PcP and ScS generally perform well and in a similar fashion, while Pdiff yields unsatisfactory results. We investigate also how 3-D mantle correction influences the output models, and find that despite the disturbance introduced, the models recovered do not appear to be biased, provided that the 3-D model is correct. Using cross-correlated traveltimes, we derive new <span class="hlt">topography</span> models from both P and S waves. The static corrections used to remove the mantle effect are likely to affect the inversion, compromising the agreement between models derived from P and S data. By modelling traveltime residuals starting from sensitivity kernels, we show how the simultaneous use of volumetric and boundary kernels can reduce the bias coming from mantle structures. The joint inversion approach should be the only reliable method to invert for CMB <span class="hlt">topography</span> using <span class="hlt">absolute</span> cross-correlation traveltimes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4878386','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4878386"><span id="translatedtitle">A Million-Plus Neuron Model of the Hippocampal Dentate Gyrus: Dependency of Spatio-Temporal Network <span class="hlt">Dynamics</span> on <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hendrickson, Phillip J.; Yu, Gene J.; Song, Dong; Berger, Theodore W.</p> <p>2016-01-01</p> <p>This paper describes a million-plus granule cell compartmental model of the rat hippocampal dentate gyrus, including excitatory, perforant path input from the entorhinal cortex, and feedforward and feedback inhibitory input from dentate interneurons. The model includes experimentally determined morphological and biophysical properties of granule cells, together with glutamatergic AMPA-like EPSP and GABAergic GABAA-like IPSP synaptic excitatory and inhibitory inputs, respectively. Each granule cell was composed of approximately 200 compartments having passive and active conductances distributed throughout the somatic and dendritic regions. Modeling excitatory input from the entorhinal cortex was guided by axonal transport studies documenting the topographical organization of projections from subregions of the medial and lateral entorhinal cortex, plus other important details of the distribution of glutamatergic inputs to the dentate gyrus. Results showed that when medial and lateral entorhinal cortical neurons maintained Poisson random firing, dentate granule cells expressed, throughout the million-cell network, a robust, non-random pattern of spiking best described as spatiotemporal “clustering”. To identify the network property or properties responsible for generating such firing “clusters”, we progressively eliminated from the model key mechanisms such as feedforward and feedback inhibition, intrinsic membrane properties underlying rhythmic burst firing, and/or topographical organization of entorhinal afferents. Findings conclusively identified topographical organization of inputs as the key element responsible for generating a spatio-temporal distribution of clustered firing. These results uncover a functional organization of perforant path afferents to the dentate gyrus not previously recognized: <span class="hlt">topography</span>-dependent clusters of granule cell activity as “functional units” that organize the processing of entorhinal signals. PMID:26737346</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26737346','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26737346"><span id="translatedtitle">A million-plus neuron model of the hippocampal dentate gyrus: Dependency of spatio-temporal network <span class="hlt">dynamics</span> on <span class="hlt">topography</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hendrickson, Phillip J; Yu, Gene J; Dong Song; Berger, Theodore W</p> <p>2015-08-01</p> <p>This paper describes a million-plus granule cell compartmental model of the rat hippocampal dentate gyrus, including excitatory, perforant path input from the entorhinal cortex, and feedforward and feedback inhibitory input from dentate interneurons. The model includes experimentally determined morphological and biophysical properties of granule cells, together with glutamatergic AMPA-like EPSP and GABAergic GABAA-like IPSP synaptic excitatory and inhibitory inputs, respectively. Each granule cell was composed of approximately 200 compartments having passive and active conductances distributed throughout the somatic and dendritic regions. Modeling excitatory input from the entorhinal cortex was guided by axonal transport studies documenting the topographical organization of projections from subregions of the medial and lateral entorhinal cortex, plus other important details of the distribution of glutamatergic inputs to the dentate gyrus. Results showed that when medial and lateral entorhinal cortical neurons maintained Poisson random firing, dentate granule cells expressed, throughout the million-cell network, a robust, non-random pattern of spiking best described as spatiotemporal "clustering". To identify the network property or properties responsible for generating such firing "clusters", we progressively eliminated from the model key mechanisms such as feedforward and feedback inhibition, intrinsic membrane properties underlying rhythmic burst firing, and/or topographical organization of entorhinal afferents. Findings conclusively identified topographical organization of inputs as the key element responsible for generating a spatio-temporal distribution of clustered firing. These results uncover a functional organization of perforant path afferents to the dentate gyrus not previously recognized: <span class="hlt">topography</span>-dependent clusters of granule cell activity as "functional units" that organize the processing of entorhinal signals. PMID:26737346</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GGG....16.1771V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GGG....16.1771V"><span id="translatedtitle"><span class="hlt">Dynamics</span> of intraoceanic subduction initiation: 2. Suprasubduction zone ophiolite formation and metamorphic sole exhumation in context of <span class="hlt">absolute</span> plate motions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>van Hinsbergen, Douwe J. J.; Peters, Kalijn; Maffione, Marco; Spakman, Wim; Guilmette, Carl; Thieulot, Cedric; Plümper, Oliver; Gürer, Derya; Brouwer, Fraukje M.; Aldanmaz, Ercan; Kaymakcı, Nuretdin</p> <p>2015-06-01</p> <p>Analyzing subduction initiation is key for understanding the coupling between plate tectonics and the underlying mantle. Here we focus on suprasubduction zone (SSZ) ophiolites and how their formation links to intraoceanic subduction initiation in an <span class="hlt">absolute</span> plate motion frame. SSZ ophiolites form the majority of exposed oceanic lithosphere fragments and are widely recognized to have formed during intraoceanic subduction initiation. Structural, petrological, geochemical, and plate kinematic constraints on their kinematic evolution show that SSZ crust forms at fore-arc spreading centers at the expense of a mantle wedge, thereby flattening the nascent slab. This leads to the typical inverted pressure gradients found in metamorphic soles that form at the subduction plate contact below and during SSZ crust crystallization. Former spreading centers are preserved in forearcs when subduction initiates along transform faults or off-ridge oceanic detachments. We show how these are reactivated when subduction initiates in the <span class="hlt">absolute</span> plate motion direction of the inverting weakness zone. Upon inception of slab pull due to, e.g., eclogitization, the sole is separated from the slab, remains welded to the thinned overriding plate lithosphere, and can become intruded by mafic dikes upon asthenospheric influx into the mantle wedge. We propound that most ophiolites thus formed under special geodynamic circumstances and may not be representative of normal oceanic crust. Our study highlights how far-field geodynamic processes and <span class="hlt">absolute</span> plate motions may force intraoceanic subduction initiation as key toward advancing our understanding of the entire plate tectonic cycle.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009SRL....16..697P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009SRL....16..697P"><span id="translatedtitle"><span class="hlt">Dynamics</span> and <span class="hlt">Topography</span> of QUASI-2D Needle-Like Silver Electrochemical Deposits Under a Quasi-Steady Regime</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pasquale, M. A.; Vicente, J. L.; Arvia, A. J.</p> <p></p> <p>The electrochemical formation of single silver needles from aqueous silver sulfate was studied under both potentiostatic and galvanostatic conditions utilizing different quasi-2D cells. Under potentiostatic conditions, four (I-IV) stages of growth were distinguished. Stage III involved single needle growth under a quasi-steady-state (q-ss) regime in which, at the millimeter scale, the tip profile remained almost unchanged. Fast growing needles exhibited a truncated quasi-conical tip, and slow growing ones approached prolate hemispheroids. At stage III, the almost constant q-ss silver deposition rate was evaluated from the tip front displacement (dLz/dt) perpendicularly to the tangential plane of the tip. For the cathode to anode potential difference in the range -1.00 ? Ec-a ? -0.22 V, values of (dLz/dt) in the range 0.08-2.0 ?m s-1 were obtained. At the needle stem, the q-ss radial silver deposition rate (dLx/dt) was about two orders of magnitude lower than (dLz/dt). The transition from stage III to IV was characterized by tip thickening, i.e. a change in the tip q-conical profile to that of a prolate hemispheroid, and eventual tip splitting. Scanning electron micrographs at the micrometer scale of single silver needle tips from potentiostatic runs showed either a defined crystallography or an irregular <span class="hlt">topography</span> covered by a large number of tiny crystals. In contrast, stems were always faceted. This difference indicated that surface relaxation processes following silver ion mass transport and discharge played a relevant role in the needle growth mode. At stage III, the growth regime is described utilizing a dual diffusion (D) and migration (M) model consisting of a DM direct contribution that becomes dominant at the needle stem, and a space charge (SC)-assisted DM contribution that operates at the tip apex. This explanation is consistent with the local cathodic current density values, the concentration ratio of silver clusters at the stem and tip apex surface, and the distinct kinetic behavior of needles produced from potentiostatic and galvanostatic runs. The complex link between mass transport phenomena of silver ions from the binary solution side, the silver ion discharge at the interface and the surface relaxation of silver adatoms and clusters at the metal lattice shed new light on the aspects of single silver needle formation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.T13D..07P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.T13D..07P"><span id="translatedtitle">Effects of rheology on the <span class="hlt">dynamics</span> and development of <span class="hlt">topography</span> in 3D numerical simulations of continental collision, with an application to the India-Asia collision zone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pusok, A. E.; Kaus, B.; Popov, A.</p> <p>2014-12-01</p> <p>The Himalayas and the adjacent Tibetan Plateau represent the largest region of elevated <span class="hlt">topography</span> and anomalously thick crust on Earth. Understanding the formation and evolution of the region has been the focus of many tectonic and numerical models. While some of these models (i.e. thin sheet model) have successfully illustrated some of the basic physics of continental collision, none can simultaneously represent active processes such as subduction, underthrusting, channel flow or extrusion, for which fully 3D models are required. Here, we employed the 3D code LaMEM to investigate the role that subduction, continental collision and indentation play on lithosphere <span class="hlt">dynamics</span> at convergent margins, and the implications they have for the Asian tectonics. Our model setup resembles a simplified tectonic map of the India-Asia collision zone and we performed a large number of 3D simulations to analyse the <span class="hlt">dynamics</span> and the conditions under which large topographic plateaus, such as the Tibetan Plateau can form in an integrated lithospheric and upper-mantle scale model. Results of models with linear viscous rheologies show different modes between the oceanic subduction side (continuous subduction, trench retreat and slab roll-back) and the continental collision side (trench advance, slab detachment, topographic uplift and lateral extrusion of material). Despite the complex <span class="hlt">dynamics</span> and the great variation in slab shape across the subduction-collision zone, which are consistent with tomographic observations, we note that slab-pull alone is insufficient to generate high <span class="hlt">topography</span> in the upper plate. Several studies suggested that external forces (i.e. ridge push, plume push or slab suction) must be important in order to sustain the on-going convergence of India towards Eurasia. We show that external forcing and the presence of strong blocks such as the Tarim Basin within the Asian lithosphere are necessary to create and shape anomalously high topographic fronts and plateaus, analogous to the Himalayas and the Tibetan Plateau. Next, we present a few models with more complex (power-law viscous and plastic) rheologies and compare them with linear viscous models. Funding was provided by the ERC under the European Community's Seventh Framework Program (FP7/2007-2013) / ERC Grant agreement #258830.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014DyAtO..66...28T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014DyAtO..66...28T"><span id="translatedtitle">Introducing Variable-Step <span class="hlt">Topography</span> (VST) coordinates within <span class="hlt">dynamically</span> constrained Nonhydrostatic Modeling System (NMS). Part 1: VST formulation within NMS host model framework</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tripoli, Gregory J.; Smith, Eric A.</p> <p>2014-06-01</p> <p>A Variable-Step <span class="hlt">Topography</span> (VST) surface coordinate system is introduced into a <span class="hlt">dynamically</span> constrained, scalable, nonhydrostatic atmospheric model for reliable simulations of flows over both smooth and steep terrain without sacrificing <span class="hlt">dynamical</span> integrity over either type of surface. Backgrounds of both terrain-following and step coordinate model developments are presented before justifying the turn to a VST approach within an appropriately configured host model. In this first part of a two-part sequence of papers, the full formulation of the VST model, prefaced by a description of the framework of its apposite host, i.e., a re-tooled Nonhydrostatic Modeling System (NMS), are presented. [The second part assesses the performance and benefits of the new VST coordinate system in conjunction with seven orthodox obstacle flow problems.] The NMS is a 3-dimensional, nonhydrostatic cloud-mesoscale model, designed for integrations from plume-cloud scales out to regional-global scales. The derivative properties of VST in conjunction with the NMS's newly designed <span class="hlt">dynamically</span> constrained core are capable of accurately capturing the deformations of flows by any type of terrain variability. Numerical differencing schemes needed to satisfy critical integral constraints, while also effectively enabling the VST lower boundary, are described. The host model constraints include mass, momentum, energy, vorticity and enstrophy conservation. A quasi-compressible closure cast on multiple-nest rotated spherical grids is the underlying framework used to study the advantages of the VST coordinate system. The principle objective behind the VST formulation is to combine the advantages of both terrain-following and step coordinate systems without suffering either of their disadvantages, while at the same time creating a vertical surface coordinate setting suitable for a scalable, nonhydrostatic model, safeguarded with physically realistic <span class="hlt">dynamical</span> constraints.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012JGRF..117.4016S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012JGRF..117.4016S"><span id="translatedtitle">Coupled <span class="hlt">dynamics</span> of the co-evolution of gravel bed <span class="hlt">topography</span>, flow turbulence and sediment transport in an experimental channel</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, Arvind; Foufoula-Georgiou, Efi; Porté-Agel, Fernando; Wilcock, Peter R.</p> <p>2012-12-01</p> <p>A series of flume experiments were conducted in a large experimental channel at the St. Anthony Falls Laboratory to understand the coupled <span class="hlt">dynamics</span> of flow and bed forms above the sediment-water interface. Simultaneous high resolution measurements of velocity fluctuations, bed elevations and sediment flux at the downstream end of the channel, were made for a range of discharges. The probability density functions (pdfs) of bed elevation increments and instantaneous Reynolds stress reveal a power law tail behavior and a wavelet cross-correlation analysis depicts a strong dependence of these series across a range of scales, indicating a feedback between bed form <span class="hlt">dynamics</span> and near-bed turbulence. These results complement our previous findings in which the signature of bed form evolution on the near-bed velocity fluctuations was confirmed via the presence of a spectral gap and two distinct power law scaling regimes in the spectral density of velocity fluctuations. We report herein a strong asymmetry in the probability distribution of bed elevation increments and instantaneous Reynolds stresses, the latter being further analyzed and interpreted via a quadrant analysis of velocity fluctuations in the longitudinal and vertical directions. We also report the presence of intermittency (multifractality) in bed elevation increments and interpret it, in view of the asymmetric nature of the pdfs, as the result of scale coupling. In other words, the geometric asymmetry at the bed form scale gets transferred down to a probabilistic asymmetry at all smaller scales indicating a local anisotropy in the energy transfer. Finally, we propose a predictive relationship between bed form averaged sediment transport rates and bed form averaged instantaneous Reynolds stress and validate it using our experimental data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3888926','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3888926"><span id="translatedtitle">Neuronal correlates of decisions to speak and act: Spontaneous emergence and <span class="hlt">dynamic</span> <span class="hlt">topographies</span> in a computational model of frontal and temporal areas</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Garagnani, Max; Pulvermüller, Friedemann</p> <p>2013-01-01</p> <p>The neural mechanisms underlying the spontaneous, stimulus-independent emergence of intentions and decisions to act are poorly understood. Using a neurobiologically realistic model of frontal and temporal areas of the brain, we simulated the learning of perception–action circuits for speech and hand-related actions and subsequently observed their spontaneous behaviour. Noise-driven accumulation of reverberant activity in these circuits leads to their spontaneous ignition and partial-to-full activation, which we interpret, respectively, as model correlates of action intention emergence and action decision-and-execution. Importantly, activity emerged first in higher-association prefrontal and temporal cortices, subsequently spreading to secondary and finally primary sensorimotor model-areas, hence reproducing the <span class="hlt">dynamics</span> of cortical correlates of voluntary action revealed by readiness-potential and verb-generation experiments. This model for the first time explains the cortical origins and <span class="hlt">topography</span> of endogenous action decisions, and the natural emergence of functional specialisation in the cortex, as mechanistic consequences of neurobiological principles, anatomical structure and sensorimotor experience. PMID:23489583</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23489583','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23489583"><span id="translatedtitle">Neuronal correlates of decisions to speak and act: Spontaneous emergence and <span class="hlt">dynamic</span> <span class="hlt">topographies</span> in a computational model of frontal and temporal areas.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Garagnani, Max; Pulvermüller, Friedemann</p> <p>2013-10-01</p> <p>The neural mechanisms underlying the spontaneous, stimulus-independent emergence of intentions and decisions to act are poorly understood. Using a neurobiologically realistic model of frontal and temporal areas of the brain, we simulated the learning of perception-action circuits for speech and hand-related actions and subsequently observed their spontaneous behaviour. Noise-driven accumulation of reverberant activity in these circuits leads to their spontaneous ignition and partial-to-full activation, which we interpret, respectively, as model correlates of action intention emergence and action decision-and-execution. Importantly, activity emerged first in higher-association prefrontal and temporal cortices, subsequently spreading to secondary and finally primary sensorimotor model-areas, hence reproducing the <span class="hlt">dynamics</span> of cortical correlates of voluntary action revealed by readiness-potential and verb-generation experiments. This model for the first time explains the cortical origins and <span class="hlt">topography</span> of endogenous action decisions, and the natural emergence of functional specialisation in the cortex, as mechanistic consequences of neurobiological principles, anatomical structure and sensorimotor experience. PMID:23489583</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015E%26PSL.421..107S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015E%26PSL.421..107S"><span id="translatedtitle">Australian plate motion and <span class="hlt">topography</span> linked to fossil New Guinea slab below Lake Eyre</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Schellart, W. P.; Spakman, W.</p> <p>2015-07-01</p> <p>Unravelling causes for <span class="hlt">absolute</span> plate velocity change and continental <span class="hlt">dynamic</span> <span class="hlt">topography</span> change is challenging because of the interdependence of large-scale geodynamic driving processes. Here, we unravel a clear spatio-temporal relation between latest Cretaceous-Early Cenozoic subduction at the northern edge of the Australian plate, Early Cenozoic Australian plate motion changes and Cenozoic <span class="hlt">topography</span> evolution of the Australian continent. We present evidence for a ∼4000 km wide subduction zone, which culminated in ophiolite obduction and arc-continent collision in the New Guinea-Pocklington Trough region during subduction termination, coinciding with cessation of spreading in the Coral Sea, a ∼5 cm/yr decrease in northward Australian plate velocity, and slab detachment. Renewed northward motion caused the Australian plate to override the sinking subduction remnant, which we detect with seismic tomography at 800-1200 km depth in the mantle under central-southeast Australia at a position predicted by our <span class="hlt">absolute</span> plate reconstructions. With a numerical model of slab sinking and mantle flow we predict a long-wavelength subsidence (negative <span class="hlt">dynamic</span> <span class="hlt">topography</span>) migrating southward from ∼50 Ma to present, explaining Eocene-Oligocene subsidence of the Queensland Plateau, ∼330 m of late Eocene-early Oligocene subsidence in the Gulf of Carpentaria, Oligocene-Miocene subsidence of the Marion Plateau, and providing a first-order fit to the present-day, ∼200 m deep, topographic depression of the Lake Eyre Basin and Murray-Darling Basin. We propound that <span class="hlt">dynamic</span> <span class="hlt">topography</span> evolution provides an independent means to couple geological processes to a mantle reference frame. This is complementary to, and can be integrated with, other approaches such as hotspot and slab reference frames.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4363941','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4363941"><span id="translatedtitle">Membrane related <span class="hlt">dynamics</span> and the formation of actin in cells growing on micro-<span class="hlt">topographies</span>: a spatial computational model</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2014-01-01</p> <p>Background Intra-cellular processes of cells at the interface to an implant surface are influenced significantly by their extra-cellular surrounding. Specifically, when growing osteoblasts on titanium surfaces with regular micro-ranged geometry, filaments are shorter, less aligned and they concentrate at the top of the geometric structures. Changes to the cytoskeleton network, i. e., its localization, alignment, orientation, and lengths of the filaments, as well as the overall concentration and distribution of key-actors are induced. For example, integrin is distributed homogeneously, whereas integrin in activated state and vinculin, both components of focal adhesions, have been found clustered on the micro-ranged geometries. Also, the concentration of Rho, an intracellular signaling protein related to focal adhesion regulation, was significantly lower. Results To explore whether regulations associated with the focal adhesion complex can be responsible for the changed actin filament patterns, a spatial computational model has been developed using ML-Space, a rule-based model description language, and its associated Brownian-motion-based simulator. The focus has been on the deactivation of cofilin in the vicinity of the focal adhesion complex. The results underline the importance of sensing mechanisms to support a clustering of actin filament nucleations on the micro-ranged geometries, and of intracellular diffusion processes, which lead to spatially heterogeneous distributions of active (dephosphorylated) cofilin, which in turn influences the organization of the actin network. We find, for example, that the spatial heterogeneity of key molecular actors can explain the difference in filament lengths in cells on different micro-geometries partly, but to explain the full extent, further model assumptions need to be added and experimentally validated. In particular, our findings and hypothesis referring to the role, distribution, and amount of active cofilin have still to be verified in wet-lab experiments. Conclusion Letting cells grow on surface structures is a possibility to shed new light on the intricate mechanisms that relate membrane and actin related <span class="hlt">dynamics</span> in the cell. Our results demonstrate the need for declarative expressive spatial modeling approaches that allow probing different hypotheses, and the central role of the focal adhesion complex not only for nucleating actin filaments, but also for regulating possible severing agents locally. PMID:25200251</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22304423','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22304423"><span id="translatedtitle">Two-dimensional fluorescence-detected coherent spectroscopy with <span class="hlt">absolute</span> phasing by confocal imaging of a <span class="hlt">dynamic</span> grating and 27-step phase-cycling</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>De, Arijit K. Fleming, Graham R.; Monahan, Daniele; Dawlaty, Jahan M.</p> <p>2014-05-21</p> <p>We present a novel experimental scheme for two-dimensional fluorescence-detected coherent spectroscopy (2D-FDCS) using a non-collinear beam geometry with the aid of “confocal imaging” of <span class="hlt">dynamic</span> (population) grating and 27-step phase-cycling to extract the signal. This arrangement obviates the need for distinct experimental designs for previously developed transmission detected non-collinear two-dimensional coherent spectroscopy (2D-CS) and collinear 2D-FDCS. We also describe a novel method for <span class="hlt">absolute</span> phasing of the 2D spectrum. We apply this method to record 2D spectra of a fluorescent dye in solution at room temperature and observe “spectral diffusion.”.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/456978','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/456978"><span id="translatedtitle">Fluorescence of excited charge-transfer complexes and <span class="hlt">absolute</span> <span class="hlt">dynamics</span> of radical-ion pairs in acetonitrile</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gould, I.R.; Farid, S.</p> <p>1992-09-17</p> <p>An analysis of the <span class="hlt">dynamics</span> of the radical-ion pairs of a series of 2,6,9,10-tetracyanoanthracene acceptor/alkylbenzene donor systems in acetonitrile is described in this paper. This analysis is carried out by using a combination of time-resolved emission and absorption spectroscopies and measurements of {Phi} {sub ions} from the contact radical-ion pair (CRIP) and the solvent-separated radical-ion pair (SSRIP).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SGeo...35..661J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SGeo...35..661J"><span id="translatedtitle">Toward Improved Estimation of the <span class="hlt">Dynamic</span> <span class="hlt">Topography</span> and Ocean Circulation in the High Latitude and Arctic Ocean: The Importance of GOCE</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Johannessen, J. A.; Raj, R. P.; Nilsen, J. E. Ø.; Pripp, T.; Knudsen, P.; Counillon, F.; Stammer, D.; Bertino, L.; Andersen, O. B.; Serra, N.; Koldunov, N.</p> <p>2014-05-01</p> <p>The Arctic plays a fundamental role in the climate system and shows significant sensitivity to anthropogenic climate forcing and the ongoing climate change. Accelerated changes in the Arctic are already observed, including elevated air and ocean temperatures, declines of the summer sea ice extent and sea ice thickness influencing the albedo and CO2 exchange, melting of the Greenland Ice Sheet and increased thawing of surrounding permafrost regions. In turn, the hydrological cycle in the high latitude and Arctic is expected to undergo changes although to date it is challenging to accurately quantify this. Moreover, changes in the temperature and salinity of surface waters in the Arctic Ocean and Nordic Seas may also influence the flow of dense water through the Denmark Strait, which are found to be a precursor for changes in the Atlantic meridional overturning circulation with a lead time of around 10 years (Hawkins and Sutton in Geophys Res Lett 35:L11603, 2008). Evidently changes in the Arctic and surrounding seas have far reaching influences on regional and global environment and climate variability, thus emphasizing the need for advanced quantitative understanding of the ocean circulation and transport variability in the high latitude and Arctic Ocean. In this respect, this study combines in situ hydrographical data, surface drifter data and direct current meter measurements, with coupled sea ice-ocean models, radar altimeter data and the latest GOCE-based geoid in order to estimate and assess the quality, usefulness and validity of the new GOCE-derived mean <span class="hlt">dynamic</span> <span class="hlt">topography</span> for studies of the ocean circulation and transport estimates in the Nordic Seas and Arctic Ocean.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14...31V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14...31V"><span id="translatedtitle">A first outlook of GOCE contribution to the determination of the <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span> and ocean circulation in the Mediterranean Sea</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vergos, G. S.; Tziavos, I. N.</p> <p>2012-04-01</p> <p>The exploitation of altimetric data sets from past and current satellite missions is crucial to both oceanographic and geodetic applications, since it allows the determination of sea level anomalies as deviations from a static mean sea level, while it is also fundamental for marine geoid determination. In this work, altimetric data sets from the satellite missions of JASON1 and ENVISAT have been used towards the determination of Mean Sea Surface (MSS) models in the Mediterranean Sea. The raw data used are Sea Level Anomaly (SLA) values and their total inverse barometer corrections from the respective altimetric missions. Along-track records of the SLA have been first used to derive linear trends of the SLA variation in the area under study and then determine empirical covariance functions to estimate single and multi-satellite models of the mean sea surface through least squares collocation. The latter is then employed along with the GOCE/GRACE GOCO02s GGM in order to estimate the <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span> (DOT) in the Mediterranean Sea and consequently the steady-state circulation in the area. The resulting initial DOT estimates are treated through various filters in order to remove high-frequency information that results from computing the residuals between the high-resolution MSS and the lower resolution GOCE geoid heights (degree and order 250 corresponding to ~80 km). To this respect three types of filters are used, namely boxcar, Gaussian and Wiener ones employing various spatial wavelengths for the filter width to accommodate their cut-off frequency. The finally derived solutions presented refer to filters with spatial wavelengths set to 150 km and 200 km (75 km and 100 half-wavelength, respectively), which are used to determine the steady-state circulation in the Mediterranean Sea. The results are validated against the RioMed model for the DOT, the DTU2010 DOT and a solution based on the DTU2010 MSS and GOCO02s.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..1413998B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..1413998B"><span id="translatedtitle">Open<span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baru, C.; Arrowsmith, R.; Crosby, C.; Nandigam, V.; Phan, M.; Cowart, C.</p> <p>2012-04-01</p> <p>Open<span class="hlt">Topography</span> is a cyberinfrastructure-based facility for online access to high-resolution <span class="hlt">topography</span> and tools. The project is an outcome of the Geosciences Network (GEON) project, which was a research project funded several years ago in the US to investigate the use of cyberinfrastructure to support research and education in the geosciences. Open<span class="hlt">Topography</span> provides online access to large LiDAR point cloud datasets along with services for processing these data. Users are able to generate custom DEMs by invoking DEM services provided by Open<span class="hlt">Topography</span> with custom parameter values. Users can track the progress of their jobs, and a private myOpenTopo area retains job information and job outputs. Data available at Open<span class="hlt">Topography</span> are provided by a variety of data acquisition groups under joint agreements and memoranda of understanding (MoU). These include national facilities such as the National Center for Airborne Lidar Mapping, as well as local, state, and federal agencies. Open<span class="hlt">Topography</span> is also being designed as a hub for high-resolution <span class="hlt">topography</span> resources. Datasets and services available at other locations can also be registered here, providing a "one-stop shop" for such information. We will describe the Open<span class="hlt">Topography</span> system architecture and its current set of features, including the service-oriented architecture, a job-tracking database, and social networking features. We will also describe several design and development activities underway to archive and publish datasets using digital object identifiers (DOIs); create a more flexible and scalable high-performance environment for processing of large datasets; extend support for satellite-based and terrestrial lidar as well as synthetic aperture radar (SAR) data; and create a "pluggable" infrastructure for third-party services. Open<span class="hlt">Topography</span> has successfully created a facility for sharing lidar data. In the next phase, we are developing a facility that will also enable equally easy and successful sharing of services related to these data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=value&pg=4&id=EJ1000865','ERIC'); return false;" href="http://eric.ed.gov/?q=value&pg=4&id=EJ1000865"><span id="translatedtitle">Teaching <span class="hlt">Absolute</span> Value Meaningfully</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Wade, Angela</p> <p>2012-01-01</p> <p>What is the meaning of <span class="hlt">absolute</span> value? And why do teachers teach students how to solve <span class="hlt">absolute</span> value equations? <span class="hlt">Absolute</span> value is a concept introduced in first-year algebra and then reinforced in later courses. Various authors have suggested instructional methods for teaching <span class="hlt">absolute</span> value to high school students (Wei 2005; Stallings-Roberts…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001SPIE.4419...50M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001SPIE.4419...50M"><span id="translatedtitle">Moire <span class="hlt">topography</span> in odontology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moreno Yeras, A.</p> <p>2001-08-01</p> <p>For several decades measurement optical techniques have been used in different branches of Science and Technology and in medicine. One of these techniques is the so-called Moire <span class="hlt">topography</span> that allows the accurate measurement of different parts of the human body <span class="hlt">topography</span>. This investigation presents the measurement of <span class="hlt">topographies</span> of teeth and gums using an automated system of shadow moire, with which precision can be reached up to the order of the microns by the phase shift instrumentation in an original way. Advantages and disadvantages of using the Moire <span class="hlt">topography</span> and its comparison with other techniques used in the optical metrology are presented. Also, some positive and negative aspects of the implementation of this technique are shown in dentistry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1714981I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1714981I"><span id="translatedtitle">Post-fire Vegetation Regeneration <span class="hlt">Dynamics</span> to <span class="hlt">Topography</span> and Burn Severity in two contrasting ecosystems: the Case of the Montane Cordillera Ecozones of Western Canada & that of a Typical Mediterranean site in Greece</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ireland, Gareth; Petropoulos, George P.; Kalivas, Dionissios; Griffirths, Hywel M.; Louka, Panagiota</p> <p>2015-04-01</p> <p>Altering land cover <span class="hlt">dynamics</span> is currently regarded as the single most important variable of global change affecting ecological systems. Wildfires are an integral part of many terrestrial ecosystems and are considered to dramatically affect land cover <span class="hlt">dynamics</span> at a variety of spatial and temporal scales. In this context, knowledge of the spatio-temporal distribution of post-fire vegetation recovery <span class="hlt">dynamics</span> is of key importance. In this study, we explore the relationships between vegetation recovery <span class="hlt">dynamics</span> to <span class="hlt">topography</span> and burn severity for two different ecosystems using a chronosequence of Landsat TM data images analysis. One of our experimental sites is the Okanagan Mountain Park, located in the Montane Cordillera Ecozones of western Canada at which a fire occurred in 2003. The other is Mt. Parnitha, located in Greece, representing a typical Mediterranean setting. The spatio-temporal patterns of regrowth for 8 years following the fire events were quantified based on the analysis of 2 widely used indices, the Normalized Difference Vegetation Index (NDVI) and the Regeneration Index (RI). Burn severity was derived from the differenced Normalized Burn Ratio (dNBR) index computed from the Landsat TM images. Topographical information for the studied area was obtained from the ASTER global operational product. Relationships of vegetation regrowth to both <span class="hlt">topography</span> and burn severity was quantified using a series of additional statistical metrics. In overall, results indicated noticeable differences in the recovery rates of both ecosystems to the pre-fire patterns. Re-growth rates appeared to be somewhat higher in north-facing slopes in comparison to south facing ones for both experimental sites, in common with other similar studies in different ecosystems. Lastly, areas of lower burn severity exhibited a higher recovery rate compared to areas of high severity burns. Results are presented in detail and an explanation of the main observation trends is also attempted to be provided. To our knowledge, this study is one of the few attempting to explore the relationships between post-fire vegetation regrowth and <span class="hlt">topography</span> or burn severity, particularly so in such a comparative and systematic manner between two contrasting ecosystem types. It corroborates the significance of EO technology as a successful and cost-effective solution in providing information related to post-fire regeneration assessment. Keywords: post-fire vegetation regeneration, <span class="hlt">topography</span>, burn severity, Landsat, remote sensing, Cordillera Ecozones, Canada, Mt. Parnitha, Greece</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JVGR..310..172S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JVGR..310..172S"><span id="translatedtitle">The oscillation model of hydrothermal <span class="hlt">dynamics</span> beneath Aso volcano, southwest Japan after small eruption on May 2011: A new understanding model using repeated <span class="hlt">absolute</span> and relative gravity measurement</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sofyan, Yayan; Nishijima, Jun; Fujimitsu, Yasuhiro; Yoshikawa, Shin; Kagiyama, Tsuneomi; Ohkura, Takahiro</p> <p>2016-01-01</p> <p>At the end of 2010, the seismic activity in Aso volcano intensely increased and water level in the Nakadake crater decreased until early in 2011, then was followed by a small eruption in May 2011. After the eruption and heavy rain, the volcanic activity subsided to calm period, crater bottom was refilled with water, and water level increased in the Nakadake crater. The next tremor reappeared in 2014 and tracked to eruption in November 2014. This eruptive pattern and water level variation in the crater repeatedly appeared on the surface, and it should be related to the hydrothermal <span class="hlt">dynamics</span> beneath Aso volcano. We initiated the gravity measurements in relation to hydrothermal <span class="hlt">dynamics</span> in the subsurface of Aso volcano using Scintrex CG-5 (549) and LaCoste Romberg type G-1016 relative gravimeter at 28 benchmarks in April 2011, one month before the eruption. The repeated gravity measurements continue to monitor Aso volcano with a series of the measurement after the eruption in every three months to a half year. We analyze the gravity variation from 2011 to 2014 between the time of the phreatic and strombolian eruption. The measurements covered the area more than 60 km2 in the west side of Aso caldera. A new gravity network was also installed in May 2010 at seven benchmarks using A10-017 <span class="hlt">absolute</span> gravimeter, which re-occupied in October 2010, June 2011 and two benchmarks in June 2014. As a result, the gravity changes distinguish hydrothermal <span class="hlt">dynamic</span> in the subsurface, which has a direct correlation to water level fluctuation in the crater, after the first eruption and before the second discharge. The monitoring data notice large gravity changes between the surveys at benchmarks around Nakadake crater and Kusasenri area. The simple 3D inversion models of the 4-D gravity data deduce the density contrast distribution beneath Aso volcano. The inversion and mass change result generate the oscillation typical as a new understanding model. The variation of the mass shows a similar trend with the hydrothermal input rate to the crater of past research. The third year monitoring from April 2013 displays a large gravity and mass variation, while precipitation data in this period is smaller than the previous season. The largest increased mass about 43 million tons by Gaussian method occurred between May 2013 and September 2013. According to the three year gravity monitoring, the calm period in Aso volcano happens after May 2011 eruption until September 2013, which is followed by the active period, before the November 2014 eruption. This result will contribute to understand the process of eruption.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhyA..439....1O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhyA..439....1O"><span id="translatedtitle"><span class="hlt">Absolute</span> negative mobility of interacting Brownian particles</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ou, Ya-li; Hu, Cai-tian; Wu, Jian-chun; Ai, Bao-quan</p> <p>2015-12-01</p> <p>Transport of interacting Brownian particles in a periodic potential is investigated in the presence of an ac force and a dc force. From Brownian <span class="hlt">dynamic</span> simulations, we find that both the interaction between particles and the thermal fluctuations play key roles in the <span class="hlt">absolute</span> negative mobility (the particle noisily moves backwards against a small constant bias). When no the interaction acts, there is only one region where the <span class="hlt">absolute</span> negative mobility occurs. In the presence of the interaction, the <span class="hlt">absolute</span> negative mobility may appear in multiple regions. The weak interaction can be helpful for the <span class="hlt">absolute</span> negative mobility, while the strong interaction has a destructive impact on it.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014P%26SS..102...51W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014P%26SS..102...51W"><span id="translatedtitle">Phobos' shape and <span class="hlt">topography</span> models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Willner, K.; Shi, X.; Oberst, J.</p> <p>2014-11-01</p> <p>The global shape and the <span class="hlt">dynamic</span> environment are fundamental properties of a body. Other properties such as volume, bulk density, and models for the <span class="hlt">dynamic</span> environment can subsequently be computed based on such models. Stereo-photogrammetric methods were applied to derive a global digital terrain model (DTM) with 100 m/pixel resolution using High Resolution Stereo Camera images of the Mars Express mission and Viking Orbiter images. In a subsequent least-squares fit, coefficients of the spherical harmonic function to degree and order 45 are computed. The <span class="hlt">dynamic</span> models for Phobos were derived from a polyhedron representation of the DTM. The DTM, spherical harmonic function model, and <span class="hlt">dynamic</span> models, have been refined and represent Phobos' <span class="hlt">dynamic</span> and geometric <span class="hlt">topography</span> with much more detail when compared to Shi et al. (2012) and Willner et al. (2010) models, respectively. The volume of Phobos has been re-determined to be in the order of 5741 km3 with an uncertainty of only 0.6% of the total volume. This reduces the bulk density to 1.86±0.013 g/cm3 in comparison to previous results. Assuming a homogeneous mass distribution a forced libration amplitude for Phobos of 1.14° is computed that is in better agreement with observations by Willner et al. (2010) than previous estimates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/993087','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/993087"><span id="translatedtitle"><span class="hlt">Absolute</span> nuclear material assay</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.</p> <p>2010-07-13</p> <p>A method of <span class="hlt">absolute</span> nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an <span class="hlt">absolute</span> nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an <span class="hlt">absolute</span> nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1042637','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1042637"><span id="translatedtitle"><span class="hlt">Absolute</span> nuclear material assay</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.</p> <p>2012-05-15</p> <p>A method of <span class="hlt">absolute</span> nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an <span class="hlt">absolute</span> nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an <span class="hlt">absolute</span> nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SSRv..163..487R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SSRv..163..487R"><span id="translatedtitle">The Dawn <span class="hlt">Topography</span> Investigation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Raymond, C. A.; Jaumann, R.; Nathues, A.; Sierks, H.; Roatsch, T.; Preusker, F.; Scholten, F.; Gaskell, R. W.; Jorda, L.; Keller, H.-U.; Zuber, M. T.; Smith, D. E.; Mastrodemos, N.; Mottola, S.</p> <p>2011-12-01</p> <p>The objective of the Dawn <span class="hlt">topography</span> investigation is to derive the detailed shapes of 4 Vesta and 1 Ceres in order to create orthorectified image mosaics for geologic interpretation, as well as to study the asteroids’ landforms, interior structure, and the processes that have modified their surfaces over geologic time. In this paper we describe our approaches for producing shape models, plans for acquiring the needed image data for Vesta, and the results of a numerical simulation of the Vesta mapping campaign that quantify the expected accuracy of our results. Multi-angle images obtained by Dawn’s framing camera will be used to create topographic models with 100 m/pixel horizontal resolution and 10 m height accuracy at Vesta, and 200 m/pixel horizontal resolution and 20 m height accuracy at Ceres. Two different techniques, stereophotogrammetry and stereophotoclinometry, are employed to model the shape; these models will be merged with the asteroidal gravity fields obtained by Dawn to produce geodetically controlled topographic models for each body. The resulting digital <span class="hlt">topography</span> models, together with the gravity data, will reveal the tectonic, volcanic and impact history of Vesta, and enable co-registration of data sets to determine Vesta’s geologic history. At Ceres, the <span class="hlt">topography</span> will likely reveal much about processes of surface modification as well as the internal structure and evolution of this dwarf planet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140010845','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140010845"><span id="translatedtitle">The Dawn <span class="hlt">Topography</span> Investigation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Raymond, C. A.; Jaumann, R.; Nathues, A.; Sierks, H.; Roatsch, T.; Preusker, E; Scholten, F.; Gaskell, R. W.; Jorda, L.; Keller, H.-U.; Zuber, M. T.; Smith, D. E.; Mastrodemos, N.; Mottola, S.</p> <p>2011-01-01</p> <p>The objective of the Dawn <span class="hlt">topography</span> investigation is to derive the detailed shapes of 4 Vesta and 1 Ceres in order to create orthorectified image mosaics for geologic interpretation, as well as to study the asteroids' landforms, interior structure, and the processes that have modified their surfaces over geologic time. In this paper we describe our approaches for producing shape models, plans for acquiring the needed image data for Vesta, and the results of a numerical simulation of the Vesta mapping campaign that quantify the expected accuracy of our results. Multi-angle images obtained by Dawn's framing camera will be used to create topographic models with 100 m/pixel horizontal resolution and 10 m height accuracy at Vesta, and 200 m/pixel horizontal resolution and 20 m height accuracy at Ceres. Two different techniques, stereophotogrammetry and stereophotoclinometry, are employed to model the shape; these models will be merged with the asteroidal gravity fields obtained by Dawn to produce geodetically controlled topographic models for each body. The resulting digital <span class="hlt">topography</span> models, together with the gravity data, will reveal the tectonic, volcanic and impact history of Vesta, and enable co-registration of data sets to determine Vesta's geologic history. At Ceres, the <span class="hlt">topography</span> will likely reveal much about processes of surface modification as well as the internal structure and evolution of this dwarf planet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009ECSS...85..593K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009ECSS...85..593K"><span id="translatedtitle">Exploring LiDAR data for mapping the micro-<span class="hlt">topography</span> and tidal hydro-<span class="hlt">dynamics</span> of mangrove systems: An example from southeast Queensland, Australia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Knight, Jon M.; Dale, Pat E. R.; Spencer, John; Griffin, Lachlan</p> <p>2009-12-01</p> <p>The aim was to explore the use of Light Detection and Ranging (LiDAR) data to map the micro-<span class="hlt">topography</span> of an intertidal wetland in southeast Queensland Australia. The driver for this was the need to identify and map the habitats of the immature stages of an aedine disease vector mosquito ( Aedes vigilax (Skuse)). We derived a high resolution digital elevation model (DEM) data set at a vertical resolution of 0.05 m from LiDAR data. The relative accuracy of the DEM across the site was tested by comparing water depth predictions derived from the DEM against in-situ water depth readings from pressure sensors over a 10-day tidal cycle, which included high spring tides. We found that the field observations of micro-topographic units important for mosquito management matched those delineated from the DEM. The micro-<span class="hlt">topography</span> included a low berm or central ridge that was more or less continuous across the site, a shallow back basin and fringing mangroves. The fringing mangroves had unimpeded connection to the tidal source, however the central ridge blocked tidal water from the back basin for all but the highest tides. Eggshell survey indicated that the back basin was the area suitable for immature mosquitoes. We conclude that LiDAR data has application for understanding and mapping the structure of mangrove wetlands. We have also demonstrated (in a small area) that LiDAR is useful for modelling the effect of sea level changes on the coastal fringe. LiDAR may be the only method to inform research on changes to land use and ecosystems caused by sea level change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8209E..1US','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8209E..1US"><span id="translatedtitle">Toward optical coherence <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sayegh, Samir; Jiang, Yanshui</p> <p>2012-03-01</p> <p>Commercial OCT systems provide pachymetry measurements. Full corneal topographic information of anterior and posterior corneal surfaces for use in cataract surgery and refractive procedures is a desirable goal and would add to the usefulness of anterior and posterior segment evaluation. While substantial progress has been made towards obtaining "average" central corneal power (D Huang), power in different meridians and <span class="hlt">topography</span> are still missing. This is usually reported to be due to eye movement. We analyze the role of centration, eye movements and develop a model that allows for the formulation of criteria for obtaining reliable topographic data within ¼ diopter.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996AAS...189.4511R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996AAS...189.4511R"><span id="translatedtitle">Supernova <span class="hlt">Absolute</span> Magnitude Distributions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Richardson, D.; Branch, D.; Casebeer, D.; Deaton, J.; Baron, E.</p> <p>1996-12-01</p> <p>We have extended the 1990 study of supernova <span class="hlt">absolute</span>-magnitude distributions by Miller and Branch. Supernova apparent magnitudes are taken from an updated version of the Asiago Supernova Catalog. Where possible, distances are based on Cepheid variables in the SN parent galaxy or a galaxy in the same group; otherwise re-scaled distances from the Nearby Galaxies Catalog, or Hubble-Law distances (for SNe with recession velocities that aren't too small), are used. Mean <span class="hlt">absolute</span> magnitudes, dispersions, and other characteristics of the observational <span class="hlt">absolute</span>-magnitude distributions of each of the SN types will be presented. A preliminary model for the statistical distribution of extinction in the parent galaxies, for each of the SN types, is used to estimate the form of the extinction-free <span class="hlt">absolute</span> magnitude distributions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23586876','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23586876"><span id="translatedtitle"><span class="hlt">Absolute</span> biological needs.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>McLeod, Stephen</p> <p>2014-07-01</p> <p><span class="hlt">Absolute</span> needs (as against instrumental needs) are independent of the ends, goals and purposes of personal agents. Against the view that the only needs are instrumental needs, David Wiggins and Garrett Thomson have defended <span class="hlt">absolute</span> needs on the grounds that the verb 'need' has instrumental and <span class="hlt">absolute</span> senses. While remaining neutral about it, this article does not adopt that approach. Instead, it suggests that there are <span class="hlt">absolute</span> biological needs. The <span class="hlt">absolute</span> nature of these needs is defended by appeal to: their objectivity (as against mind-dependence); the universality of the phenomenon of needing across the plant and animal kingdoms; the impossibility that biological needs depend wholly upon the exercise of the abilities characteristic of personal agency; the contention that the possession of biological needs is prior to the possession of the abilities characteristic of personal agency. Finally, three philosophical usages of 'normative' are distinguished. On two of these, to describe a phenomenon or claim as 'normative' is to describe it as value-dependent. A description of a phenomenon or claim as 'normative' in the third sense does not entail such value-dependency, though it leaves open the possibility that value depends upon the phenomenon or upon the truth of the claim. It is argued that while survival needs (or claims about them) may well be normative in this third sense, they are normative in neither of the first two. Thus, the idea of <span class="hlt">absolute</span> need is not inherently normative in either of the first two senses. PMID:23586876</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050170605','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050170605"><span id="translatedtitle">RADAR Reveals Titan <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kirk, R. L.; Callahan, P.; Seu, R.; Lorenz, R. D.; Paganelli, F.; Lopes, R.; Elachi, C.</p> <p>2005-01-01</p> <p>The Cassini Titan RADAR Mapper is a K(sub u)-band (13.78 GHz, lambda = 2.17 cm) linear polarized RADAR instrument capable of operating in synthetic aperture (SAR), scatterometer, altimeter and radiometer modes. During the first targeted flyby of Titan on 26 October, 2004 (referred to as Ta) observations were made in all modes. Evidence for topographic relief based on the Ta altimetry and SAR data are presented here. Additional SAR and altimetry observations are planned for the T3 encounter on 15 February, 2005, but have not been carried out at this writing. Results from the T3 encounter relevant to <span class="hlt">topography</span> will be included in our presentation. Data obtained in the Ta encounter include a SAR image swath</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA00740&hterms=Dark+web&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DDark%2Bweb','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA00740&hterms=Dark+web&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DDark%2Bweb"><span id="translatedtitle"><span class="hlt">Topography</span> of Io (color)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1997-01-01</p> <p>The images used to create this color composite of Io were acquired by Galileo during its ninth orbit (C9) of Jupiter and are part of a sequence of images designed to map the <span class="hlt">topography</span> or relief on Io and to monitor changes in the surface color due to volcanic activity. Obtaining images at low illumination angles is like taking a picture from a high altitude around sunrise or sunset. Such lighting conditions emphasize the <span class="hlt">topography</span> of the volcanic satellite. Several mountains up to a few miles high can be seen in this view, especially near the upper right. Some of these mountains appear to be tilted crustal blocks. Most of the dark spots correspond to active volcanic centers.<p/>North is to the top of the picture which merges images obtained with the clear, red, green, and violet filters of the solid state imaging (CCD) system on NASA's Galileo spacecraft. . The resolution is 8.3 kilometers per picture element. The image was taken on June 27, 1997 at a range of 817,000 kilometers by the solid state imaging (CCD) system on NASA's Galileo spacecraft.<p/>The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).<p/>This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20000110271&hterms=statistics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dstatistics','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20000110271&hterms=statistics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dstatistics"><span id="translatedtitle">Implications of MOLA Global Roughness, Statistics, and <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Aharonson, O.; Zuber, M. T.; Neumann, G. A.</p> <p>1999-01-01</p> <p>New insights are emerging as the ongoing high-quality measurements of the Martian surface <span class="hlt">topography</span> by Mars Orbiter Laser Altimeter (MOLA) on board the Mars Global Surveyor (MGS) spacecraft increase in coverage, resolution, and diversity. For the first time, a global characterization of the statistical properties of <span class="hlt">topography</span> is possible. The data were collected during the aerobreaking hiatus, science phasing, and mapping orbits of MGS, and have a resolution of 300-400 m along track, a range resolution of 37.5 cm, a range precision of 1-10 m for surface slopes up to 30 deg., and an <span class="hlt">absolute</span> accuracy of <span class="hlt">topography</span> of 13 m. The spacecraft's orbit inclination dictates that nadir observations have latitude coverage of about 87.1S to 87.1N; the addition of observations obtained during a period of off-nadir pointing over the north pole extended coverage to 90N. Additional information is contained in the original extended abstract.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23757308','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23757308"><span id="translatedtitle"><span class="hlt">Absolute</span> pitch may not be so <span class="hlt">absolute</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hedger, Stephen C; Heald, Shannon L M; Nusbaum, Howard C</p> <p>2013-08-01</p> <p>Most people cannot name the musical note that corresponds to a particular pitch without being provided a reference note, but those people with <span class="hlt">absolute</span> pitch (AP) can do this accurately. Early experience during a developmental period is often thought to convey identity and stability of the note categories in people with AP, but the plasticity of these categories has not been investigated. Here we provide the first evidence that the note categories of adults with AP can change with listening experience. Participants with AP showed shifts in perception in direct accord with prior exposure to music detuned by a fraction of a semitone. This suggests that the apparent stability of AP categories is conferred not by early experience but rather by the cultural norms adopted for tuning music. PMID:23757308</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4028274','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4028274"><span id="translatedtitle">Lake <span class="hlt">Topography</span> and Wind Waves Determining Seasonal-Spatial <span class="hlt">Dynamics</span> of Total Suspended Matter in Turbid Lake Taihu, China: Assessment Using Long-Term High-Resolution MERIS Data</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhang, Yunlin; Shi, Kun; Liu, Xiaohan; Zhou, Yongqiang; Qin, Boqiang</p> <p>2014-01-01</p> <p>Multiple comprehensive in situ bio-optical investigations were conducted from 2005 to 2010 and covered a large variability of total suspended matter (TSM) in Lake Taihu to calibrate and validate a TSM concentration estimation model based on Medium Resolution Imaging Spectrometer (MERIS) data. The estimation model of the TSM concentration in Lake Taihu was developed using top-of-atmosphere (TOA) radiance of MERIS image data at band 9 in combination with a regional empirical atmospheric correction model, which was strongly correlated with the in situ TSM concentration (r2 = 0.720, p<0.001, and n = 73). The relative root mean square error (RRMSE) and mean relative error (MRE) were 36.9% and 31.6%, respectively, based on an independent validation dataset that produced reliable estimations of the TSM concentration. The developed algorithm was applied to 50 MERIS images from 2003 to 2011 to obtain a high spatial and temporal heterogeneity of TSM concentrations in Lake Taihu. Seasonally, the highest and lowest TSM concentrations were found in spring and autumn, respectively. Spatially, TSM concentrations were high in the southern part and center of the lake and low in Xukou Bay, East Lake Taihu. The lake <span class="hlt">topography</span>, including the water depth and distance from the shore, had a significant effect on the TSM spatial distribution. A significant correlation was found between the daily average wind speed and TSM concentration (r2 = 0.685, p<0.001, and n = 50), suggesting a critical role of wind speed in the TSM variations in Lake Taihu. In addition, a low TSM concentration was linked to the appearance of submerged aquatic vegetation (SAV). Therefore, TSM <span class="hlt">dynamics</span> were controlled by the lake <span class="hlt">topography</span>, wind-driven sediment resuspension and SAV distribution. PMID:24846206</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4315668','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4315668"><span id="translatedtitle"><span class="hlt">Absolute</span> Quantitation of Myocardial Blood Flow in Human Subjects with or without Myocardial Ischemia using <span class="hlt">Dynamic</span> Flurpiridaz F 18 Positron Emission Tomography</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Packard, René R. S.; Huang, Sung-Cheng; Dahlbom, Magnus; Czernin, Johannes; Maddahi, Jamshid</p> <p>2015-01-01</p> <p><span class="hlt">Absolute</span> quantitation of myocardial blood flow (MBF) by positron emission tomography (PET) is an established method of analyzing coronary artery disease (CAD) but subject to the various shortcomings of available radiotracers. Flurpiridaz F 18 is a novel PET radiotracer which exhibits properties of an ideal tracer. Methods A new <span class="hlt">absolute</span> perfusion quantitation method with Flurpiridaz was developed, taking advantage of the early kinetics and high first-pass extraction by the myocardium of this radiotracer, and the first in human measurements of MBF performed in 7 normal subjects and 8 patients with documented CAD. PET images with time-activity curves were acquired at rest and during adenosine stress. Results In normal subjects, regional MBF between coronary artery territories did not differ significantly, leading to a mean global MBF of 0.73 mL/min/g at rest and 2.53 mL/min/g during stress, with a mean global myocardial flow reserve (MFR) of 3.70. CAD vascular territories with <50% stenosis demonstrated a mean MBF of 0.73 at rest and 2.02 during stress, leading to a mean MFR of 2.97. CAD vascular territories with ≥50% stenosis exhibited a mean MBF of 0.86 at rest and 1.43 during stress, leading to a mean MFR of 1.86. Differences in stress MBF and MFR between normal and CAD territories, as well as between <50% and ≥50% stenosis vascular territories, were significant (P<0.01). Conclusion <span class="hlt">Absolute</span> quantitation of MBF in humans with the novel PET radiotracer Flurpiridaz is feasible over a wide range of cardiac flow in the presence or absence of stress-inducible myocardial ischemia. The significant decrease in stress MBF and ensuing MFR in CAD territories allows a clear distinction between vascular territories exhibiting stress-inducible myocardial ischemia and those with normal perfusion. PMID:25071096</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1231575-absolute-path-command','SCIGOV-ESTSC'); return false;" href="http://www.osti.gov/scitech/biblio/1231575-absolute-path-command"><span id="translatedtitle">The <span class="hlt">absolute</span> path command</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech/">Energy Science and Technology Software Center (ESTSC)</a></p> <p></p> <p>2012-05-11</p> <p>The ap command traveres all symlinks in a given file, directory, or executable name to identify the final <span class="hlt">absolute</span> path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it canmore » provide the <span class="hlt">absolute</span> path to a relative directory from the current working directory.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRE..120..287J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRE..120..287J"><span id="translatedtitle">Support of long-wavelength <span class="hlt">topography</span> on Mercury inferred from MESSENGER measurements of gravity and <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>James, Peter B.; Zuber, Maria T.; Phillips, Roger J.; Solomon, Sean C.</p> <p>2015-02-01</p> <p>To explore the mechanisms of support of surface <span class="hlt">topography</span> on Mercury, we have determined the admittances and correlations of <span class="hlt">topography</span> and gravity in Mercury's northern hemisphere from measurements obtained by NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft. These admittances and correlations can be interpreted in the context of a number of theoretical scenarios, including flexural loading and <span class="hlt">dynamic</span> flow. We find that long-wavelength (spherical harmonic degree l < 15) surface <span class="hlt">topography</span> on Mercury is primarily supported through a combination of crustal thickness variations and deep mass anomalies. The deep mass anomalies may be interpreted either as lateral variations in mantle density or as relief on compositional interfaces. Domical topographic swells are associated with high admittances and are compensated at 300-400 km depth in the lower reaches of Mercury's mantle. Quasi-linear topographic rises are primarily associated with shallow crustal compensation and are weakly correlated with positive mass anomalies in the mantle. The center of the Caloris basin features some of the thinnest crust on the planet, and the basin is underlain by a large negative mass anomaly. We also explore models of <span class="hlt">dynamic</span> flow in the presence of compositional stratification above the liquid core. If there is substantial compositional stratification in Mercury's solid outer shell, relaxation of perturbed compositional interfaces may be capable of creating and sustaining long-wavelength <span class="hlt">topography</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19940007593&hterms=Gravity+Mars&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DGravity%2BMars','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19940007593&hterms=Gravity+Mars&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DGravity%2BMars"><span id="translatedtitle">Spectral analysis of the gravity and <span class="hlt">topography</span> of Mars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bills, Bruce G.; Frey, Herbert V.; Kiefer, Walter S.; Nerem, R. Steven; Zuber, Maria T.</p> <p>1993-01-01</p> <p>New spherical harmonic models of the gravity and <span class="hlt">topography</span> of Mars place important constraints on the structure and <span class="hlt">dynamics</span> of the interior. The gravity and <span class="hlt">topography</span> models are significantly phase coherent for harmonic degrees n less than 30 (wavelengths greater than 700 km). Loss of coherence below that wavelength is presumably due to inadequacies of the models, rather than a change in behavior of the planet. The gravity/<span class="hlt">topography</span> admittance reveals two very different spectral domains: for n greater than 4, a simple Airy compensation model, with mean depth of 100 km, faithfully represents the observed pattern; for degrees 2 and 3, the effective compensation depths are 1400 and 550 km, respectively, strongly arguing for <span class="hlt">dynamic</span> compensation at those wavelengths. The gravity model has been derived from a reanalysis of the tracking data for Mariner 9 and the Viking Orbiters, The <span class="hlt">topography</span> model was derived by harmonic analysis of the USGS digital elevation model of Mars. Before comparing gravity and <span class="hlt">topography</span> for internal structure inferences, we must ensure that both are consistently referenced to a hydrostatic datum. For the gravity, this involves removal of hydrostatic components of the even degree zonal coefficients. For the <span class="hlt">topography</span>, it involves adding the degree 4 equipotential reference surface, to get spherically referenced values, and then subtracting the full degree 50 equipotential. Variance spectra and phase coherence of orthometric heights and gravity anomalies are addressed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060043634&hterms=topography&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dtopography','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060043634&hterms=topography&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dtopography"><span id="translatedtitle">Satellite remote sensing of landscape freeze/thaw state <span class="hlt">dynamics</span> for complex <span class="hlt">Topography</span> and Fire Disturbance Areas Using multi-sensor radar and SRTM digital elevation models</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Podest, Erika; McDonald, Kyle; Kimball, John; Randerson, James</p> <p>2003-01-01</p> <p>We characterize differences in radar-derived freeze/thaw state, examining transitions over complex terrain and landscape disturbance regimes. In areas of complex terrain, we explore freezekhaw <span class="hlt">dynamics</span> related to elevation, slope aspect and varying landcover. In the burned regions, we explore the timing of seasonal freeze/thaw transition as related to the recovering landscape, relative to that of a nearby control site. We apply in situ biophysical measurements, including flux tower measurements to validate and interpret the remotely sensed parameters. A multi-scale analysis is performed relating high-resolution SAR backscatter and moderate resolution scatterometer measurements to assess trade-offs in spatial and temporal resolution in the remotely sensed fields.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JMoSt.966...18J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JMoSt.966...18J"><span id="translatedtitle"><span class="hlt">Absolute</span> configuration of neostenine</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jiang, Ren-Wang; Ye, Wencai; Shaw, Pang-Chui; But, Paul Pui-Hay; Mak, Thomas C. W.</p> <p>2010-03-01</p> <p>Heavy atoms bromine and iodine were incorporated into the neostenine ( 1) skeleton through reductive cleavage of the lactone ring, followed by acylation with 4-bromobenzoyl chloride, and salt formation with methyl iodide, respectively. The <span class="hlt">absolute</span> configuration of the seven chiral centers C1, C9, C9a, C10, C11, C1 and C13 in 1 were assigned as S, S, R, R, R, R, and S, respectively, based on the Flack parameters in X-ray structure refinement, and results from the two heavy atom derivatives are consistent with each other. As many Stemona alkaloids share the same lactone and pyrrolo[1,2-α]azepine nucleus as those in 1, the facile method reported in this paper can be applied for the determination of <span class="hlt">absolute</span> configurations of similar alkaloids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26022836','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26022836"><span id="translatedtitle"><span class="hlt">Absolutely</span> relative or relatively <span class="hlt">absolute</span>: violations of value invariance in human decision making.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Teodorescu, Andrei R; Moran, Rani; Usher, Marius</p> <p>2016-02-01</p> <p>Making decisions based on relative rather than <span class="hlt">absolute</span> information processing is tied to choice optimality via the accumulation of evidence differences and to canonical neural processing via accumulation of evidence ratios. These theoretical frameworks predict invariance of decision latencies to <span class="hlt">absolute</span> intensities that maintain differences and ratios, respectively. While information about the <span class="hlt">absolute</span> values of the choice alternatives is not necessary for choosing the best alternative, it may nevertheless hold valuable information about the context of the decision. To test the sensitivity of human decision making to <span class="hlt">absolute</span> values, we manipulated the intensities of brightness stimuli pairs while preserving either their differences or their ratios. Although asked to choose the brighter alternative relative to the other, participants responded faster to higher <span class="hlt">absolute</span> values. Thus, our results provide empirical evidence for human sensitivity to task irrelevant <span class="hlt">absolute</span> values indicating a hard-wired mechanism that precedes executive control. Computational investigations of several modelling architectures reveal two alternative accounts for this phenomenon, which combine <span class="hlt">absolute</span> and relative processing. One account involves accumulation of differences with activation dependent processing noise and the other emerges from accumulation of <span class="hlt">absolute</span> values subject to the temporal <span class="hlt">dynamics</span> of lateral inhibition. The potential adaptive role of such choice mechanisms is discussed. PMID:26022836</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110013051','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110013051"><span id="translatedtitle">Electronic <span class="hlt">Absolute</span> Cartesian Autocollimator</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Leviton, Douglas B.</p> <p>2006-01-01</p> <p>An electronic <span class="hlt">absolute</span> Cartesian autocollimator performs the same basic optical function as does a conventional all-optical or a conventional electronic autocollimator but differs in the nature of its optical target and the manner in which the position of the image of the target is measured. The term <span class="hlt">absolute</span> in the name of this apparatus reflects the nature of the position measurement, which, unlike in a conventional electronic autocollimator, is based <span class="hlt">absolutely</span> on the position of the image rather than on an assumed proportionality between the position and the levels of processed analog electronic signals. The term Cartesian in the name of this apparatus reflects the nature of its optical target. Figure 1 depicts the electronic functional blocks of an electronic <span class="hlt">absolute</span> Cartesian autocollimator along with its basic optical layout, which is the same as that of a conventional autocollimator. Referring first to the optical layout and functions only, this or any autocollimator is used to measure the compound angular deviation of a flat datum mirror with respect to the optical axis of the autocollimator itself. The optical components include an illuminated target, a beam splitter, an objective or collimating lens, and a viewer or detector (described in more detail below) at a viewing plane. The target and the viewing planes are focal planes of the lens. Target light reflected by the datum mirror is imaged on the viewing plane at unit magnification by the collimating lens. If the normal to the datum mirror is parallel to the optical axis of the autocollimator, then the target image is centered on the viewing plane. Any angular deviation of the normal from the optical axis manifests itself as a lateral displacement of the target image from the center. The magnitude of the displacement is proportional to the focal length and to the magnitude (assumed to be small) of the angular deviation. The direction of the displacement is perpendicular to the axis about which the mirror is slightly tilted. Hence, one can determine the amount and direction of tilt from the coordinates of the target image on the viewing plane.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3579786','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3579786"><span id="translatedtitle">Comparison of Sum <span class="hlt">Absolute</span> QRST Integral, and Temporal Variability in Depolarization and Repolarization, Measured by <span class="hlt">Dynamic</span> Vectorcardiography Approach, in Healthy Men and Women</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tereshchenko, Larisa G.</p> <p>2013-01-01</p> <p>Background Recently we showed the predictive value of sum <span class="hlt">absolute</span> QRST integral (SAI QRST) and repolarization lability for risk stratification of sudden cardiac death (SCD) in heart failure patients. The goal of this study was to compare SAI QRST and metrics of depolarization and repolarization variability in healthy men and women. Methods Orthogonal ECGs were recorded at rest for 10 minutes in 160 healthy men and women (mean age 39.6±14.6, 80 men). Mean spatial TT′ angle, and normalized variances of T loop area, of spatial T vector amplitude, of QT interval and Tpeak-Tend area were measured for assessment of repolarization lability. Normalized variances of spatial QRS vector and QRS loop area characterized variability of depolarization. In addition, variability indices (VI) were calculated to adjust for normalized heart rate variance. SAI QRST was measured as the averaged arithmetic sum of areas under the QRST curve. Results Men were characterized by shorter QTc (430.3±21.7 vs. 444.7±22.2 ms; P<0.0001) and larger SAI QRST (282.1±66.7 vs.204.9±58.5 mV*ms; P<0.0001). Repolarization lability negatively correlated with spatial T vector amplitude. Adjusted by normalized heart rate variance, QT variability index was significantly higher in women than in men (−1.54±0.38 vs. −1.70±0.33; P = 0.017). However, in multivariate logistic regression after adjustment for body surface area, QTc, and spatial T vector amplitude, healthy men had 1.5–3 fold higher probability of having larger repolarization lability, as compared to healthy women (T vector amplitude variability index odds ratio 3.88(95%CI 1.4–11.1; P = 0.012). Conclusions Healthy men more likely than women have larger repolarization lability. PMID:23451181</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890000284&hterms=absolute+stability&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dabsolute%2Bstability','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890000284&hterms=absolute+stability&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dabsolute%2Bstability"><span id="translatedtitle"><span class="hlt">Absolute</span> Stability And Hyperstability In Hilbert Space</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wen, John Ting-Yung</p> <p>1989-01-01</p> <p>Theorems on stabilities of feedback control systems proved. Paper presents recent developments regarding theorems of <span class="hlt">absolute</span> stability and hyperstability of feedforward-and-feedback control system. Theorems applied in analysis of nonlinear, adaptive, and robust control. Extended to provide sufficient conditions for stability in system including nonlinear feedback subsystem and linear time-invariant (LTI) feedforward subsystem, state space of which is Hilbert space, and input and output spaces having finite numbers of dimensions. (In case of <span class="hlt">absolute</span> stability, feedback subsystem memoryless and possibly time varying. For hyperstability, feedback system <span class="hlt">dynamical</span> system.)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21055221','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21055221"><span id="translatedtitle"><span class="hlt">Absolute</span> polarimetry at RHIC</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Okada, H.; Saito, N.; Alekseev, I.; Sviridia, D.; Bravar, A.; Gill, R.; Huang, H.; Makdisi, Y.; Nass, A.; Wood, J.; Zelenski, A.; Bunce, G.; Dhawan, S.; Eyser, K. O.; Haeberli, W.; Wise, T.; Jinnouchi, O.; Nakagawa, I.; Stephenson, E.</p> <p>2008-02-06</p> <p>Precise and <span class="hlt">absolute</span> beam polarization measurements are critical for the RHIC spin physics program. Because all experimental spin-dependent results are normalized by beam polarization, the normalization uncertainty contributes directly to final physics uncertainties. We aimed to perform the beam polarization measurement to an accuracy of {delta}P{sub beam}/P{sub beam}<5%. The <span class="hlt">absolute</span> polarimeter consists of Polarized Atomic Hydrogen Gas Jet Target and left-right pairs of silicon strip detectors and was installed in the RHIC-ring in 2004. This system features proton-proton elastic scattering in the Coulomb nuclear interference (CNI) region. Precise measurements of the analyzing power A{sub N} of this process has allowed us to achieve {delta}P{sub beam}/P{sub beam} = 4.2% in 2005 for the first long spin-physics run. In this report, we describe the entire set up and performance of the system. The procedure of beam polarization measurement and analysis results from 2004-2005 are described. Physics topics of A{sub N} in the CNI region (four-momentum transfer squared 0.001<-t<0.032(GeV/c){sup 2}) are also discussed. We point out the current issues and expected optimum accuracy in 2006 and the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/921934','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/921934"><span id="translatedtitle"><span class="hlt">ABSOLUTE</span> POLARIMETRY AT RHIC.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>OKADA; BRAVAR, A.; BUNCE, G.; GILL, R.; HUANG, H.; MAKDISI, Y.; NASS, A.; WOOD, J.; ZELENSKI, Z.; ET AL.</p> <p>2007-09-10</p> <p>Precise and <span class="hlt">absolute</span> beam polarization measurements are critical for the RHIC spin physics program. Because all experimental spin-dependent results are normalized by beam polarization, the normalization uncertainty contributes directly to final physics uncertainties. We aimed to perform the beam polarization measurement to an accuracy Of {Delta}P{sub beam}/P{sub beam} < 5%. The <span class="hlt">absolute</span> polarimeter consists of Polarized Atomic Hydrogen Gas Jet Target and left-right pairs of silicon strip detectors and was installed in the RHIC-ring in 2004. This system features proton-proton elastic scattering in the Coulomb nuclear interference (CNI) region. Precise measurements of the analyzing power A{sub N} of this process has allowed us to achieve {Delta}P{sub beam}/P{sub beam} = 4.2% in 2005 for the first long spin-physics run. In this report, we describe the entire set up and performance of the system. The procedure of beam polarization measurement and analysis results from 2004-2005 are described. Physics topics of AN in the CNI region (four-momentum transfer squared 0.001 < -t < 0.032 (GeV/c){sup 2}) are also discussed. We point out the current issues and expected optimum accuracy in 2006 and the future.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23907862','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23907862"><span id="translatedtitle"><span class="hlt">Absolute</span>-structure reports.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Flack, Howard D</p> <p>2013-08-01</p> <p>All the 139 noncentrosymmetric crystal structures published in Acta Crystallographica Section C between January 2011 and November 2012 inclusive have been used as the basis of a detailed study of the reporting of <span class="hlt">absolute</span> structure. These structure determinations cover a wide range of space groups, chemical composition and resonant-scattering contribution. Defining A and D as the average and difference of the intensities of Friedel opposites, their level of fit has been examined using 2AD and selected-D plots. It was found, regardless of the expected resonant-scattering contribution to Friedel opposites, that the Friedel-difference intensities are often dominated by random uncertainty and systematic error. An analysis of data collection strategy is provided. It is found that crystal-structure determinations resulting in a Flack parameter close to 0.5 may not necessarily be from crystals twinned by inversion. Friedifstat is shown to be a robust estimator of the resonant-scattering contribution to Friedel opposites, very little affected by the particular space group of a structure nor by the occupation of special positions. There is considerable confusion in the text of papers presenting achiral noncentrosymmetric crystal structures. Recommendations are provided for the optimal way of treating noncentrosymmetric crystal structures for which the experimenter has no interest in determining the <span class="hlt">absolute</span> structure. PMID:23907862</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SGeo...37..339P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SGeo...37..339P"><span id="translatedtitle">Toward a High-Resolution Monitoring of Continental Surface Water Extent and <span class="hlt">Dynamics</span>, at Global Scale: from GIEMS (Global Inundation Extent from Multi-Satellites) to SWOT (Surface Water Ocean <span class="hlt">Topography</span>)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prigent, Catherine; Lettenmaier, Dennis P.; Aires, Filipe; Papa, Fabrice</p> <p>2016-03-01</p> <p>Up to now, high-resolution mapping of surface water extent from satellites has only been available for a few regions, over limited time periods. The extension of the temporal and spatial coverage was difficult, due to the limitation of the remote sensing technique [e.g., the interaction of the radiation with vegetation or cloud for visible observations or the temporal sampling with the synthetic aperture radar (SAR)]. The advantages and the limitations of the various satellite techniques are reviewed. The need to have a global and consistent estimate of the water surfaces over long time periods triggered the development of a multi-satellite methodology to obtain consistent surface water all over the globe, regardless of the environments. The Global Inundation Extent from Multi-satellites (GIEMS) combines the complementary strengths of satellite observations from the visible to the microwave, to produce a low-resolution monthly dataset (0.25^circ × 0.25^circ) of surface water extent and <span class="hlt">dynamics</span>. Downscaling algorithms are now developed and applied to GIEMS, using high-spatial-resolution information from visible, near-infrared, and synthetic aperture radar (SAR) satellite images, or from digital elevation models. Preliminary products are available down to 500-m spatial resolution. This work bridges the gaps and prepares for the future NASA/CNES Surface Water Ocean <span class="hlt">Topography</span> (SWOT) mission to be launched in 2020. SWOT will delineate surface water extent estimates and their water storage with an unprecedented spatial resolution and accuracy, thanks to a SAR in an interferometry mode. When available, the SWOT data will be adopted to downscale GIEMS, to produce a long time series of water surfaces at global scale, consistent with the SWOT observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SGeo..tmp...28P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SGeo..tmp...28P"><span id="translatedtitle">Toward a High-Resolution Monitoring of Continental Surface Water Extent and <span class="hlt">Dynamics</span>, at Global Scale: from GIEMS (Global Inundation Extent from Multi-Satellites) to SWOT (Surface Water Ocean <span class="hlt">Topography</span>)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prigent, Catherine; Lettenmaier, Dennis P.; Aires, Filipe; Papa, Fabrice</p> <p>2015-10-01</p> <p>Up to now, high-resolution mapping of surface water extent from satellites has only been available for a few regions, over limited time periods. The extension of the temporal and spatial coverage was difficult, due to the limitation of the remote sensing technique [e.g., the interaction of the radiation with vegetation or cloud for visible observations or the temporal sampling with the synthetic aperture radar (SAR)]. The advantages and the limitations of the various satellite techniques are reviewed. The need to have a global and consistent estimate of the water surfaces over long time periods triggered the development of a multi-satellite methodology to obtain consistent surface water all over the globe, regardless of the environments. The Global Inundation Extent from Multi-satellites (GIEMS) combines the complementary strengths of satellite observations from the visible to the microwave, to produce a low-resolution monthly dataset (0.25° × 0.25°) of surface water extent and <span class="hlt">dynamics</span>. Downscaling algorithms are now developed and applied to GIEMS, using high-spatial-resolution information from visible, near-infrared, and synthetic aperture radar (SAR) satellite images, or from digital elevation models. Preliminary products are available down to 500-m spatial resolution. This work bridges the gaps and prepares for the future NASA/CNES Surface Water Ocean <span class="hlt">Topography</span> (SWOT) mission to be launched in 2020. SWOT will delineate surface water extent estimates and their water storage with an unprecedented spatial resolution and accuracy, thanks to a SAR in an interferometry mode. When available, the SWOT data will be adopted to downscale GIEMS, to produce a long time series of water surfaces at global scale, consistent with the SWOT observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6119079','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6119079"><span id="translatedtitle">Shallow-water flow past isolated <span class="hlt">topography</span>. Part II: Transition to vortex shedding</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schaer, C.; Smith, R.B. )</p> <p>1993-05-15</p> <p>The formation of Karman vortex streets is studied within the framework of single-layer shallow-water <span class="hlt">dynamics</span> and in absence of surface friction and background rotation. In the first part of this study, steady numerical solutions for flow past circular <span class="hlt">topography</span> were obtained by imposing a symmetry condition that essentially suppressed vortex shedding. In the second part, this symmetry condition is relaxed in order to study the transition into the vortex-shedding regime. This transition is due to an instability of the symmetric wake pattern. The most unstable global normal mode of this instability is derived by a numerical method. Most of the features of this mode can be understood in terms of the <span class="hlt">absolute</span> instability theory. The mode is essentially barotropic and relies on a positive feedback between the perturbations located on the two shearlines on either side of the wake. The classical shear modes centered on a single shearline are, on the other hand, shown to be <span class="hlt">absolutely</span> stable even though their convective growth rates are substantial. It is also shown that a recently suggested frequency selection criteria pertaining to <span class="hlt">absolute</span> instabilities in slowly varying shear flow successfully predicts the growth rate of the most unstable global normal mode. Finite-difference numerical simulations are utilized to trace the evolution of the most unstable global normal mode. It is demonstrated that the evolution to finite amplitude of the most unstable global normal mode leads to the breakup of the steady wake into an oscillating Karman vortex street. The frequency of eddy shedding in the numerical simulations agrees well with that from observations of eddies behind mountainous islands. 16 refs., 9 figs., 1 tab.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20040110742','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20040110742"><span id="translatedtitle"><span class="hlt">Absolute</span> Equilibrium Entropy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shebalin, John V.</p> <p>1997-01-01</p> <p>The entropy associated with <span class="hlt">absolute</span> equilibrium ensemble theories of ideal, homogeneous, fluid and magneto-fluid turbulence is discussed and the three-dimensional fluid case is examined in detail. A sigma-function is defined, whose minimum value with respect to global parameters is the entropy. A comparison is made between the use of global functions sigma and phase functions H (associated with the development of various H-theorems of ideal turbulence). It is shown that the two approaches are complimentary though conceptually different: H-theorems show that an isolated system tends to equilibrium while sigma-functions allow the demonstration that entropy never decreases when two previously isolated systems are combined. This provides a more complete picture of entropy in the statistical mechanics of ideal fluids.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011Metro..48..290D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011Metro..48..290D"><span id="translatedtitle">Revisiting <span class="hlt">absolute</span> gravimeter intercomparisons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>de Viron, O.; Van Camp, M.; Francis, O.</p> <p>2011-10-01</p> <p>An <span class="hlt">absolute</span> gravimeter allows us to determine the local value of gravity, which makes its accuracy assessment challenging. The instrumental offsets are classically estimated by performing comparisons of the results obtained by a set of instruments measuring at the same location but at different epochs (measuring at the same place and epoch is physically impossible). Such intercomparison campaigns have been done a few times since 1980. In this paper, we discuss the method of data processing used for those comparisons. We demonstrate that one of the methods used is inadequate, as it underestimates the dispersion of the instrumental offsets, which is the only reliable quantity that can be obtained from such a comparison. We also propose a new criterion, based on the minimization of the L1 norm of the offsets, for fixing the constant of the ill-conditioned problem, which we show to be statistically more precise than the one classically used.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25658956','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25658956"><span id="translatedtitle"><span class="hlt">Absolute</span> Bioavailability of Tasimelteon.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Torres, Rosarelis; Dressman, Marlene A; Kramer, William G; Baroldi, Paolo</p> <p>2015-01-01</p> <p>Tasimelteon is a novel dual melatonin receptor agonist and is the first treatment approved by the US Food and Drug Administration for Non-24-Hour Sleep-Wake Disorder. This study was conducted to assess the <span class="hlt">absolute</span> bioavailability of tasimelteon and to further assess the single-dose pharmacokinetics, safety, and tolerability of oral and intravenous (IV) routes of administration of the drug. This study was an open-label, single-dose, randomized, 2-period, 2-treatment, 2-sequence, crossover study in which 14 healthy volunteers were randomly administered tasimelteon as either a 20-mg capsule or IV administration of 2 mg infused over 30 minutes. Each subject received both treatments in a random order, separated by a washout period of 5 ± 2 days. The total clearance and volume of distribution of tasimelteon, from the IV treatment, were 505 mL per minute and 42.7 L, respectively. Based on the statistical comparison of dose-corrected area under the curve to infinity, the <span class="hlt">absolute</span> bioavailability was 38%, with a 90% confidence interval of 27%-54%. The mean elimination half-life was the same for the oral and IV routes. The exposure ratios, oral-to-IV, for metabolites M9, M11, M12, and M13, were 133.27%, 118.28%, 138.76%, and 112.36%, respectively, suggesting presystemic or first-pass metabolism. Three (21.4%) subjects experienced a treatment-emergent adverse event (TEAE) during the study. All TEAEs were mild, considered related to study medication, and consistent with what has been seen in other studies. There were no deaths, serious adverse events, or discontinuations due to TEAEs. Both tasimelteon treatments were well tolerated during the study. PMID:25658956</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/992646','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/992646"><span id="translatedtitle">Measurement of the <span class="hlt">absolute</span> \</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Aunion, Jose Luis Alcaraz; /Barcelona, IFAE</p> <p>2010-07-01</p> <p>This thesis presents the measurement of the charged current quasi-elastic (CCQE) neutrino-nucleon cross section at neutrino energies around 1 GeV. This measurement has two main physical motivations. On one hand, the neutrino-nucleon interactions at few GeV is a region where existing old data are sparse and with low statistics. The current measurement populates low energy regions with higher statistics and precision than previous experiments. On the other hand, the CCQE interaction is the most useful interaction in neutrino oscillation experiments. The CCQE channel is used to measure the initial and final neutrino fluxes in order to determine the neutrino fraction that disappeared. The neutrino oscillation experiments work at low neutrino energies, so precise measurement of CCQE interactions are essential for flux measurements. The main goal of this thesis is to measure the CCQE <span class="hlt">absolute</span> neutrino cross section from the SciBooNE data. The SciBar Booster Neutrino Experiment (SciBooNE) is a neutrino and anti-neutrino scattering off experiment. The neutrino energy spectrum works at energies around 1 GeV. SciBooNE was running from June 8th 2007 to August 18th 2008. In that period, the experiment collected a total of 2.65 x 10{sup 20} protons on target (POT). This thesis has used full data collection in neutrino mode 0.99 x 10{sup 20} POT. A CCQE selection cut has been performed, achieving around 70% pure CCQE sample. A fit method has been exclusively developed to determine the <span class="hlt">absolute</span> CCQE cross section, presenting results in a neutrino energy range from 0.2 to 2 GeV. The results are compatible with the NEUT predictions. The SciBooNE measurement has been compared with both Carbon (MiniBoonE) and deuterium (ANL and BNL) target experiments, showing a good agreement in both cases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002E%26PSL.195....1M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002E%26PSL.195....1M"><span id="translatedtitle">The relationship between Martian gravity and <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McKenzie, Dan; Barnett, David N.; Yuan, Dah-Ning</p> <p>2002-01-01</p> <p>The relationship between gravity and <span class="hlt">topography</span> of various regions of Mars is used to estimate their effective elastic thicknesses Te using direct measurements of line of sight velocity, rather than spherical harmonic coefficients. Estimates of Te vary from 70 km for Tharsis, 29 km for Elysium, to 14.5 km for the southern hemisphere, and show that the thickness of the Martian lithosphere increases with age as the radioactive isotopes of K, Th, and U decay. A simple parameterised model of the convective thermal history is used to estimate the temperature structure of the lithosphere, and shows that the base of the elastic layer has a temperature of 300±50°C, or similar to the value for terrestrial continents. In both cases the rheology is probably affected by the presence of water. The short wavelength behaviour of the gravity field allows the density of the rocks that form the <span class="hlt">topography</span> to be estimated, and gives values of about 3.0 Mg/m 3 for Tharsis and Elysium. This value is substantially greater than that of 2.7 Mg/m 3 obtained for Earth, and is in agreement with estimates from SNC (Shergottites-Nahklites-Chassigny) meteorites of 3.3 Mg/m 3. The density of the <span class="hlt">topography</span> of Valles Marineris is only 2.35 Mg/m 3, and suggests that ice may be present below the surface. In the heavily bombarded southern hemisphere, isostatic compensation occurs at wavelengths as short as 700 km, which requires the effective compensation depth to be no more than 10 km. The gravity field with wavelengths greater than 1500 km may be supported <span class="hlt">dynamically</span>, by a plume rising beneath the Tharsis region. The difference in temperature between the solidus and the present areotherm is less than 250°C, so melt generation can occur in rising plumes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4411208','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4411208"><span id="translatedtitle">Hybrid Steered Molecular <span class="hlt">Dynamics</span> Approach to Computing <span class="hlt">Absolute</span> Binding Free Energy of Ligand–Protein Complexes: A Brute Force Approach That Is Fast and Accurate</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2015-01-01</p> <p>Computing the free energy of binding a ligand to a protein is a difficult task of essential importance for which purpose various theoretical/computational approaches have been pursued. In this paper, we develop a hybrid steered molecular <span class="hlt">dynamics</span> (hSMD) method capable of resolving one ligand–protein complex within a few wall-clock days with high enough accuracy to compare with the experimental data. This hSMD approach is based on the relationship between the binding affinity and the potential of mean force (PMF) in the established literature. It involves simultaneously steering n (n = 1, 2, 3, ...) centers of mass of n selected segments of the ligand using n springs of infinite stiffness. Steering the ligand from a single initial state chosen from the bound state ensemble to the corresponding dissociated state, disallowing any fluctuations of the pulling centers along the way, one can determine a 3n-dimensional PMF curve connecting the two states by sampling a small number of forward and reverse pulling paths. This PMF constitutes a large but not the sole contribution to the binding free energy. Two other contributors are (1) the partial partition function containing the equilibrium fluctuations of the ligand at the binding site and the deviation of the initial state from the PMF minimum and (2) the partial partition function containing rotation and fluctuations of the ligand around one of the pulling centers that is fixed at a position far from the protein. We implement this hSMD approach for two ligand–protein complexes whose structures were determined and whose binding affinities were measured experimentally: caprylic acid binding to bovine β-lactoglobulin and glutathione binding to Schistosoma japonicum glutathione S-transferase tyrosine 7 to phenylalanine mutant. Our computed binding affinities agree with the experimental data within a factor of 1.5. The total time of computation for these two all-atom model systems (consisting of 96K and 114K atoms, respectively) was less than one wall-clock week using 512 cores (32 Xeon E5-2680 processors). PMID:25937822</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25937822','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25937822"><span id="translatedtitle">Hybrid Steered Molecular <span class="hlt">Dynamics</span> Approach to Computing <span class="hlt">Absolute</span> Binding Free Energy of Ligand-Protein Complexes: A Brute Force Approach That Is Fast and Accurate.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Liao Y</p> <p>2015-04-14</p> <p>Computing the free energy of binding a ligand to a protein is a difficult task of essential importance for which purpose various theoretical/computational approaches have been pursued. In this paper, we develop a hybrid steered molecular <span class="hlt">dynamics</span> (hSMD) method capable of resolving one ligand–protein complex within a few wall-clock days with high enough accuracy to compare with the experimental data. This hSMD approach is based on the relationship between the binding affinity and the potential of mean force (PMF) in the established literature. It involves simultaneously steering n (n = 1, 2, 3, ...) centers of mass of n selected segments of the ligand using n springs of infinite stiffness. Steering the ligand from a single initial state chosen from the bound state ensemble to the corresponding dissociated state, disallowing any fluctuations of the pulling centers along the way, one can determine a 3n-dimensional PMF curve connecting the two states by sampling a small number of forward and reverse pulling paths. This PMF constitutes a large but not the sole contribution to the binding free energy. Two other contributors are (1) the partial partition function containing the equilibrium fluctuations of the ligand at the binding site and the deviation of the initial state from the PMF minimum and (2) the partial partition function containing rotation and fluctuations of the ligand around one of the pulling centers that is fixed at a position far from the protein. We implement this hSMD approach for two ligand–protein complexes whose structures were determined and whose binding affinities were measured experimentally: caprylic acid binding to bovine β-lactoglobulin and glutathione binding to Schistosoma japonicum glutathione S-transferase tyrosine 7 to phenylalanine mutant. Our computed binding affinities agree with the experimental data within a factor of 1.5. The total time of computation for these two all-atom model systems (consisting of 96K and 114K atoms, respectively) was less than one wall-clock week using 512 cores (32 Xeon E5-2680 processors). PMID:25937822</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870011267','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870011267"><span id="translatedtitle">Linear baroclinic instability in the presence of large scale <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Reynolds, Nathaniel Dunton</p> <p>1987-01-01</p> <p>The effect of a planetary-scale, wavenumber 2 <span class="hlt">topography</span> on baroclinically active disturbances is investigated for a channel domain in a two-layer, quasi-geostrophic context. When the lower-layer zonal velocity is nonzero, the <span class="hlt">topography</span> influences the disturbances by forcing a stationary wave, and the <span class="hlt">topography</span> and the forced wave influence the growth rates and the spatial structures of the time-dependent solutions. The case of zero zonal velocity in the lower layer was also investigated, for which no forced wave exists. Asymptotic forms of the equations, valid when the topographic effect (governed by the ratio of the nondimensional topographic height to the rotational Froude number) is small, are used to obtain both the stationary and time-dependent solutions. The latter are also obtained using a numerical approach, in which is determined the eigenvalues and eigenfunctions of a matrix representing the <span class="hlt">dynamical</span> equations. Agreement is good between the two approaches. Recent laboratory experiments with a baroclinic annulus in which there is a false bottom with wavenumber 2 <span class="hlt">topography</span>, are used to select governing parameters. The simultaneous presence of a stationary forced wave of wavenumber 2 and a time-dependent baroclinic wave of wavenumber 4, which has wavenumber 2 and 6 sidebands due to the <span class="hlt">topography</span>, yields a flow field that exhibits some principal features of the laboratory experiments. The position of the forced wave and the location of an excursion in latitude of the storm track show qualitative resemblance to those features observed in the atmosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19990076710&hterms=Gravity+Mars&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DGravity%2BMars','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19990076710&hterms=Gravity+Mars&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DGravity%2BMars"><span id="translatedtitle">Mars Gravity and <span class="hlt">Topography</span> Interpretations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zuber, Maria T.; Smith, David E.; Solomon, Sean C.; Phillips, Roger J.</p> <p>1999-01-01</p> <p>New models of the <span class="hlt">topography</span> of Mars and its gravity field from the Mars Global Surveyor mission are shedding new light on the structure of the planet and the state of isostatic compensation. Gravity field observations over the flat northern hemisphere plains show a number of anomalies at the 100 to 200 mGal level that have no apparent manifestation in the surface <span class="hlt">topography</span>. We believe that these anomalies are probably the result of ancient impacts and represent regions of denser material buried beneath the outer depositional crust. Similar anomalies are also found in the region of the north polar ice cap even though a gravity anomaly resulting from the 3 km high icecap has not been uniquely identified. This leads us to speculate that the ice cap is largely compensated and is older than the timescale of isostatic compensation, about 10(exp 15) years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20000118208&hterms=planets+shape&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dplanets%2Bshape','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20000118208&hterms=planets+shape&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dplanets%2Bshape"><span id="translatedtitle">Shape and <span class="hlt">Topography</span> of Mars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, David E.</p> <p>2000-01-01</p> <p>Observations by the Mars Orbiter Laser Altimeter (MOLA) on the Mars Global Surveyor (MGS) spacecraft are showing a new planet in its range of <span class="hlt">topography</span> and in the detail of the geological features. MGS arrived at Mars in Sept 1997 and since Feb. 28, 1999 the laser altimeter has operated continuously. By the end of April 2000 MOLA had acquired over 350 million measurements of the planet's shape and <span class="hlt">topography</span>. These observations show a strong down-hill topographic gradient from the south pole to the north pole with an extremely low and flat basin encompassing most of the northern hemisphere. Large outflow channels are seen in the Chyrse region that strongly suggest considerable quantities of water once flowed into the lower northern hemisphere from the south. The northern icecap, which rises to a height of three kilometers above the surrounding terrain, is shown to be largely composed of water ice and at the center of a large basin. The southern hemisphere is about five kilometers higher than the low northern plains and dominated by the Hellas impact basin whose ejecta is the major contributor to the <span class="hlt">topography</span> of the hemisphere and the crustal dichotomy. The south polar icecap, which is part of a much larger region of layered terrain composed of water ice and dust, reaches an elevation of nearly five kilometers and except for the large Tharsis volcanoes is the highest part of the planet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890001054','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890001054"><span id="translatedtitle">Earth rotation and core <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hager, Bradford H.; Clayton, Robert W.; Spieth, Mary Ann</p> <p>1988-01-01</p> <p>The NASA Geodynamics program has as one of its missions highly accurate monitoring of polar motion, including changes in length of day (LOD). These observations place fundamental constraints on processes occurring in the atmosphere, in the mantle, and in the core of the planet. Short-timescale (t less than or approx 1 yr) variations in LOD are mainly the result of interaction between the atmosphere and the solid earth, while variations in LOD on decade timescales result from the exchange of angular momentum between the mantle and the fluid core. One mechanism for this exchange of angular momentum is through topographic coupling between pressure variations associated with flow in the core interacting with <span class="hlt">topography</span> at the core-mantel boundary (CMB). Work done under another NASA grant addressing the origin of long-wavelength geoid anomalies as well as evidence from seismology, resulted in several models of CMB <span class="hlt">topography</span>. The purpose of work supported by NAG5-819 was to study further the problem of CMB <span class="hlt">topography</span>, using geodesy, fluid mechanics, geomagnetics, and seismology. This is a final report.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/18396925','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/18396925"><span id="translatedtitle">Dial A440 for <span class="hlt">absolute</span> pitch: <span class="hlt">absolute</span> pitch memory by non-<span class="hlt">absolute</span> pitch possessors.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Smith, Nicholas A; Schmuckler, Mark A</p> <p>2008-04-01</p> <p>Listeners without <span class="hlt">absolute</span> (or "perfect") pitch have difficulty identifying or producing isolated musical pitches from memory. Instead, they process the relative pattern of pitches, which remains invariant across pitch transposition. Musically untrained non-<span class="hlt">absolute</span> pitch possessors demonstrated <span class="hlt">absolute</span> pitch memory for the telephone dial tone, a stimulus that is always heard at the same <span class="hlt">absolute</span> frequency. Listeners accurately classified pitch-shifted versions of the dial tone as "normal," "higher than normal" or "lower than normal." However, the role of relative pitch processing was also evident, in that listeners' pitch judgments were also sensitive to the frequency range of stimuli. PMID:18396925</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930043862&hterms=Gravity+Mars&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DGravity%2BMars','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930043862&hterms=Gravity+Mars&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DGravity%2BMars"><span id="translatedtitle">Gravity and <span class="hlt">topography</span>. [of planet Mars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Esposito, P. B.; Banerdt, W. B.; Lindal, G. F.; Sjogren, W. L.; Slade, M. A.; Bills, B. G.; Smith, D. E.; Balmino, G.</p> <p>1992-01-01</p> <p>The paper summarizes the fundamental gravity field constants for Mars and a brief historical review of early determinations and current-day accurate estimates. These include the planetary gravitational constant, global figure, <span class="hlt">dynamical</span> oblateness, mean density, and rotational period. Topographic results from data acquired from the 1967 opposition to the most recent, 1988, opposition are presented. Both global and selected local topographic variations and features are discussed. The inertia tensor and the nonhydrostatic component of Mars are examined in detail. The dimensionless moment of inertia about the rotational axis is 0.4 for a body of uniform density and 0.37621 if Mars were in hydrostatic equilibrium. By comparing models of both gravity and <span class="hlt">topography</span>, inferences are made about the degree and depth of compensation in the interior and stresses in the lithosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009GGG....10.3014R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009GGG....10.3014R"><span id="translatedtitle">Global Multi-Resolution <span class="hlt">Topography</span> synthesis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ryan, William B. F.; Carbotte, Suzanne M.; Coplan, Justin O.; O'Hara, Suzanne; Melkonian, Andrew; Arko, Robert; Weissel, Rose Anne; Ferrini, Vicki; Goodwillie, Andrew; Nitsche, Frank; Bonczkowski, Juliet; Zemsky, Richard</p> <p>2009-03-01</p> <p>Seafloor bathymetric data acquired with modern swath echo sounders provide coverage for only a small fraction of the global seabed yet are of high value for studies of the <span class="hlt">dynamic</span> processes of seafloor volcanism, tectonics, mass wasting, and sediment transport that create and shape the undersea landscape. A new method for compilation of global seafloor bathymetry that preserves the native resolution of swath sonars is presented. The Global Multi-Resolution <span class="hlt">Topography</span> synthesis consists of a hierarchy of tiles with digital elevations and shaded relief imagery spanning nine magnification doublings from pole to pole (http://www.marine-geo.org/portals/gmrt). The compilation is updated and accessible as surveys are contributed, edited, and added to the tiles. Access to the bathymetry tiles is via Web services and with WMS-enabled client applications such as GeoMapApp®, Virtual Ocean, NASA World Wind®, and Google Earth®.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19720035627&hterms=absolute+stability&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dabsolute%2Bstability','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19720035627&hterms=absolute+stability&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dabsolute%2Bstability"><span id="translatedtitle">Singular perturbation of <span class="hlt">absolute</span> stability.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Siljak, D. D.</p> <p>1972-01-01</p> <p>The influence of a small parameter at the higher derivatives in the differential equations describing nonlinear systems of the Lur'e-Postnikov class on <span class="hlt">absolute</span> stability in the parameter space is investigated. The conditions leading to singular perturbations of <span class="hlt">absolute</span> stability are examined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3016849','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3016849"><span id="translatedtitle"><span class="hlt">Topography</span>, Cell Response, and Nerve Regeneration</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hoffman-Kim, Diane; Mitchel, Jennifer A.; Bellamkonda, Ravi V.</p> <p>2010-01-01</p> <p>In the body, cells encounter a complex milieu of signals, including topographical cues. Imposed <span class="hlt">topography</span> can affect cells on surfaces by promoting adhesion, spreading, alignment, morphological changes, and changes in gene expression. Neural response to <span class="hlt">topography</span> is complex, and depends on the dimensions and shapes of physical features. Looking toward repair of nerve injuries, strategies are being explored to engineer guidance conduits with precise surface <span class="hlt">topographies</span>. How neurons and other cell types sense and interpret <span class="hlt">topography</span> remains to be fully elucidated. Studies reviewed here include those of <span class="hlt">topography</span> on cellular organization and function as well as potential cellular mechanisms of response. PMID:20438370</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20000025063&hterms=Gravity+Mars&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DGravity%2BMars','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20000025063&hterms=Gravity+Mars&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DGravity%2BMars"><span id="translatedtitle">Preliminary Correlations of Gravity and <span class="hlt">Topography</span> from Mars Global Surveyor</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zuber, M. T.; Tyler, G. L.; Smith, D. E.; Balmino, G. S.; Johnson, G. L.; Lemoine, F. G.; Neumann, G. A.; Phillips, R. J.; Sjogren, W. L.; Solomon, S. C.</p> <p>1999-01-01</p> <p>The Mars Global Surveyor (MGS) spacecraft is currently in a 400-km altitude polar mapping orbit and scheduled to begin global mapping of Mars in March of 1999. Doppler tracking data collected in this Gravity Calibration Orbit prior to the nominal mapping mission combined with observations from the MGS Science Phasing Orbit in Spring - Summer 1999 and the Viking and mariner 9 orbiters has led to preliminary high resolution gravity fields. Spherical harmonic expansions have been performed to degree and order 70 and are characterized by the first high spatial resolution coverage of high latitudes. Topographic mapping by the Mars Orbiter Laser Altimeter on MGS is providing measurements of the height of the martian surface with sub-meter vertical resolution and 5-30 m <span class="hlt">absolute</span> accuracy. Data obtained during the circular mapping phase are expected to provide the first high resolution measurements of surface heights in the southern hemisphere. The combination of gravity and <span class="hlt">topography</span> measurements provides information on the structure of the planetary interior, i.e. the rigidity and distribution of internal density. The observations can also be used to address the mechanisms of support of surface <span class="hlt">topography</span>. Preliminary results of correlations of gravity and <span class="hlt">topography</span> at long planetary wavelengths will be presented and the implications for internal structure will be addressed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EPSC...10..514S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EPSC...10..514S"><span id="translatedtitle">Estimation of Ganymede's <span class="hlt">Topography</span>, Rotation and Tidal Deformation - a Study of Synthetic Ganymede Laser Altimeter Observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Steinke, T.; Stark, A.; Steinbrügge, G.; Hussmann, H.; Oberst, J.</p> <p>2015-10-01</p> <p>We implement an iterative least-squares inversion routine to study the estimation of several <span class="hlt">dynamic</span> Ganymede rotation parameters by laser altimetry. Based on spherical harmonic expansions of the global <span class="hlt">topography</span> we use simulated Ganymede Laser Al-timeter observations representing the synthetic <span class="hlt">topography</span> of the satellite. Besides the static <span class="hlt">topography</span> we determine the <span class="hlt">dynamical</span> parameters, such as the rotation rate, the amplitudes of physical librations, the spin pole orientation, and the tidal deformation. This parameters may strengthen implications for a liquid ocean beneath Ganymede's icy shell and, in addition, constrain geodetic frame parameters essential for various space-borne experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMED11B3407G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMED11B3407G"><span id="translatedtitle">The <span class="hlt">Topography</span> Tub Learning Activity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Glesener, G. B.</p> <p>2014-12-01</p> <p>Understanding the basic elements of a topographic map (i.e. contour lines and intervals) is just a small part of learning how to use this abstract representational system as a resource in geologic mapping. Interpretation of a topographic map and matching its features with real-world structures requires that the system is utilized for visualizing the shapes of these structures and their spatial orientation. To enrich students' skills in visualizing <span class="hlt">topography</span> from topographic maps a spatial training activity has been developed that uses 3D objects of various shapes and sizes, a sighting tool, a plastic basin, water, and transparencies. In the first part of the activity, the student is asked to draw a topographic map of one of the 3D objects. Next, the student places the object into a plastic tub in which water is added to specified intervals of height. The shoreline at each interval is used to reference the location of the contour line the student draws on a plastic inkjet transparency directly above the object. A key part of this activity is the use of a sighting tool by the student to assist in keeping the pencil mark directly above the shoreline. It (1) ensures the accurate positioning of the contour line and (2) gives the learner experience with using a sight before going out into the field. Finally, after the student finishes drawing the contour lines onto the transparency, the student can compare and contrast the two maps in order to discover where improvements in their visualization of the contours can be made. The teacher and/or peers can also make suggestions on ways to improve. A number of objects with various shapes and sizes are used in this exercise to produce contour lines representing the different types of <span class="hlt">topography</span> the student may encounter while field mapping. The intended outcome from using this visualization training activity is improvement in performance of visualizing <span class="hlt">topography</span> as the student moves between the topographic representation and corresponding <span class="hlt">topography</span> in the field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1985JGR....90..827B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1985JGR....90..827B"><span id="translatedtitle">Venus <span class="hlt">topography</span> - A harmonic analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bills, B. G.; Kobrick, M.</p> <p>1985-01-01</p> <p>A model of Venusian global <span class="hlt">topography</span> has been obtained by fitting an eighteenth-degree harmonic series to Pioneer Venus orbiter radar altimeter data. The mean radius is (6051.45 + or - 0.04) km. The corresponding mean density is (5244.8 + or 0.5) kg/cu m. The center of figure is displaced from the center of mass by (0.339 + or - 0.088) km towards (6.6 + or 10.1) deg N, (148. 8 + or - 7.7) deg. The figure of Venus is distinctly triaxial, but the orientation and magnitudes of the principal topographic axes correlate rather poorly with the gravitational principal axes. However, the higher-degree harmonics of <span class="hlt">topography</span> and gravity are significantly correlated. The topographic variance spectrum of Venus is very similar in form to those of the moon, Mars, and especially earth. It is suggested that this spectral similarity simply reflects a statistical balance between constructional and degradational geomorphic proceses. Venus and earth are particularly similar (and differ from the moon and Mars) in that the larger bodies both exhibit a significant low degree deficit (relative to the extrapolated trend of the higher harmonics).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19720059878&hterms=absolute+stability&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dabsolute%2Bstability','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19720059878&hterms=absolute+stability&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dabsolute%2Bstability"><span id="translatedtitle">Singular perturbation of <span class="hlt">absolute</span> stability.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Siljak, D. D.</p> <p>1972-01-01</p> <p>It was previously shown (author, 1969) that the regions of <span class="hlt">absolute</span> stability in the parameter space can be determined when the parameters appear on the right-hand side of the system equations, i.e., the regular case. Here, the effect on <span class="hlt">absolute</span> stability of a small parameter attached to higher derivatives in the equations (the singular case) is studied. The Lur'e-Postnikov class of nonlinear systems is considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUSM...S21B02G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUSM...S21B02G"><span id="translatedtitle">Simultaneous inversion for mantle shear velocity and the <span class="hlt">topography</span> of transition zone discontinuities</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gu, Y. J.; Dziewonski, A. M.</p> <p>2001-05-01</p> <p>A method is presented for the simultaneous inversions of shear velocity in the mantle and the <span class="hlt">topography</span> of transition zone discontinuities. Each travel time residual, corrected for crust and free surface <span class="hlt">topography</span>, is modeled as resulting from contributions from three-dimensional shear velocity perturbations to a spherical Earth model and boundary undulations to the 410 and 660 km discontinuities. This approach minimizes tradeoffs between velocity and <span class="hlt">topography</span>. We expand the lateral variations in velocity and the <span class="hlt">topography</span> of each discontinuity using 362 spherical B-splines; we expand the radial variations using 14 cubic B-splines. To increase the reliability of the measurements, particularly in the undersampled southern hemisphere, we re-examine the <span class="hlt">topography</span> of the 410- and 660 km discontinuities from more than 21,000 SH-component records. This new data set is significantly larger than those used earlier studies of SS precursors. The long-wavelength features of our new <span class="hlt">topography</span> maps of the 410- and 660-km discontinuities are compatible with results of earlier studies: the large-scale patterns are dominated by low degree spherical harmonics, particularly at degrees 1 and 2. We also include an independent measurement of the global transition zone thickness for additional constraints on the structure in the transition zone. The best-fit model from the joint inversion reduces the variance of the <span class="hlt">absolute</span> and differential travel times of S, SS and ScS by 40 to 70 %, and the differential travel times of SS precursors by up to 90%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012Tectp.526....5H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012Tectp.526....5H"><span id="translatedtitle">Unraveling <span class="hlt">topography</span> around subduction zones from laboratory models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Husson, Laurent; Guillaume, Benjamin; Funiciello, Francesca; Faccenna, Claudio; Royden, Leigh H.</p> <p>2012-03-01</p> <p>The relief around subduction zones results from the interplay of <span class="hlt">dynamic</span> processes that may locally exceed the (iso)static contributions. The viscous dissipation of the energy in and around subduction zones is capable of generating kilometer scale vertical ground movements. In order to evaluate <span class="hlt">dynamic</span> <span class="hlt">topography</span> in a self-consistent subduction system, we carried out a set of laboratory experiments, wherein the lithosphere and mantle are simulated by means of Newtonian viscous materials, namely silicone putty and glucose syrup. Models are kept in their most simple form and are made of negative buoyancy plates, of variable width and thickness, freely plunging into the syrup. The surface of the model and the top of the slab are scanned in three dimensions. A forebulge systematically emerges from the bending of the viscous plate, adjacent to the trench. With a large wavelength, <span class="hlt">dynamic</span> pressure offsets the foreside and backside of the slab by ~ 500 m on average. The suction, that accompanies the vertical descent of the slab depresses the surface on both sides. At a distance equal to the half-width of the slab, the topographic depression amounts to ~ 500 m on average and becomes negligible at a distance that equals the width of the slab. In order to explore the impact of slab rollback on the <span class="hlt">topography</span>, the trailing edge of the plates is alternatively fixed to (fixed mode) and freed from (free mode) the end wall of the tank. Both the pressure and suction components of the <span class="hlt">topography</span> are ~ 30% lower in the free mode, indicating that slab rollback fosters the <span class="hlt">dynamic</span> subsidence of upper plates. Our models are compatible with first order observations of the <span class="hlt">topography</span> around the East Scotia, Tonga, Kermadec and Banda subduction zones, which exhibit anomalous depths of nearly 1 km as compared to adjacent sea floor of comparable age.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1304601','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1304601"><span id="translatedtitle">Simultaneous <span class="hlt">Topography</span> and Recognition Imaging Using Force Microscopy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Stroh, Cordula M.; Ebner, Andreas; Geretschläger, Manfred; Freudenthaler, Günter; Kienberger, Ferry; Kamruzzahan, A. S. M.; Smith-Gill, Sandra J.; Gruber, Hermann J.; Hinterdorfer, Peter</p> <p>2004-01-01</p> <p>We present a method for simultaneously recording <span class="hlt">topography</span> images and localizing specific binding sites with nm positional accuracy by combining <span class="hlt">dynamic</span> force microscopy with single molecule recognition force spectroscopy. For this we used lysozyme adsorbed to mica, the functionality of which was characterized by enzyme immunoassays. The <span class="hlt">topography</span> and recognition images were acquired using tips that were magnetically oscillated during scanning and contained antibodies directed against lysozyme. For cantilevers with low Q-factor (∼1 in liquid) driven at frequencies below resonance, the surface contact only affected the downward deflections (minima) of the oscillations, whereas binding of the antibody on the tip to lysozyme on the surface only affected the upwards deflections (maxima) of the oscillations. The recognition signals were therefore well separated from the topographic signals, both in space (Δz ∼ 5 nm) and time (∼0.1 ms). <span class="hlt">Topography</span> and recognition images were simultaneously recorded using a specially designed electronic circuit with which the maxima (Uup) and the minima (Udown) of each sinusoidal cantilever deflection period were depicted. Udown was used for driving the feedback loop to record the height (<span class="hlt">topography</span>) image, and Uup provided the data for the recognition image. PMID:15345574</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvE..92f2114B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvE..92f2114B"><span id="translatedtitle">Understanding the mechanisms of solid-water reactions through analysis of surface <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bandstra, Joel Z.; Brantley, Susan L.</p> <p>2015-12-01</p> <p>The <span class="hlt">topography</span> of a reactive surface contains information about the reactions that form or modify the surface and, therefore, it should be possible to characterize reactivity using <span class="hlt">topography</span> parameters such as surface area, roughness, or fractal dimension. As a test of this idea, we consider a two-dimensional (2D) lattice model for crystal dissolution and examine a suite of <span class="hlt">topography</span> parameters to determine which may be useful for predicting rates and mechanisms of dissolution. The model is based on the assumption that the reactivity of a surface site decreases with the number of nearest neighbors. We show that the steady-state surface <span class="hlt">topography</span> in our model system is a function of, at most, two variables: the ratio of the rate of loss of sites with two neighbors versus three neighbors (d2/d3) and the ratio of the rate of loss of sites with one neighbor versus three neighbors (d1/d3) . This means that relative rates can be determined from two parameters characterizing the <span class="hlt">topography</span> of a surface provided that the two parameters are independent of one another. It also means that <span class="hlt">absolute</span> rates cannot be determined from measurements of surface <span class="hlt">topography</span> alone. To identify independent sets of <span class="hlt">topography</span> parameters, we simulated surfaces from a broad range of d1/d3 and d2/d3 and computed a suite of common <span class="hlt">topography</span> parameters for each surface. Our results indicate that the fractal dimension D and the average spacing between steps, E [s ] , can serve to uniquely determine d1/d3 and d2/d3 provided that sufficiently strong correlations exist between the steps. Sufficiently strong correlations exist in our model system when D >1.5 (which corresponds to D >2.5 for real 3D reactive surfaces). When steps are uncorrelated, surface <span class="hlt">topography</span> becomes independent of step retreat rate and D is equal to 1.5. Under these conditions, measures of surface <span class="hlt">topography</span> are not independent and any single <span class="hlt">topography</span> parameter contains all of the available mechanistic information about the surface. Our results also indicate that root-mean-square roughness cannot be used to reliably characterize the surface <span class="hlt">topography</span> of fractal surfaces because it is an inherently noisy parameter for such surfaces with the scale of the noise being independent of length scale.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20010012851&hterms=farr&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dfarr','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20010012851&hterms=farr&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dfarr"><span id="translatedtitle">The Shuttle Radar <span class="hlt">Topography</span> Mission</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Farr, Tom G.; Kobrick, Mike</p> <p>2000-01-01</p> <p>On February 22, 2000 Space Shuttle Endeavour landed at Kennedy Space Center, completing the highly successful 11-day flight of the Shuttle Radar <span class="hlt">Topography</span> Mission (SRTM). Onboard were over 300 high-density tapes containing data for the highest resolution, most complete digital topographic map of Earth ever made. SRTM is a cooperative project between NASA and the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense. The mission was designed to use a single-pass radar interferometer to produce a digital elevation model (DEM) of the Earth's land surface between about 60 deg north and 56 deg south latitude. When completed, the DEM will have 30 m pixel spacing and about 15 m vertical accuracy. Two orthorectified image mosaics (one from the ascending passes with illumination from the southeast and one from descending passes with illumination from the southwest) will also be produced.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/7023362','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/7023362"><span id="translatedtitle"><span class="hlt">Absolute</span> flux scale for radioastronomy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ivanov, V.P.; Stankevich, K.S.</p> <p>1986-07-01</p> <p>The authors propose and provide support for a new <span class="hlt">absolute</span> flux scale for radio astronomy, which is not encumbered with the inadequacies of the previous scales. In constructing it the method of relative spectra was used (a powerful tool for choosing reference spectra). A review is given of previous flux scales. The authors compare the AIS scale with the scale they propose. Both scales are based on <span class="hlt">absolute</span> measurements by the ''artificial moon'' method, and they are practically coincident in the range from 0.96 to 6 GHz. At frequencies above 6 GHz, 0.96 GHz, the AIS scale is overestimated because of incorrect extrapolation of the spectra of the primary and secondary standards. The major results which have emerged from this review of <span class="hlt">absolute</span> scales in radio astronomy are summarized.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19750052391&hterms=ocean+surface+topography&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Docean%2Bsurface%2Btopography','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19750052391&hterms=ocean+surface+topography&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Docean%2Bsurface%2Btopography"><span id="translatedtitle">Satellite altimetry applications. [ocean surface <span class="hlt">topography</span> measurements</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Mcgoogan, J. T.</p> <p>1975-01-01</p> <p>In satellite altimetry the highly stable platform provided by a satellite is utilized as a moving reference system from which vertical measurements to the ocean surface are made. Satellite altimetry applications are related to geoid determination, questions concerning the consideration of local <span class="hlt">topography</span>, geological-structure studies, investigations regarding the distribution of wave heights, current detection, and the mapping of land <span class="hlt">topography</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930063997&hterms=1609&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2526%25231609','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930063997&hterms=1609&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D%2526%25231609"><span id="translatedtitle"><span class="hlt">Absolute</span> classification with unsupervised clustering</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jeon, Byeungwoo; Landgrebe, D. A.</p> <p>1992-01-01</p> <p>An <span class="hlt">absolute</span> classification algorithm is proposed in which the class definition through training samples or otherwise is required only for a particular class of interest. The <span class="hlt">absolute</span> classification is considered as a problem of unsupervised clustering when one cluster is known initially. The definitions and statistics of the other classes are automatically developed through the weighted unsupervised clustering procedure, which is developed to keep the cluster corresponding to the class of interest from losing its identity as the class of interest. Once all the classes are developed, a conventional relative classifier such as the maximum-likelihood classifier is used in the classification.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004AGUFM.G53A0105C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004AGUFM.G53A0105C"><span id="translatedtitle"><span class="hlt">Absolute</span> local sea surface in the Vanuatu Archipelago from GPS, satellite altimetry and pressure gauge data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cheng, K. K.; Ballu, V.; Bouin, M.; Calmant, S.; Shum, C.</p> <p>2004-12-01</p> <p>Water height measurements provided by seafloor tide gauges are a combination of sea level variation and local ground motion. Both signals are of scientific interest, but they must be separated in order to be useful. A reliable estimation of the vertical ground motion is important in very seismically areas such as the Pacific Ocean rim. One promising method to separate the two contributions is to use satellite altimetry which gives <span class="hlt">absolute</span> water height that is independent of the local ground motion. However, the altimeter data must be calibrated using ground truth measurements. Once different components of the signal are separated, bottom pressure gauges can be used to detect vertical movements of the seafloor. The Vanuatu Archipelago is part of the Pacific "ring of fire", where plates are quickly converging. In this area, movements are very rapid and the seismic activity is intense, which gives a good opportunity to study deformation and seismic cycle. To get an integrate picture of vertical deformation over one plate and between the two plates, one needs to be able to monitor vertical movements on both underwater and emerged areas. We conducted an experiment in this area to compare measurements from bottom pressure gauges located beneath altimetry satellite tracks with sea surface altitude measurements from GPS. Two bottom pressure gauge are immerged since Nov. 1999 in this region. In order to perform <span class="hlt">absolute</span> calibration for multiple satellite altimeters that overfly the region, we conducted 2 campaigns of GPS measurements of instantaneous sea surface height onboard the R/V Alis and using a GPS buoy. We present results of GPS computations for the March 2003 and March 2004 campaigns. These sea level GPS measurements are compared with multiple altimeter-measured sea surface heights, and sampling differences and high frequency variations were removed using continuous pressure gauge data. The observed discrepancies are likely to be explained by local geoid variations or <span class="hlt">dynamic</span> <span class="hlt">topography</span> and we conducted GPS surveys to map these differences.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://geology.er.usgs.gov/eespteam/terrainmodeling/ds_136.htm','USGSPUBS'); return false;" href="http://geology.er.usgs.gov/eespteam/terrainmodeling/ds_136.htm"><span id="translatedtitle"><span class="hlt">Topography</span> and Landforms of Ecuador</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Chirico, Peter G.; Warner, Michael B.</p> <p>2005-01-01</p> <p>EXPLANATION The digital elevation model of Ecuador represented in this data set was produced from over 40 individual tiles of elevation data from the Shuttle Radar <span class="hlt">Topography</span> Mission (SRTM). Each tile was downloaded, converted from its native Height file format (.hgt), and imported into a geographic information system (GIS) for additional processing. Processing of the data included data gap filling, mosaicking, and re-projection of the tiles to form one single seamless digital elevation model. For 11 days in February of 2000, NASA, the National Geospatial-Intelligence Agency (NGA), the German Aerospace Center (DLR), and the Italian Space Agency (ASI) flew X-band and C-band radar interferometry onboard the Space Shuttle Endeavor. The mission covered the Earth between 60?N and 57?S and will provide interferometric digital elevation models (DEMs) of approximately 80% of the Earth's land mass when processing is complete. The radar-pointing angle was approximately 55? at scene center. Ascending and descending orbital passes generated multiple interferometric data scenes for nearly all areas. Up to eight passes of data were merged to form the final processed SRTM DEMs. The effect of merging scenes averages elevation values recorded in coincident scenes and reduces, but does not completely eliminate, the amount of area with layover and terrain shadow effects. The most significant form of data processing for the Ecuador DEM was gap-filling areas where the SRTM data contained a data void. These void areas are a result of radar shadow, layover, standing water, and other effects of terrain, as well as technical radar interferometry phase unwrapping issues. To fill these gaps, topographic contours were digitized from 1:50,000 - scale topographic maps which date from the mid-late 1980's (Souris, 2001). Digital contours were gridded to form elevation models for void areas and subsequently were merged with the SRTM data through GIS and remote sensing image-processing techniques. The data contained in this publication includes a gap filled, countrywide SRTM DEM of Ecuador projected in Universal Transverse Mercator (UTM) Zone 17 North projection, Provisional South American, 1956, Ecuador datum and a non gap filled SRTM DEM of the Galapagos Islands projected in UTM Zone 15 North projection. Both the Ecuador and Galapagos Islands DEMs are available as an ESRI Grid, stored as ArcInfo Export files (.e00), and in Erdas Imagine (IMG) file formats with a 90 meter pixel resolution. Also included in this publication are high and low resolution Adobe Acrobat (PDF) files of <span class="hlt">topography</span> and landforms maps in Ecuador. The high resolution map should be used for printing and display, while the lower resolution map can be used for quick viewing and reference purposes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeoJI.203.1263K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeoJI.203.1263K"><span id="translatedtitle">High surface <span class="hlt">topography</span> related to upper mantle flow beneath Eastern Anatolia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Komut, Tolga</p> <p>2015-11-01</p> <p>Eastern Anatolia region between north-south colliding Arabian and Eurasian plates has no significant crustal root and shallow (upper) mantle flow beneath seems to be vertically supporting its high <span class="hlt">topography</span>. It has a high surface heat flow and the underlying mantle is characterized by low seismic velocity zones. Using a mantle density/temperature variation field derived from P-wave seismic velocity, current shallow mantle flow and resultant <span class="hlt">dynamic</span> <span class="hlt">topography</span> of Eastern Anatolia and adjacent Arabian foreland and Caucasus areas were calculated along a vertical section. The section crosses the tectonic boundaries interrelated with slab bodies (high seismic velocity/cold regions) and the low velocity zones above the slabs. According to the modelling experiments, the surface <span class="hlt">topography</span> of Eastern Anatolia seems to be supported by shallow mantle flow <span class="hlt">dynamics</span>. On the other hand, residual <span class="hlt">topography</span> for the region was calculated using high resolution crustal thickness data. Positive residual <span class="hlt">topography</span> that suggests an undercompensated state of Eastern Anatolia is in concordance with the <span class="hlt">dynamic</span> <span class="hlt">topography</span> anomaly. The modelled local shallow mantle flow support due to the density contrast between hot (low velocity) zones and underlying cold slab bodies beneath the area may be the present-day snapshot of the mantle flow uplift in Eastern Anatolia presence of which was previously suggested.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19720027445&hterms=Phosphorus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DPhosphorus','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19720027445&hterms=Phosphorus&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DPhosphorus"><span id="translatedtitle"><span class="hlt">Absolute</span> transition probabilities of phosphorus.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Miller, M. H.; Roig, R. A.; Bengtson, R. D.</p> <p>1971-01-01</p> <p>Use of a gas-driven shock tube to measure the <span class="hlt">absolute</span> strengths of 21 P I lines and 126 P II lines (from 3300 to 6900 A). Accuracy for prominent, isolated neutral and ionic lines is estimated to be 28 to 40% and 18 to 30%, respectively. The data and the corresponding theoretical predictions are examined for conformity with the sum rules.-</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19700000696','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19700000696"><span id="translatedtitle"><span class="hlt">Absolute</span> focus lock for microscopes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cone, C. D., Jr.; Loop, R. W.; Tongier, M., Jr.</p> <p>1970-01-01</p> <p>Mechanism <span class="hlt">absolutely</span> immobilizes microscope stage at a preset focus, preserving focus indefinitely. The lock is a second-class lever consisting of a straight body having a fulcrum with a cylindrical bearing surface at one end and a thumbscrew at the other end.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EPSC...10..856Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EPSC...10..856Z"><span id="translatedtitle">Venus atmosphere and extreme surface <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zasova, L.; Khatuntsev, I.; Patsaeva, M.; Ignatiev, N.; Rodin, A.; Turin, A.; Markiewicz, W.; Piccioni, G.</p> <p>2015-10-01</p> <p>The temperature fields at several levels in the Venus mesosphere(60-95 km)as well as the altitude of the upper boundary of clouds retrieved from Venera-15 (FS-V15) [1], and the zonal wind fields and albedo of the upper clouds, measured by VMC Venus Express [2], and altitude of the upper boundary of clouds VIRTIS-M VEX [3] data are compared with the topographic map, obtained by Magellan [4] . The results show that the isotherms and the altitude isolines of the upper clouds boundary reproduce the extended surface features Ishtar and Atalanta Planitia. In turn, the shapes of wind isovelocities and albedo at the upper boundary of clouds (VMC) closely follow the details of relief of Terra Aphrodite as well the isolines of altitude of the cloud tops (VIRTIS). In all cases the isolines are shifted with respect to <span class="hlt">topography</span> by about 30° in the direction of superrotation. Non-hydrostatic general circulation model of the Venus atmosphere[5] demonstrates that the major topographic features such as Maxwell Montes and Terra Aphrodite provide a prominent impact on the atmospheric <span class="hlt">dynamics</span> at levels as high as 90-95 km.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/fs/2003/0071/report.pdf','USGSPUBS'); return false;" href="http://pubs.usgs.gov/fs/2003/0071/report.pdf"><span id="translatedtitle">Shuttle Radar <span class="hlt">Topography</span> Mission (SRTM)</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>U.S. Geological Survey</p> <p>2003-01-01</p> <p>Under an agreement with the National Aeronautics and Space Administration (NASA) and the Department of Defense's National Imagery and Mapping Agency (NIMA), the U.S. Geological Survey (USGS) is now distributing elevation data from the Shuttle Radar <span class="hlt">Topography</span> Mission (SRTM). The SRTM is a joint project between NASA and NIMA to map the Earth's land surface in three dimensions at a level of detail unprecedented for such a large area. Flown aboard the NASA Space Shuttle Endeavour February 11-22, 2000, the SRTM successfully collected data over 80 percent of the Earth's land surface, for most of the area between 60? N. and 56? S. latitude. The SRTM hardware included the Spaceborne Imaging Radar-C (SIR-C) and X-band Synthetic Aperture Radar (X-SAR) systems that had flown twice previously on other space shuttle missions. The SRTM data were collected specifically with a technique known as interferometry that allows image data from dual radar antennas to be processed for the extraction of ground heights.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/fs/2009/3087/','USGSPUBS'); return false;" href="http://pubs.usgs.gov/fs/2009/3087/"><span id="translatedtitle">Shuttle Radar <span class="hlt">Topography</span> Mission (SRTM)</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>U.S. Geological Survey</p> <p>2009-01-01</p> <p>Under an agreement with the National Aeronautics and Space Administration (NASA) and the Department of Defense's National Geospatial-Intelligence Agency (NGA), the U.S. Geological Survey (USGS) is distributing elevation data from the Shuttle Radar <span class="hlt">Topography</span> Mission (SRTM). The SRTM is a joint project of NASA and NGA to map the Earth's land surface in three dimensions at an unprecedented level of detail. As part of space shuttle Endeavour's flight during February 11-22, 2000, the SRTM successfully collected data over 80 percent of the Earth's land surface for most of the area between latitudes 60 degrees north and 56 degrees south. The SRTM hardware included the Spaceborne Imaging Radar-C (SIR-C) and X-band Synthetic Aperture Radar (X-SAR) systems that had flown twice previously on other space shuttle missions. The SRTM data were collected with a technique known as interferometry that allows image data from dual radar antennas to be processed for the extraction of ground heights.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.H23L..01S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.H23L..01S"><span id="translatedtitle"><span class="hlt">Topography</span> driven conceptual modelling (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Savenije, H.</p> <p>2009-12-01</p> <p>Heterogeneity and complexity of hydrological processes offer substantial challenges to the hydrological modeller. Some hydrologists try to tackle this problem by introducing more and more detail in their models, or by setting-up more and more complex models starting from basic principles at the smallest possible level. As we know, this reductionist approach leads to ever higher levels of equifinality and predictive uncertainty. On the other hand, simple, lumped and parsimonious models may be too simple to be realistic or representative of the dominant hydrological processes. In this paper, a new model approach is proposed that tries to find the middle way between complex distributed and simple lumped modelling approaches. It addresses an aspect often overlooked in model uncertainty assessment: the structural errors made by conceptual misrepresentation. It uses a flexible model architecture based on a classification system that is <span class="hlt">topography</span> driven. Catchments are divided into different conceptual model classes, which are subsequently modelled with parsimonious conceptual models. The approach is process based, but not physically based in the traditional sense. Instead, it is based on a conceptual representation of the dominant physical processes in certain key elements of the landscape.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950027808&hterms=stereo+vision&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dstereo%2Bvision','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950027808&hterms=stereo+vision&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dstereo%2Bvision"><span id="translatedtitle"><span class="hlt">Topography</span> from shading and stereo</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Horn, Berthold P.; Caplinger, Michael</p> <p>1993-01-01</p> <p>Methods exploiting photometric information in images that have been developed in machine vision can be applied to planetary imagery. Present techniques, however, focus on one visual cue, such as shading or binocular stereo, and produce results that are either not very accurate in an <span class="hlt">absolute</span> sense or provide information only at few points on the surface. We plan to integrate shape from shading, binocular stereo and photometric stereo to yield a robust system for recovering detailed surface shape and surface reflectance information. Such a system will be useful in producing quantitative information from the vast volume of imagery being received, as well as in helping visualize the underlying surface. The work will be carried out on a popular computing platform so that it will be easily accessible to other workers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930016614&hterms=stereo+vision&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dstereo%2Bvision','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930016614&hterms=stereo+vision&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dstereo%2Bvision"><span id="translatedtitle"><span class="hlt">Topography</span> from shading and stereo</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Horn, Berthold P.; Caplinger, Michael</p> <p>1992-01-01</p> <p>Methods exploiting photometric information in images that have been developed in machine vision can be applied to planetary imagery. Present techniques, however, focus on one visual cue, such as shading or binocular stereo, and produce results that are either not very accurate in an <span class="hlt">absolute</span> sense or provide information only at few points on the surface. We plan to integrate shape from shading, binocular stereo and photometric stereo to yield a robust system for recovering detailed surface shape and surface reflectance information. Such a system will be useful in producing quantitative information from the vast volume of imagery being received, as well as in helping visualize the underlying surface. The work will be carried out on a popular computing platform so that it will be easily accessible to other workers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JAGeo...8..195S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JAGeo...8..195S"><span id="translatedtitle"><span class="hlt">Absolute</span> Performance of AUSGeoid09 in Mountainous Regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sussanna, Vittorio; Janssen, Volker; Gibbings, Peter</p> <p>2014-09-01</p> <p>The Australian Height Datum (AHD) is the current national vertical datum for Australia, and AUSGeoid09 is the latest quasigeoid model used to compute (normal-orthometric)AHDheights fromGlobalNavigation Satellite System (GNSS) derived ellipsoidal heights. While previous studies have evaluated the AUSGeoid09 model across Australia, such studies have not focused on mountainous regions in particular. This paper investigates the performance of AUSGeoid09 in an <span class="hlt">absolute</span> sense in the Mid Hunter and Snowy Mountains regions of New South Wales. <span class="hlt">Absolute</span> (i.e. single point) comparisons were undertaken between AUSGeoid09-derived heights and published AHD heights. The performance of AUSGeoid09 was evaluated relative to its predecessor AUSGeoid98. In both study areas, an overall improvement is evident when applying AUSGeoid09 to compute AHD heights in an <span class="hlt">absolute</span> sense. In the MidHunter, AUSGeoid09 provided a substantial improvement over its predecessor, clearly demonstrating the benefits of its new geometric component on GNSS-derived AHD height determination. In the Snowy Mountains, moderate improvement over AUSGeoid98 was evident. However, a slope was detected for AUSGeoid09 residuals, and it appears that the geometric component may have overcompensated for sea surface <span class="hlt">topography</span> in this area. While this appraisal of AUSGeoid09 performance in mountainous regions is encouraging, it has been shown that some discrepancies still remain between AUSGeoid09-derived heights and AHD. Eventually, a new vertical datum will be necessary to ensure homogeneity across Australia.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3801007','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3801007"><span id="translatedtitle">Genetic <span class="hlt">topography</span> of brain morphology</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chen, Chi-Hua; Fiecas, Mark; Gutiérrez, E. D.; Panizzon, Matthew S.; Eyler, Lisa T.; Vuoksimaa, Eero; Thompson, Wesley K.; Fennema-Notestine, Christine; Hagler, Donald J.; Jernigan, Terry L.; Neale, Michael C.; Franz, Carol E.; Lyons, Michael J.; Fischl, Bruce; Tsuang, Ming T.; Dale, Anders M.; Kremen, William S.</p> <p>2013-01-01</p> <p>Animal data show that cortical development is initially patterned by genetic gradients largely along three orthogonal axes. We previously reported differences in genetic influences on cortical surface area along an anterior-posterior axis using neuroimaging data of adult human twins. Here, we demonstrate differences in genetic influences on cortical thickness along a dorsal-ventral axis in the same cohort. The phenomenon of orthogonal gradations in cortical organization evident in different structural and functional properties may originate from genetic gradients. Another emerging theme of cortical patterning is that patterns of genetic influences recapitulate the spatial <span class="hlt">topography</span> of the cortex within hemispheres. The genetic patterning of both cortical thickness and surface area corresponds to cortical functional specializations. Intriguingly, in contrast to broad similarities in genetic patterning, two sets of analyses distinguish cortical thickness and surface area genetically. First, genetic contributions to cortical thickness and surface area are largely distinct; there is very little genetic correlation (i.e., shared genetic influences) between them. Second, organizing principles among genetically defined regions differ between thickness and surface area. Examining the structure of the genetic similarity matrix among clusters revealed that, whereas surface area clusters showed great genetic proximity with clusters from the same lobe, thickness clusters appear to have close genetic relatedness with clusters that have similar maturational timing. The discrepancies are in line with evidence that the two traits follow different mechanisms in neurodevelopment. Our findings highlight the complexity of genetic influences on cortical morphology and provide a glimpse into emerging principles of genetic organization of the cortex. PMID:24082094</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1175308','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1175308"><span id="translatedtitle"><span class="hlt">Absolute</span> calibration of optical flats</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sommargren, Gary E.</p> <p>2005-04-05</p> <p>The invention uses the phase shifting diffraction interferometer (PSDI) to provide a true point-by-point measurement of <span class="hlt">absolute</span> flatness over the surface of optical flats. Beams exiting the fiber optics in a PSDI have perfect spherical wavefronts. The measurement beam is reflected from the optical flat and passed through an auxiliary optic to then be combined with the reference beam on a CCD. The combined beams include phase errors due to both the optic under test and the auxiliary optic. Standard phase extraction algorithms are used to calculate this combined phase error. The optical flat is then removed from the system and the measurement fiber is moved to recombine the two beams. The newly combined beams include only the phase errors due to the auxiliary optic. When the second phase measurement is subtracted from the first phase measurement, the <span class="hlt">absolute</span> phase error of the optical flat is obtained.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20100014902&hterms=asp&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dasp','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20100014902&hterms=asp&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dasp"><span id="translatedtitle">The <span class="hlt">Absolute</span> Spectrum Polarimeter (ASP)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kogut, A. J.</p> <p>2010-01-01</p> <p>The <span class="hlt">Absolute</span> Spectrum Polarimeter (ASP) is an Explorer-class mission to map the <span class="hlt">absolute</span> intensity and linear polarization of the cosmic microwave background and diffuse astrophysical foregrounds over the full sky from 30 GHz to 5 THz. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r much greater than 1O(raised to the power of { -3}) and Compton distortion y < 10 (raised to the power of{-6}). We describe the ASP instrument and mission architecture needed to detect the signature of an inflationary epoch in the early universe using only 4 semiconductor bolometers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMIN31C1015M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMIN31C1015M"><span id="translatedtitle">The Glacier and Land Ice Surface <span class="hlt">Topography</span> Interferometer: An Airborne Proof-of-concept Mapping Sensor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moller, D.; Hensley, S.; Chuang, C.; Fisher, C.; Muellerschoen, R.; Milligan, L.; Sadowy, G.; Rignot, E. J.</p> <p>2009-12-01</p> <p>In May 2009 a new radar technique for mapping ice surface <span class="hlt">topography</span> was demonstrated in a Greenland campaign as part of the NASA International Polar Year activities. This was achieved by integrating a Ka-band single-pass interferometric synthetic radar on the NASA Dryden Gulfstream III for a coordinated deployment. Although the technique of using radar interferometry for mapping terrain has been demonstrated before, this is the first such application at millimeter-wave frequencies. This proof-of-concept demonstration was motivated by the Glacier and Land Ice Surface <span class="hlt">Topography</span> Interferometer (GLISTIN) Instrument Incubator Program and furthermore, highly leveraged existing ESTO hardware and software assets (the Unmanned Airborne Vehicle Synthetic Aperture Radar (UAVSAR) and processor and the PR2 (precipitation radar 2) RF assembly and power amplifier). Initial Ka-band test flights occurred in March and April of 2009 followed by the Greenland deployment. Instrument performance indicates swath widths over the ice between 5-7km, with height precisions ranging from 30cm-3m at a posting of 3m x 3m. However, for this application the electromagnetic wave will penetrate an unknown amount into the snow cover thus producing an effective bias that must be calibrated. This penetration will be characterized as part of this program and is expected to vary as a function of snow wetness and radar incidence angle. To evaluate this, we flew a coordinated collection with the NASA Wallops Airborne Topographic Mapper on a transect from Greenland’s Summit its West coast. This flight included two field calibration sites at Colorado Institute for Research in Environmental Science’s Swiss Camp and the National Science Foundation’s Summit station. Additional collections entailed flying a grid over Jakobshavn glacier which were repeated after 6 days to reveal surface <span class="hlt">dynamics</span>. In this time frame we were able to observe horizontal motion of over 1km on the glacier. While developed for relevancy to ice surface mapping, the Ka-band interferometer was able to make targeted observations relevant for the Surface Water and Ocean <span class="hlt">Topography</span> (SWOT) mission. Most notably, en route to Greenland via North Dakota, data was collected in the “SWOT-like” geometry by rolling the GIII toward nadir and collecting nadir data over surface water targets (Red and Missouri Rivers, Devils Lake, ND and the Big Bog, MN). Flying into Thule, SWOT data was also collected over sea ice. In summary, the campaign and demonstration was highly successful. Not only were we able to achieve the primary objective of validated data collections for ice-surface <span class="hlt">topography</span>, but we also gathered unique observations that will be used by the SWOT mission. In the next year, the detailed processing, <span class="hlt">absolute</span> calibration and intersensor comparisons will enable us ultimately to produce a high quality topographic map of Jakobshavn as an IPY reference for measuring future changes in ice elevation. Finally, our experiment has paved the way to make more topographic products available to glaciologists, either through dedicated airborne campaigns, or ultimately as a satellite mission.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/1031324','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/1031324"><span id="translatedtitle">Enhanced Characterization of Niobium Surface <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chen Xu, Hui Tian, Charles Reece, Michael Kelley</p> <p>2011-12-01</p> <p>Surface <span class="hlt">topography</span> characterization is a continuing issue for the Superconducting Radio Frequency (SRF) particle accelerator community. Efforts are underway to both to improve surface <span class="hlt">topography</span>, and its characterization and analysis using various techniques. In measurement of <span class="hlt">topography</span>, Power Spectral Density (PSD) is a promising method to quantify typical surface parameters and develop scale-specific interpretations. PSD can also be used to indicate how chemical processes modifiesy the roughnesstopography at different scales. However, generating an accurate and meaningful topographic PSD of an SRF surface requires careful analysis and optimization. In this report, polycrystalline surfaces with different process histories are sampled with AFM and stylus/white light interferometer profilometryers and analyzed to indicate trace <span class="hlt">topography</span> evolution at different scales. evolving during etching or polishing. Moreover, Aan optimized PSD analysis protocol will be offered to serve the SRF surface characterization needs is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JGRE..118..908B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JGRE..118..908B"><span id="translatedtitle">Convection-driven compaction as a possible origin of Enceladus's long wavelength <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Besserer, J.; Nimmo, F.; Roberts, J. H.; Pappalardo, R. T.</p> <p>2013-05-01</p> <p>The long wavelength surface <span class="hlt">topography</span> of Enceladus shows depressions about 1 km in depth and ˜102 km wide. One possible cause of this <span class="hlt">topography</span> is spatially variable amounts of compaction of an initially porous ice shell, driven by spatial variations in heat flux. Here, we show that the heat flux variations associated with convection in the shell can quantitatively match the observed features. We develop a simple model of viscous compaction that includes the effect of porosity on thermal conductivity, and find that an initial shell porosity of at least 20-25% is required to develop the observed <span class="hlt">topography</span> over ˜1 Ga. This mechanism produces topographic depressions, not rises, above convective upwellings, and does not generate detectable gravity anomalies. Unlike transient <span class="hlt">dynamic</span> <span class="hlt">topography</span>, it can potentially leave a permanent record of ancient convective processes in the shallow lithospheres of icy satellites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980018849','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980018849"><span id="translatedtitle"><span class="hlt">Topography</span> of the Moon from the Clementine Lidar</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, David E.; Zuber, Maria T.; Neumann, Gregory A.; Lemoine, Frank G.</p> <p>1997-01-01</p> <p>Range measurements from the lidar instrument carried aboard the Clementine spacecraft have been used to produce an accurate global topographic model of the Moon. This paper discusses the function of the lidar; the acquisition, processing, and filtering of observations to produce a global topographic model; and the determination of parameters that define the fundamental shape of the Moon. Our topographic model: a 72nd degree and order spherical harmonic expansion of lunar radii, is designated Goddard Lunar <span class="hlt">Topography</span> Model 2 (GLTM 2). This topographic field has an <span class="hlt">absolute</span> vertical accuracy of approximately 100 m and a spatial resolution of 2.5 deg. The field shows that the Moon can be described as a sphere with maximum positive and negative deviations of approx. 8 km, both occurring on the farside, in the areas of the Korolev and South Pole-Aitken (S.P.-Aitken) basins. The amplitude spectrum of the <span class="hlt">topography</span> shows more power at longer wavelengths as compared to previous models, owing to more complete sampling of the surface, particularly the farside. A comparison of elevations derived from the Clementine lidar to control point elevations from the Apollo laser altimeters indicates that measured relative topographic heights generally agree to within approx. 200 in over the maria. While the major axis of the lunar gravity field is aligned in the Earth-Moon direction, the major axis of <span class="hlt">topography</span> is displaced from this line by approximately 10 deg to the cast and intersects the farside 24 deg north of the equator. The magnitude of impact basin <span class="hlt">topography</span> is greater than the lunar flattening (approx. 2 km) and equatorial ellipticity (approx. 800 m), which imposes a significant challenge to interpreting the lunar figure. The floors of mare basins are shown to lie close to an equipotential surface, while the floors of unflooded large basins, except for S.P.-Aitken, lie above this equipotential. The radii of basin floors are thus consistent with a hydrostatic mechanism for the absence of significant farside maria except for S.P.-Aitken, whose depth and lack of mare require significant internal compositional and/or thermal heterogeneity. A macroscale surface roughness map shows that roughness at length scales of 10(exp 1) - 10(exp 2) km correlates with elevation and surface age.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhDT.......154L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhDT.......154L"><span id="translatedtitle">Corneal <span class="hlt">topography</span> measurements for biometric applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lewis, Nathan D.</p> <p></p> <p>The term biometrics is used to describe the process of analyzing biological and behavioral traits that are unique to an individual in order to confirm or determine his or her identity. Many biometric modalities are currently being researched and implemented including, fingerprints, hand and facial geometry, iris recognition, vein structure recognition, gait, voice recognition, etc... This project explores the possibility of using corneal <span class="hlt">topography</span> measurements as a trait for biometric identification. Two new corneal topographers were developed for this study. The first was designed to function as an operator-free device that will allow a user to approach the device and have his or her corneal <span class="hlt">topography</span> measured. Human subject <span class="hlt">topography</span> data were collected with this device and compared to measurements made with the commercially available Keratron Piccolo topographer (Optikon, Rome, Italy). A third topographer that departs from the standard Placido disk technology allows for arbitrary pattern illumination through the use of LCD monitors. This topographer was built and tested to be used in future research studies. <span class="hlt">Topography</span> data was collected from 59 subjects and modeled using Zernike polynomials, which provide for a simple method of compressing <span class="hlt">topography</span> data and comparing one topographical measurement with a database for biometric identification. The data were analyzed to determine the biometric error rates associated with corneal <span class="hlt">topography</span> measurements. Reasonably accurate results, between three to eight percent simultaneous false match and false non-match rates, were achieved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.C31E0569M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.C31E0569M"><span id="translatedtitle">Satellite Altimetric Mappings of Arctic Sea Surface <span class="hlt">Topography</span>: An Evaluation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McAdoo, D. C.; Farrell, S. L.; Laxon, S. W.; Zwally, H. J.; Yi, D.; Coakley, B.; Cochran, J. R.</p> <p>2008-12-01</p> <p>Increasingly precise mappings of sea surface <span class="hlt">topography</span> (SST) in the Arctic Ocean are being derived from near-polar satellite altimeters such as the laser system - Geoscience Laser Altimeter System (GLAS) - onboard NASA's ICESat and the radar systems onboard ESA's ERS-2 and Envisat. These mappings of sea surface <span class="hlt">topography</span> (SST) have important oceanographic and geodetic applications. For example, because the geoid does conform closely to sea surface <span class="hlt">topography</span> we can use altimetric SST measurements to estimate gravity (e.g., see the ARCtic Satellite-only (ARCS) field, McAdoo et al. 2008) particularly in regions lacking "true" surface gravity observations. Also, by differencing mappings of mean SST with a gravimetric geoid - particularly a geoid underpinned by a GRACE mean field model - we can estimate the <span class="hlt">dynamic</span> ocean <span class="hlt">topography</span> (DOT) and circulation of the Arctic Ocean. However, accurate estimates of DOT (e.g. accuracies better than a decimeter) require that we have very precise knowledge of the geoid and mean SST. Comparing a mean SST derived from ICESat/GLAS data spanning several years with a corresponding mean SST derived from ERS-2 data reveals short- wavelength differences or discrepancies of order 40 - 60 cm in certain areas of the Arctic Ocean such as the Chukchi Borderland. In order to attribute a portion of these discrepancies to laser or radar altimeter measurement error, we convert these mean SST fields to equivalent gravity fields and compare with gravity observations from several of the unclassified SCICEX/U.S. Navy submarine cruises (Edwards and Coakley, 2003; http://www.ldeo.columbia.edu/res/pi/SCICEX/ ). This comparison enables us to quantify short-wavelength errors in both laser and radar altimetric mean SST models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ClDy...46.2535J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ClDy...46.2535J"><span id="translatedtitle">Influence of <span class="hlt">topography</span> on tropical African vegetation coverage</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jung, Gerlinde; Prange, Matthias; Schulz, Michael</p> <p>2016-04-01</p> <p>Hominid evolution in the late Miocene has long been hypothesized to be linked to the retreat of the tropical rainforest in Africa. One cause for the climatic and vegetation change often considered was uplift of Africa, but also uplift of the Himalaya and the Tibetan Plateau was suggested to have impacted rainfall distribution over Africa. Recent proxy data suggest that in East Africa open grassland habitats were available to the common ancestors of hominins and apes long before their divergence and do not find evidence for a closed rainforest in the late Miocene. We used the coupled global general circulation model CCSM3 including an interactively coupled <span class="hlt">dynamic</span> vegetation module to investigate the impact of <span class="hlt">topography</span> on African hydro-climate and vegetation. We performed sensitivity experiments altering elevations of the Himalaya and the Tibetan Plateau as well as of East and Southern Africa. The simulations confirm the dominant impact of African <span class="hlt">topography</span> for climate and vegetation development of the African tropics. Only a weak influence of prescribed Asian uplift on African climate could be detected. The model simulations show that rainforest coverage of Central Africa is strongly determined by the presence of elevated African <span class="hlt">topography</span>. In East Africa, despite wetter conditions with lowered African <span class="hlt">topography</span>, the conditions were not favorable enough to maintain a closed rainforest. A discussion of the results with respect to other model studies indicates a minor importance of vegetation-atmosphere or ocean-atmosphere feedbacks and a large dependence of the simulated vegetation response on the land surface/vegetation model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014E%26PSL.408..362H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014E%26PSL.408..362H"><span id="translatedtitle">Evaluating Marie Byrd Land stability using an improved basal <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Holschuh, N.; Pollard, D.; Alley, R. B.; Anandakrishnan, S.</p> <p>2014-12-01</p> <p>Prior understanding of the ice-sheet setting in Marie Byrd Land (MBL) was derived primarily from geologic and geochemical studies of the current nunataks, with very few geophysical surveys imaging the ice covered regions. The geologic context suggested that the ice rests on a broad regional high, in contrast to the deep basins and trenches that characterize the majority of West Antarctica. This assumed <span class="hlt">topography</span> would favor long-term stability for the West Antarctic Ice Sheet (WAIS) in MBL. Airborne geophysical data collected in 2009 reveal a much deeper bed than previously estimated, including a significant trough underlying DeVicq Glacier and evidence for extensive glacial erosion. Using these data, we produce a new map of subglacial <span class="hlt">topography</span>, with which we model the sensitivity of WAIS to a warming ocean using the ice-sheet model of Pollard and DeConto (2012b). We compare the results to estimates of ice loss during WAIS collapse using the previously defined subglacial <span class="hlt">topography</span>, to determine the impact of the newly discovered subglacial features. Our results indicate that the topographic changes are not sufficient to destabilize the northern margin of MBL currently feeding the Getz Ice Shelf; the majority of ice loss occurs from flow toward the Siple Coast. However, despite only slight <span class="hlt">dynamic</span> differences, using the new bed as a boundary condition results in an additional 8 cm of sea-level rise during major glacial retreat, an increase of just over 2%. Precise estimation of past and future ice retreat, as well as a complete understanding of the geologic history of the region, will require a higher resolution picture of the bed <span class="hlt">topography</span> around the Executive Committee mountains.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ClDy..tmp..257J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ClDy..tmp..257J"><span id="translatedtitle">Influence of <span class="hlt">topography</span> on tropical African vegetation coverage</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jung, Gerlinde; Prange, Matthias; Schulz, Michael</p> <p>2015-07-01</p> <p>Hominid evolution in the late Miocene has long been hypothesized to be linked to the retreat of the tropical rainforest in Africa. One cause for the climatic and vegetation change often considered was uplift of Africa, but also uplift of the Himalaya and the Tibetan Plateau was suggested to have impacted rainfall distribution over Africa. Recent proxy data suggest that in East Africa open grassland habitats were available to the common ancestors of hominins and apes long before their divergence and do not find evidence for a closed rainforest in the late Miocene. We used the coupled global general circulation model CCSM3 including an interactively coupled <span class="hlt">dynamic</span> vegetation module to investigate the impact of <span class="hlt">topography</span> on African hydro-climate and vegetation. We performed sensitivity experiments altering elevations of the Himalaya and the Tibetan Plateau as well as of East and Southern Africa. The simulations confirm the dominant impact of African <span class="hlt">topography</span> for climate and vegetation development of the African tropics. Only a weak influence of prescribed Asian uplift on African climate could be detected. The model simulations show that rainforest coverage of Central Africa is strongly determined by the presence of elevated African <span class="hlt">topography</span>. In East Africa, despite wetter conditions with lowered African <span class="hlt">topography</span>, the conditions were not favorable enough to maintain a closed rainforest. A discussion of the results with respect to other model studies indicates a minor importance of vegetation-atmosphere or ocean-atmosphere feedbacks and a large dependence of the simulated vegetation response on the land surface/vegetation model.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMPP33B1231C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMPP33B1231C"><span id="translatedtitle">Reconstructing Pliocene coastlines, <span class="hlt">topography</span> and bathymetry: A geodynamic perspective</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chandan, D.; Peltier, W. R.</p> <p>2014-12-01</p> <p>The middle Pliocene period (~3.3-3.0 Mya) was characterized by warm temperatures (2-3℃ higher) and high carbon-dioxide (~400 ppmv) concentrations which has led to its recognition as a possible analogue for the future climate. Under the auspices of the Pliocene Modeling and Intercomparison Project (PlioMIP), general circulation models (GCM's) are being employed to simulate mid-Pliocene climate to better understand the biases in these models, which are presently used to make future climate predictions. Necessary boundary conditions for these simulations — land mask, <span class="hlt">topography</span>, surface albedo and vegetation cover are being provided by the Pliocene Research, Interpretation and Synoptic Mapping (PRISM) project. Bathymetry, which is not part of the PRISM supplied dataset has been adjusted by raising the sea-level by an assumed constant eustatic amount. At present the PRISM land mask, <span class="hlt">topography</span> and bathymetry reconstructions do not incorporate the gravitationally self consistent changes that would be required to account for the mass loss from the Greenland and Antarctic ice-sheets that produced the assumed rise in eustatic sea level. The effects of <span class="hlt">dynamic</span> <span class="hlt">topography</span> induced corrections, due to the action of the mantle convection process, have also been neglected.The influence of these corrections on the predictions of Pliocene climate using modern GCM's remains unexplored. The continuing failure of these models to simulate proxy inferred levels of warming in high-latitude [Dowsett et al., 2013, Sci. Rep.] regions where the magnitude of the required corrections are expected to be largest make it especially important that their impact be assessed. Here, we present the results from a preliminary of the required modifications to the boundary condition data sets.We compute the gravitationally self consistent corrections using the viscoelastic theory of global, glacial isostatic adjustment and relative sea level history for a spherically symmetric Earth model. <span class="hlt">Dynamic</span> <span class="hlt">topography</span> related changes are computed using a 3D convection model initialized using seismic tomography. Together, this creates an updated picture of the mid-Pliocene shoreline, <span class="hlt">topography</span> and bathymetry that can be employed as boundary conditions for future Pliocene climate modeling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19820026516&hterms=registration+parameters&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dregistration%2Bparameters','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19820026516&hterms=registration+parameters&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dregistration%2Bparameters"><span id="translatedtitle"><span class="hlt">Absolute</span> image registration for geosynchronous satellites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nankervis, R.; Koch, D.; Sielski, H.; Hall, D.</p> <p>1980-01-01</p> <p>A procedure for the <span class="hlt">absolute</span> registration of earth images acquired by cameras on geosynchronous satellites is described. A conventional least squares process is used to estimate navigational parameters and camera pointing biases from observed minus computed landmark line and element numbers. These estimated parameters along with orbit and attitude <span class="hlt">dynamic</span> models are used to register images, employing an automated grey-level correlation technique, inside the span represented by the landmark data. Experimental results obtained from processing the SMS-2 observation data base covering May 2, 1979 through May 20, 1979 show registration accuracies with a standard deviation of less than two pixels if the registration is within the landmark data span. It is also found that accurate registration can be expected for images obtained up to 48 hours outside of the landmark data span.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NHESD...2.1433M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NHESD...2.1433M"><span id="translatedtitle">Numerical modeling and analysis of the effect of Greek complex <span class="hlt">topography</span> on tornado genesis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matsangouras, I. T.; Pytharoulis, I.; Nastos, P. T.</p> <p>2014-02-01</p> <p>Tornadoes have been reported in Greece over the last decades in specific sub-geographical areas and have been associated with strong synoptic forcing. It is well known that meteorological conditions over Greece are affected at various scales by the significant variability of <span class="hlt">topography</span>, the Ionian Sea at the west and the Aegean Sea at the east. However, there is still uncertainty regarding <span class="hlt">topography</span>'s importance on tornadic generation and development. The aim of this study is to investigate the role of <span class="hlt">topography</span> in significant tornado genesis events that were triggered under strong synoptic scale forcing over Greece. Three tornado events that occurred over the last years in Thiva (Boeotia, 17 November 2007), Vrastema (Chalkidiki, 12 February 2010) and Vlychos (Lefkada, 20 September 2011) have been selected for numerical experiments. These events were associated with synoptic scale forcing, while their intensity was T4-T5 (Torro scale) and caused significant damage. The simulations were performed using the non-hydrostatic Weather Research and Forecasting model (WRF), initialized with ECMWF gridded analyses, with telescoping nested grids that allow the representation of atmospheric circulations ranging from the synoptic scale down to the meso scale. In the experiments the <span class="hlt">topography</span> of the inner grid was modified by: (a) 0% (actual <span class="hlt">topography</span>) and (b) -100% (without <span class="hlt">topography</span>). The aim was to determine whether the occurrence of tornadoes - mainly identified by various severe weather instability indices - could be indicated by modifying <span class="hlt">topography</span>. The main utilized instability variables concerned the Bulk Richardson number shear (BRN), the energy helicity index (EHI), the storm-relative environmental helicity (SRH) and the maximum convective available potential energy (MCAPE, for parcel with maximum theta-e). Additional a verification of model was conducted for every sensitivity experiment accompanied with analysis <span class="hlt">absolute</span> vorticity budget. Numerical simulations revealed that the complex <span class="hlt">topography</span> was denoted as an important factor during 17 November 2007 and 12 February 2010 events, based on EHI and BRN analyses. <span class="hlt">Topography</span> around 20 September 2011 event was characterized as the least factor based on EHI, SRH, BRN analyses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NHESS..14.1905M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NHESS..14.1905M"><span id="translatedtitle">Numerical modeling and analysis of the effect of complex Greek <span class="hlt">topography</span> on tornadogenesis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Matsangouras, I. T.; Pytharoulis, I.; Nastos, P. T.</p> <p>2014-07-01</p> <p>Tornadoes have been reported in Greece over recent decades in specific sub-geographical areas and have been associated with strong synoptic forcing. While it has been established that meteorological conditions over Greece are affected at various scales by the significant variability of <span class="hlt">topography</span>, the Ionian Sea to the west and the Aegean Sea to the east, there is still uncertainty regarding <span class="hlt">topography</span>'s importance on tornadic generation and development. The aim of this study is to investigate the role of <span class="hlt">topography</span> in significant tornadogenesis events that were triggered under strong synoptic scale forcing over Greece. Three tornado events that occurred over the last years in Thebes (Boeotia, 17 November 2007), Vrastema (Chalkidiki, 12 February 2010) and Vlychos (Lefkada, 20 September 2011) were selected for numerical experiments. These events were associated with synoptic scale forcing, while their intensities were T4-T5 (on the TORRO scale), causing significant damage. The simulations were performed using the non-hydrostatic weather research and forecasting model (WRF), initialized by European Centre for Medium-Range Weather Forecasts (ECMWF) gridded analyses, with telescoping nested grids that allow for the representation of atmospheric circulations ranging from the synoptic scale down to the mesoscale. In the experiments, the <span class="hlt">topography</span> of the inner grid was modified by: (a) 0% (actual <span class="hlt">topography</span>) and (b) -100% (without <span class="hlt">topography</span>), making an effort to determine whether the occurrence of tornadoes - mainly identified by various severe weather instability indices - could be indicated by modifying <span class="hlt">topography</span>. The principal instability variables employed consisted of the bulk Richardson number (BRN) shear, the energy helicity index (EHI), the storm-relative environmental helicity (SRH), and the maximum convective available potential energy (MCAPE, for parcels with maximum θe). Additionally, a model verification was conducted for every sensitivity experiment accompanied by analysis of the <span class="hlt">absolute</span> vorticity budget. Numerical simulations revealed that the complex <span class="hlt">topography</span> constituted an important factor during the 17 November 2007 and 12 February 2010 events, based on EHI, SRH, BRN, and MCAPE analyses. Conversely, <span class="hlt">topography</span> around the 20 September 2011 event was characterized as the least significant factor based on EHI, SRH, BRN, and MCAPE analyses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/8206802','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/8206802"><span id="translatedtitle"><span class="hlt">Absolute</span> pitch--electrophysiological evidence.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Barnea, A; Granot, R; Pratt, H</p> <p>1994-02-01</p> <p>People who have the ability to label or to produce notes without any reference are considered to possess <span class="hlt">Absolute</span> Pitch (AP). Others, who need a reference in order to identify the notes, possess Relative Pitch (RP). The AP ability is assumed to reflect a unique, language-like representation of non-lexical musical notes in memory. The purpose of this study was to examine this assumption by comparing Event Related Potentials (ERP) of musicians with and without AP, to lexical and non-lexical representation of musical material. Subjects were eighteen young adult musicians. Seven were AP and eleven RP. Auditory stimuli, presented through earphones, were piano notes (non-lexical) or a voice saying the note's name (lexical). Visual stimuli, presented on a computer display were note symbols (non-lexical) or letters (lexical). Subjects performed a number of tasks, combining the two modalities (visual and auditory) and stimulus types (lexical and non-lexical), and reaction times (RT), performance accuracy and evoked potentials were recorded. The tasks forced the subjects to transfer mental representations of musical material from one mode to another. Our most important findings were the differences, between groups, in the scalp distribution of P300 amplitudes. We conclude that <span class="hlt">absolute</span> pitch possessors use the same internal language as relative pitch possessors, when possible, but the distribution of the underlying brain activity is different between AP and RP subjects. PMID:8206802</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010APS..MAR.K1090L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010APS..MAR.K1090L"><span id="translatedtitle"><span class="hlt">Absolute</span> Measurement of STIRAP Efficiency</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, Xiaoxu; Sun, Yuan; Allred, Claire; Metcalf, Harold</p> <p>2010-03-01</p> <p>Driving atoms from an initial to a final state of the same parity via an intermediate state of opposite parity is most efficiently done using STIRAPfootnotetextU. Gaubatz et al., J. Chem. Phys., 92, 5363 (1990)., because it doesn't populate the intermediate state. For optical transitions this requires appropriate pulses of light in the counter-intuitive order - first coupling the intermediate and final states. We populate Rydberg states of He (n = 26) in a beam of average velocity 1070 m/s by having them cross two laser beams in a tunable dc electric field of ˜100 V/cm. The ``red" light near λ= 796 nm connects the 3^3P states to the Rydberg states and the ``blue" beam connects the metastable 2^3S state atoms emitted by our source to their 3^3P states. By varying the relative position of these beams we can vary the order and overlap encountered by the atoms. We vary the dc field to sweep across several Stark states of the Rydberg manifold. We measure the <span class="hlt">absolute</span> efficiency using a curved wavefront beam of λ= 1.083,m light to deflect residual 2^3S atoms out of the beam, and we measure their flux with and without the STIRAP beams. This uncontaminated measurement has high <span class="hlt">absolute</span> accuracy. *Presently at Columbia Univ., 1027 Pupin Hall, New York, NY 10027</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010APS..DMP.M1153L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010APS..DMP.M1153L"><span id="translatedtitle"><span class="hlt">Absolute</span> Measurement of STIRAP Efficiency</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lu, Xiaoxu; Sun, Yuan; Allred, Claire; Metcalf, Harold</p> <p>2010-03-01</p> <p>Driving atoms from an initial to a final state of the same parity via an intermediate state of opposite parity is most efficiently done using STIRAPootnotetextU. Gaubatz et al., J. Chem. Phys., 92, 5363 (1990)., because it doesn't populate the intermediate state. For optical transitions this requires appropriate pulses of light in the counter-intuitive order - first coupling the intermediate and final states. We populate Rydberg states of He (n = 26) in a beam of average velocity 1070 m/s by having them cross two laser beams in a tunable dc electric field of ˜100 V/cm. The ``red" light near λ= 796 nm connects the 3^3P states to the Rydberg states and the ``blue" beam connects the metastable 2^3S state atoms emitted by our source to their 3^3P states. By varying the relative position of these beams we can vary the order and overlap encountered by the atoms. We vary the dc field to sweep across several Stark states of the Rydberg manifold. We measure the <span class="hlt">absolute</span> efficiency using a curved wavefront beam of λ= 1.083,m light to deflect residual 2^3S atoms out of the beam, and we measure their flux with and without the STIRAP beams. This uncontaminated measurement has high <span class="hlt">absolute</span> accuracy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2001AGUFM.G41B0228R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2001AGUFM.G41B0228R"><span id="translatedtitle"><span class="hlt">Absolute</span> Gravimeter Helium Immersion Experiment</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Robertson, D. S.; Courtier, N.; Winester, D.</p> <p>2001-12-01</p> <p>The FG5 <span class="hlt">absolute</span> gravimeter uses a laser interferometer to measure the acceleration of a mirror that is free-falling in a vacuum chamber. The recoil caused by the release of the falling mirror produces vibrations in the gravimeter that can systematically affect the measured gravity values. The major effect of the vibrations is to change the vertical position of the window on the vacuum dropping chamber where the laser interferometer beam enters the chamber. Because the window represents an air-vacuum interface, any motion of the window will change the length of the laser path that passes through air and thereby change the total time that the laser beam takes to traverse the interferometer path. Therefore these window vibrations will have the same effect on the measured interferometer phase as changes in the position of the falling mirror. Operating an FG-5 <span class="hlt">absolute</span> gravimeter in a helium atmosphere should reduce these systematic errors. The helium atmosphere decreases the change in refractivity across the interface by up to 88%, depending on the purity of the helium. We observe a marked reduction in the post-fit residuals at frequencies of about 50 Hz and little or no effect at higher frequencies, and we develop a qualitative explanation of the frequency cutoff in terms of motion of air under compression. Further experiments to measure and characterize the effects of the vibrations are planned.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4460076','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4460076"><span id="translatedtitle">Electronic Cigarette <span class="hlt">Topography</span> in the Natural Environment</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Morabito, P. N.; Roundtree, K. A.</p> <p>2015-01-01</p> <p>This paper presents the results of a clinical, observational, descriptive study to quantify the use patterns of electronic cigarette users in their natural environment. Previously published work regarding puff <span class="hlt">topography</span> has been widely indirect in nature, and qualitative rather than quantitative, with the exception of three studies conducted in a laboratory environment for limited amounts of time. The current study quantifies the variation in puffing behaviors among users as well as the variation for a given user throughout the course of a day. Puff <span class="hlt">topography</span> characteristics computed for each puffing session by each subject include the number of subject puffs per puffing session, the mean puff duration per session, the mean puff flow rate per session, the mean puff volume per session, and the cumulative puff volume per session. The same puff <span class="hlt">topography</span> characteristics are computed across all puffing sessions by each single subject and across all subjects in the study cohort. Results indicate significant inter-subject variability with regard to puffing <span class="hlt">topography</span>, suggesting that a range of representative puffing <span class="hlt">topography</span> patterns should be used to drive machine-puffed electronic cigarette aerosol evaluation systems. PMID:26053075</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015E%26PSL.430....9F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015E%26PSL.430....9F"><span id="translatedtitle">Influence of subduction history on South American <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Flament, Nicolas; Gurnis, Michael; Müller, R. Dietmar; Bower, Dan J.; Husson, Laurent</p> <p>2015-11-01</p> <p>The Cenozoic evolution of South American <span class="hlt">topography</span> is marked by episodes of large-scale uplift and subsidence not readily explained by lithospheric deformation. The drying up of the inland Pebas system, the drainage reversal of the Amazon river, the uplift of the Sierras Pampeanas and the uplift of Patagonia have all been linked to the evolution of mantle flow since the Miocene in separate studies. Here we investigate the evolution of long-wavelength South American <span class="hlt">topography</span> as a function of subduction history in a time-dependent global geodynamic model. This model is shown to be consistent with these inferred changes, as well as with the migration of the Chaco foreland basin depocentre, that we partly attribute to the inboard migration of subduction resulting from Andean mountain building. We suggest that the history of subduction along South America has had an important influence on the evolution of the <span class="hlt">topography</span> of the continent because time-dependent mantle flow models are consistent with the history of vertical motions as constrained by the geological record at four distant areas over a whole continent. Testing alternative subduction scenarios reveals flat slab segments are necessary to reconcile inferred Miocene shorelines with a simple model paleogeography. As recently suggested, we find that the flattening of a subduction zone results in <span class="hlt">dynamic</span> uplift between the leading edge of the flat slab segment and the trench, and in a wave of <span class="hlt">dynamic</span> subsidence associated with the inboard migration of the leading edge of flat subduction. For example, the flattening of the Peruvian subduction contributed to the demise of Pebas shallow-water sedimentation, while continental-scale tilting also contributed to the drainage reversal of the Amazon River. The best correlation to P-wave tomography models for the Peruvian flat slab segment is obtained for a case when the asthenosphere, here considered to be 150 km thick and 10 times less viscous than the upper mantle, is restricted to the oceanic domain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GGG....16.1378P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GGG....16.1378P"><span id="translatedtitle">Development of <span class="hlt">topography</span> in 3-D continental-collision models</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pusok, A. E.; Kaus, Boris J. P.</p> <p>2015-05-01</p> <p>Understanding the formation and evolution of high mountain belts, such as the Himalayas and the adjacent Tibetan Plateau, has been the focus of many tectonic and numerical models. Here we employ 3-D numerical simulations to investigate the role that subduction, collision, and indentation play on lithosphere <span class="hlt">dynamics</span> at convergent margins, and to analyze the conditions under which large topographic plateaus can form in an integrated lithospheric and upper mantle-scale model. Distinct <span class="hlt">dynamics</span> are obtained for the oceanic subduction side (trench retreat, slab rollback) and the continental-collision side (trench advance, slab detachment, topographic uplift, lateral extrusion). We show that slab pull alone is insufficient to generate high <span class="hlt">topography</span> in the upper plate, and that external forcing and the presence of strong blocks such as the Tarim Basin are necessary to create and shape anomalously high topographic fronts and plateaus. Moreover, scaling is used to predict four different modes of surface expression in continental-collision models: (I) low-amplitude homogeneous shortening, (II) high-amplitude homogeneous shortening, (III) Alpine-type <span class="hlt">topography</span> with topographic front and low plateau, and (IV) Tibet-Himalaya-type <span class="hlt">topography</span> with topographic front and high plateau. Results of semianalytical models suggest that the Argand number governs the formation of high topographic fronts, while the amplitude of plateaus is controlled by the initial buoyancy ratio of the upper plate. Applying these results to natural examples, we show that the Alps belong to regime (III), the Himalaya-Tibet to regime (IV), whereas the Andes-Altiplano fall at the boundary between regimes (III) and (IV).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4221264','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4221264"><span id="translatedtitle">Determining <span class="hlt">absolute</span> protein numbers by quantitative fluorescence microscopy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Verdaasdonk, Jolien Suzanne; Lawrimore, Josh; Bloom, Kerry</p> <p>2014-01-01</p> <p>Biological questions are increasingly being addressed using a wide range of quantitative analytical tools to examine protein complex composition. Knowledge of the <span class="hlt">absolute</span> number of proteins present provides insights into organization, function, and maintenance and is used in mathematical modeling of complex cellular <span class="hlt">dynamics</span>. In this chapter, we outline and describe three microscopy-based methods for determining <span class="hlt">absolute</span> protein numbers—fluorescence correlation spectroscopy, stepwise photobleaching, and ratiometric comparison of fluorescence intensity to known standards. In addition, we discuss the various fluorescently labeled proteins that have been used as standards for both stepwise photobleaching and ratiometric comparison analysis. A detailed procedure for determining <span class="hlt">absolute</span> protein number by ratiometric comparison is outlined in the second half of this chapter. Counting proteins by quantitative microscopy is a relatively simple yet very powerful analytical tool that will increase our understanding of protein complex composition. PMID:24974037</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1210875W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1210875W"><span id="translatedtitle">A large-eddy simulation study of turbulent flow over multiscale <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wan, Feng; Porté-Agel, Fernando</p> <p>2010-05-01</p> <p>Most natural landscapes are characterized by multiscale (often multifractal) <span class="hlt">topography</span> with well-established scale-invariance properties. For example, the spectral density of landscape elevation fields is often found to have a power-law scaling behavior (with a -2 slope in log-log scale) over a wide span of spatial scales, typically ranging from tens of kilometers down to a few meters. Even though the effect of <span class="hlt">topography</span> on the atmospheric boundary layer (ABL) has been the subject of numerous studies, few of them have focused on multiscale <span class="hlt">topography</span>. In this study, Large-Eddy Simulation (LES) is used to investigate boundary layer flow over multiscale <span class="hlt">topography</span>, and guide the development of parameterizations needed to represent the effects of subgrid-scale (SGS) <span class="hlt">topography</span> in numerical models. Particular emphasis is placed on the formulation of an effective roughness used to account for the increased aerodynamic roughness associated with SGS <span class="hlt">topography</span>. The LES code uses the scale-dependent Lagrangian <span class="hlt">dynamic</span> SGS model for the turbulent stresses (Stoll and Porté-Agel, 2006) and a terrain-following coordinate transformation to explicitly resolve the effects of the <span class="hlt">topography</span> at scales larger than the LES resolution. The terrain used in the simulations is generated using a restricted solid-on-solid (RSOS) landscape evolution model, and it is characterized by a -2 slope of the elevation power spectrum, similar to that of natural landscapes. Results from simulations performed using elevation fields filtered at different spatial resolutions indicate a clear scaling of the effective roughness with the standard deviation of the elevation field. Based on these findings, recommendations are provided for the parameterization of the effective roughness associated with SGS <span class="hlt">topography</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003OptLE..40..143M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003OptLE..40..143M"><span id="translatedtitle">Moiré <span class="hlt">topography</span> in odontology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moreno Yeras, A.</p> <p>2003-07-01</p> <p>For several decades, measurement of optical techniques has been used in different branches of science and technology. One of these techniques is the so-called moiré <span class="hlt">topography</span> (MT) that enables the accurate measurement of different parts of the human body <span class="hlt">topography</span>. This investigation presents the measurement of <span class="hlt">topographies</span> of teeth and gums using an automated system of shadow moiré and the phase shift method in an original way. The fringe patterns used to compute the shape and the shape matrix itself are presented in the article. The phase shift method ensures precisions up to the order of microns. Advantages and disadvantages of using the MT are included. Besides, some positive and negative aspects concerned with the implementation of this technique in odontology are shown in the article.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DFDL29008M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DFDL29008M"><span id="translatedtitle">Experiments on <span class="hlt">topographies</span> lacking tidal conversion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maas, Leo; Paci, Alexandre; Yuan, Bing</p> <p>2015-11-01</p> <p>In a stratified sea, internal tides are supposedly generated when the tide passes over irregular <span class="hlt">topography</span>. It has been shown that for any given frequency in the internal wave band there are an infinite number of exceptions to this rule of thumb. This ``stealth-like'' property of the <span class="hlt">topography</span> is due to a subtle annihilation of the internal waves generated during the surface tide's passage over the irregular bottom. We here demonstrate this in a lab-experiment. However, for any such <span class="hlt">topography</span>, subsequently changing the surface tide's frequency does lead to tidal conversion. The upshot of this is that a tidal wave passing over an irregular bottom is for a substantial part trapped to this irregularity, and only partly converted into freely propagating internal tides. Financially supported by the European Community's 7th Framework Programme HYDRALAB IV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ISPAn.II5..301H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ISPAn.II5..301H"><span id="translatedtitle"><span class="hlt">Topography</span> Restoration of Historic City Research</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>ho, L. Sung; soo, H. Dong</p> <p>2015-08-01</p> <p>The preservation of historic cities requires a balance between conservation and development because the urban structures of the old and new city are interwoven on same space. Existing restoration plans rely on old records and excavation reports and are based on the present <span class="hlt">topography</span>. However, historic cities have undergone significant natural and anthropogenic topographic changes such as alluvial sediment accumulation and uneven terrain construction. Therefore, considering only the present <span class="hlt">topography</span> is misleading. Thus, to understand a historic city's structure more appropriately, it is necessary to comprehend the ancient geographic environment. This study provides an analysis and GIS visualization of the ancient <span class="hlt">topography</span> of a historic city, Sabi capital city of the Baekje Dynasty, which collapsed 1,500 years ago.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21136780','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21136780"><span id="translatedtitle"><span class="hlt">Absolute</span> Neutron Emission Measurement in Burning Plasma Experiments</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nishitani, Takeo; Ishikawa, Masao; Kondoh, Takashi; Kusama, Yoshinori; Asai, Keisuke; Sasao, Mmamiko</p> <p>2008-03-12</p> <p>The <span class="hlt">absolute</span> measurement of neutron emission rate from the whole plasma is a very important diagnostics as a fusion power monitor in fusion experimental devices with D-T or D-T operations. Here measurement techniques of time-resolved and time-integrated <span class="hlt">absolute</span> neutron emission on the present tokamaks and ITER are reviewed. In the present tokamaks, fission chamber installed outside the vacuum vessel are very popular in the <span class="hlt">absolute</span> neutron emission rate measurement. As well as conventional neutron monitors installed outside the vacuum vessel, in-vessel neutron monitors using micro fission chamber are proposed for the <span class="hlt">absolute</span> neutron emission rate measurement in ITER. The neutron activation system provides time-integrated measurements of the total neutron yield with high accuracy by using well known neutron reaction cross sections, which is useful to maintain a robust measure of fusion energy production with stability and wide <span class="hlt">dynamic</span> range. The calibration of the relation between the neutron emission rate in the whole plasma and the output of neutron monitor is the most important issue in the <span class="hlt">absolute</span> neutron emission rate measurements. The calibration of the neutron detectors has been performed by moving a neutron source such as a {sup 252}Cf neutron or a small accelerator-based neutron generator. For the calibration in ITER, the neutron generator with neutron emission rate of 10{sup 11} s{sup -1} or stronger is required to obtain high accuracy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AIPC..988..267N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AIPC..988..267N"><span id="translatedtitle"><span class="hlt">Absolute</span> Neutron Emission Measurement in Burning Plasma Experiments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nishitani, Takeo; Ishikawa, Masao; Kondoh, Takashi; Kusama, Yoshinori; Asai, Keisuke; Sasao, Mmamiko</p> <p>2008-03-01</p> <p>The <span class="hlt">absolute</span> measurement of neutron emission rate from the whole plasma is a very important diagnostics as a fusion power monitor in fusion experimental devices with D-T or D-T operations. Here measurement techniques of time-resolved and time-integrated <span class="hlt">absolute</span> neutron emission on the present tokamaks and ITER are reviewed. In the present tokamaks, fission chamber installed outside the vacuum vessel are very popular in the <span class="hlt">absolute</span> neutron emission rate measurement. As well as conventional neutron monitors installed outside the vacuum vessel, in-vessel neutron monitors using micro fission chamber are proposed for the <span class="hlt">absolute</span> neutron emission rate measurement in ITER. The neutron activation system provides time-integrated measurements of the total neutron yield with high accuracy by using well known neutron reaction cross sections, which is useful to maintain a robust measure of fusion energy production with stability and wide <span class="hlt">dynamic</span> range. The calibration of the relation between the neutron emission rate in the whole plasma and the output of neutron monitor is the most important issue in the <span class="hlt">absolute</span> neutron emission rate measurements. The calibration of the neutron detectors has been performed by moving a neutron source such as a 252Cf neutron or a small accelerator-based neutron generator. For the calibration in ITER, the neutron generator with neutron emission rate of 1011 s-1 or stronger is required to obtain high accuracy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..DFD.M8005L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..DFD.M8005L"><span id="translatedtitle">Transient coating of substrates with variable <span class="hlt">topography</span> by viscous films</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lampropoulos, Nikos; Dimakopoulos, Yiannis; Tsamopoulos, John</p> <p>2015-11-01</p> <p>We study the transient coating of substrates exhibiting orthogonal trenches. We use the VoF method via OpenFOAM to solve the transient NS eqs on an unstructured grid, which <span class="hlt">dynamically</span> undergoes local refinement around the interfaces. An Euler implicit method is used with adjustable time-step. The computational cost is reduced by parallel execution via MPI. Completely different wetting patterns result depending on the 3 dimensions of the <span class="hlt">topography</span>, the capillary and Reynolds numbers and the <span class="hlt">dynamic</span> contact angle. On one hand, continuous coating can be achieved in which the thin film of fluid wets the entire trench, while a steady flow is established upstream and downstream the <span class="hlt">topography</span>. This is the desirable pattern in coating microelectronic devices for their protection and planarization. The other extreme possibility is that the film completely bypasses the trench, entrapping air inside it. This pattern reduces the drag coefficient on the film and, therefore, it is desirable in super-hydrophobic surfaces for microfluidic applications. Between these two extremes, a large variety of patterns exists in which the film partially wets the trench forming an air inclusion all along its bottom surface or its upstream or downstream inner corners or the film may breakup periodically. We produce comprehensive maps of film configurations covering a wide range of parameter values. GSRT of Greece via the program ``Excellence,'' Grant 1918.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AIPC.1685i0005M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AIPC.1685i0005M"><span id="translatedtitle">Structures of lee waves over combined <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Makarenko, Nikolay; Maltseva, Janna; Cherevko, Alexander</p> <p>2015-10-01</p> <p>The problem on non-homogeneous shear flows over rough terrain is considered semi-analytically. A non-linear model of stratified flow over combined obstacle is constructed in the small amplitude limit for the <span class="hlt">topography</span>. The method uses a Fourier series in modal decomposition of waves caused by a localized multi-bump obstacle modeling a mountain range. The focus of attention is on the stationary wave patterns formed directly above the mountain range. Wave solutions corresponding to <span class="hlt">topography</span> with a finite number of peaks are calculated. These solutions predict rigorously the splitting of a near-field flow into separate wave zones having different spatial scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhDT........79V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhDT........79V"><span id="translatedtitle">Effects of patterned <span class="hlt">topography</span> on biofilm formation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vasudevan, Ravikumar</p> <p>2011-12-01</p> <p>Bacterial biofilms are a population of bacteria attached to each other and irreversibly to a surface, enclosed in a matrix of self-secreted polymers, among others polysaccharides, proteins, DNA. Biofilms cause persisting infections associated with implanted medical devices and hospital acquired (nosocomial) infections. Catheter-associated urinary tract infections (CAUTIs) are the most common type of nosocomial infections accounting for up to 40% of all hospital acquired infections. Several different strategies, including use of antibacterial agents and genetic cues, quorum sensing, have been adopted for inhibiting biofilm formation relevant to CAUTI surfaces. Each of these methods pertains to certain types of bacteria, processes and has shortcomings. Based on eukaryotic cell <span class="hlt">topography</span> interaction studies and Ulva linza spore studies, topographical surfaces were suggested as a benign control method for biofilm formation. However, <span class="hlt">topographies</span> tested so far have not included a systematic variation of size across basic <span class="hlt">topography</span> shapes. In this study patterned <span class="hlt">topography</span> was systematically varied in size and shape according to two approaches 1) confinement and 2) wetting. For the confinement approach, using scanning electron microscopy and confocal microscopy, orienting effects of tested <span class="hlt">topography</span> based on staphylococcus aureus (s. aureus) (SH1000) and enterobacter cloacae (e. cloacae) (ATCC 700258) bacterial models were identified on features of up to 10 times the size of the bacterium. Psuedomonas aeruginosa (p. aeruginosa) (PAO1) did not show any orientational effects, under the test conditions. Another important factor in medical biofilms is the identification and quantification of phenotypic state which has not been discussed in the literature concerning bacteria <span class="hlt">topography</span> characterizations. This was done based on antibiotic susceptibility evaluation and also based on gene expression analysis. Although orientational effects occur, phenotypically no difference was observed between the patterned <span class="hlt">topography</span> tested. Another potential strategy for biofilm control through patterned <span class="hlt">topography</span> is based on the design of robust non-wetting surfaces with undercut feature geometries, characterized by 1) breakthrough pressure and 2) triple phase contact line model. It was found that height and presence of undercut had statistically significant effects, directly proportional to breakthrough pressures, whereas extent of undercut did not. A predictive triple phase contact line model was also developed. (Full text of this dissertation may be available via the University of Florida Libraries web site. Please check http://www.uflib.ufl.edu/etd.html)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SuTMP...3a3001L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SuTMP...3a3001L"><span id="translatedtitle">Open questions in surface <span class="hlt">topography</span> measurement: a roadmap</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leach, Richard; Evans, Christopher; He, Liangyu; Davies, Angela; Duparré, Angela; Henning, Andrew; Jones, Christopher W.; O'Connor, Daniel</p> <p>2015-03-01</p> <p>Control of surface <span class="hlt">topography</span> has always been of vital importance for manufacturing and many other engineering and scientific disciplines. However, despite over one hundred years of quantitative surface <span class="hlt">topography</span> measurement, there are still many open questions. At the top of the list of questions is ‘Are we getting the right answer?’ This begs the obvious question ‘How would we know?’ There are many other questions relating to applications, the appropriateness of a technique for a given scenario, or the relationship between a particular analysis and the function of the surface. In this first ‘open questions’ article we have gathered together some experts in surface <span class="hlt">topography</span> measurement and asked them to address timely, unresolved questions about the subject. We hope that their responses will go some way to answer these questions, address areas where further research is required, and look at the future of the subject. The first section ‘Spatial content characterization for precision surfaces’ addresses the need to characterise the spatial content of precision surfaces. Whilst we have been manufacturing optics for centuries, there still isn’t a consensus on how to specify the surface for manufacture. The most common three methods for spatial characterisation are reviewed and compared, and the need for further work on quantifying measurement uncertainties is highlighted. The article is focussed on optical surfaces, but the ideas are more pervasive. Different communities refer to ‘figure, mid-spatial frequencies, and finish’ and ‘form, waviness, and roughness’, but the mathematics are identical. The second section ‘Light scattering methods’ is focussed on light scattering techniques; an important topic with in-line metrology becoming essential in many manufacturing scenarios. The potential of scattering methods has long been recognized; in the ‘smooth surface limit’ functionally significant relationships can be derived from first principles for statistically stationary, random surfaces. For rougher surfaces, correlations can be found experimentally for specific manufacturing processes. Improvements in computational methods encourage us to revisit light scattering as a powerful and versatile tool to investigate surface and thin film <span class="hlt">topographies</span>, potentially providing information on both <span class="hlt">topography</span> and defects over large areas at high speed. Future scattering techniques will be applied for complex film systems and for sub-surface damage measurement, but more research is required to quantify and standardise such measurements. A fundamental limitation of all <span class="hlt">topography</span> measurement systems is their finite spatial bandwidth, which limits the slopes that they can detect. The third section ‘Optical measurements of surfaces containing high slope angles’ discusses this limitation and potential methods to overcome it. In some cases, a rough surface can allow measurement of slopes outside the classical optics limit, but more research is needed to fully understand this process. The last section ‘What are the challenges for high <span class="hlt">dynamic</span> range surface measurement?’ presents the challenge facing metrologists by the use of surfaces that need measurement systems with very high spatial and temporal bandwidths, for example, those found in roll-to-roll manufacturing. High resolution, large areas and fast measurement times are needed, and these needs are unlikely to be fulfilled by developing a single all-purpose instrument. A toolbox of techniques needs to be developed which can be applied for any specific manufacturing scenario. The functional significance of surface <span class="hlt">topography</span> has been known for centuries. Mirrors are smooth. Sliding behaviour depends on roughness. We have been measuring surfaces for centuries, but we still face many challenges. New manufacturing paradigms suggest that we need to make rapid measurements online that relate to the functional performance of the surface. This first ‘open questions’ collection addresses a subset of the challenges facing the surface metrology community. There are many more challenges which we would like to address in future ‘open questions’ articles. We welcome your feedback and your suggestions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMOS12B..01L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMOS12B..01L"><span id="translatedtitle">Overland Tsunami Flow through Complex <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lynett, P. J.; Cox, D. T.; Park, H.; Wiebe, D. M.</p> <p>2012-12-01</p> <p>As seen in numerous Japanese eyewitness videos that captured the tsunami inundation on March 11th 2011, flow interaction with the built environment is extremely complex. In addition to the entrainment of sediment and large discrete objects such as cars and ships, tsunami energy amplification due to topographic focusing was widely observed. In coastal towns and cities, this topographic focusing was due to large structures which channelled the flow to either side, often through roadways or other low-obstruction pathways. Structures in the "line-of-fire" of this channelized flow were often found to have been inflicted with relatively greater levels of damage, while the opposite was true for structures in the flow-shadow of large buildings. In this presentation, we attempt to quantify the hydrodynamic variability of flow through complex <span class="hlt">topography</span>, such as a city layout. Understanding this variability is of particular relevance to on-going engineering efforts to develop standards for tsunami design of coastal structures. A novel set of large-scale experimental data will be introduced and used to validate a depth-integrated model. The experiment was performed in the Tsunami Wave Basin at Oregon State University. Transient long wave flooding in a 1/50 scale model of the town of Seaside, Oregon was tested. Data from the experiment, including water elevations and co-located flow speeds, are used to confirm the simulated <span class="hlt">dynamics</span> in the numerical model. The model is shown to be capable of accurately reproducing the instantaneous wave elevation, velocity, and momentum flux of a long wave flooding a town. It is found that the numerical prediction is sensitive to the value of the bottom roughness coefficient. The model is then extended to look at the hydrodynamics in more detail and for other cases. Predicted momentum flux values from with structures resolved, with-out structures resolved, and with spatially variable bottom roughness will be discussed. It is found that localized maximum momentum flux values can be two orders of magnitude greater than the alongshore-transect mean. A method to calculate statistical variability of hydrodynamic flow properties, such as might be used in a risk-based analysis, will be discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20000080640&hterms=Gravity+Mars&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DGravity%2BMars','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20000080640&hterms=Gravity+Mars&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DGravity%2BMars"><span id="translatedtitle">Localized Gravity/<span class="hlt">Topography</span> Admittances on Mars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>McGovern, Patrick J.; Solomon, Sean C.; Smith, David E.; Zuber, Maria T.; Neumann, Gregory A.; Head, James W.</p> <p>2000-01-01</p> <p>Admittances from Mars Global Surveyor (MGS) gravity and <span class="hlt">topography</span> yield estimates of lithosphere thickness on Mars: central Tharsis > 100 km, Alba Patera = 50 km, southern highlands < 20 km (but south polar cap > 50 km). Alba Patera and Elysium Rise are similar structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9661E..0EK','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9661E..0EK"><span id="translatedtitle">OPC verification considering CMP induced <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kuncha, Rakesh Kumar; Narayana Samy, Aravind; Katakamsetty, Ushasree</p> <p>2015-09-01</p> <p>OPC Verification is important to identify the critical wafer hotspots prior to mask fabrication. It helps to identify process limiting structures and possible yield limiters. These hotspots are also used by litho engineers to set up process conditions upfront. OPC Verification generally involves verification done at nominal and process window conditions. The process window conditions take into consideration typical process variations for lithography. In this standard flow, the post CMP <span class="hlt">topography</span> variation was also lumped into these process variations via focus. But in current technologies especially in higher metal layers, CMP induced <span class="hlt">topography</span> variation has become a major contributor to limit the overall process window. This results in different best focus for structures with different <span class="hlt">topography</span>. This gives rises to requirement of OPC Verification flow taking into account these location-specific variations in order to know if the mask data can be used or not. This paper proposes a method to incorporate the <span class="hlt">topography</span> induced focus shift into the OPC Verification flow. OPC Verification checks are performed at the new nominal and Process window conditions to identify the real hotspots seen on wafer. Results are shown where the highlighted hotspots with the proposed new flow correlate better with wafer results. Runtime was also taken into consideration when the flow was developed. Experiments on various products show better accuracy with minimal runtime impact.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940012272','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940012272"><span id="translatedtitle">Sea bottom <span class="hlt">topography</span> imaging with SAR</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Vanderkooij, M. W. A.; Wensink, G. J.; Vogelzang, J.</p> <p>1992-01-01</p> <p>It is well known that under favorable meteorological and hydrodynamical conditions the bottom <span class="hlt">topography</span> of shallow seas can be mapped with airborne or spaceborne imaging radar. This phenomenon was observed for the first time in 1969 by de Loor and co-workers in Q-band Side Looking Airborne Radar (SLAR) imagery of sandwaves in the North Sea. It is now generally accepted that the imaging mechanism consists of three steps: (1) interaction between (tidal) current and bottom <span class="hlt">topography</span> causes spatial modulations in the surface current velocity; (2) modulations in the surface current velocity give rise to variations in the spectrum of wind-generated waves, as described by the action balance equation; and (3) variations in the wave spectrum show up as intensity modulations in radar imagery. In order to predict radar backscatter modulations caused by sandwaves, an imaging model, covering the three steps, was developed by the Dutch Sea Bottom <span class="hlt">Topography</span> Group. This model and some model results will be shown. On 16 Aug. 1989 an experiment was performed with the polarimetric P-, L-, and C-band synthetic aperture radar (SAR) of NASA/JPL. One scene was recorded in SAR mode. On 12 Jul. 1991 another three scenes were recorded, of which one was in the ATI-mode (Along-Track Interferometer). These experiments took place in the test area of the Sea Bottom <span class="hlt">Topography</span> Group, 30 km off the Dutch coast, where the bottom <span class="hlt">topography</span> is dominated by sand waves. In-situ data were gathered by a ship in the test area and on 'Measuring Platform Noordwijk', 20 km from the center of the test area. The radar images made during the experiment were compared with digitized maps of the bottom. Furthermore, the profiles of radar backscatter modulation were compared with the results of the model. During the workshop some preliminary results of the ATI measurements will be shown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012Metro..49..706S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012Metro..49..706S"><span id="translatedtitle">Frequency-domain analysis of <span class="hlt">absolute</span> gravimeters</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Svitlov, S.</p> <p>2012-12-01</p> <p>An <span class="hlt">absolute</span> gravimeter is analysed as a linear time-invariant system in the frequency domain. Frequency responses of <span class="hlt">absolute</span> gravimeters are derived analytically based on the propagation of the complex exponential signal through their linear measurement functions. Depending on the model of motion and the number of time-distance coordinates, an <span class="hlt">absolute</span> gravimeter is considered as a second-order (three-level scheme) or third-order (multiple-level scheme) low-pass filter. It is shown that the behaviour of an atom <span class="hlt">absolute</span> gravimeter in the frequency domain corresponds to that of the three-level corner-cube <span class="hlt">absolute</span> gravimeter. Theoretical results are applied for evaluation of random and systematic measurement errors and optimization of an experiment. The developed theory agrees with known results of an <span class="hlt">absolute</span> gravimeter analysis in the time and frequency domains and can be used for measurement uncertainty analyses, building of vibration-isolation systems and synthesis of digital filtering algorithms.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16103017','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16103017"><span id="translatedtitle"><span class="hlt">Absolute</span> pitch: music and beyond.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ross, David A; Gore, John C; Marks, Lawrence E</p> <p>2005-12-01</p> <p>"Perfect pitch," known in the scientific literature as "<span class="hlt">absolute</span> pitch" (AP), is a rare phenomenon that has fascinated musicians and scientists alike for over a century. There has been a great deal of conflict in the literature between advocates of the two main theories on the etiology of AP: some believe that AP is learned early in life through intensive musical training, whereas others believe AP to be largely innate. Both theories are alike, however, in considering AP to be exclusively a musical phenomenon. We propose a paradigm shift by presenting here a new model of AP, one that is predicated on two principles: (1) that AP may be relatively independent of musical experience; and (2) that there are different types of AP, each of which can be ascribed to discrete neurobiological mechanisms. We also review data from a diverse series of experiments that were designed to test explicitly both the predictions of our model and a series of historical myths about AP. In each case, the data strongly support our model. We conclude with a general discussion on the nature of AP, the relevance of these findings for other areas of research, and future directions of study. PMID:16103017</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26172788','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26172788"><span id="translatedtitle">Anomalous sea surface structures as an object of statistical <span class="hlt">topography</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Klyatskin, V I; Koshel, K V</p> <p>2015-06-01</p> <p>By exploiting ideas of statistical <span class="hlt">topography</span>, we analyze the stochastic boundary problem of emergence of anomalous high structures on the sea surface. The kinematic boundary condition on the sea surface is assumed to be a closed stochastic quasilinear equation. Applying the stochastic Liouville equation, and presuming the stochastic nature of a given hydrodynamic velocity field within the diffusion approximation, we derive an equation for a spatially single-point, simultaneous joint probability density of the surface elevation field and its gradient. An important feature of the model is that it accounts for stochastic bottom irregularities as one, but not a single, perturbation. Hence, we address the assumption of the infinitely deep ocean to obtain statistic features of the surface elevation field and the squared elevation gradient field. According to the calculations, we show that clustering in the <span class="hlt">absolute</span> surface elevation gradient field happens with the unit probability. It results in the emergence of rare events such as anomalous high structures and deep gaps on the sea surface almost in every realization of a stochastic velocity field. PMID:26172788</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvE..91f3003K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvE..91f3003K"><span id="translatedtitle">Anomalous sea surface structures as an object of statistical <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klyatskin, V. I.; Koshel, K. V.</p> <p>2015-06-01</p> <p>By exploiting ideas of statistical <span class="hlt">topography</span>, we analyze the stochastic boundary problem of emergence of anomalous high structures on the sea surface. The kinematic boundary condition on the sea surface is assumed to be a closed stochastic quasilinear equation. Applying the stochastic Liouville equation, and presuming the stochastic nature of a given hydrodynamic velocity field within the diffusion approximation, we derive an equation for a spatially single-point, simultaneous joint probability density of the surface elevation field and its gradient. An important feature of the model is that it accounts for stochastic bottom irregularities as one, but not a single, perturbation. Hence, we address the assumption of the infinitely deep ocean to obtain statistic features of the surface elevation field and the squared elevation gradient field. According to the calculations, we show that clustering in the <span class="hlt">absolute</span> surface elevation gradient field happens with the unit probability. It results in the emergence of rare events such as anomalous high structures and deep gaps on the sea surface almost in every realization of a stochastic velocity field.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011BoLMe.141..201W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011BoLMe.141..201W"><span id="translatedtitle">A Large-Eddy Simulation Study of Turbulent Flow Over Multiscale <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wan, Feng; Porté-Agel, Fernando</p> <p>2011-11-01</p> <p>Most natural landscapes are characterized by multiscale (often multifractal) <span class="hlt">topography</span> with well-known scale-invariance properties. For example, the spectral density of landscape elevation fields is often found to have a power-law scaling behaviour (with a -2 slope on a log-log scale) over a wide span of spatial scales, typically ranging from tens of kilometres down to a few metres. Even though the effect of <span class="hlt">topography</span> on the atmospheric boundary layer (ABL) has been the subject of numerous studies, few have focussed on multiscale <span class="hlt">topography</span>. In this study, large-eddy simulation (LES) is used to investigate boundary-layer flow over multiscale <span class="hlt">topography</span>, and guide the development of parametrizations needed to represent the effects of subgrid-scale (SGS) <span class="hlt">topography</span> in numerical models of ABL flow. Particular emphasis is placed on the formulation of an effective roughness used to account for the increased aerodynamic roughness associated with SGS <span class="hlt">topography</span>. The LES code uses the scale-dependent Lagrangian <span class="hlt">dynamic</span> SGS model for the turbulent stresses and a terrain-following coordinate transformation to explicitly resolve the effects of the <span class="hlt">topography</span> at scales larger than the LES resolution. The terrain used in the simulations is generated using a restricted solid-on-solid landscape evolution model, and it is characterized by a -2 slope of the elevation power spectrum. Results from simulations performed using elevation fields band-pass filtered at different spatial resolutions indicate a clear linear relation between the square of the effective roughness and the variance of elevation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010ems..confE.673W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010ems..confE.673W"><span id="translatedtitle">A large-eddy simulation study of turbulent flow over multiscale <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wan, F.; Porté-Agel, F.</p> <p>2010-09-01</p> <p>Most natural landscapes are characterized by multiscale (often multifractal) <span class="hlt">topography</span> with well-established scale-invariance properties. For example, the spectral density of landscape elevation fields is often found to have a power-law scaling behavior (with a -2 slope in log-log scale) over a wide span of spatial scales, typically ranging from tens of kilometers down to a few meters. Even though the effect of <span class="hlt">topography</span> on the atmospheric boundary layer (ABL) has been the subject of numerous studies, few of them have focused on multiscale <span class="hlt">topography</span>. In this study, Large-Eddy Simulation (LES) is used to investigate boundary layer flow over multiscale <span class="hlt">topography</span>, and guide the development of parameterizations needed to represent the effects of subgrid-scale (SGS) <span class="hlt">topography</span> in numerical models. Particular emphasis is placed on the formulation of an effective roughness used to account for the increased aerodynamic roughness associated with SGS <span class="hlt">topography</span>. The LES code uses the scale-dependent Lagrangian <span class="hlt">dynamic</span> SGS model for the turbulent stresses (Stoll and Porté-Agel, 2006) and a terrain-following coordinate transformation to explicitly resolve the effects of the <span class="hlt">topography</span> at scales larger than the LES resolution. The terrain used in the simulations is generated using a restricted solid-on-solid (RSOS) landscape evolution model, and it is characterized by a -2 slope of the elevation power spectrum, similar to that of natural landscapes. Results from simulations performed using elevation fields filtered at different spatial resolutions indicate a clear scaling region of the effective roughness with SGS standard deviation of elevation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010shcg.book.1425R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010shcg.book.1425R"><span id="translatedtitle">X-Ray <span class="hlt">Topography</span> Techniques for Defect Characterization of Crystals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Raghothamachar, Balaji; Dudley, Michael; Dhanaraj, Govindhan</p> <p></p> <p>X-ray <span class="hlt">topography</span> is the general term for a family of x-ray diffraction imaging techniques capable of providing information on the nature and distribution of structural defects such as dislocations, inclusions/precipitates, stacking faults, growth sector boundaries, twins, and low-angle grain boundaries in single-crystal materials. From the first x-ray diffraction image, recorded by Berg in 1931, to the double-crystal technique developed by Bond and Andrus in 1952 and the transmission technique developed by Lang in 1958 through to present-day synchrotron-radiation-based techniques, x-ray <span class="hlt">topography</span> has evolved into a powerful, nondestructive method for the rapid characterization of large single crystals of a wide range of chemical compositions and physical properties, such as semiconductors, oxides, metals, and organic materials. Different defects are readily identified through interpretation of contrast using well-established kinematical and <span class="hlt">dynamical</span> theories of x-ray diffraction. This method is capable of imaging extended defects in the entire volume of the crystal and in some cases in wafers with devices fabricated on them. It is well established as an indispensable tool for the development of growth techniques for highly perfect crystals (for, e.g., Czochralski growth of silicon) for semiconductor and electronic applications. The capability of in situ characterization during crystal growth, heat treatment, stress application, device operation, etc. to study the generation, interaction, and propagation of defects makes it a versatile technique to study many materials processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/978296','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/978296"><span id="translatedtitle">Structural Characterization of Doped GaSb Single Crystals by X-ray <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Honnicke, M.G.; Mazzaro, I.; Manica, J.; Benine, E.; M da Costa, E.; Dedavid, B. A.; Cusatis, C.; Huang, X. R.</p> <p>2009-09-13</p> <p>We characterized GaSb single crystals containing different dopants (Al, Cd and Te), grown by the Czochralski method, by x-ray <span class="hlt">topography</span> and high angular resolution x-ray diffraction. Lang <span class="hlt">topography</span> revealed dislocations parallel and perpendicular to the crystal's surface. Double-crystal GaSb 333 x-ray <span class="hlt">topography</span> shows dislocations and vertical stripes than can be associated with circular growth bands. We compared our high-angular resolution x-ray diffraction measurements (rocking curves) with the findings predicted by the <span class="hlt">dynamical</span> theory of x-ray diffraction. These measurements show that our GaSb single crystals have a relative variation in the lattice parameter ({Delta}d/d) on the order of 10{sup -5}. This means that they can be used as electronic devices (detectors, for example) and as x-ray monochromators.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=standard+AND+deviation&pg=2&id=EJ1050985','ERIC'); return false;" href="http://eric.ed.gov/?q=standard+AND+deviation&pg=2&id=EJ1050985"><span id="translatedtitle">Introducing the Mean <span class="hlt">Absolute</span> Deviation "Effect" Size</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Gorard, Stephen</p> <p>2015-01-01</p> <p>This paper revisits the use of effect sizes in the analysis of experimental and similar results, and reminds readers of the relative advantages of the mean <span class="hlt">absolute</span> deviation as a measure of variation, as opposed to the more complex standard deviation. The mean <span class="hlt">absolute</span> deviation is easier to use and understand, and more tolerant of extreme…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060044287&hterms=Metrology&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DMetrology','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060044287&hterms=Metrology&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DMetrology"><span id="translatedtitle"><span class="hlt">Absolute</span> optical metrology : nanometers to kilometers</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dubovitsky, Serge; Lay, O. P.; Peters, R. D.; Liebe, C. C.</p> <p>2005-01-01</p> <p>We provide and overview of the developments in the field of high-accuracy <span class="hlt">absolute</span> optical metrology with emphasis on space-based applications. Specific work on the Modulation Sideband Technology for <span class="hlt">Absolute</span> Ranging (MSTAR) sensor is described along with novel applications of the sensor.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/EJ853800.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/EJ853800.pdf"><span id="translatedtitle">Investigating <span class="hlt">Absolute</span> Value: A Real World Application</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Kidd, Margaret; Pagni, David</p> <p>2009-01-01</p> <p>Making connections between various representations is important in mathematics. In this article, the authors discuss the numeric, algebraic, and graphical representations of sums of <span class="hlt">absolute</span> values of linear functions. The initial explanations are accessible to all students who have experience graphing and who understand that <span class="hlt">absolute</span> value simply…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4490812','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4490812"><span id="translatedtitle">Estimating the <span class="hlt">absolute</span> wealth of households</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gerkey, Drew; Hadley, Craig</p> <p>2015-01-01</p> <p>Abstract Objective To estimate the <span class="hlt">absolute</span> wealth of households using data from demographic and health surveys. Methods We developed a new metric, the <span class="hlt">absolute</span> wealth estimate, based on the rank of each surveyed household according to its material assets and the assumed shape of the distribution of wealth among surveyed households. Using data from 156 demographic and health surveys in 66 countries, we calculated <span class="hlt">absolute</span> wealth estimates for households. We validated the method by comparing the proportion of households defined as poor using our estimates with published World Bank poverty headcounts. We also compared the accuracy of <span class="hlt">absolute</span> versus relative wealth estimates for the prediction of anthropometric measures. Findings The median <span class="hlt">absolute</span> wealth estimates of 1 403 186 households were 2056 international dollars per capita (interquartile range: 723–6103). The proportion of poor households based on <span class="hlt">absolute</span> wealth estimates were strongly correlated with World Bank estimates of populations living on less than 2.00 United States dollars per capita per day (R2 = 0.84). <span class="hlt">Absolute</span> wealth estimates were better predictors of anthropometric measures than relative wealth indexes. Conclusion <span class="hlt">Absolute</span> wealth estimates provide new opportunities for comparative research to assess the effects of economic resources on health and human capital, as well as the long-term health consequences of economic change and inequality. PMID:26170506</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19740050786&hterms=2312&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D2312','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19740050786&hterms=2312&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3D2312"><span id="translatedtitle"><span class="hlt">Absolute</span> line strengths for carbon and sulfur</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Miller, M. H.; Wilkerson, T. D.; Roig, R. A.; Bengtson, R. D.</p> <p>1974-01-01</p> <p>Work has been conducted to reduce substantially uncertainties concerning the line strengths for carbon and sulfur. Two or more independent methods were used to measure thermodynamic variables and to calibrate detectors for <span class="hlt">absolute</span> sensitivity and spectral response. The <span class="hlt">absolute</span> transition probabilities of 124 visible and infrared lines of C I, S I, and S II were measured in a consistent way.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=happiness&pg=6&id=EJ804151','ERIC'); return false;" href="http://eric.ed.gov/?q=happiness&pg=6&id=EJ804151"><span id="translatedtitle"><span class="hlt">Absolute</span> Income, Relative Income, and Happiness</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Ball, Richard; Chernova, Kateryna</p> <p>2008-01-01</p> <p>This paper uses data from the World Values Survey to investigate how an individual's self-reported happiness is related to (i) the level of her income in <span class="hlt">absolute</span> terms, and (ii) the level of her income relative to other people in her country. The main findings are that (i) both <span class="hlt">absolute</span> and relative income are positively and significantly…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010SPIE.7792E..1AS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010SPIE.7792E..1AS"><span id="translatedtitle"><span class="hlt">Topography</span> measurement of specular and diffuse surfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Serrano García, David Ignacio; Martínez García, Amalia; Rayas-Alvarez, Juan Antonio</p> <p>2010-08-01</p> <p>We measured the <span class="hlt">topography</span> of lens by using a technique of diffuse reflection (fringe projection technique) and by a method based on specular reflection technique (similar to Placido disk system). The obtained results with both techniques are compared with those obtained with a spherometer. The retrieval of the three-dimensional shape of the lens is an issue of great interest for wide medical application, particularly in ophthalmology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19980216243&hterms=Herbs&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DHerbs','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19980216243&hterms=Herbs&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DHerbs"><span id="translatedtitle"><span class="hlt">Topography</span> over South America from ERS altimetry</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Brenner, Anita; Frey, Herb; DiMarzio, John; Tsaoussi, Lucia</p> <p>1997-01-01</p> <p>The results of the surface <span class="hlt">topography</span> mapping of South America during the ERS-1 geodetic mission are presented. The altimeter waveforms, the range measurement, and the internal and Doppler range corrections were obtained. The atmospheric corrections and solid tides were calculated. Comparisons between Shuttle laser altimetry and ERS-1 altimetry grid showed good agreement. Satellite radar altimetry data can be used to improve the topographic knowledge of regions for which only poor elevation data currently exist.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20060036482&hterms=farr&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dfarr','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20060036482&hterms=farr&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dfarr"><span id="translatedtitle">(abstract) The Shuttle Radar <span class="hlt">Topography</span> Mapper</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Farr, Tom G.; Kobrick, Mike</p> <p>1996-01-01</p> <p>The Shuttle Radar <span class="hlt">Topography</span> Mapper (SRTM), is a cooperative project between NASA and the Defense Mapping Agency of the U.S. Department of Defense. The mission is designed to use a single-pass radar interferometer to produce a digital elevation model of the Earth's land surface between about 60 degrees north and south latitude. The DEM will have 30 m horizontal resolution and about 10 m vertical errors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19880021047','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19880021047"><span id="translatedtitle">Diffraction imaging (<span class="hlt">topography</span>) with monochromatic synchrotron radiation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Steiner, Bruce; Kuriyama, Masao; Dobbyn, Ronald C.; Laor, Uri</p> <p>1988-01-01</p> <p>Structural information of special interest to crystal growers and device physicists is now available from high resolution monochromatic synchrotron diffraction imaging (<span class="hlt">topography</span>). In the review, the importance of superior resolution in momentum transfer and in space is described, and illustrations are taken from a variety of crystals: gallium arsenide, cadmium telluride, mercuric iodide, bismuth silicon oxide, and lithium niobate. The identification and understanding of local variations in crystal growth processes are shown. Finally, new experimental opportunities now available for exploitation are indicated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19870033574&hterms=Global+cooling&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DGlobal%2Bcooling','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19870033574&hterms=Global+cooling&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DGlobal%2Bcooling"><span id="translatedtitle">Global relationship between oceanic geoid and <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cazenave, A.; Dominh, K.; Allegre, C. J.; Marsh, J. G.</p> <p>1986-01-01</p> <p>The transfer function of geoid over <span class="hlt">topography</span> as a function of wavelength is derived. The relationship between oceanic geoid and seafloor depth is analyzed. The correction of the geoid and topological data for thermal cooling of the oceanic lithosphere, sediment loading, and crustal thickening induced by volcanism under large ocean plateaus is discussed. The global residual depth and geoid anomalies are computed. The admittance and correlation between residual depth and geoid anomalies as a function of wavelength are examined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/ds/418/','USGSPUBS'); return false;" href="http://pubs.usgs.gov/ds/418/"><span id="translatedtitle">ATM Coastal <span class="hlt">Topography</span>-Alabama 2001</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Nayegandhi, Amar; Yates, Xan; Brock, John C.; Sallenger, A.H.; Bonisteel, Jamie M.; Klipp, Emily S.; Wright, C. Wayne</p> <p>2009-01-01</p> <p>These remotely sensed, geographically referenced elevation measurements of Lidar-derived first surface (FS) <span class="hlt">topography</span> were produced collaboratively by the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL, and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of the Alabama coastline, acquired October 3-4, 2001. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative scanning Lidar instrument originally developed by NASA, and known as the Airborne Topographic Mapper (ATM), was used during data acquisition. The ATM system is a scanning Lidar system that measures high-resolution <span class="hlt">topography</span> of the land surface, and incorporates a green-wavelength laser operating at pulse rates of 2 to 10 kilohertz. Measurements from the laser ranging device are coupled with data acquired from inertial navigation system (INS) attitude sensors and differentially corrected global positioning system (GPS) receivers to measure <span class="hlt">topography</span> of the surface at accuracies of +/-15 centimeters. The nominal ATM platform is a Twin Otter or P-3 Orion aircraft, but the instrument may be deployed on a range of light aircraft. Elevation measurements were collected over the survey area using the ATM system, and the resulting data were then processed using the Airborne Lidar Processing System (ALPS), a custom-built processing system developed in a NASA-USGS collaboration. ALPS supports the exploration and processing of Lidar data in an interactive or batch mode. Modules for pre-survey flight line definition, flight path plotting, Lidar raster and waveform investigation, and digital camera image playback have been developed. Processing algorithms have been developed to extract the range to the first and last significant return within each waveform. ALPS is routinely used to create maps that represent submerged or first surface <span class="hlt">topography</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/ds/450/','USGSPUBS'); return false;" href="http://pubs.usgs.gov/ds/450/"><span id="translatedtitle">ATM Coastal <span class="hlt">Topography</span>-Mississippi, 2001</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Nayegandhi, Amar; Yates, Xan; Brock, John C.; Sallenger, A.H.; Klipp, Emily S.; Wright, C. Wayne</p> <p>2009-01-01</p> <p>These remotely sensed, geographically referenced elevation measurements of lidar-derived first-surface (FS) <span class="hlt">topography</span> were produced collaboratively by the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL, and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of the Mississippi coastline, from Lakeshore to Petit Bois Island, acquired September 9-10, 2001. The datasets are made available for use as a management tool to research scientists and natural-resource managers. An innovative scanning lidar instrument originally developed by NASA, and known as the Airborne Topographic Mapper (ATM), was used during data acquisition. The ATM system is a scanning lidar system that measures high-resolution <span class="hlt">topography</span> of the land surface and incorporates a green-wavelength laser operating at pulse rates of 2 to 10 kilohertz. Measurements from the laser-ranging device are coupled with data acquired from inertial navigation system (INS) attitude sensors and differentially corrected global positioning system (GPS) receivers to measure <span class="hlt">topography</span> of the surface at accuracies of +/-15 centimeters. The nominal ATM platform is a Twin Otter or P-3 Orion aircraft, but the instrument may be deployed on a range of light aircraft. Elevation measurements were collected over the survey area using the ATM system, and the resulting data were then processed using the Airborne Lidar Processing System (ALPS), a custom-built processing system developed in a NASA-USGS collaboration. ALPS supports the exploration and processing of lidar data in an interactive or batch mode. Modules for presurvey flight-line definition, flight-path plotting, lidar raster and waveform investigation, and digital camera image playback have been developed. Processing algorithms have been developed to extract the range to the first and last significant return within each waveform. ALPS is used routinely to create maps that represent submerged or first-surface <span class="hlt">topography</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/of/2007/1179/','USGSPUBS'); return false;" href="http://pubs.usgs.gov/of/2007/1179/"><span id="translatedtitle">EAARL <span class="hlt">topography</span>: George Washington Birthplace National Monument</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Brock, John C.; Wright, C. Wayne; Patterson, Matt; Nayegandhi, Amar; Patterson, Judd</p> <p>2007-01-01</p> <p>This Web site contains Lidar-derived <span class="hlt">topography</span> (first return and bare earth) maps and GIS files for George Washington Birthplace National Monument in Virginia. These lidar-derived <span class="hlt">topography</span> maps were produced as a collaborative effort between the U.S. Geological Survey (USGS) Coastal and Marine Geology Program, FISC St. Petersburg, the National Park Service (NPS), Northeast Coastal and Barrier Network, Inventory and Monitoring Program, and the National Aeronautics and Space Administration (NASA) Wallops Flight Facility. One objective of this research is to create techniques to survey coral reefs and barrier islands for the purposes of geomorphic change studies, habitat mapping, ecological monitoring, change detection, and event assessment. As part of this project, data from an innovative instrument under development at the NASA Wallops Flight Facility, the NASA Experimental Airborne Advanced Research Lidar (EAARL) are being used. This sensor has the potential to make significant contributions in this realm for measuring subaerial and submarine <span class="hlt">topography</span> wthin cross-environment surveys. High spectral resolution, water-column correction, and low costs were found to be key factors in providing accurate and affordable imagery to coastal resource managers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22508094','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22508094"><span id="translatedtitle">Wholemount immunohistochemistry for revealing complex brain <span class="hlt">topography</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>White, Joshua J; Reeber, Stacey L; Hawkes, Richard; Sillitoe, Roy V</p> <p>2012-01-01</p> <p>The repeated and well-understood cellular architecture of the cerebellum make it an ideal model system for exploring brain <span class="hlt">topography</span>. Underlying its relatively uniform cytoarchitecture is a complex array of parasagittal domains of gene and protein expression. The molecular compartmentalization of the cerebellum is mirrored by the anatomical and functional organization of afferent fibers. To fully appreciate the complexity of cerebellar organization we previously refined a wholemount staining approach for high throughput analysis of patterning defects in the mouse cerebellum. This protocol describes in detail the reagents, tools, and practical steps that are useful to successfully reveal protein expression patterns in the adult mouse cerebellum by using wholemount immunostaining. The steps highlighted here demonstrate the utility of this method using the expression of zebrinII/aldolaseC as an example of how the fine <span class="hlt">topography</span> of the brain can be revealed in its native three-dimensional conformation. Also described are adaptations to the protocol that allow for the visualization of protein expression in afferent projections and large cerebella for comparative studies of molecular <span class="hlt">topography</span>. To illustrate these applications, data from afferent staining of the rat cerebellum are included. PMID:22508094</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011SPIE.8011E..7TA','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011SPIE.8011E..7TA"><span id="translatedtitle">Digital holography system for <span class="hlt">topography</span> measurement</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Amezquita, R.; Rincon, O. J.; Torres, Y. M.; Amezquita, S.</p> <p>2011-08-01</p> <p>The optical characteristics of Diffractive Optical Elements are determined by the properties of the photosensitive film on which they are produced. When working with photoresist plates, the most important property is the change in the plate's <span class="hlt">topography</span> for different exposures. In this case, the required characterization involves a topographic measurement that can be made using digital holography. This work presents a digital holography system in which a hologram's phase map is obtained from a single recorded image. The phase map is calculated by applying a phase-shifting algorithm to a set of images that are created using a digital phase-shifting/tilteliminating procedure. Also, the curvatures, introduced by the imaging elements used in the experimental setup, are digitally compensated for using a polynomial fitting-method. The object's <span class="hlt">topography</span> is then obtained from this modified phase map. To demonstrate the proposed procedure, the <span class="hlt">topography</span> of patches exposed on a Shipley 1818 photoresist plate by microlithography equipment-which is currently under construction-is shown.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/ofr20071431','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/ofr20071431"><span id="translatedtitle">EAARL <span class="hlt">Topography</span>-Padre Island National Seashore</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Brock, John C.; Wright, C. Wayne; Nayegandhi, Amar; Patterson, Matt; Wilson, Iris; Travers, Laurinda J.</p> <p>2007-01-01</p> <p>This Web site contains 116 Lidar-derived bare earth <span class="hlt">topography</span> maps and GIS files for Padre Island National Seashore-Texas. These Lidar-derived <span class="hlt">topography</span> maps were produced as a collaborative effort between the U.S. Geological Survey (USGS) Florida Integrated Science Center (FISC) St. Petersburg, Florida, the National Park Service (NPS) Gulf Coast Network, Inventory and Monitoring Program, and the National Aeronautics and Space Administration (NASA) Wallops Flight Facility. One objective of this research is to create techniques to survey coral reefs and barrier islands for the purposes of geomorphic change studies, habitat mapping, ecological monitoring, change detection, and event assessment. As part of this project, data from an innovative instrument under development at the NASA Wallops Flight Facility, the NASA Experimental Airborne Advanced Research Lidar (EAARL) are being used. This sensor has the potential to make significant contributions in this realm for measuring subaerial and submarine <span class="hlt">topography</span> wthin cross-environment surveys. High spectral resolution, water-column correction, and low costs were found to be key factors in providing accurate and affordable imagery to costal resource managers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19880033615&hterms=absolute+stability&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dabsolute%2Bstability','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19880033615&hterms=absolute+stability&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dabsolute%2Bstability"><span id="translatedtitle"><span class="hlt">Absolute</span> instability of the Gaussian wake profile</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hultgren, Lennart S.; Aggarwal, Arun K.</p> <p>1987-01-01</p> <p>Linear parallel-flow stability theory has been used to investigate the effect of viscosity on the local <span class="hlt">absolute</span> instability of a family of wake profiles with a Gaussian velocity distribution. The type of local instability, i.e., convective or <span class="hlt">absolute</span>, is determined by the location of a branch-point singularity with zero group velocity of the complex dispersion relation for the instability waves. The effects of viscosity were found to be weak for values of the wake Reynolds number, based on the center-line velocity defect and the wake half-width, larger than about 400. <span class="hlt">Absolute</span> instability occurs only for sufficiently large values of the center-line wake defect. The critical value of this parameter increases with decreasing wake Reynolds number, thereby indicating a shrinking region of <span class="hlt">absolute</span> instability with decreasing wake Reynolds number. If backflow is not allowed, <span class="hlt">absolute</span> instability does not occur for wake Reynolds numbers smaller than about 38.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19850044003&hterms=FLOW+STATIONARY&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DFLOW%2BSTATIONARY','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19850044003&hterms=FLOW+STATIONARY&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DFLOW%2BSTATIONARY"><span id="translatedtitle">Large-scale stationary and turbulent flow over <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Vallis, G. K.; Roads, J. O.</p> <p>1984-01-01</p> <p>The contributions made to the formation of stationary features of flow over <span class="hlt">topography</span> by linear and nonlinear <span class="hlt">dynamics</span> were examined with an integrated quasi-geostrophic model with idealized topographic forcing. The simulation was run out to several months and generated time-averaged values which were compared with those obtained with linear theory. Linear predictions were converted to turbulent features through the addition of stationary, nonlinear thermodynamic and transient vorticity fluxes. The turbulence features matched atmospheric data on energy spectra, the direction and magnitude of energy transfers, and the spatial magnitudes involved. Transient flow transferred the majority of energy absorbed by the upscale flow and, by absorbing energy, reduced the energy of stationary flow while retaining resonance signatures. Instability was a pervasive feature of the topographically forced flow except at high wavenumbers. The results confirm that transient eddies are interactive with both asymmetric and zonal flow and cannot be adequately described by linear theory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007PhRvL..99a6103J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007PhRvL..99a6103J"><span id="translatedtitle">Imaging Surface <span class="hlt">Topography</span> using Lloyd's Mirror in Photoemission Electron Microscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jesson, D. E.; Pavlov, K. M.; Morgan, M. J.; Usher, B. F.</p> <p>2007-07-01</p> <p>We use Lloyd’s mirror to modulate electron photoemission in photoemission electron microscopy. This results in the projection of Lloyd’s fringes on to three-dimensional (3D) surface objects. An iterative reconstruction method is used to correct for distortions in the fringe pattern due to the cathode immersion lens, thereby providing a quantitative interpretation of surface shape. It is therefore possible to extract 3D height information directly from a two-dimensional, plan-view image. The technique is of sufficient intensity and contrast to study real-time changes in surface <span class="hlt">topography</span> and we apply the method to study unusual contact-line <span class="hlt">dynamics</span> during the reactive wetting of metal droplets.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1513326C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1513326C"><span id="translatedtitle">Open<span class="hlt">Topography</span>: Enabling Online Access to High-Resolution Lidar <span class="hlt">Topography</span> Data and Processing Tools</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crosby, Christopher; Nandigam, Viswanath; Baru, Chaitan; Arrowsmith, J. Ramon</p> <p>2013-04-01</p> <p>High-resolution <span class="hlt">topography</span> data acquired with lidar (light detection and ranging) technology are revolutionizing the way we study the Earth's surface and overlying vegetation. These data, collected from airborne, tripod, or mobile-mounted scanners have emerged as a fundamental tool for research on topics ranging from earthquake hazards to hillslope processes. Lidar data provide a digital representation of the earth's surface at a resolution sufficient to appropriately capture the processes that contribute to landscape evolution. The U.S. National Science Foundation-funded Open<span class="hlt">Topography</span> Facility (http://www.opentopography.org) is a web-based system designed to democratize access to earth science-oriented lidar <span class="hlt">topography</span> data. Open<span class="hlt">Topography</span> provides free, online access to lidar data in a number of forms, including the raw point cloud and associated geospatial-processing tools for customized analysis. The point cloud data are co-located with on-demand processing tools to generate digital elevation models, and derived products and visualizations which allow users to quickly access data in a format appropriate for their scientific application. The Open<span class="hlt">Topography</span> system is built using a service-oriented architecture (SOA) that leverages cyberinfrastructure resources at the San Diego Supercomputer Center at the University of California San Diego to allow users, regardless of expertise level, to access these massive lidar datasets and derived products for use in research and teaching. Open<span class="hlt">Topography</span> hosts over 500 billion lidar returns covering 85,000 km2. These data are all in the public domain and are provided by a variety of partners under joint agreements and memoranda of understanding with Open<span class="hlt">Topography</span>. Partners include national facilities such as the NSF-funded National Center for Airborne Lidar Mapping (NCALM), as well as non-governmental organizations and local, state, and federal agencies. Open<span class="hlt">Topography</span> has become a hub for high-resolution <span class="hlt">topography</span> resources. Datasets hosted by other organizations, as well as lidar-specific software, can be registered into the Open<span class="hlt">Topography</span> catalog, providing users a "one-stop shop" for such information. With several thousand active users, Open<span class="hlt">Topography</span> is an excellent example of a mature Spatial Data Infrastructure system that is enabling access to challenging data for research, education and outreach. Ongoing Open<span class="hlt">Topography</span> design and development work includes the archive and publication of datasets using digital object identifiers (DOIs); creation of a more flexible and scalable high-performance environment for processing of large datasets; expanded support for satellite and terrestrial lidar; and creation of a "pluggable" infrastructure for third-party programs and algorithms. Open<span class="hlt">Topography</span> has successfully created a facility for sharing lidar data. In the project's next phase, we are working to enable equally easy and successful sharing of services for processing and analysis of these data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25930697','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25930697"><span id="translatedtitle"><span class="hlt">Absolute</span> quantitation of protein posttranslational modification isoform.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Zhu; Li, Ning</p> <p>2015-01-01</p> <p>Mass spectrometry has been widely applied in characterization and quantification of proteins from complex biological samples. Because the numbers of <span class="hlt">absolute</span> amounts of proteins are needed in construction of mathematical models for molecular systems of various biological phenotypes and phenomena, a number of quantitative proteomic methods have been adopted to measure <span class="hlt">absolute</span> quantities of proteins using mass spectrometry. The liquid chromatography-tandem mass spectrometry (LC-MS/MS) coupled with internal peptide standards, i.e., the stable isotope-coded peptide dilution series, which was originated from the field of analytical chemistry, becomes a widely applied method in <span class="hlt">absolute</span> quantitative proteomics research. This approach provides more and more <span class="hlt">absolute</span> protein quantitation results of high confidence. As quantitative study of posttranslational modification (PTM) that modulates the biological activity of proteins is crucial for biological science and each isoform may contribute a unique biological function, degradation, and/or subcellular location, the <span class="hlt">absolute</span> quantitation of protein PTM isoforms has become more relevant to its biological significance. In order to obtain the <span class="hlt">absolute</span> cellular amount of a PTM isoform of a protein accurately, impacts of protein fractionation, protein enrichment, and proteolytic digestion yield should be taken into consideration and those effects before differentially stable isotope-coded PTM peptide standards are spiked into sample peptides have to be corrected. Assisted with stable isotope-labeled peptide standards, the <span class="hlt">absolute</span> quantitation of isoforms of posttranslationally modified protein (AQUIP) method takes all these factors into account and determines the <span class="hlt">absolute</span> amount of a protein PTM isoform from the <span class="hlt">absolute</span> amount of the protein of interest and the PTM occupancy at the site of the protein. The <span class="hlt">absolute</span> amount of the protein of interest is inferred by quantifying both the <span class="hlt">absolute</span> amounts of a few PTM-site-independent peptides in the total cellular protein and their peptide yields. The PTM occupancy determination is achieved by measuring the <span class="hlt">absolute</span> amounts of both PTM and non-PTM peptides from the highly purified protein sample expressed in transgenic organisms or directly isolated from an organism using affinity purification. The <span class="hlt">absolute</span> amount of each PTM isoform in the total cellular protein extract is finally calculated from these two variables. Following this approach, the ion intensities given by mass spectrometers are used to calculated the peptide amounts, from which the amounts of protein isoforms are then deduced. In this chapter, we describe the principles underlying the experimental design and procedures used in AQUIP method. This quantitation method basically employs stable isotope-labeled peptide standards and affinity purification from a tagged recombinant protein of interest. Other quantitation strategies and purification techniques related to this method are also discussed. PMID:25930697</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Geomo.246..394G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Geomo.246..394G"><span id="translatedtitle">Reenvisioning cross-sectional at-a-station hydraulic geometry as spatially explicit hydraulic <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gonzalez, R. L.; Pasternack, G. B.</p> <p>2015-10-01</p> <p>Transect-based hydraulic geometry is well established but depends on a complex set of subjective fieldwork and computational decisions that sometimes go unexplained. As a result, it is ripe for reenvisioning in the light of the emergence of meter-scale, spatially explicit data and algorithmic geospatial analysis. This study developed and evaluated a new spatially explicit method for analyzing discharge-dependent hydraulics coined 'hydraulic <span class="hlt">topography</span>' that not only increases accuracy but also eliminates several sample- and assumption-based inconsistencies. Using data and hydrodynamic simulations from the regulated, gravel-cobble-bed lower Yuba River in California, power functions were fitted to discharge-dependent average width, depth, and depth-weighted velocity for three spatial scales and then their corresponding exponents and coefficients were compared across scales and against ones computed using traditional approaches. Average hydraulic values from cross sections at the segment scale spanned up to 1.5 orders of magnitude for a given discharge. Transect-determined exponents for reach-scale depth and velocity relations were consistently over- and underestimated, respectively, relative to the hydraulic <span class="hlt">topography</span> benchmark. Overall, 73% of cross-sectional power regression parameters assessed fell between 10 and 50 <span class="hlt">absolute</span> percent error with respect to the spatially explicit hydraulic <span class="hlt">topography</span> baseline. Although traditional transect-based sampling may be viable for certain uses, percent errors of this magnitude could compromise engineering applications in river management and training works.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.6526G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.6526G"><span id="translatedtitle">Geophysical, petrological and mineral physics constraints on Earth's surface <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guerri, Mattia; Cammarano, Fabio; Tackley, Paul J.</p> <p>2015-04-01</p> <p>Earth's surface <span class="hlt">topography</span> is controlled by isostatically compensated density variations within the lithosphere, but <span class="hlt">dynamic</span> <span class="hlt">topography</span> - i.e. the <span class="hlt">topography</span> due to adjustment of surface to mantle convection - is an important component, specially at a global scale. In order to separate these two components it is fundamental to estimate crustal and mantle density structure and rheological properties. Usually, crustal density is constrained from interpretation of available seismic data (mostly VP profiles) based on empirical relationships such those in Brocher [2005]. Mantle density structure is inferred from seismic tomography models. Constant coefficients are used to interpret seismic velocity anomalies in density anomalies. These simplified methods are unable to model the effects that pressure and temperature variations have on mineralogical assemblage and physical properties. Our approach is based on a multidisciplinary method that involves geophysical observables, mineral physics constraints, and petrological data. Mantle density is based on the thermal interpretation of global seismic tomography models assuming various compositional structures, as in Cammarano et al. [2011]. We further constrain the top 150 km by including heat-flow data and considering the thermal evolution of the oceanic lithosphere. Crustal density is calculated as in Guerri and Cammarano [2015] performing thermodynamic modeling of various average chemical compositions proposed for the crust. The modeling, performed with the code PerpleX [Connolly, 2005], relies on the thermodynamic dataset from Holland and Powell [1998]. Compressional waves velocity and crustal layers thickness from the model CRUST 1.0 [Laske et al., 2013] offer additional constrains. The resulting lithospheric density models are tested against gravity (GOCE) data. Various crustal and mantle density models have been tested in order to ascertain the effects that uncertainties in the estimate of those features have on the modeled <span class="hlt">topography</span>. We also test several viscosity models, either radially symmetric, the V1 profile from Mitrovica and Forte [2004], or more complex laterally varying structures. All the property fields are expanded in spherical harmonics, until degree 24, and implemented in the code StagYY [Tackley, 2008] to perform mantle instantaneous flow modeling and compute surface <span class="hlt">topography</span> and gravitational field. Our results show the importance of constraining the crustal and mantle density structure relying on a multidisciplinary approach that involves experimentally robust thermodynamic datasets. Crustal density field has a strong effect on the isostatic component of <span class="hlt">topography</span>. The models that we test, CRUST 1.0 and those in Guerri and Cammarano [2015], produce strong differences in the computed isostatic <span class="hlt">topography</span>, in the range ±600 m. For the lithospheric mantle, relying on experimentally robust material properties constraints is necessary to infer a reliable density model that takes into account chemical heterogeneities. This approach is also fundamental to correctly interpret seismic models in temperature, a crucial parameter, necessary to determine the lithosphere-asthenosphere boundary, where static effects on <span class="hlt">topography</span> leave place to <span class="hlt">dynamic</span> ones. The comparison between results obtained with different viscosity fields, either radially symmetric or vertically and laterally varying, shows how lateral viscosity variations affect the results, in particular the modeled geoid, at different wavelengths. References: Brocher, T. M. (2005), Empirical Relations between Elastic Wavespeeds and Density in the Earth's Crust, Bulletin of the Seismological Society of America, 95(6), 2081-2092. Cammarano, F., P. J. Tackley, and L. Boschi (2011), Seismic, petrological and geodynamical constraints on thermal and compositional structure of the upper mantle: global thermochemical models, Geophys. J. Int. Connolly, J. A. D. (2005), Computation of phase equilibria by linear programming: A tool for geodynamic modeling and its application to subduction zone decarbonation, Earth and Planetary Science Letters (236), 524-541. Guerri, M., and F. Cammarano (2015), On the effects of chemical composition, water and temperature on physical properties of the Earth's continental crust, submitted to Geochemistry, Geophysics, Geosystem. Holland, T. J. B., and R. Powell (1998), An internally consistent thermodynamic data set for phases of petrological interest, J. metamorphic Geol., 16(309-343). Laske, G., G. Masters, Z. Ma, and M. E. Pasyanos (2013), CRUST1.0: An updated global model of Earth's crust, in EGU General Assembly 2013, edited, Geophysical Research Abstracts, Vienna. Mitrovica, J. X., and A. M. Forte (2004), A new inference of mantle viscosity based upon joint inversion of convection and glacial isostatic adjustment data, Earth and Planetary Science Letters, 225, 177-189. Tackley, P. J. (2008), Modelling compressible mantle convection with large viscosity contrasts in a three-dimensional spherical shell using the yin-yang grid, Phys. Earth Planet. Int.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4530887','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4530887"><span id="translatedtitle">NMR and MD Studies Reveal That the Isolated Dengue NS3 Protease Is an Intrinsically Disordered Chymotrypsin Fold Which <span class="hlt">Absolutely</span> Requests NS2B for Correct Folding and Functional <span class="hlt">Dynamics</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gupta, Garvita; Lim, Liangzhong; Song, Jianxing</p> <p>2015-01-01</p> <p>Dengue genome encodes a two component protease complex (NS2B-NS3pro) essential for the viral maturation/infectivity, thus representing a key drug target. Previously, due to its “complete insolubility”, the isolated NS3pro could not be experimentally studied and it remains elusive what structure it adopts without NS2B and why NS2B is indispensable. Here as facilitated by our previous discovery, the isolated NS3pro has been surprisingly deciphered by NMR to be the first intrinsically-disordered chymotrypsin-like fold, which exists in a loosely-packed state with non-native long-range interactions as revealed by paramagnetic relaxation enhancement (PRE). The disordered NS3pro appears to be needed for binding a human host factor to trigger the membrane remodeling. Moreover, we have in vitro refolded the NS3pro in complex with either NS2B (48–100) or the full-length NS2B (1–130) anchored into the LMPC micelle, and the two complexes have similar activities but different <span class="hlt">dynamics</span>. We also performed molecular <span class="hlt">dynamics</span> (MD) simulations and the results revealed that NS2B shows the highest structural fluctuations in the complex, thus providing the <span class="hlt">dynamic</span> basis for the observation on its conformational exchange between open and closed states. Remarkably, the NS2B cofactor plays a central role in maintaining the correlated motion network required for the catalysis as we previously decoded for the SARS 3CL protease. Indeed, a truncated NS2B (48–100;Δ77–84) with the flexible loop deleted is able to trap the NS2B-NS3pro complex in a highly <span class="hlt">dynamic</span> and catalytically-impotent state. Taken together, our study implies potential strategies to perturb the NS2B-NS3pro interface for design of inhibitors for treating dengue infection. PMID:26258523</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26258523','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26258523"><span id="translatedtitle">NMR and MD Studies Reveal That the Isolated Dengue NS3 Protease Is an Intrinsically Disordered Chymotrypsin Fold Which <span class="hlt">Absolutely</span> Requests NS2B for Correct Folding and Functional <span class="hlt">Dynamics</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gupta, Garvita; Lim, Liangzhong; Song, Jianxing</p> <p>2015-01-01</p> <p>Dengue genome encodes a two component protease complex (NS2B-NS3pro) essential for the viral maturation/infectivity, thus representing a key drug target. Previously, due to its "complete insolubility", the isolated NS3pro could not be experimentally studied and it remains elusive what structure it adopts without NS2B and why NS2B is indispensable. Here as facilitated by our previous discovery, the isolated NS3pro has been surprisingly deciphered by NMR to be the first intrinsically-disordered chymotrypsin-like fold, which exists in a loosely-packed state with non-native long-range interactions as revealed by paramagnetic relaxation enhancement (PRE). The disordered NS3pro appears to be needed for binding a human host factor to trigger the membrane remodeling. Moreover, we have in vitro refolded the NS3pro in complex with either NS2B (48-100) or the full-length NS2B (1-130) anchored into the LMPC micelle, and the two complexes have similar activities but different <span class="hlt">dynamics</span>. We also performed molecular <span class="hlt">dynamics</span> (MD) simulations and the results revealed that NS2B shows the highest structural fluctuations in the complex, thus providing the <span class="hlt">dynamic</span> basis for the observation on its conformational exchange between open and closed states. Remarkably, the NS2B cofactor plays a central role in maintaining the correlated motion network required for the catalysis as we previously decoded for the SARS 3CL protease. Indeed, a truncated NS2B (48-100;Δ77-84) with the flexible loop deleted is able to trap the NS2B-NS3pro complex in a highly <span class="hlt">dynamic</span> and catalytically-impotent state. Taken together, our study implies potential strategies to perturb the NS2B-NS3pro interface for design of inhibitors for treating dengue infection. PMID:26258523</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010RScI...81c3301B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010RScI...81c3301B"><span id="translatedtitle"><span class="hlt">Absolute</span> charge calibration of scintillating screens for relativistic electron detection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Buck, A.; Zeil, K.; Popp, A.; Schmid, K.; Jochmann, A.; Kraft, S. D.; Hidding, B.; Kudyakov, T.; Sears, C. M. S.; Veisz, L.; Karsch, S.; Pawelke, J.; Sauerbrey, R.; Cowan, T.; Krausz, F.; Schramm, U.</p> <p>2010-03-01</p> <p>We report on new charge calibrations and linearity tests with high-<span class="hlt">dynamic</span> range for eight different scintillating screens typically used for the detection of relativistic electrons from laser-plasma based acceleration schemes. The <span class="hlt">absolute</span> charge calibration was done with picosecond electron bunches at the ELBE linear accelerator in Dresden. The lower detection limit in our setup for the most sensitive scintillating screen (KODAK Biomax MS) was 10 fC/mm2. The screens showed a linear photon-to-charge dependency over several orders of magnitude. An onset of saturation effects starting around 10-100 pC/mm2 was found for some of the screens. Additionally, a constant light source was employed as a luminosity reference to simplify the transfer of a one-time <span class="hlt">absolute</span> calibration to different experimental setups.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19830045160&hterms=primary+data+secondary+data&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dprimary%2Bdata%2Bsecondary%2Bdata','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19830045160&hterms=primary+data+secondary+data&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dprimary%2Bdata%2Bsecondary%2Bdata"><span id="translatedtitle">Secondary standard stars for <span class="hlt">absolute</span> spectrophotometry</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Oke, J. B.; Gunn, J. E.</p> <p>1983-01-01</p> <p>Based on an adopted <span class="hlt">absolute</span> spectral energy distribution for the primary standard star Alpha Lyrae, <span class="hlt">absolute</span> fluxes are given for the four very metal-deficient F type subdwarfs HD 19445, HD 84937, BD + 26.2606 deg, and BD + 17.4703 deg. Somewhat inferior data are also given for HD 140283. The data are given for 40-A bands and cover the wavelength range from 3080 A to 12,000 A. The four stars, all near magnitude 9 and distributed around the sky, are intended as secondary standards for <span class="hlt">absolute</span> spectrophotometry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhRvA..92e3827T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhRvA..92e3827T"><span id="translatedtitle"><span class="hlt">Absolute</span> optical instruments without spherical symmetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tyc, Tomáš; Dao, H. L.; Danner, Aaron J.</p> <p>2015-11-01</p> <p>Until now, the known set of <span class="hlt">absolute</span> optical instruments has been limited to those containing high levels of symmetry. Here, we demonstrate a method of mathematically constructing refractive index profiles that result in asymmetric <span class="hlt">absolute</span> optical instruments. The method is based on the analogy between geometrical optics and classical mechanics and employs Lagrangians that separate in Cartesian coordinates. In addition, our method can be used to construct the index profiles of most previously known <span class="hlt">absolute</span> optical instruments, as well as infinitely many different ones.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/22905865','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/22905865"><span id="translatedtitle">Determination of ¹⁵N-incorporation into plant proteins and their <span class="hlt">absolute</span> quantitation: a new tool to study nitrogen flux <span class="hlt">dynamics</span> and protein pool sizes elicited by plant-herbivore interactions.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ullmann-Zeunert, Lynn; Muck, Alexander; Wielsch, Natalie; Hufsky, Franziska; Stanton, Mariana A; Bartram, Stefan; Böcker, Sebastian; Baldwin, Ian T; Groten, Karin; Svatoš, Aleš</p> <p>2012-10-01</p> <p>Herbivory leads to changes in the allocation of nitrogen among different pools and tissues; however, a detailed quantitative analysis of these changes has been lacking. Here, we demonstrate that a mass spectrometric data-independent acquisition approach known as LC-MS(E), combined with a novel algorithm to quantify heavy atom enrichment in peptides, is able to quantify elicited changes in protein amounts and (15)N flux in a high throughput manner. The reliable identification/quantitation of rabbit phosphorylase b protein spiked into leaf protein extract was achieved. The linear <span class="hlt">dynamic</span> range, reproducibility of technical and biological replicates, and differences between measured and expected (15)N-incorporation into the small (SSU) and large (LSU) subunits of ribulose-1,5-bisphosphate-carboxylase/oxygenase (RuBisCO) and RuBisCO activase 2 (RCA2) of Nicotiana attenuata plants grown in hydroponic culture at different known concentrations of (15)N-labeled nitrate were used to further evaluate the procedure. The utility of the method for whole-plant studies in ecologically realistic contexts was demonstrated by using (15)N-pulse protocols on plants growing in soil under unknown (15)N-incorporation levels. Additionally, we quantified the amounts of lipoxygenase 2 (LOX2) protein, an enzyme important in antiherbivore defense responses, demonstrating that the approach allows for in-depth quantitative proteomics and (15)N flux analyses of the metabolic <span class="hlt">dynamics</span> elicited during plant-herbivore interactions. PMID:22905865</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26553885','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26553885"><span id="translatedtitle"><span class="hlt">Topography</span> Influences Adherent Cell Regulation of Osteoclastogenesis.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nagasawa, M; Cooper, L F; Ogino, Y; Mendonca, D; Liang, R; Yang, S; Mendonca, G; Uoshima, K</p> <p>2016-03-01</p> <p>The importance of osteoclast-mediated bone resorption in the process of osseointegration has not been widely considered. In this study, cell culture was used to investigate the hypothesis that the function of implant-adherent bone marrow stromal cells (BMSCs) in osteoclastogenesis is influenced by surface <span class="hlt">topography</span>. BMSCs isolated from femur and tibia of Sprague-Dawley rats were seeded onto 3 types of titanium surfaces (smooth, micro, and nano) and a control surface (tissue culture plastic) with or without osteogenic supplements. After 3 to 14 d, conditioned medium (CM) was collected. Subsequently, rat bone marrow-derived macrophages (BMMs) were cultured in media supplemented with soluble receptor activator of NF-κB ligand (RANKL) and macrophage colony-stimulating factor (M-CSF) as well as BMSC CM from each of the 4 surfaces. Gene expression levels of soluble RANKL, osteoprotegerin, tumor necrosis factor α, and M-CSF in cultured BMSCs at different time points were measured by real-time polymerase chain reaction. The number of differentiated osteoclastic cells was determined after tartrate-resistant acid phosphatase staining. Analysis of variance and t test were used for statistical analysis. The expression of prominent osteoclast-promoting factors tumor necrosis factor α and M-CSF was increased by BMSCs cultured on both micro- and nanoscale titanium <span class="hlt">topographies</span> (P < 0.01). BMSC CM contained a heat-labile factor that increased BMMs osteoclastogenesis. CM from both micro- and nanoscale surface-adherent BMSCs increased the osteoclast number (P < 0.01). Difference in surface <span class="hlt">topography</span> altered BMSC phenotype and influenced BMM osteoclastogenesis. Local signaling by implant-adherent cells at the implant-bone interface may indirectly control osteoclastogenesis and bone accrual around endosseous implants. PMID:26553885</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20030067822&hterms=topography&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dtopography','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20030067822&hterms=topography&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dtopography"><span id="translatedtitle">Macromolecular <span class="hlt">Topography</span> Leaps into the Digital Age</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lovelace, J.; Bellamy, H.; Snell, E. H.; Borgstahl, G.</p> <p>2003-01-01</p> <p>A low-cost, real-time digital <span class="hlt">topography</span> system is under development which will replace x-ray film and nuclear emulsion plates. The imaging system is based on an inexpensive surveillance camera that offers a 1000x1000 array of 8 im square pixels, anti-blooming circuitry, and very quick read out. Currently, the system directly converts x-rays to an image with no phosphor. The system is small and light and can be easily adapted to work with other crystallographic equipment. Preliminary images have been acquired of cubic insulin at the NSLS x26c beam line. NSLS x26c was configured for unfocused monochromatic radiation. Six reflections were collected with stills spaced from 0.002 to 0.001 degrees apart across the entire oscillation range that the reflections were in diffracting condition. All of the reflections were rotated to the vertical to reduce Lorentz and beam related effects. This particular CCD is designed for short exposure applications (much less than 1 sec) and so has a relatively high dark current leading to noisy raw images. The images are processed to remove background and other system noise with a multi-step approach including the use of wavelets, histogram, and mean window filtering. After processing, animations were constructed with the corresponding reflection profile to show the diffraction of the crystal volume vs. the oscillation angle as well as composite images showing the parts of the crystal with the strongest diffraction for each reflection. The final goal is to correlate features seen in reflection profiles captured with fine phi slicing to those seen in the <span class="hlt">topography</span> images. With this development macromolecular <span class="hlt">topography</span> finally comes into the digital age.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013SuTMP...1a0201L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013SuTMP...1a0201L"><span id="translatedtitle">Welcome to Surface <span class="hlt">Topography</span>: Metrology and Properties</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leach, Richard</p> <p>2013-11-01</p> <p>I am delighted to welcome readers to this inaugural issue of Surface <span class="hlt">Topography</span>: Metrology and Properties (STMP). In these days of citation indexes and academic reviews, it is a tough, and maybe a brave, job to start a new journal. But the subject area has never been more active and we are seeing genuine breakthroughs in the use of surfaces to control functional performance. Most manufactured parts rely on some form of control of their surface characteristics. The surface is usually defined as that feature on a component or device, which interacts with either the environment in which it is housed (or in which the device operates), or with another surface. The surface <span class="hlt">topography</span> and material characteristics of a part can affect how fluids interact with it, how the part looks and feels and how two bearing parts will slide together. The need to control, and hence measure, surface features is becoming increasingly important as we move into a miniaturized world. Surface features can become the dominant functional features of a part and may become large in comparison to the overall size of an object. Research into surface texture measurement and characterization has been carried out for over a century and is now more active than ever, especially as new areal surface texture specification standards begin to be introduced. The range of disciplines for which the function of a surface relates to its <span class="hlt">topography</span> is very diverse; from metal sheet manufacturing to art restoration, from plastic electronics to forensics. Until now, there has been no obvious publishing venue to bring together all these applications with the underlying research and theory, or to unite those working in academia with engineering and industry. Hence the creation of Surface <span class="hlt">Topography</span>: Metrology and Properties . STMP will publish the best work being done across this broad discipline in one journal, helping researchers to share common themes and highlighting and promoting the extraordinary benefits this field yields across an array of applications in the modern world. To this end, we have gathered leading experts from across our scope to form our inaugural editorial board. Their broad subject knowledge and experience will help to guide the journal and ensure we meet our goal of high-quality research, published quickly, across the breadth of the subject. We are committed to providing a rapid and yet rigorous peer review process. As a launch promotion, all STMP's published content will be free to readers during 2013. The editorial board and I hope you will be as excited by the possibilities of this new journal as we are, and that you will choose to both submit your research and read STMP in the months and years to come. We look forward to reading your papers!</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/983262','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/983262"><span id="translatedtitle">Carbon contamination <span class="hlt">topography</span> analysis of EUV masks</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Fan, Y.-J.; Yankulin, L.; Thomas, P.; Mbanaso, C.; Antohe, A.; Garg, R.; Wang, Y.; Murray, T.; Wuest, A.; Goodwin, F.; Huh, S.; Cordes, A.; Naulleau, P.; Goldberg, K. A.; Mochi, I.; Gullikson, E.; Denbeaux, G.</p> <p>2010-03-12</p> <p>The impact of carbon contamination on extreme ultraviolet (EUV) masks is significant due to throughput loss and potential effects on imaging performance. Current carbon contamination research primarily focuses on the lifetime of the multilayer surfaces, determined by reflectivity loss and reduced throughput in EUV exposure tools. However, contamination on patterned EUV masks can cause additional effects on absorbing features and the printed images, as well as impacting the efficiency of cleaning process. In this work, several different techniques were used to determine possible contamination <span class="hlt">topography</span>. Lithographic simulations were also performed and the results compared with the experimental data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/ds/393/','USGSPUBS'); return false;" href="http://pubs.usgs.gov/ds/393/"><span id="translatedtitle">EAARL Coastal <span class="hlt">Topography</span> - Sandy Hook 2007</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Nayegandhi, Amar; Brock, John C.; Wright, C. Wayne; Stevens, Sara; Yates, Xan; Bonisteel, Jamie M.</p> <p>2008-01-01</p> <p>These remotely sensed, geographically referenced elevation measurements of Lidar-derived <span class="hlt">topography</span> were produced as a collaborative effort between the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL; the National Park Service (NPS), Northeast Coastal and Barrier Network, Kingston, RI; and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of Gateway National Recreation Area's Sandy Hook Unit in New Jersey, acquired on May 16, 2007. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative airborne Lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL) was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) Lidar designed to map near-shore bathymetry, <span class="hlt">topography</span>, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive Lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multi-spectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers and an integrated miniature digital inertial measurement unit, which provide for submeter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a Lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal <span class="hlt">topography</span> within cross-environmental surveys. Elevation measurements were collected over the survey area using the EAARL system, and the resulting data were then processed using the Airborne Lidar Processing System (ALPS), a custom-built processing system developed in a NASA-USGS collaboration. ALPS supports the exploration and processing of Lidar data in an interactive or batch mode. Modules for pre-survey flight line definition, flight path plotting, Lidar raster and waveform investigation, and digital camera image playback have been developed. Processing algorithms have been developed to extract the range to the first and last significant return within each waveform. ALPS is routinely used to create maps that represent submerged or first surface <span class="hlt">topography</span>. Specialized filtering algorithms have been implemented to determine the 'bare earth' under vegetation from a point cloud of last return elevations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19720060188&hterms=absolute+stability&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dabsolute%2Bstability','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19720060188&hterms=absolute+stability&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dabsolute%2Bstability"><span id="translatedtitle">A note on exponential <span class="hlt">absolute</span> stability.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Siljak, D. D.; Sun, C. K.</p> <p>1972-01-01</p> <p>A new sufficient condition is formulated for the Lur'e type nonlinear continuous system to be exponentially <span class="hlt">absolutely</span> stable. The condition relaxes the assumptions on the nonlinear characteristic by modifying the requirements on the linear part of the system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=chiral&pg=4&id=EJ288694','ERIC'); return false;" href="http://eric.ed.gov/?q=chiral&pg=4&id=EJ288694"><span id="translatedtitle">A New Gimmick for Assigning <span class="hlt">Absolute</span> Configuration.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Ayorinde, F. O.</p> <p>1983-01-01</p> <p>A five-step procedure is provided to help students in making the assignment <span class="hlt">absolute</span> configuration less bothersome. Examples for both single (2-butanol) and multi-chiral carbon (3-chloro-2-butanol) molecules are included. (JN)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22068622','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22068622"><span id="translatedtitle">Magnifying <span class="hlt">absolute</span> instruments for optically homogeneous regions</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tyc, Tomas</p> <p>2011-09-15</p> <p>We propose a class of magnifying <span class="hlt">absolute</span> optical instruments with a positive isotropic refractive index. They create magnified stigmatic images, either virtual or real, of optically homogeneous three-dimensional spatial regions within geometrical optics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26579911','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26579911"><span id="translatedtitle">Monte Carlo Free Ligand Diffusion with Markov State Model Analysis and <span class="hlt">Absolute</span> Binding Free Energy Calculations.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Takahashi, Ryoji; Gil, Víctor A; Guallar, Victor</p> <p>2014-01-14</p> <p>Obtaining <span class="hlt">absolute</span> binding free energies from unbiased ligand diffusion has attracted a significant amount of attention due to its implications in drug design. Several studies have used special purpose computers and software to achieve microsecond molecular <span class="hlt">dynamics</span> which, combined with a Markov state model analysis, are capable of providing <span class="hlt">absolute</span> binding free energies. We have recently developed a Monte Carlo based technique, PELE, capable of performing a <span class="hlt">dynamical</span> exploration of the protein-ligand energy landscape including free ligand diffusion into the active site, at a fraction of the computational cost of molecular <span class="hlt">dynamics</span> techniques. We demonstrate here the capabilities of our Monte Carlo technique in obtaining <span class="hlt">absolute</span> binding free energies for a series of benzamidine like inhibitors into trypsin. Our results are in good agreement with experimental data and other molecular <span class="hlt">dynamics</span> simulations, indicating that PELE can be a useful tool for quick estimates of binding free energies and mechanisms. PMID:26579911</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.C41A0513M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.C41A0513M"><span id="translatedtitle">High-precision Ice Surface <span class="hlt">Topography</span> Mapping Using Radar Interferometry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Moller, D.; Hensley, S.; Michel, T.; Rignot, E. J.; Simard, M.; Krabill, W. B.; Sonntag, J. G.</p> <p>2010-12-01</p> <p>In May 2009 a new radar technique for mapping ice surface <span class="hlt">topography</span> was demonstrated in a Greenland campaign as part of the NASA International Polar Year activities. This was achieved with the airborne Glacier and Ice Surface <span class="hlt">Topography</span> Interferometer (GLISTIN-A): a 35.6 GHz single-pass interferometer. Although the technique of using radar interferometry for mapping terrain has been demonstrated before, this is the first such application at millimeter-wave frequencies. Instrument performance indicates swath widths over the ice between 5-7km, with height precisions ranging from 30cm-3m at a posting of 3m x 3m. However, for this application the electromagnetic wave will penetrate an unknown amount into the snow cover thus producing an effective bias that must be calibrated. To evaluate this, GLISTIN-A flew a coordinated collection with the NASA Wallops Airborne Topographic Mapper (ATM) on a transect from Greenland’s Summit to its West coast. Two field calibration sites were established at Colorado Institute for Research in Environmental Science’s Swiss Camp and the National Science Foundation’s Summit station. Additional collections entailed flying a mosaic over Jakobshavn glacier which was repeated after 6 days to reveal surface <span class="hlt">dynamics</span>. Through detailed calibration and inter-sensor comparisons we were able to observe penetration biases and compare them with theoretical expectations. We also demonstrated GLISTIN-A’s capability to measure the <span class="hlt">topography</span> of large glacier systems in a seamless fashion and accurately measuring volume changes with a high level of spatial detail. In particular, repeating the airborne campaigns to observe elevation changes over time will allow very accurate volume change measurements. Not only is this very important for mass balance studies to have a precise mass-loss estimate, but the spatial pattern can reveal ice <span class="hlt">dynamics</span> effects and surface mass balance effects. In this manner a high resolution, high-precision topographic mapping capability is an ideal complement to the ICESat, ICESat II and Cryosat altimeters. Interpolating between the high-accuracy elevation profiles from altimeters such as the ATM or ICESat II with the high-resolution GLISTIN-A swath will enable detailed ice-surface <span class="hlt">topography</span> maps and extended spatial coverage. The result is the potential for higher fidelity mass-balance estimates and improved observational coverage. Upgrades are currently underway to improve the performance and portability of GLISTIN-A such that, onboard a long-range aircraft this radar can map Greenland’s significant glaciers in a few days. The upgraded GLISTIN-A will be compatible with GlobalHawk installation making, Antarctica basin and coastal mapping feasible. GLISTIN will make more topographic products available to glaciologists, initially through dedicated airborne campaigns or ultimately, perhaps, as a satellite mission.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19800023351','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800023351"><span id="translatedtitle">State estimation and <span class="hlt">absolute</span> image registration for geosynchronous satellites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nankervis, R.; Koch, D. W.; Sielski, H.</p> <p>1980-01-01</p> <p>Spacecraft state estimation and the <span class="hlt">absolute</span> registration of Earth images acquired by cameras onboard geosynchronous satellites are described. The basic data type of the procedure consists of line and element numbers of image points called landmarks whose geodetic coordinates, relative to United States Geodetic Survey topographic maps, are known. A conventional least squares process is used to estimate navigational parameters and camera pointing biases from observed minus computed landmark line and element numbers. These estimated parameters along with orbit and attitude <span class="hlt">dynamic</span> models are used to register images, using an automated grey level correlation technique, inside the span represented by the landmark data. In addition, the <span class="hlt">dynamic</span> models can be employed to register images outside of the data span in a near real time mode. An important application of this mode is in support of meteorological studies where rapid data reduction is required for the rapid tracking and predicting of <span class="hlt">dynamic</span> phenomena.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20010044472&hterms=Gravity+Mars&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DGravity%2BMars','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20010044472&hterms=Gravity+Mars&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DGravity%2BMars"><span id="translatedtitle">Gravity/<span class="hlt">Topography</span> Admittances and Lithospheric Evolution on Mars: The Importance of Finite-Amplitude <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>McGovern, Patrick J.; Solomon, Sean C.; Smith, David E.; Zuber, Maria T.; Neumann, Gregory A.; Head, J. W., III; Phillips, Roger J.; Simons, Mark</p> <p>2001-01-01</p> <p>We calculate localized gravity/<span class="hlt">topography</span> admittances for Mars, in order to estimate elastic lithosphere thickness. A finite-amplitude correction to modeled gravity is required to properly interpret admittances in high-relief regions of Mars. Additional information is contained in the original extended abstract.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19840015444&hterms=fluvial+topography&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dfluvial%2Btopography','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19840015444&hterms=fluvial+topography&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dfluvial%2Btopography"><span id="translatedtitle">Inversion of <span class="hlt">topography</span> in Martian highlands terrains</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dehon, R. A.</p> <p>1984-01-01</p> <p>One unique feature on Mars is the presence of ring furrows which are apparently produced by inversion of <span class="hlt">topography</span> at the rims of partially buried craters. Ring furrows are flat-floored trenches, circular in plan view, forming rings 7 to 50 km in diameter. The moat is on the order of 0.5 km deep and 2 to 10 km wide, and it surrounds a flat topped circular mesa or plateau that is 5 to 40 km across. The central plateau is at the same elevation or lower than the surrounding plain outside the ring. The circular nature and size range of ring furrows tend to suggest that these features are related to craters partially buried by younger lava flows. The rings have been formed by preferential removal of the exposed crater rims. Ground ice decay, sapping, or fluvial erosion removed the less resistant, porous material of crater rims while leaving the more resistant volcanic flow material. Differential erosion has thus led to a reversal of <span class="hlt">topography</span> in which the original positive relief of the rim is reduced to a negative relief feature.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983SPIE..361..111T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983SPIE..361..111T"><span id="translatedtitle">Analysis Of Scoliosis By Back Shape <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Turner-Smith, Alan R.; Harris, John D.</p> <p>1983-07-01</p> <p>The use of surface <span class="hlt">topography</span> for the assessment of scoliotic deformity in the clinic depends firstly on the quality of measures which reliably characterise deformity of the back, and secondly on the ease and speed with which these measures can be applied. A method of analysis of back shape measurements is presented which can be applied to any topographic measurement system. Measures presented are substantially independent of minor changes in the patient's posture in rotation and flexion from one clinic to the next, and yet sensitive enough to indicate significant improvement or degeneration of the disease. The presentation shows (1) horizontal cross-sections at ten levels up the back from sacrum to vertebra prominens, (2) angles of rotation of the surface over a small region about the spine, (3) three vertical profiles following the line of the spine, and (4) measures of maximum kyphosis and lordosis. Dependence on the operator has been reduced to a minimum. Extreme care in positioning the patient is unnecessary and those spinous processes which are easily palpable, the vertebra prominens and the two dimples over the posterior superior iliac spines are marked. Analysis proceeds entirely automatically once the basic shape data have been supplied. Applications of the technique to indirect moire <span class="hlt">topography</span> and a television topographic measurement system are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/of/2008/1326/','USGSPUBS'); return false;" href="http://pubs.usgs.gov/of/2008/1326/"><span id="translatedtitle">EAARL <span class="hlt">Topography</span>-Colonial National Historical Park</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Brock, John C.; Wright, C. Wayne; Nayegandhi, Amar; Stevens, Sara; Travers, Laurinda J.</p> <p>2008-01-01</p> <p>These Lidar-derived <span class="hlt">topography</span> maps were produced as a collaborative effort between the U.S. Geological Survey (USGS) Coastal and Marine Geology Program, Florida Integrated Science Center (FISC) St. Petersburg, the National Park Service (NPS) Inventory and Monitoring Program, Northeast Coastal and Barrier Network, and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility. One objective of this research is to create techniques to survey coral reefs, barrier islands, and various nearshore coastal environments for the purposes of geomorphic change studies, habitat mapping, ecological monitoring, change detection, and event assessment. As part of this project, data from an innovative instrument under development at the NASA Wallops Flight Facility, the NASA Experimental Airborne Advanced Research Lidar (EAARL) are being used. This sensor has the potential to make significant contributions in this realm for measuring subaerial and submarine <span class="hlt">topography</span> wthin cross-environment surveys. High spectral resolution, water-column correction, and low costs were found to be key factors in providing accurate and affordable imagery to coastal resource managers.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SuTMP...3c5004H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SuTMP...3c5004H"><span id="translatedtitle">Uncertainty in measurement of surface <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haitjema, Han</p> <p>2015-09-01</p> <p>The 2.5-dimensional (2.5D) roughness parameters were standardized in 2012. With their increasing use in science and industry, the request for traceability and uncertainty evaluation for these parameters follows logically. This paper gives an overview of the problems and possibilities that appear when uncertainties have to be associated with values that are derived from a measured surface <span class="hlt">topography</span>, such as the Ra-value of a periodic specimen, the RSm value of a type-D standard, and the Sa-value of a single cutoff length of a type D standard. It is shown that straightforward implementation of the methods described in the ‘Guide to the Expression of Uncertainty in Measurement’ (GUM) leads to impossible and impracticable equations because of the correlations between some millions of measurement points. A practical solution is found by considering the main aspects of uncertainty, as these are given in the recent ISO 25178 standards series, and applying these to a measured surface <span class="hlt">topography</span> as a whole.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900027966&hterms=synchrotron+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsynchrotron%2Bradiation','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900027966&hterms=synchrotron+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dsynchrotron%2Bradiation"><span id="translatedtitle"><span class="hlt">Dynamical</span> diffraction imaging (<span class="hlt">topography</span>) with X-ray synchrotron radiation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kuriyama, M.; Steiner, B. W.; Dobbyn, R. C.</p> <p>1989-01-01</p> <p>By contrast to electron microscopy, which yields information on the location of features in small regions of materials, X-ray diffraction imaging can portray minute deviations from perfect crystalline order over larger areas. Synchrotron radiation-based X-ray optics technology uses a highly parallel incident beam to eliminate ambiguities in the interpretation of image details; scattering phenomena previously unobserved are now readily detected. Synchrotron diffraction imaging renders high-resolution, real-time, in situ observations of materials under pertinent environmental conditions possible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.T43D2149W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.T43D2149W"><span id="translatedtitle">Reconstructing hotspot-induced <span class="hlt">dynamic</span> <span class="hlt">topography</span> through palaeogeomorphology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Whitchurch, A. L.; Gupta, S.; Barfod, D.</p> <p>2009-12-01</p> <p>The interaction of a buoyant mantle plume head with the overlying lithosphere is thought to generate significant, kilometre-scale topographic doming of the crust. Consequently, continental mantle plumes should have an observable response in river drainage systems and should potentially drive large-scale erosional denudation. The key to understanding the complex landscape evolution associated with the life cycle of a mantle plume is therefore locked within the sedimentary record of basins neighbouring such uplifts. The Yellowstone region, western USA, provides the perfect natural laboratory in which to test the above hypothesis. The Yellowstone hotspot initiated at the Oregon-Nevada border ca. 16 Ma. It is associated with a hotspot track, marked by time-transgressive volcanic centres which line the Snake River Plain, generated through migration of the North American plate across this stationary mantle plume. Today the hotspot is located beneath Yellowstone National Park and is thought to generate crustal-scale doming. We investigate the Mio-Pliocene Sixmile Creek Formation within the Ruby Basin, a rift basin located on the northern shoulder of the hotspot track between ~16-6 Ma. Through the temporal reconstruction of sedimentary architecture, grain size, palaeoslope and palaeocurrent trends, we show that hotspot-related crustal doming acted to uplift the headwaters of a fluvial system supplying the basin, driving exhumation that was associated with distinct fluvial reconfiguration. Evolution of the axial river system is evidenced by the transition from isolated, single-storey ribbon channels to amalgamated, multi-storey, braided fluvial deposition. This subsequently drove a pulse of coarse-grained gravel progradation through the basin. Detailed grain size analysis and calculation of fluvial palaeoslopes indicates a distinct coarsening of the axial river sediment and an increase in depositional slope from ~0.47 m/km to ~1.90 m/km between ~12-6 Ma. Our results help to constrain the scale, geometry and evolution of hotspot-generated topographic doming over the life cycle of the Yellowstone mantle plume. This study demonstrates the use of field geologic work in providing insight into large-scale geodynamic problems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19950057699&hterms=inherited&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dinherited','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19950057699&hterms=inherited&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dinherited"><span id="translatedtitle"><span class="hlt">Topography</span> and subduction geometry in the central Andes: Clues to the mechanics of a noncollisional orogen</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Gephart, John W.</p> <p>1994-01-01</p> <p>The central Andeean orogen between 12 deg and 32 deg S latitude exhibits a high degree of spatial order: principally an extraordinary bilateral symmetry that is common to the Earth's surface, the underlying Wadati-Benioff zone, and the Nazca/South America plate kinematics, which has been stable since the mid-Tertiary. This spatial order must reflect the physical mechanisms of mountain building in this noncollisional orogen. The shapes of the <span class="hlt">topography</span> and subduction zone can be reduced to symmetric and antisummeric components relative to any verical symmetry plane; the particular plaen which minimizes the antisymmetry (and maximizes the symmetry) is well resolved and is essentially coincident with the stable Euler equator of Nacza/South America relative motion since the mid-Tertiary. That the <span class="hlt">topography</span>, subduction geometry, and persistent mid-Tertiary plate kinematics share common spatial and geometric elements suggests that he distribution of <span class="hlt">topography</span> in this orogen depends strongly on the <span class="hlt">dynamics</span> of subduction. Other factors that might affect the <span class="hlt">topography</span> and underlying tectonics, such as climate and inherited strutura fabric, which have different spatial characterisitcs, must be of less significance at a continental scale. Furthermore, the small components of asymmetry among the various elements of the orogen appear to be mutually relate in a simple way; it is possible that this coupled asymmetry is associated with a late Teriary change in plate kinematics. These observations suggest that there is a close connection between plate tectonics and the form of the Earth's surface in this noncollisional setting. It follows hta the distribution of <span class="hlt">topography</span> near convergent plate boundaries may provide a powerful constraing for understanding the <span class="hlt">dynamics</span> of subduction.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25058275','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25058275"><span id="translatedtitle">Reconstituting ring-rafts in bud-mimicking <span class="hlt">topography</span> of model membranes.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ryu, Yong-Sang; Lee, In-Ho; Suh, Jeng-Hun; Park, Seung Chul; Oh, Soojung; Jordan, Luke R; Wittenberg, Nathan J; Oh, Sang-Hyun; Jeon, Noo Li; Lee, Byoungho; Parikh, Atul N; Lee, Sin-Doo</p> <p>2014-01-01</p> <p>During vesicular trafficking and release of enveloped viruses, the budding and fission processes <span class="hlt">dynamically</span> remodel the donor cell membrane in a protein- or a lipid-mediated manner. In all cases, in addition to the generation or relief of the curvature stress, the buds recruit specific lipids and proteins from the donor membrane through restricted diffusion for the development of a ring-type raft domain of closed topology. Here, by reconstituting the bud <span class="hlt">topography</span> in a model membrane, we demonstrate the preferential localization of cholesterol- and sphingomyelin-enriched microdomains in the collar band of the bud-neck interfaced with the donor membrane. The geometrical approach to the recapitulation of the <span class="hlt">dynamic</span> membrane reorganization, resulting from the local radii of curvatures from nanometre-to-micrometre scales, offers important clues for understanding the active roles of the bud <span class="hlt">topography</span> in the sorting and migration machinery of key signalling proteins involved in membrane budding. PMID:25058275</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4124864','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4124864"><span id="translatedtitle">Reconstituting ring-rafts in bud-mimicking <span class="hlt">topography</span> of model membranes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ryu, Yong-Sang; Lee, In-Ho; Suh, Jeng-Hun; Park, Seung Chul; Oh, Soojung; Jordan, Luke R.; Wittenberg, Nathan J.; Oh, Sang-Hyun; Jeon, Noo Li; Lee, Byoungho; Parikh, Atul N.; Lee, Sin-Doo</p> <p>2014-01-01</p> <p>During vesicular trafficking and release of enveloped viruses, the budding and fission processes <span class="hlt">dynamically</span> remodel the donor cell membrane in a protein- or a lipid-mediated manner. In all cases, in addition to the generation or relief of the curvature stress, the buds recruit specific lipids and proteins from the donor membrane through restricted diffusion for the development of a ring-type raft domain of closed topology. Here, by reconstituting the bud <span class="hlt">topography</span> in a model membrane, we demonstrate the preferential localization of cholesterol- and sphingomyelin-enriched microdomains in the collar band of the bud-neck interfaced with the donor membrane. The geometrical approach to the recapitulation of the <span class="hlt">dynamic</span> membrane reorganization, resulting from the local radii of curvatures from nanometre-to-micrometre scales, offers important clues for understanding the active roles of the bud <span class="hlt">topography</span> in the sorting and migration machinery of key signalling proteins involved in membrane budding. PMID:25058275</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014NatCo...5E4507R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014NatCo...5E4507R"><span id="translatedtitle">Reconstituting ring-rafts in bud-mimicking <span class="hlt">topography</span> of model membranes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ryu, Yong-Sang; Lee, In-Ho; Suh, Jeng-Hun; Park, Seung Chul; Oh, Soojung; Jordan, Luke R.; Wittenberg, Nathan J.; Oh, Sang-Hyun; Jeon, Noo Li; Lee, Byoungho; Parikh, Atul N.; Lee, Sin-Doo</p> <p>2014-07-01</p> <p>During vesicular trafficking and release of enveloped viruses, the budding and fission processes <span class="hlt">dynamically</span> remodel the donor cell membrane in a protein- or a lipid-mediated manner. In all cases, in addition to the generation or relief of the curvature stress, the buds recruit specific lipids and proteins from the donor membrane through restricted diffusion for the development of a ring-type raft domain of closed topology. Here, by reconstituting the bud <span class="hlt">topography</span> in a model membrane, we demonstrate the preferential localization of cholesterol- and sphingomyelin-enriched microdomains in the collar band of the bud-neck interfaced with the donor membrane. The geometrical approach to the recapitulation of the <span class="hlt">dynamic</span> membrane reorganization, resulting from the local radii of curvatures from nanometre-to-micrometre scales, offers important clues for understanding the active roles of the bud <span class="hlt">topography</span> in the sorting and migration machinery of key signalling proteins involved in membrane budding.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/ds/384/','USGSPUBS'); return false;" href="http://pubs.usgs.gov/ds/384/"><span id="translatedtitle">EAARL Coastal <span class="hlt">Topography</span> - Northern Gulf of Mexico</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Nayegandhi, Amar; Brock, John C.; Sallenger, Abby; Wright, C. Wayne; Travers, Laurinda J.; Lebonitte, James</p> <p>2008-01-01</p> <p>These remotely sensed, geographically referenced elevation measurements of Lidar-derived coastal <span class="hlt">topography</span> were produced as a collaborative effort between the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. One objective of this research is to create techniques to survey areas for the purposes of geomorphic change studies following major storm events. The USGS Coastal and Marine Geology Program's National Assessment of Coastal Change Hazards project is a multi-year undertaking to identify and quantify the vulnerability of U.S. shorelines to coastal change hazards such as effects of severe storms, sea-level rise, and shoreline erosion and retreat. Airborne Lidar surveys conducted during periods of calm weather are compared to surveys collected following extreme storms in order to quantify the resulting coastal change. Other applications of high-resolution <span class="hlt">topography</span> include habitat mapping, ecological monitoring, volumetric change detection, and event assessment. The purpose of this project is to provide highly detailed and accurate datasets of the northern Gulf of Mexico coastal areas, acquired on September 19, 2004, immediately following Hurricane Ivan. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative airborne Lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Airborne Advanced Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532 nanometer) Lidar designed to map near-shore bathymetry, <span class="hlt">topography</span>, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive Lidar, a down-looking RGB (red-green-blue) digital camera, a high-resolution multi-spectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers and an integrated miniature digital inertial measurement unit which provide for sub-meter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a Lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal <span class="hlt">topography</span> within cross-environmental surveys. Elevation measurements were collected over the survey area using the EAARL system on September 19, 2004. The survey resulted in the acquisition of 3.2 gigabytes of data. The data were processed using the Airborne Lidar Processing System (ALPS), a custom-built processing system developed in a NASA-USGS collaboration. ALPS supports the exploration and processing of Lidar data in an interactive or batch mode. Modules for pre-survey flight line definition, flight path plotting, Lidar raster and waveform investigation, and digital camera image playback have been developed. Processing algorithms have been developed to extract the range to the first and last significant return within each waveform. ALPS is routinely used to create maps that represent submerged or sub-aerial <span class="hlt">topography</span>. Specialized filtering algorithms have been implemented to determine the 'bare earth' under vegetation from a point cloud of 'last return' elevations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1610934T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1610934T"><span id="translatedtitle">Hydrothermal circulation in fault slots with <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Titarenko, Sofya; McCaig, Andrew</p> <p>2014-05-01</p> <p>There are numerous cases where the circulation of hydrothermal fluid is likely to be confined within a permeable fault slot. Examples are (1) the Lost City Hydrothermal Field (LCHF) at 30 N in the Atlantic, which is likely to be controlled by large E-W faults related to the Atlantis transform fault and mass wasting on the southern wall of the Atlantis Massif, and (2) large normal faults bounding the Hess Deep rift in the East Pacific, which contain intense hydrothermal metamorphic assemblages in lower crustal gabbros formed at 200-350 ° C. This type of circulation could occur anywhere where steep faults cut the oceanic crust, including large near-axis normal faults, transform faults and faults at subduction bend zones, and could be the major way in which the upper mantle and lower crust are hydrated. It is therefore important to constrain the controls on temperature conditions of alteration and hence mineral assemblages. Previous 2-D modelling of the LCHF shows that seafloor <span class="hlt">topography</span> and permeability structure combine together to localise the field near the highest point of the Atlantis Massif. Our new models are 3-D, based on a 10km cube with seafloor <span class="hlt">topography</span> of ~ 2km affecting both the fault slot and impermeable wall rocks. We have used Comsol multiphysics in this modelling, with a constant basal heatflow corresponding to the near conductive thermal gradient measured in IODP Hole 1309D, 5km north of the LCHF, and a constant temperature seafloor boundary condition. The wall rocks of the slot have a permeability of 10-17 m2 while permeability in the slot is varied between 10-14 and 10-15 m2. Initial conditions are a conductive thermal structure corresponding to the basal heatflow at steady state. Generic models not based on any particular known <span class="hlt">topography</span> quickly stabilise a hydrothermal system in the fault slot with a single upflow zone close to the model edge with highest <span class="hlt">topography</span>. In models with a depth of circulation in the fault slot of about 6 km, after an initial period of higher temperature venting which removes heat from the initial condition, venting temperature is approximately 200 ° C with a permeability of 3x10-15 m2. This falls to about 170 ° C with a permeability of 5x10-15 m2. Temperatures can be reduced by restricting the depth of hydrothermal circulation. These temperatures correspond to prehnite-chlorite assemblages seen in fault rocks at Hess Deep, but are higher than those observed at the LCHF. Work is continuing to vary permeability, fault slot geometry and <span class="hlt">topography</span> to better match the conditions in the Atlantis Massif, and to model the effects of dyke intrusion into the fault zone as observed at Hess Deep.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1996JCli....9.2443H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1996JCli....9.2443H"><span id="translatedtitle">Optimal Spectral <span class="hlt">Topography</span> and Its Effect on Model Climate.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Holzer, Mark</p> <p>1996-10-01</p> <p>Gibbs oscillations in the truncated spectral representation of the earth's <span class="hlt">topography</span> are strongly reduced by determining its spectral coefficients as a minimum of a nonuniformly weighted, nonquadratic cost function. The cost function penalizes the difference between spectral and true <span class="hlt">topography</span> with weights that are explicit functions of the topographic height and its gradient. The sensitivity of the Canadian Climate Centre general circulation model's climate to the presence of Gibbs oscillations is determined for T32 and T48 resolutions by comparing the climates with optimal spectral <span class="hlt">topography</span> to those with standard spectral <span class="hlt">topography</span>. The main effect of Gibbs oscillations in the standard spectral <span class="hlt">topography</span> is to induce spurious grid-scale ripples in the surface fluxes, which, for the surface energy balance, can be on the order of several tens of watts per square meter. Ripples in the surface fluxes are nearly absent in the model climate with the optimal spectral <span class="hlt">topography</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100033697','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100033697"><span id="translatedtitle">STS-99 Shuttle Radar <span class="hlt">Topography</span> Mission Stability and Control</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hamelin, Jennifer L.; Jackson, Mark C.; Kirchwey, Christopher B.; Pileggi, Roberto A.</p> <p>2001-01-01</p> <p>The Shuttle Radar <span class="hlt">Topography</span> Mission (SRTM) flew aboard Space Shuttle Endeavor February 2000 and used interferometry to map 80% of the Earth's landmass. SRTM employed a 200-foot deployable mast structure to extend a second antenna away from the main antenna located in the Shuttle payload bay. Mapping requirements demanded precision pointing and orbital trajectories from the Shuttle on-orbit Flight Control System (PCS). Mast structural <span class="hlt">dynamics</span> interaction with the FCS impacted stability and performance of the autopilot for attitude maneuvers and pointing during mapping operations. A damper system added to ensure that mast tip motion remained with in the limits of the outboard antenna tracking system while mapping also helped to mitigate structural <span class="hlt">dynamic</span> interaction with the FCS autopilot. Late changes made to the payload damper system, which actually failed on-orbit, required a redesign and verification of the FCS autopilot filtering schemes necessary to ensure rotational control stability. In-flight measurements using three sensors were used to validate models and gauge the accuracy and robustness of the pre-mission notch filter design.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22280530','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22280530"><span id="translatedtitle">Origin of bending in uncoated microcantilever - Surface <span class="hlt">topography</span>?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lakshmoji, K.; Prabakar, K.; Tripura Sundari, S. Jayapandian, J.; Tyagi, A. K.; Sundar, C. S.</p> <p>2014-01-27</p> <p>We provide direct experimental evidence to show that difference in surface <span class="hlt">topography</span> on opposite sides of an uncoated microcantilever induces bending, upon exposure to water molecules. Examination on opposite sides of the microcantilever by atomic force microscopy reveals the presence of localized surface features on one side, which renders the induced stress non-uniform. Further, the root mean square inclination angle characterizing the surface <span class="hlt">topography</span> shows a difference of 73° between the opposite sides. The absence of deflection in another uncoated microcantilever having similar surface <span class="hlt">topography</span> confirms that in former microcantilever bending is indeed induced by differences in surface <span class="hlt">topography</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014DPS....4640108S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014DPS....4640108S"><span id="translatedtitle">The Influence of <span class="hlt">Topography</span> on Volatile Transport</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stansberry, John A.; Grundy, Will; Young, Leslie</p> <p>2014-11-01</p> <p><span class="hlt">Topography</span> can exert important influences on volatile transport on bodies, such as Pluto and Triton, with global atmospheres supported by vapor pressure equilibrium with volatile frost on the surface. First, because local energy balance depends on the illumination angle, volatile frost will preferentially sublime from (condense on) areas tilted towards (away from) the Sun, as has been previously modelled at small spatial scales [e.g. 1]. Topographic features can also cause a completely different kind of vertical volatile transport resulting from the decrease in atmospheric pressure with altitude. On Pluto and Triton the sublimation flux from a topographic feature approximately one km high is comparable to the seasonal or inter-hemispheric sublimation flux (1 g/cm2^/year). To the extent that seasonal transport influences the distribution of volatile ices (and related characteristics such as albedo, emissivity, reflectance spectrum), <span class="hlt">topography</span>-driven transport will exert a comparable influence around features a km or more above (or below) the global mean altitude of the frost deposits. This implies that in addition to there being a global "frost temperature" (defined by the temperature at which the frost vapor pressure equals the atmospheric pressure), there is a "frost altitude" (defined by the globally-averaged altitude of all the volatile frost). The sense of <span class="hlt">topography</span>-driven volatile transport is to denude high areas. Consider two frost patches with equilibrium temperatures equal to the frost temperature, but at different altitudes. The high(low)-altitude patch is in contact with a lower(higher)-pressure atmosphere due to the e^(-z/H) dependence of atmospheric pressure. If the high(low)-altitude patch is above(below) the frost altitude, frost will sublime from (condense on) the high (low) frost patch, resulting in net downhill transport. We present models for the combined effects of illumination and altitude on frost transport rates for simple topographic features and discuss how these may influence the appearance of Pluto's surface as it will be seen by the New Horizons spacecraft in July 2015. [1] Yelle (1992) Science 255, 1553-1555.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ufm..conf..509K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ufm..conf..509K"><span id="translatedtitle">Universal Cosmic <span class="hlt">Absolute</span> and Modern Science</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kostro, Ludwik</p> <p></p> <p>The official Sciences, especially all natural sciences, respect in their researches the principle of methodic naturalism i.e. they consider all phenomena as entirely natural and therefore in their scientific explanations they do never adduce or cite supernatural entities and forces. The purpose of this paper is to show that Modern Science has its own self-existent, self-acting, and self-sufficient Natural All-in Being or Omni-Being i.e. the entire Nature as a Whole that justifies the scientific methodic naturalism. Since this Natural All-in Being is one and only It should be considered as the own scientifically justified Natural <span class="hlt">Absolute</span> of Science and should be called, in my opinion, the Universal Cosmic <span class="hlt">Absolute</span> of Modern Science. It will be also shown that the Universal Cosmic <span class="hlt">Absolute</span> is ontologically enormously stratified and is in its ultimate i.e. in its most fundamental stratum trans-reistic and trans-personal. It means that in its basic stratum. It is neither a Thing or a Person although It contains in Itself all things and persons with all other sentient and conscious individuals as well, On the turn of the 20th century the Science has begun to look for a theory of everything, for a final theory, for a master theory. In my opinion the natural Universal Cosmic <span class="hlt">Absolute</span> will constitute in such a theory the radical all penetrating Ultimate Basic Reality and will substitute step by step the traditional supernatural personal <span class="hlt">Absolute</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19930005783&hterms=Schroeter&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DSchroeter','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19930005783&hterms=Schroeter&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DSchroeter"><span id="translatedtitle">Assimilation of altimeter <span class="hlt">topography</span> into oceanic models</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Demey, Pierre; Menard, Yves; Pinardi, Nadia; Schroeter, J.; Verron, J.</p> <p>1991-01-01</p> <p>The primary goals of the authors are to build an intuition for assimilation techniques and to investigate the impact of variable altimeter <span class="hlt">topography</span> on simple or complex oceanic models. In particular, applying various techniques and sensitivity studies to model and data constraints plays a key role. We are starting to use quasi-geostrophic, semigeostrophic, and primitive-equation (PE) models and to test the schemes in regions of interest to the World Ocean Circulation Experiment (WOCE), as well as in the northeast Atlantic and the Mediterranean. The impact of scatterometer wind forcing on the results is also investigated. The use of Geosat, European Remote Sensing satellite (ERS-1), and TOPEX/POSEIDON altimetry data is crucial in fine tuning the models and schemes to the selected areas of interest.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1984pggp.rept..240R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1984pggp.rept..240R"><span id="translatedtitle">Temporal and spatial distribution of exhumed <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rhodes, D. D.</p> <p>1984-04-01</p> <p>Perhaps the greatest chance for exhumation, or burial, of a landscape by terrestrial processes exists near the boundaries of the climatic belts. In the Southern Hemisphere, there is comparatively little land area within Budel's zone of extra-tropical valley formation, which contains most of the examples of exhumed <span class="hlt">topography</span> in the Northern Hemisphere. The only examples of resurrected landforms that occur within Budel's tropical zone are located near the boundary of this zone, where climate may have changed during the Pleistocene. The ages of exhumed landforms sampled are not equally distributed through geologic time. Most of the exhumed features were created either during the Precambrian or the Tertiary periods which are commonly cited as episodes of significant landform development.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19840015449&hterms=exhumation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dexhumation','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19840015449&hterms=exhumation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dexhumation"><span id="translatedtitle">Temporal and spatial distribution of exhumed <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rhodes, D. D.</p> <p>1984-01-01</p> <p>Perhaps the greatest chance for exhumation, or burial, of a landscape by terrestrial processes exists near the boundaries of the climatic belts. In the Southern Hemisphere, there is comparatively little land area within Budel's zone of extra-tropical valley formation, which contains most of the examples of exhumed <span class="hlt">topography</span> in the Northern Hemisphere. The only examples of resurrected landforms that occur within Budel's tropical zone are located near the boundary of this zone, where climate may have changed during the Pleistocene. The ages of exhumed landforms sampled are not equally distributed through geologic time. Most of the exhumed features were created either during the Precambrian or the Tertiary periods which are commonly cited as episodes of significant landform development.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1980JFM...101..281B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1980JFM...101..281B"><span id="translatedtitle">Rotating barotropic flow over finite isolated <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bannon, P. R.</p> <p>1980-11-01</p> <p>A study is presented of the flow of a rotating incompressible fluid over isolated <span class="hlt">topography</span> whose nondimensional height (i.e., topographic height divided by the mean fluid depth) is large compared with the Rossby number. Attention is restricted to the flow which is sufficiently shallow that the free-surface equations provide an adequate description. The flow is forced laterally by a specified upstream inflow and by a prescribed surface stress; dissipation is incorporated using a Rayleigh friction acting antiparallel to the flow. Steady state solutions for uniform inflow on an f-plane are found for linear viscous flow, quasi-geostrophic flow with and without friction, and inviscid flow with and without a rigid lid.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/of/2006/1244/','USGSPUBS'); return false;" href="http://pubs.usgs.gov/of/2006/1244/"><span id="translatedtitle">EAARL <span class="hlt">topography</span>: Dry Tortugas National Park</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Brock, John C.; Wright, C. Wayne; Patterson, Matt; Nayegandhi, Amar; Patterson, Judd</p> <p>2008-01-01</p> <p>This lidar-derived submarine <span class="hlt">topography</span> map was produced as a collaborative effort between the U.S. Geological Survey (USGS) Coastal and Marine Geology Program, National Park Service (NPS) South Florida/Caribbean Network Inventory and Monitoring Program, and the National Aeronautics and Space Administration (NASA) Wallops Flight Facility. One objective of this research is to create techniques to survey coral reefs for the purposes of habitat mapping, ecological monitoring, change detection, ad event assessment (for example: bleaching, hurricanes, disease outbreaks). As part of this project, data from an innovative instrument under development at the NASA Wallops Flight Facility, the NASA Experimental Airborne Advanced Research Lidar (EAARL) are being used. This sensor has the potential to make significant contributions in this realm for measuring water depth and conducting cross-environment surveys. High spectral resolution, water-column correction, and low costs were found to be key factors in providing accurate and affordable imagery to managers of coastal tropical habitats.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.usgs.gov/of/2006/1118/','USGSPUBS'); return false;" href="http://pubs.usgs.gov/of/2006/1118/"><span id="translatedtitle">EAARL submarine <span class="hlt">topography</span>: Biscayne National Park</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Brock, John C.; Wright, C. Wayne; Patterson, Matt; Nayegandhi, Amar; Patterson, Judd; Harris, Melanie S.; Mosher, Lance</p> <p>2006-01-01</p> <p>This lidar-derived submarine <span class="hlt">topography</span> map was produced as a collaborative effort between the U.S. Geological Survey (USGS) Coastal and Marine Geology Program, National Park Service (NPS) South Florida/Caribbean Network Inventory and Monitoring Program, and the National Aeronautics and Space Administration (NASA) Wallops Flight Facility. One objective of this research is to create techniques to survey coral reefs for the purposes of habitat mapping, ecological monitoring, change detection, and event assessment (for example: bleaching, hurricanes, disease outbreaks). As part of this project, data from an innovative instrument under development at the NASA Wallops Flight Facility, the NASA Experimental Airborne Advanced Research Lidar (EAARL) are being used. This sensor has the potential to make significant contributions in this realm for measuring water depth and conducting cross-environment surveys. High spectral resolution, water-column correction, and low costs were found to be key factors in providing accurate and affordable imagery to managers of coastal tropical habitats.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3534185','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3534185"><span id="translatedtitle">Architecture and development of olivocerebellar circuit <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Reeber, Stacey L.; White, Joshua J.; George-Jones, Nicholas A.; Sillitoe, Roy V.</p> <p>2013-01-01</p> <p>The cerebellum has a simple tri-laminar structure that is comprised of relatively few cell types. Yet, its internal micro-circuitry is anatomically, biochemically, and functionally complex. The most striking feature of cerebellar circuit complexity is its compartmentalized <span class="hlt">topography</span>. Each cell type within the cerebellar cortex is organized into an exquisite map; molecular expression patterns, dendrite projections, and axon terminal fields divide the medial-lateral axis of the cerebellum into topographic sagittal zones. Here, we discuss the mechanisms that establish zones and highlight how gene expression and neural activity contribute to cerebellar pattern formation. We focus on the olivocerebellar system because its developmental mechanisms are becoming clear, its topographic termination patterns are very precise, and its contribution to zonal function is debated. This review deconstructs the architecture and development of the olivocerebellar pathway to provide an update on how brain circuit maps form and function. PMID:23293588</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983SPIE..361..107D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983SPIE..361..107D"><span id="translatedtitle">Measurement Of Kyphosis Using Moire <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Drerup, Burkhard</p> <p>1983-07-01</p> <p>Contour line patterns, as they are produced by moire <span class="hlt">topography</span> are dependent on position, posture and body shape of the patient. For all medical applications data are needed, which are only dependent on shape and posture and which therefore are independent of positioning. The measurement of the kyphotic angle from topograms can be performed to meet these requirements and to yield results, which are independent of positioning. Different techniques for measuring this angle are discussed. Digitization and reconstruction of profiles from moire topograms are presented. In order to get reproducible results, landmarks are needed on the body surface. Landmarks may be found either by palpation or by analytical investigation of the back shape. Here, the inflectional points of the sagittal back profile are taken as intrinsic landmarks. Their relation to anatomical landmarks, which are found e.g. by palpation, is studied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.H42C..04Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.H42C..04Q"><span id="translatedtitle">Karst Water System Investigated by <span class="hlt">Absolute</span> Gravimetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Quinif, Y.; Meus, P.; van Camp, M.; Kaufmann, O.; van Ruymbeke, M.; Vandiepenbeeck, M.; Camelbeeck, T.</p> <p>2006-12-01</p> <p>The highly anisotropic and heterogeneous hydrogeological characteristics of karst aquifers are difficult to characterize and present challenges for modeling of storage capacities. Little is known about the surface and groundwater interconnection, about the connection between the porous formations and the draining cave and conduits, and about the variability of groundwater volume within the system. Usually, an aquifer is considered as a black box, where water fluxes are monitored as input and output. However, water inflow and outflow are highly variable and cannot be measured directly. A recent project, begun in 2006 sought to constrain the water budget in a Belgian karst aquifer and to assess the porosity and water <span class="hlt">dynamics</span>, combining <span class="hlt">absolute</span> gravity (AG) measurements and piezometric levels around the Rochefort cave. The advantage of gravity measurements is that they integrate all the subsystems in the karst system. This is not the case with traditional geophysical tools like boring or monitoring wells, which are soundings affected by their near environment and its heterogeneity. The investigated cave results from the meander cutoff system of the Lomme River. The main inputs are swallow holes of the river crossing the limestone massif. The river is canalized and the karst system is partly disconnected from the hydraulic system. In February and March 2006, when the river spilled over its dyke and sank into the most important swallow hole, this resulted in dramatic and nearly instantaneous increases in the piezometric levels in the cave, reaching up to 13 meters. Meanwhile, gravity increased by 50 and 90 nms-2 in February and March, respectively. A first conclusion is that during these sudden floods, the pores and fine fissures were poorly connected with the enlarged fractures, cave, and conduits. With a rise of 13 meters in the water level and a 5% porosity, a gravity change of 250 nms-2 should have been expected. This moderate gravity variation suggests either a weaker porosity or that only the filling of the cave and conduits with water was responsible for the observed gravitational effect. This paper presents the results obtained in 2006 and the project planned in 2007.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/5808031','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/5808031"><span id="translatedtitle">Bedrock <span class="hlt">topography</span> beneath the Red Lake peatlands</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Miller, P.; Shaw, G.H. . Geology Dept.); Glaser, P. . Limnological Research Center); Siegel, D. . Dept. of Geology)</p> <p>1992-01-01</p> <p>Detailed hydrologic investigations of peat landforms in the Red Lake Peatlands have revealed that groundwater flow is significantly related to the type of landform and vegetation community present at a given site. Hydrogeologic modeling of shallow groundwater systems suggests that bedrock <span class="hlt">topography</span> is an important, perhaps the vital, boundary condition controlling groundwater flow. Determination of depth to bedrock beneath different peat landforms is necessary to test the hydrogeologic models and obtain a better understanding of the processes which produce them. Direct determination of bedrock depth in peatlands is hampered by the difficult conditions and high costs of boring. In addition, environmental impacts from boring activities would probably be substantial in these sensitive ecosystems. Shallow seismic methods appear to be the most promising approach to obtain the necessary data. Unfortunately the 2+ meters of peat covering Lake Agassiz sediments overlying the bedrock is not only a poor substrate for geophone emplacement, but is a strong attenuator of seismic waves. These difficulties have been overcome by constructing a tool which allows the geophones to be emplaced beneath the peat and into the top of the sediments. The shotgun cartridge source is also located beneath the peat. This combination results in very good seismic records, far better than those possible with surface sources and geophones. The results from a preliminary survey along a 600m line show that there are significant variations in bedrock <span class="hlt">topography</span> below the peat. In a distance of less than 500m, depth to bedrock changes by about 30%, from about 55m to about 40m. This is similar to variations indicated by the models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9635E..0GS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9635E..0GS"><span id="translatedtitle">Absorber <span class="hlt">topography</span> dependence of phase edge effects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shanker, Aamod; Sczyrba, Martin; Connolly, Brid; Waller, Laura; Neureuther, Andy</p> <p>2015-10-01</p> <p>Mask <span class="hlt">topography</span> contributes to phase at the wafer plane, even for OMOG binary masks currently in use at the 22nm node in deep UV (193nm) lithography. Here, numerical experiments with rigorous FDTD simulation are used to study the impact of mask 3D effects on aerial imaging, by varying the height of the absorber stack and its sidewall angle. Using a thin mask boundary layer model to fit to rigorous simulations it is seen that increasing the absorber thickness, and hence the phase through the middle of a feature (bulk phase) monotonically changes the wafer-plane phase. Absorber height also influences best focus, revealed by an up/down shift in the Bossung plot (linewidth vs. defocus). Bossung plot tilt, however, responsible for process window variability at the wafer, is insensitive to changes in the absorber height (and hence also the bulk phase). It is seen to depend instead on EM edge diffraction from the thick mask edge (edge phase), but stays constant for variations in mask thickness within a 10% range. Both bulk phase and edge phase are also independent of sidewall angle fluctuation, which is seen to linearly affect the CD at the wafer, but does not alter wafer phase or the defocus process window. Notably, as mask <span class="hlt">topography</span> varies, the effect of edge phase can be replicated by a thin mask model with 8nm wide boundary layers, irrespective of absorber height or sidewall angle. The conclusions are validated with measurements on phase shifting masks having different topographic parameters, confirming the strong dependence of phase variations at the wafer on bulk phase of the mask absorber.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006DPS....38.3009G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006DPS....38.3009G"><span id="translatedtitle">An Assessment of <span class="hlt">Topography</span> Measurements on Europa</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Greenberg, Richard; Hurford, T.; Foley, M.</p> <p>2006-09-01</p> <p>Many small patches of chaotic terrain on Europa appear to be bulged upward, giving qualitative impressions that chaos might represent "cryovolcanic" and/or convective upwelling. The same bulged appearance is explained by the oceanic melt-through model, as simply the <span class="hlt">topography</span> expected after refreezing and buoyant equilibrium. Greenberg et al. suggested an observational test to discriminate between these models, based on whether the up-bulged chaos is higher than the typical tectonic terrain in the region (for up-welling) or only higher than its immediate moat-like surroundings (melt-through and refreezing). Several authors have taken up this challenge, presenting topographic maps to refute the melt-through model by showing high elevations for chaos. However, details on the methods (based on combinations of stereo images and photoclinometry) have been sketchy, and without quantitative analyses of precision. For example, near Tyre, topographic maps and profiles reportedly show elevated chaos areas. Yet the elevations differ between published results by much more than the purported 10m precision. Moreover, high-elevation portions of profiles that were labeled as chaos are actually tectonic terrain. Stereo actually shows that major chaos areas are lower than the tectonic terrain in the area. Also, variations in elevation within the tectonic terrain are so great that differences from chaotic terrain are in the noise. Moreover, our error-analyses for both stereo and photoclinometry indicate that uncertainties are greater than reported differences between elevations of chaotic and tectonic terrain. For example, stereo-based models may exaggerate the height of chaos by favoring rafts as tie features, and photoclinometry is sensitive to an uncertain photometric function and to sub-pixel slope variations. To paraphrase Mark Twain, reports of the death of the melt-through model have been greatly exaggerated. Any results based on <span class="hlt">topography</span> should not be accepted until the methods involved have been subjected to rigorous and transparent quantitative evaluation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008CG.....34.1886H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008CG.....34.1886H"><span id="translatedtitle">Geostatistical modeling of <span class="hlt">topography</span> using auxiliary maps</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hengl, Tomislav; Bajat, Branislav; Blagojevi?, Dragan; Reuter, Hannes I.</p> <p>2008-12-01</p> <p>This paper recommends computational procedures for employing auxiliary maps, such as maps of drainage patterns, land cover and remote-sensing-based indices, directly in the geostatistical modeling of <span class="hlt">topography</span>. The methodology is based on the regression-kriging technique, as implemented in the R package gstat. The computational procedures are illustrated using a case study in the south-west part of Serbia. Two point data sets were used for geostatistical modeling: (1) 2051 elevation points were used to generate DEMs and (2) an independent error assessment data set (1020 points) was used to assess errors in the topo-DEM and the SRTM-DEM. Four auxiliary maps were used to improve generation of DEMs from point data: (1) distance to streams, (2) terrain complexity measured by standard deviation filter, (3) analytical hillshading map and (4) NDVI map derived from the Landsat image. The auxiliary predictors were significantly correlated with elevations (adj.R2=0.20) and DEM errors (adj.R2=0.27). By including auxiliary maps in the geostatistical modeling of <span class="hlt">topography</span>, realizations of DEMs can be generated that represent geomorphology of a terrain more accurately. In addition, downscaling of a coarse 3 arcsec SRTM DEM using auxiliary maps and regression-kriging is demonstrated using the same case study. A methodological advantage of regression-kriging, compared to splines, is the possibility to automate the data processing and incorporate multiple auxiliary predictors. The remaining open issues are computational efficiency, application of local regression-kriging algorithms and preparation of suitable auxiliary data layers for such analyses.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26478959','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26478959"><span id="translatedtitle">Stimulus probability effects in <span class="hlt">absolute</span> identification.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kent, Christopher; Lamberts, Koen</p> <p>2016-05-01</p> <p>This study investigated the effect of stimulus presentation probability on accuracy and response times in an <span class="hlt">absolute</span> identification task. Three schedules of presentation were used to investigate the interaction between presentation probability and stimulus position within the set. Data from individual participants indicated strong effects of presentation probability on both proportion correct and response times. The effects were moderated by the ubiquitous stimulus position effect. The accuracy and response time data were predicted by an exemplar-based model of perceptual cognition (Kent & Lamberts, 2005). The bow in discriminability was also attenuated when presentation probability for middle items was relatively high, an effect that will constrain future model development. The study provides evidence for item-specific learning in <span class="hlt">absolute</span> identification. Implications for other theories of <span class="hlt">absolute</span> identification are discussed. (PsycINFO Database Record PMID:26478959</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20070035064&hterms=Distance&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DDistance','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20070035064&hterms=Distance&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3DDistance"><span id="translatedtitle"><span class="hlt">Absolute</span> Distance Measurement with the MSTAR Sensor</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lay, Oliver P.; Dubovitsky, Serge; Peters, Robert; Burger, Johan; Ahn, Seh-Won; Steier, William H.; Fetterman, Harrold R.; Chang, Yian</p> <p>2003-01-01</p> <p>The MSTAR sensor (Modulation Sideband Technology for <span class="hlt">Absolute</span> Ranging) is a new system for measuring <span class="hlt">absolute</span> distance, capable of resolving the integer cycle ambiguity of standard interferometers, and making it possible to measure distance with sub-nanometer accuracy. The sensor uses a single laser in conjunction with fast phase modulators and low frequency detectors. We describe the design of the system - the principle of operation, the metrology source, beamlaunching optics, and signal processing - and show results for target distances up to 1 meter. We then demonstrate how the system can be scaled to kilometer-scale distances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1989afmo.conf..130T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989afmo.conf..130T"><span id="translatedtitle"><span class="hlt">Absolute</span> interferometric testing of spherical surfaces.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Truax, B. E.</p> <p></p> <p>In typical interferometric testing the part under test is measured against a reference standard. The measured result is the difference between the errors in the test and reference surfaces plus any additional errors introduced by the interferometer. For accurate qualification of the reference surface it is necessary to employ a technique that can measure the part <span class="hlt">absolutely</span>. This paper examines an existing technique for <span class="hlt">absolute</span> testing of spherical surfaces which produces a map of the entire surface. The capabilities of this technique, error sources, and experimental data will be examined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991SPIE.1400...61T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991SPIE.1400...61T"><span id="translatedtitle"><span class="hlt">Absolute</span> interferometric testing of spherical surfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Truax, Bruce E.</p> <p>1991-03-01</p> <p>In typical interferometric testing the part under test is measured against a reference standard. The measured result is the difference between the errors in the test and reference surfaces plus any addition errors introduced by the interferometer. For accurate qualification of the reference surface it is necessary to employ a technique that can measure the part <span class="hlt">absolutely</span>. This paper examines an existing technique for <span class="hlt">absolute</span> testing of spherical surfaces which produces a map of the entire surface. The capabilities of this technique, error sources, and experimental data will be examined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1989SPIE..966..130T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989SPIE..966..130T"><span id="translatedtitle"><span class="hlt">Absolute</span> Interferometric Testing Of Spherical Surfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Truax, Bruce E.</p> <p>1989-01-01</p> <p>In typical interferometric testing the part under test is measured against a reference standard. The measured result is the difference between the errors in the test and reference surfaces plus any additional errors introduced by the interferometer. For accurate qualification of the reference surface it is necessary to employ a technique that can measure the part <span class="hlt">absolutely</span>. This paper examines an existing technique) for <span class="hlt">absolute</span> testing of spherical surfaces which produces a map of the entire surface. The capabilities of this technique, error sources, and experimental data will be examined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PEPI..245...26S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PEPI..245...26S"><span id="translatedtitle">Interior structure of the Moon: Constraints from seismic tomography, gravity and <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Steinberger, Bernhard; Zhao, Dapeng; Werner, Stephanie C.</p> <p>2015-08-01</p> <p>Seismic tomography can be combined with constraints from geoid, <span class="hlt">topography</span> and other surface observations to gain information about mantle structure and <span class="hlt">dynamics</span>. This approach has been taken with much success for the Earth mantle, and here it is, for the first time, applied to the Moon. Lunar tomography has much lower resolution as for the Earth and is mostly restricted to the near side, nevertheless we can assess under what assumptions the fit between predicted geoid (based on a tomography model) and observed geoid is best. Among the models tested, we find the most similar pattern (correlation about 0.5) if we only consider tomography below 225 km depth, if density anomalies cause little or no <span class="hlt">dynamic</span> <span class="hlt">topography</span> and if we compare to the geoid with the flattening (l = 2, m = 0) term removed. This could mean that (a) like for the Earth, seismic anomalies shallower than 225 km are caused by a combination of thermal and compositional effects and therefore cannot be simply converted to density anomalies; (b) the lithosphere is sufficiently thick to prevent <span class="hlt">dynamic</span> <span class="hlt">topography</span> more than a small fraction of total <span class="hlt">topography</span>; and (c) flattening is a "fossil" bulge unrelated to present-day mantle anomalies. However, we have to be cautious with interpreting our results, because for models with a comparatively higher correlation and a conversion from seismic velocity to density anomalies similar to the Earth's upper mantle, the amplitude of the predicted geoid is much lower than observed. This could either mean that the tomography model is strongly damped, or that the geoid is mostly due to shallow causes such as crustal thickness variations, with only a small part coming from the deeper mantle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/27151628','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/27151628"><span id="translatedtitle">Graphene <span class="hlt">Topographies</span>: Multiscale Graphene <span class="hlt">Topographies</span> Programmed by Sequential Mechanical Deformation (Adv. Mater. 18/2016).</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chen, Po-Yen; Sodhi, Jaskiranjeet; Qiu, Yang; Valentin, Thomas M; Steinberg, Ruben Spitz; Wang, Zhongying; Hurt, Robert H; Wong, Ian Y</p> <p>2016-05-01</p> <p>P.-Y. Chen, R. H. Hurt, I. Y. Wong and co-workers demonstrate a hierarchical graphene surface architecture generated by using various sequences and combinations of extreme mechanical deformation, as shown in the false-colored SEM image. As described on page 3564, the sequential patterning approach enables the design of feature sizes and orientations across multiple length scales which are retained during mechanical deformations of similar extent. This results in sequence-dependent surface <span class="hlt">topographies</span> with structural memory. PMID:27151628</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApGeo..13..209C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApGeo..13..209C"><span id="translatedtitle">Distribution of ice thickness and subglacial <span class="hlt">topography</span> of the "Chinese Wall" around Kunlun Station, East Antarctica</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cui, Xiang-Bin; Sun, Bo; Su, Xiao-Gang; Guo, Jing-Xue</p> <p>2016-03-01</p> <p>As fundamental parameters of the Antarctic Ice Sheet, ice thickness and subglacial <span class="hlt">topography</span> are critical factors for studying the basal conditions and mass balance in Antarctica. During CHINARE 24 (the 24th Chinese National Antarctic Research Expedition, 2007/08), the research team used a deep ice-penetrating radar system to measure the ice thickness and subglacial <span class="hlt">topography</span> of the "Chinese Wall" around Kunlun Station, East Antarctica. Preliminary results show that the ice thickness varies mostly from 1600 m to 2800 m along the "Chinese Wall", with the thickest ice being 3444 m, and the thinnest ice 1255 m. The average bedrock elevation is 1722 m, while the minimum is just 604 m. Compared with the northern side of the ice divide, the ice thickness is a little greater and the subglacial <span class="hlt">topography</span> lower on the southern side, which is also characterized by four deep valleys. We found no basal freeze-on ice in the Gamburtsev Subglacial Mountains area, subglacial lakes, or water bodies along the "Chinese Wall". Ice thickness and subglacial <span class="hlt">topography</span> data extracted from the Bedmap 2 database along the "Chinese Wall" are consistent with our results, but their resolution and accuracy are very limited in areas where the bedrock fluctuates intensely. The distribution of ice thickness and subglacial <span class="hlt">topography</span> detected by ice-penetrating radar clarifies the features of the ice sheet in this "inaccessible" region. These results will help to advance the study of ice sheet <span class="hlt">dynamics</span> and the determination of future locations of the GSM's geological and deep ice core drilling sites in the Dome A region.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/433054','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/433054"><span id="translatedtitle">Representation of <span class="hlt">topography</span> in spectral climate models and its effect on simulated precipitation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lindberg, C.; Broccoli, A.J.</p> <p>1996-11-01</p> <p>Spectral climate models are distinguished by their representation of variables as finite sums of spherical harmonics, with coefficients computed by an orthogonal projection of the variables onto the spherical harmonics. Representing the surface elevation in this manner results in its contamination by Gibbs-like truncation artifacts, which appear as spurious valleys and mountain chains in the <span class="hlt">topography</span>. These {open_quotes}Gibbs ripples{close_quotes} are present in the surface <span class="hlt">topographies</span> of spectral climate models from a number of research institutions. Integrations of the Geophysical Fluid <span class="hlt">Dynamics</span> Laboratory (GFDL) climate model over a range of horizontal resolutions indicate that the Gibbs ripples lead to spurious, small-scale extrema in the spatial distribution of precipitation. This {open_quotes}cellular precipitation pathology{close_quotes} becomes more pronounced with increasing horizontal resolution, causing a deterioration in the fidelity of simulated precipitation in higher resolution models. A method is described for reducing the Gibbs ripples that occur when making an incomplete spherical harmonic expansion of the <span class="hlt">topography</span>. The new spherical harmonic representations of <span class="hlt">topography</span> are formed by fitting a nonuniform spherical smoothing spline to geodetic data and found by solving a fixed-point problem. This regularization technique results in less distortion of features such as mountain height and continental boundaries than previous smoothing methods. These new expansions of the <span class="hlt">topography</span>, when used as a lower boundary surface in the GFDL climate model, substantially diminish the cellular precipitation pathology and produce markedly more realistic simulations of precipitation. These developments make the prospect of using higher resolution spectral models for studies of regional hydrologic climate more attractive. 34 refs., 11 figs., 1 tab.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19870008216','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19870008216"><span id="translatedtitle">Investigation of the mode of compensation of Venus <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Morgan, Paul</p> <p>1986-01-01</p> <p>The Venus gravity data derived from the Pioneer Venus Orbiter indicates a strong correlation of gravity to <span class="hlt">topography</span> at all resolvable wavelengths. Focus was on an analysis in the spatial domain, using a geophysical model of topographic compensation together with the <span class="hlt">topography</span> data to compute gravity vectors corresponding to the observed data and comparison of the calculated and observed gravity vectors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=5%3a2&pg=6&id=EJ848934','ERIC'); return false;" href="http://eric.ed.gov/?q=5%3a2&pg=6&id=EJ848934"><span id="translatedtitle">An <span class="hlt">Absolute</span> Electrometer for the Physics Laboratory</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Straulino, S.; Cartacci, A.</p> <p>2009-01-01</p> <p>A low-cost, easy-to-use <span class="hlt">absolute</span> electrometer is presented: two thin metallic plates and an electronic balance, usually available in a laboratory, are used. We report on the very good performance of the device that allows precise measurements of the force acting between two charged plates. (Contains 5 footnotes, 2 tables, and 6 figures.)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/23669658','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/23669658"><span id="translatedtitle">Precision <span class="hlt">absolute</span> positional measurement of laser beams.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fitzsimons, Ewan D; Bogenstahl, Johanna; Hough, James; Killow, Christian J; Perreur-Lloyd, Michael; Robertson, David I; Ward, Henry</p> <p>2013-04-20</p> <p>We describe an instrument which, coupled with a suitable coordinate measuring machine, facilitates the <span class="hlt">absolute</span> measurement within the machine frame of the propagation direction of a millimeter-scale laser beam to an accuracy of around ±4 μm in position and ±20 μrad in angle. PMID:23669658</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/927741','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/927741"><span id="translatedtitle"><span class="hlt">Absolute</span> partial photoionization cross sections of ozone.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Berkowitz, J.; Chemistry</p> <p>2008-04-01</p> <p>Despite the current concerns about ozone, <span class="hlt">absolute</span> partial photoionization cross sections for this molecule in the vacuum ultraviolet (valence) region have been unavailable. By eclectic re-evaluation of old/new data and plausible assumptions, such cross sections have been assembled to fill this void.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Lead&pg=7&id=EJ1070973','ERIC'); return false;" href="http://eric.ed.gov/?q=Lead&pg=7&id=EJ1070973"><span id="translatedtitle">On Relative and <span class="hlt">Absolute</span> Conviction in Mathematics</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Weber, Keith; Mejia-Ramos, Juan Pablo</p> <p>2015-01-01</p> <p>Conviction is a central construct in mathematics education research on justification and proof. In this paper, we claim that it is important to distinguish between <span class="hlt">absolute</span> conviction and relative conviction. We argue that researchers in mathematics education frequently have not done so and this has lead to researchers making unwarranted claims…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=kowalski&pg=7&id=EJ753903','ERIC'); return false;" href="http://eric.ed.gov/?q=kowalski&pg=7&id=EJ753903"><span id="translatedtitle"><span class="hlt">Absolute</span> Points for Multiple Assignment Problems</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Adlakha, V.; Kowalski, K.</p> <p>2006-01-01</p> <p>An algorithm is presented to solve multiple assignment problems in which a cost is incurred only when an assignment is made at a given cell. The proposed method recursively searches for single/group <span class="hlt">absolute</span> points to identify cells that must be loaded in any optimal solution. Unlike other methods, the first solution is the optimal solution. The…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA02765&hterms=resistant+depression&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dresistant%2Bdepression','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA02765&hterms=resistant+depression&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dresistant%2Bdepression"><span id="translatedtitle">Stereo Pair: Inverted <span class="hlt">Topography</span>, Patagonia, Argentina</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p><p/> The Meseta de Somuncura is a broad plateau capped by basalt. Near its western edge is evidence of multiple volcanic events and a complex erosion history. Most notable are the long, narrow-, and winding lava flows that run across most of the right side of the image. These formed from low-viscosity lava that flowed down gullies over fairly flat terrain. Later, erosion of the landscape continued and the solidified flows were more resistant than the older surrounding rocks. Consequently, the flows became the ridges we see here. This natural process of converting gullies to ridges is called topographic inversion. See image PIA02755 (upper left corner) for a good example of topographic inversion in its earlier stages.<p/>Other features seen here include numerous and varied closed depressions. The regional drainage is not well integrated, and drainage ends up in salty lakes (blue if shallow, black if deep). Wind streaks indicate that winds blow toward the east (right) and blow salt grains off the lakebeds when dry. The bowtie pattern in the upper left has resulted from differing grazing practices among fenced fields.<p/>This cross-eyed stereoscopic image pair was generated using topographic data from the Shuttle Radar <span class="hlt">Topography</span> Mission, combined with an enhanced Landsat 7satellite color image. The <span class="hlt">topography</span> data are used to create two differing perspectives of a single image, one perspective for each eye. In doing so, each point in the image is shifted slightly, depending on its elevation. When stereoscopically merged, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions.<p/>Landsat satellites have provided visible light and infrared images of the Earth continuously since 1972. SRTM topographic data match the 30-meter (99-foot) spatial resolution of most Landsat images and provide a valuable complement for studying the historic and growing Landsat data archive. The Landsat 7 Thematic Mapper image used here was provided to the SRTM project by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center,Sioux Falls, South Dakota.<p/>Elevation data used in this image was acquired by the Shuttle Radar <span class="hlt">Topography</span> Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise,Washington, DC.<p/>Size: 21.5 kilometers (13.4 miles) x 27.2 kilometers (16.9 miles) Location: 41.6 deg. South lat., 67.9 deg. West lon. Orientation: North toward upper left Image Data: Landsat bands 1,4,7 in blue, green, red Date Acquired: February 19, 2000 (SRTM), January 22, 2000 (Landsat)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/8587772','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/8587772"><span id="translatedtitle">PAR Corneal <span class="hlt">Topography</span> System (PAR CTS): the clinical application of close-range photogrammetry.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Belin, M W; Cambier, J L; Nabors, J R; Ratliff, C D</p> <p>1995-11-01</p> <p>The PAR Corneal <span class="hlt">Topography</span> System (CTS) is a computer-driven corneal imaging system which uses close-range photogrammetry (rasterphotogrammetry) to measure and produce a topographic map of the corneal surface. The PAR CTS makes direct point-by-point measurements of surface elevation using a stereo-triangulation technique. The CTS uses a grid pattern composed of horizontal and vertical lines spaced about 0.2 mm (200 microns) apart. Each grid intersection comprises a surface feature which can be located in multiple images and used to generate an (x,y,z) coordinate. Unlike placido disc-based videokeratoscopes, the PAR CTS requires neither a smooth reflective surface nor precise spatial alignment for accurate imaging. In addition to surface elevation, the PAR CTS computes axial and tangential curvatures and refractive power. Difference maps are available in all curvatures, refractive power, and in <span class="hlt">absolute</span> elevation. PMID:8587772</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA00738&hterms=horse&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dhorse','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA00738&hterms=horse&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Dhorse"><span id="translatedtitle"><span class="hlt">Topography</span> and Volcanoes on Io (color)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>1997-01-01</p> <p>The images used to create this enhanced color composite of Io were acquired by NASA's Galileo spacecraft during its seventh orbit (G7) of Jupiter. Low sun angles near the terminator (day-night boundary near the left side of the image) offer lighting conditions which emphasize the <span class="hlt">topography</span> or relief on the volcanic satellite. The <span class="hlt">topography</span> appears very flat near the active volcanic centers such as Loki Patera (the large dark horse-shoe shaped feature near the terminator) while a variety of mountains and plateaus exist elsewhere. The big reddish-orange ring in the lower right is formed by material deposited from the eruption of Pele, Io's largest volcanic plume.<p/>North is to the top of this picture which merges images obtained with the clear, red, green, and violet filters of the solid state imaging (CCD) system on NASA's Galileo spacecraft. The resolution is 6.1 kilometers per picture element. The images were taken on April 4th, 1997 at a range of 600,000 kilometers.<p/>The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).<p/>Concurrent results from Galileo's exploration of Io appear in the October 15th, 1997 issue of Geophysical Research Letters. The papers are: Temperature and Area Constraints of the South Volund Volcano on Io from the NIMS and SSI Instruments during the Galileo G1 Orbit, by A.G. Davies, A.S. McEwen, R. Lopes-Gautier, L. Keszthelyi, R.W. Carlson and W.D. Smythe. High-temperature hot spots on Io as seen by the Galileo Solid-State Imaging (SSI) experiment, by A. McEwen, D. Simonelli, D. Senske, K. Klassen, L. Keszthelyi, T. Johnson, P. Geissler, M. Carr, and M. Belton. Io: Galileo evidence for major variations in regolith properties, by D. Simonelli, J. Veverka, and A. McEwen.<p/>This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.G13B0659S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.G13B0659S"><span id="translatedtitle">New Global Bathymetry and <span class="hlt">Topography</span> Model Grids</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smith, W. H.; Sandwell, D. T.; Marks, K. M.</p> <p>2008-12-01</p> <p>A new version of the "Smith and Sandwell" global marine <span class="hlt">topography</span> model is available in two formats. A one-arc-minute Mercator projected grid covering latitudes to +/- 80.738 degrees is available in the "img" file format. Also available is a 30-arc-second version in latitude and longitude coordinates from pole to pole, supplied as tiles covering the same areas as the SRTM30 land <span class="hlt">topography</span> data set. The new effort follows the Smith and Sandwell recipe, using publicly available and quality controlled single- and multi-beam echo soundings where possible and filling the gaps in the oceans with estimates derived from marine gravity anomalies observed by satellite altimetry. The altimeter data have been reprocessed to reduce the noise level and improve the spatial resolution [see Sandwell and Smith, this meeting]. The echo soundings database has grown enormously with new infusions of data from the U.S. Naval Oceanographic Office (NAVO), the National Geospatial-intelligence Agency (NGA), hydrographic offices around the world volunteering through the International Hydrographic Organization (IHO), and many other agencies and academic sources worldwide. These new data contributions have filled many holes: 50% of ocean grid points are within 8 km of a sounding point, 75% are within 24 km, and 90% are within 57 km. However, in the remote ocean basins some gaps still remain: 5% of the ocean grid points are more than 85 km from the nearest sounding control, and 1% are more than 173 km away. Both versions of the grid include a companion grid of source file numbers, so that control points may be mapped and traced to sources. We have compared the new model to multi-beam data not used in the compilation and find that 50% of differences are less than 25 m, 95% of differences are less than 130 m, but a few large differences remain in areas of poor sounding control and large-amplitude gravity anomalies. Land values in the solution are taken from SRTM30v2, GTOPO30 and ICESAT data. GEBCO has agreed to adopt this model and begin updating it in 2009. Ongoing tasks include building an uncertainty model and including information from the latest IBCAO map of the Arctic Ocean.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19910006329','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19910006329"><span id="translatedtitle">Mantle <span class="hlt">dynamics</span> and geodesy</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Albee, Arden</p> <p>1990-01-01</p> <p>Both completed work and work that is still in progress are presented. The completed work presented includes: (1) core-mantle boundary <span class="hlt">topography</span>; (2) <span class="hlt">absolute</span> value for mantle viscosity; (3) code development; (4) lateral heterogeneity of subduction zone rheology; and (5) planning for the Coolfront meeting. The work presented that is still in progress includes: (1) geoid anomalies for a chemically stratified mantle; and (2) geoid anomalies with lateral variations in viscosity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1210628T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1210628T"><span id="translatedtitle">Modeling the shallow gravity-driven flows as saturated binary mixtures over temporally varying <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tai, Yih-Chin; Kuo, Chih-Yu</p> <p>2010-05-01</p> <p>Based on the "shallow water models over arbitrary <span class="hlt">topography</span>" by Bouchut and Westdickenberg [2004], and the "Coulomb-mixture theory" by Iversion and Denlinger [2001], we propose a saturated binary mixture model over temporally varying <span class="hlt">topography</span>, where the effects of the entrainment and deposition are considered. Due to the deposition or erosion processes, the interface between the moving material and the stagnant base is a non-material singular surface that moves with its own velocity. Its motion is thus determined by the mass exchange between the flowing layer and the ground. Through the introduction of the unified coordinate method (e.g. Hui [2004, 2007]) and dimension analysis, the leading-order depth-integrated mass and momentum equations are presented in the time-dependent and <span class="hlt">topography</span>-fitted curvilinear coordinate system, where the evolving curvature effect is neatly included in the total derivative operator of the variable <span class="hlt">topography</span>-fitted coordinates. The motion of the basal interface is postulated by function of basal friction coefficient, sliding velocity, local thickness of the flowing layer and a threshold kinetic energy. A shock-capturing numerical scheme is implemented to solve the derived equation system (e.g. Tai and Kuo [2008] or Tai and Lin [2008]). And the key features are investigated and illustrated by the numerical results. References: [1] F. Bouchut and M. Westdickenberg, "Gravity driven shallow water models for arbitrary <span class="hlt">topography</span>." Commun. Math. Sci. 2, 359-389 (2004). [2] R.M. Iverson and R.P. Denlinger, "Flow of variably fluidized granular masses across three-dimensional terrain. Part 1 Coulomb mixture theory." J. Geophysical Research, 106, 537-552 (2001). [3] W.H. Hui, "A unified coordinates approach to computational Fluid <span class="hlt">dynamics</span>." J. Comput. and Applied Math., 163, 15-28 (2004). [4] W.H. Hui. "The unified coordinate system in computational fluid <span class="hlt">dynamics</span>." Commun. Comput. Phys., 2(4), 577-610 (2007). [5] Y.C. Tai and C.Y. Kuo, "A new model of granular flows over general <span class="hlt">topography</span> with erosion and deposition." Acta Mechanica, 199, 71-96 (2008). [6] Y.C. Tai and Y.C. Lin, "A focused view of the behavior of granular flows down a confined inclined chute into horizontal run-out zone." Phys. Fluids, 20, 123302 (2008).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMEP41B3535N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMEP41B3535N"><span id="translatedtitle"><span class="hlt">Topography</span> and Vegetation Characterization using Dual-Wavelength Airborne Lidar</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Neuenschwander, A. L.; Bradford, B.; Magruder, L. A.</p> <p>2014-12-01</p> <p>Monitoring Earth surface <span class="hlt">dynamics</span> at an ever increasing resolution has helped to support the characterization of local <span class="hlt">topography</span>, including vegetated and urban environments. Airborne remote sensing using light detection and ranging (LIDAR) is naturally suited to characterize vegetation and landscapes as it provides detailed three-dimensional spatial data with multiple elevation recordings for each laser pulse. The full waveform LIDAR receiver is unique in this aspect as it can capture and record the complete temporal history of the reflected signal, which contains detailed information about the structure of the objects and ground surfaces illuminated by the beam. This study examines the utility of co-collected, dual-wavelength, full waveform LIDAR data to characterize vegetation and landscapes through the extraction of waveform features, including total waveform energy, canopy energy distribution, and foliage penetration metrics. Assessments are performed using data collected in May 2014 over Monterey, CA, including the Naval Postgraduate School campus area as well as the Point Lobos State Natural Reserve situated on the Monterey coast. The surveys were performed with the Chiroptera dual-laser LIDAR mapping system from Airborne Hydrography AB (AHAB), which can collect both green (515nm) and near infrared (1064nm) waveforms simultaneously. Making use of the dual waveforms allows for detailed characterization of the vegetation and landscape not previously possible with airborne LIDAR.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014Tecto..33..982W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014Tecto..33..982W"><span id="translatedtitle">Accurate measurements of residual <span class="hlt">topography</span> from the oceanic realm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Winterbourne, Jeffrey; White, Nicky; Crosby, Alistair</p> <p>2014-06-01</p> <p>In the oceans, our understanding of plate subsidence as a function of age permits residual depth anomalies to be identified and mapped. These anomalies may reflect <span class="hlt">dynamic</span> <span class="hlt">topography</span> and could be an important means for constraining convective circulation of the sublithospheric mantle. Here we analyze a global database of seismic reflection and wide-angle profiles from heavily sedimented oceanic crust, which abuts continental lithosphere. At 449 locations, we calculated water-loaded subsidence, compared it with a reference age-depth relationship, and determined residual depth. We then combined these spot measurements of residual depth with observations from mid-oceanic ridges and from selected ship track bathymetry to construct a global map of residual depth. Our results suggest that the amplitude of residual depth varies by up to ±1 km with wavelengths of order 103 km. We compare our residual depths with free-air gravity and seismic tomographic anomalies. Our results show that residual depths correlate with long-wavelength gravity anomalies. In contrast, correlations between residual depths and vertically averaged shear velocity anomalies within the upper and/or the lower mantle are weaker. The largest discrepancies occur at short (˜1000 km) wavelengths. These combined observations suggest that residual depth anomalies could be generate by density variations within a thin (˜102 km) low-viscosity layer beneath the lithosphere. Our global compilation should play a significant role in helping to refine predictive geodynamical models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015APS..MARQ50011P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015APS..MARQ50011P"><span id="translatedtitle">Renewable Interfaces: Surface <span class="hlt">Topography</span> Actuation for Complex Biological Adhesion Control</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pocivavsek, Luka; Ye, Sangho; Cao, Kathleen; Lee, Ka Yee C.; Velankar, Sachin; Wagner, William</p> <p>2015-03-01</p> <p>Controlling adhesion at biological interfaces is a complex problem with great biomedical importance. We use <span class="hlt">dynamic</span> wrinkling, generated with PDMS/UVO chemistry under different macroscopic strains (ɛij ~ 0 . 3), to create a mechanical interfacial term that frustrates particle adhesion. This device actuates surface <span class="hlt">topography</span> between flat (zero surface confinement χij) and wrinkled surfaces (χij ~(A / λ) 2 , where A and λ are wrinkle amplitude and wavelength, respectively), with a maximum rate of 0.6 Hz. Un-actuated PDMS placed in contact with whole sheep blood shows near total surface coverage with adhered platelets over 90 min. Actuation showed a nearly 100-fold decrease in platelet adhesion. Interestingly, topographic actuation is four times as effective compared to flat surface actuation in controlling platelet adhesion. Our model explores the competition between surface tension terms (Uγ = γɛij) and interfacial elastic terms (Uχ =Eij (t .ɛij2 +t3 . (χij /λ2)) generated because of actuation and wrinkling, where Eij is platelet modulus and t is characteristic platelet length scale. The condition for de-adhesion is Uχ >Uγ .</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4338017','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4338017"><span id="translatedtitle">Adaptive <span class="hlt">Topographies</span> and Equilibrium Selection in an Evolutionary Game</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Osinga, Hinke M.; Marshall, James A. R.</p> <p>2015-01-01</p> <p>It has long been known in the field of population genetics that adaptive <span class="hlt">topographies</span>, in which population equilibria maximise mean population fitness for a trait regardless of its genetic bases, do not exist. Whether one chooses to model selection acting on a single locus or multiple loci does matter. In evolutionary game theory, analysis of a simple and general game involving distinct roles for the two players has shown that whether strategies are modelled using a single ‘locus’ or one ‘locus’ for each role, the stable population equilibria are unchanged and correspond to the fitness-maximising evolutionary stable strategies of the game. This is curious given the aforementioned population genetical results on the importance of the genetic bases of traits. Here we present a <span class="hlt">dynamical</span> systems analysis of the game with roles detailing how, while the stable equilibria in this game are unchanged by the number of ‘loci’ modelled, equilibrium selection may differ under the two modelling approaches. PMID:25706762</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1214544C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1214544C"><span id="translatedtitle">Enabling Access to High-Resolution Lidar <span class="hlt">Topography</span> for Earth Science Research</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crosby, Christopher; Nandigam, Viswanath; Arrowsmith, Ramon; Baru, Chaitan</p> <p>2010-05-01</p> <p>High-resolution <span class="hlt">topography</span> data acquired with lidar (light detection and ranging a.k.a. laser scanning) technology are revolutionizing the way we study the geomorphic processes acting along the Earth's surface. These data, acquired from either an airborne platform or from a tripod-mounted scanner, are emerging as a fundamental tool for research on a variety of topics ranging from earthquake hazards to ice sheet <span class="hlt">dynamics</span>. Lidar <span class="hlt">topography</span> data allow earth scientists to study the processes that contribute to landscape evolution at resolutions not previously possible yet essential for their appropriate representation. These datasets also have significant implications for earth science education and outreach because they provide an accurate digital representation of landforms and geologic hazards. However, along with the potential of lidar <span class="hlt">topography</span> comes an increase in the volume and complexity of data that must be efficiently managed, archived, distributed, processed and integrated in order for them to be of use to the community. A single lidar data acquisition may generate terabytes of data in the form of point clouds, digital elevation models (DEMs), and derivative imagery. This massive volume of data is often difficult to manage and poses significant distribution challenges when trying to allow access to the data for a large scientific user community. Furthermore, the datasets can be technically challenging to work with and may require specific software and computing resources that are not readily available to many users. The U.S. National Science Foundation (NSF)-funded Open<span class="hlt">Topography</span> Facility (http://www.opentopography.org) is an online data access and processing system designed to address the challenges posed by lidar data, and to democratize access to these data for the scientific user community. Open<span class="hlt">Topography</span> provides free, online access to lidar data in a number of forms, including raw lidar point cloud data, standard DEMs, and easily accessible Google Earth visualizations. Open<span class="hlt">Topography</span> uses cyberinfrastructure resources to allow users, regardless of their level of expertise, to access lidar data products that can be applied to their research. In addition to data access, the system uses customized algorithms and high-performance computing resources to allow users to perform on-the-fly data processing tasks such as the generation of custom DEMs. Open<span class="hlt">Topography</span>'s primarily focus is on large, community-oriented, scientific data sets, such as those acquired by the NSF-funded EarthScope project. We are actively expanding our holdings through collaborations with researchers and data providers to include data from a wide variety of landscapes and geologic domains. Ultimately, the goal is for Open<span class="hlt">Topography</span> to be the primary clearing house for Earth science-oriented high-resolution <span class="hlt">topography</span>. This presentation will provide an overview of the Open<span class="hlt">Topography</span> Facility, including available data, processing capabilities and resources, examples from scientific use cases, and a snapshot of system and data usage thus far. We will also discuss current development activities related to deploying high-performance algorithms for hydrologic processing of DEMs, geomorphic change detection analysis, and the incorporation of full waveform lidar data into the system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4346041','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4346041"><span id="translatedtitle">Epitope <span class="hlt">topography</span> controls bioactivity in supramolecular nanofibers</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sur, Shantanu; Tantakitti, Faifan; Matson, John B.; Stupp, Samuel I.</p> <p>2015-01-01</p> <p>Incorporating bioactivity into artificial scaffolds using peptide epitopes present in the extracellular matrix (ECM) is a well-known approach. A common strategy has involved epitopes that provide cells with attachment points and external cues through interaction with integrin receptors. Although a variety of bioactive sequences have been identified so far, less is known about their optimal display in a scaffold. We report here on the use of self-assembled peptide amphiphile (PA) nanofiber matrices to investigate the impact of spatial presentation of the fibronectin derived epitope RGDS on cell response. Using one, three, or five glycine residues, RGDS epitopes were systematically spaced out from the surface of the rigid nanofibers. We found that cell morphology was strongly affected by the separation of the epitope from the nanofiber surface, with the longest distance yielding the most cell-spreading, bundling of actin filaments, and a round-to-polygonal transformation of cell shape. Cell response to this type of epitope display was also accompanied with activated integrin-mediated signaling and formation of stronger adhesions between cells and substrate. Interestingly, unlike length, changing the molecular flexibility of the linker had minimal influence on cell behavior on the substrate for reasons that remain poorly understood. The use in this study of high persistence length nanofibers rather than common flexible polymers allows us to conclude that epitope <span class="hlt">topography</span> at the nanoscale structure of a scaffold influences its bioactive properties independent of epitope density and mechanical properties. PMID:25745558</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6873599','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/6873599"><span id="translatedtitle">Inversion of <span class="hlt">topography</span> in Martian highland terrains</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>De Hon, R.A.</p> <p>1985-01-01</p> <p>Ring furrows are flat-floored trenches, circulate in plan view, forming rings 7 to 50 km in diameter. Typically, ring furrows, which are 0.5 km deep and 2 to 10 km wide, surround a central, flat-topped, circular mesa or plateau. The central plateau is about the same elevation or lower than the plain outside the ring. Ring furrows are unique features of the dissected martian uplands. Related landforms range from ring furrows with fractured central plateaus to circular mesas without encircling moats. Ring furrows are superposed on many types of materials, but they are most common cratered plateau-type materials that are interpreted as volcanic flow material overlying ancient cratered terrain. The ring shape and size suggest that they are related to craters partially buried by lava flows. Ring furrows were formed by preferential removal of exposed rims of partially buried craters. Evidence of overland flow of water is lacking except within the channels. Ground ice decay and sapping followed by fluvial erosion are responsible for removal of the less resistant rim materials. Thus, differential erosion has caused a reversal of <span class="hlt">topography</span> in which the originally elevated rim is reduced to negative relief.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/11308547','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/11308547"><span id="translatedtitle">Basins of attraction on random <span class="hlt">topography</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schorghofer, N; Rothman, D H</p> <p>2001-02-01</p> <p>We investigate the consequences of fluid flowing on a continuous surface upon the geometric and statistical distribution of the flow. We find that the ability of a surface to collect water by its mere geometrical shape is proportional to the curvature of the contour line divided by the local slope. Consequently, rivers tend to lie in locations of high curvature and flat slopes. Gaussian surfaces are introduced as a model of random <span class="hlt">topography</span>. For Gaussian surfaces the relation between convergence and slope is obtained analytically. The convergence of flow lines correlates positively with drainage area, so that lower slopes are associated with larger basins. As a consequence, we explain the observed relation between the local slope of a landscape and the area of the drainage basin geometrically. To some extent, the slope-area relation comes about not because of fluvial erosion of the landscape, but because of the way rivers choose their path. Our results are supported by numerically generated surfaces as well as by real landscapes. PMID:11308547</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/40205363','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/40205363"><span id="translatedtitle">Basins of attraction on random <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schorghofer, Norbert; Rothman, Daniel H.</p> <p>2001-02-01</p> <p>We investigate the consequences of fluid flowing on a continuous surface upon the geometric and statistical distribution of the flow. We find that the ability of a surface to collect water by its mere geometrical shape is proportional to the curvature of the contour line divided by the local slope. Consequently, rivers tend to lie in locations of high curvature and flat slopes. Gaussian surfaces are introduced as a model of random <span class="hlt">topography</span>. For Gaussian surfaces the relation between convergence and slope is obtained analytically. The convergence of flow lines correlates positively with drainage area, so that lower slopes are associated with larger basins. As a consequence, we explain the observed relation between the local slope of a landscape and the area of the drainage basin geometrically. To some extent, the slope-area relation comes about not because of fluvial erosion of the landscape, but because of the way rivers choose their path. Our results are supported by numerically generated surfaces as well as by real landscapes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2858020','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2858020"><span id="translatedtitle">Nano-<span class="hlt">topography</span> sensing by osteoclasts</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Geblinger, Dafna; Addadi, Lia; Geiger, Benjamin</p> <p>2010-01-01</p> <p>Bone resorption by osteoclasts depends on the assembly of a specialized, actin-rich adhesive ‘sealing zone’ that delimits the area designed for degradation. In this study, we show that the level of roughness of the underlying adhesive surface has a profound effect on the formation and stability of the sealing zone and the associated F-actin. As our primary model substrate, we use ‘smooth’ and ‘rough’ calcite crystals with average <span class="hlt">topography</span> values of 12 nm and 530 nm, respectively. We show that the smooth surfaces induce the formation of small and unstable actin rings with a typical lifespan of ~8 minutes, whereas the sealing zones formed on the rough calcite surfaces are considerably larger, and remain stable for more than 6 hours. It was further observed that steps or sub-micrometer cracks on the smooth surface stimulate local ring formation, raising the possibility that similar imperfections on bone surfaces may stimulate local osteoclast resorptive activity. The mechanisms whereby the physical properties of the substrate influence osteoclast behavior and their involvement in osteoclast function are discussed. PMID:20375065</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.P41A0222C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.P41A0222C"><span id="translatedtitle">Shape, <span class="hlt">Topography</span> and Roughness of 25143 Itokawa</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cheng, A. F.; Barnouin-Jha, O. S.</p> <p>2007-12-01</p> <p>The recent visit of the Hayabusa spacecraft to the small near-Earth asteroid (NEA) 25143 Itokawa yielded the surprising discovery that Itokawa was not an intact object but a low density, gravitationally accumulated, rubble pile. This contrasts with the finding, from the only other NEA visited by an asteroid lander, that 433 Eros was an intact object and not a rubble pile. Eros was visited by the NEAR Shoemaker spacecraft which landed in 2001. Accurately co-registered, high resolution imager and lidar data from NEAR Shoemaker have demonstrated the fractal properties of small scale surface <span class="hlt">topography</span> on Eros, where boulders tend to be found on the tops of long ridges, consistent with the presence of an underlying globally coherent structure. However, Itokawa is a rubble pile with a fundamentally different collisional history. Here we analyze co-registered, high resolution lidar and imager data from Itokawa, obtained by Hayabusa, to explore fractal properties and surface roughness distributions on Itokawa for comparison with the results from Eros.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1989SPIE.1161..409K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989SPIE.1161..409K"><span id="translatedtitle">Imaging, Reconstruction, And Display Of Corneal <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Klyce, Stephen D.; Wilson, Steven E.</p> <p>1989-12-01</p> <p>The cornea is the major refractive element in the eye; even minor surface distortions can produce a significant reduction in visual acuity. Standard clinical methods used to evaluate corneal shape include keratometry, which assumes the cornea is ellipsoidal in shape, and photokeratoscopy, which images a series of concentric light rings on the corneal surface. These methods fail to document many of the corneal distortions that can degrade visual acuity. Algorithms have been developed to reconstruct the three dimensional shape of the cornea from keratoscope images, and to present these data in the clinically useful display of color-coded contour maps of corneal surface power. This approach has been implemented on a new generation video keratoscope system (Computed Anatomy, Inc.) with rapid automatic digitization of the image rings by a rule-based approach. The system has found clinical use in the early diagnosis of corneal shape anomalies such as keratoconus and contact lens-induced corneal warpage, in the evaluation of cataract and corneal transplant procedures, and in the assessment of corneal refractive surgical procedures. Currently, ray tracing techniques are being used to correlate corneal surface <span class="hlt">topography</span> with potential visual acuity in an effort to more fully understand the tolerances of corneal shape consistent with good vision and to help determine the site of dysfunction in the visually impaired.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2004CSR....24.1531A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2004CSR....24.1531A"><span id="translatedtitle">Coastal currents generated by outflow and vorticity and their interaction with <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>An, Byoung Woong; McDonald, N. Robb</p> <p>2004-08-01</p> <p>The offshore spreading of coastal river outflows over shelf-like <span class="hlt">topography</span> is inhibited by the demands of potential vorticity conservation. As a result, outflows tend to remain coastally trapped and flow parallel to the coast. Alongshore currents may also form when the outflow fluid has vorticity relative to the surrounding fluid, in which case the 'image' vorticity drives the outflow parallel to the coast. In the present work, the combined effects of <span class="hlt">topography</span> and anomalous vorticity of the outflow in forming coastal currents are studied. Shelf-like <span class="hlt">topography</span> is considered in the form of a sudden step change in depth, running parallel to a straight coast, some distance offshore. A simple model incorporating these effects is formulated using quasigeostrophic <span class="hlt">dynamics</span> for a barotropic fluid with a rigid lid. The role of topographic wave radiation in establishing coastal currents is studied using the linearised barotropic potential vorticity equation for the case of a weak outflow of fluid with zero anomalous vorticity. The outflow is shown to be confined to the shelf and flows to the right of the source region. For stronger outflows, with relative vorticity, the method of contour <span class="hlt">dynamics</span> is used to study the nonlinear evolution of the outflow plume and, in particular, its interaction with <span class="hlt">topography</span>. The effects of outflow strength, magnitude and sign of the relative vorticity of the outflow fluid are considered in detail. In particular, the offshore penetration distance and rate of alongshore spreading of the outflow plume are studied. When the outflow comprises of fluid with positive (cyclonic) vorticity, the topographic and vorticity-driven image effects reinforce each other and increase the spreading rate of the outflow plume to the right of the source. For negative (anticyclonic) vorticity outflows the effects oppose each other leading to enhanced offshore spreading of the outflow. The numerical results demonstrate that the offshore transport is achieved by an efficient dipolar vortex mechanism.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760017027','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760017027"><span id="translatedtitle">Influence of planetary-scale <span class="hlt">topography</span> on the diurnal thermal tide during the 1971 Martian dust storm</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Conrath, B. J.</p> <p>1976-01-01</p> <p>Data obtained with the Mariner 9 infrared spectroscopy experiment during the Martian Dust Storm of 1971 to 1972 are examined for evidence of topographic influence on the atmospheric thermal structure. Temperature perturbations which are well correlated with the planetary scale <span class="hlt">topography</span> are found superposed on the large amplitude diurnal thermal tide. Applications of tidal theory to the data indicate that the observed perturbations result from the kinematic interaction of the westward traveling diurnal wave with the large scale components of <span class="hlt">topography</span>. The dominant mode is excited by the wave-number two <span class="hlt">topography</span> component and is a vertically evanescent eastward traveling wave with an equivalent depth comparable to the atmospheric scale height. The principle <span class="hlt">dynamic</span> effect of this mode is the enhancement of the amplitude of the near-surface diurnal wind to over 40m/sec in limited areas near 30 deg south latitude. It appears likely that dust was injected into the atmosphere in these regions during the storm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002PhDT........48D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002PhDT........48D"><span id="translatedtitle">Simulation of stratified flow over three-dimensional <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ding, Li</p> <p>2002-01-01</p> <p>Large eddy simulation is employed to study the stratified flow over three-dimensional <span class="hlt">topography</span>. Incompressible, time-dependent, three-dimensional and filtered Navier-Stokes equations are solved using a finite-volume method. The subgrid scale flow motions are modeled by a <span class="hlt">dynamic</span> mixed model. The LES code is applied to the simulation of linearly stratified flow over a bell-shaped hill. The performance of the LES code has been investigated by comparing its predictions with those from a towing tank experiment. The simulation results are in good agreement with the experimental results. The height of the dividing streamline which separates the flow over the hill from the flow around the hill can be estimated by Sheppard's formula only because the energy loss due to friction/turbulence is balanced by energy provided by the pressure field. Drazin's theory can be used to predict the flow field when F < 0.4 if there is no wake region in the flow. Lee waves caused by the perturbation of the <span class="hlt">topography</span> follow the linear theory reasonably. The effects of hill geometry have been studied by varying steepness and width of the hill. The variation of the dividing-streamline height with hill geometry is the result of the change of the pressure field. Two wake structures have been found at the leeside of the hill when F < l. One has a constant wake width and the other is similar to the wake generated by the two-dimensional flow passing around cylindrical bodies with a cross section equivalent to that of the hill at each level. In the low Froude number case (F << 1), the wake structure is dominated by the latter structure due to strong stratification. In the high Froude number case (F ˜ 1), the tilting of baroclinically-generated vortices forms a pair of vertically-oriented vortices with an approximately constant wake width. A scalar is released upstream at different heights. The major diffusion occurs when the plume approaches the hill due to the increasing shear. The distortion of streamlines by the hill has a great impact on the diffusion of the scalar.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3641906','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3641906"><span id="translatedtitle">Characterizing smoking <span class="hlt">topography</span> of cannabis in heavy users</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Stitzer, Maxine L.; Vandrey, Ryan</p> <p>2013-01-01</p> <p>Rationale Little is known about the smoking <span class="hlt">topography</span> characteristics of heavy cannabis users. Such measures may be able to predict cannabis use-related outcomes and could be used to validate self-reported measures of cannabis use. Objectives The current study was conducted to measure cannabis smoking <span class="hlt">topography</span> characteristics during periods of ad libitum use and to correlate <span class="hlt">topography</span> assessments with measures of self-reported cannabis use, withdrawal and craving during abstinence, and cognitive task performance. Methods Participants (N=20) completed an inpatient study in which they alternated between periods of ad libitum cannabis use and abstinence. Measures of self-reported cannabis use, smoking <span class="hlt">topography</span>, craving, withdrawal, and sleep measures were collected. Results Participants smoked with greater intensity (e.g., greater volume, longer duration) on initial cigarette puffs with a steady decline on subsequent puffs. Smoking characteristics were significantly correlated with severity of withdrawal, notably sleep quality and architecture, and craving during abstinence, suggesting dose-related effects of cannabis use on these outcomes. Smoking characteristics generally were not significantly associated with cognitive performance. Smoking <span class="hlt">topography</span> measures were significantly correlated with self-reported measures of cannabis use, indicating validity of these assessments, but <span class="hlt">topography</span> measures were more sensitive than self-report in predicting cannabis-related outcomes. Conclusions A dose–effect relationship between cannabis consumption and outcomes believed to be clinically important was observed. With additional research, smoking <span class="hlt">topography</span> assessments may become a useful clinical tool. PMID:21922170</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1992hst..prop.4243P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1992hst..prop.4243P"><span id="translatedtitle">FOC <span class="hlt">Absolute</span> Sensitivity (F/48 Relay)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Paresce, Francesco</p> <p>1992-06-01</p> <p>The <span class="hlt">absolute</span> DQE for the f/48 camera has not yet been directly measured in orbit. This has been in part due to the absence of faint enough standards. This proposal will attempt to correct this deficiency by observations of UV standard stars with combinations of filters and small formats to achieve count rates that are not seriously nonlinear. Because of the use of small formats, interactive acquisitions will be required as well as special commanding for nonstandard formats. Internal LED exposures will also be necessary to geometrically calibrate the nonstandard format and to tie its <span class="hlt">absolute</span> response to those of other formats (there is a significant format- dependent response variation for f/48).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22340250','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22340250"><span id="translatedtitle"><span class="hlt">Absolute</span>-magnitude distributions of supernovae</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Richardson, Dean; Wright, John; Jenkins III, Robert L.; Maddox, Larry</p> <p>2014-05-01</p> <p>The <span class="hlt">absolute</span>-magnitude distributions of seven supernova (SN) types are presented. The data used here were primarily taken from the Asiago Supernova Catalogue, but were supplemented with additional data. We accounted for both foreground and host-galaxy extinction. A bootstrap method is used to correct the samples for Malmquist bias. Separately, we generate volume-limited samples, restricted to events within 100 Mpc. We find that the superluminous events (M{sub B} < –21) make up only about 0.1% of all SNe in the bias-corrected sample. The subluminous events (M{sub B} > –15) make up about 3%. The normal Ia distribution was the brightest with a mean <span class="hlt">absolute</span> blue magnitude of –19.25. The IIP distribution was the dimmest at –16.75.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EL....10629002G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EL....10629002G"><span id="translatedtitle">Dynamo action by turbulence in <span class="hlt">absolute</span> equilibrium</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gopalakrishnan Ganga Prasath, Srinivasa; Fauve, Stéphan; Brachet, Marc</p> <p>2014-04-01</p> <p>We consider the generation of a large-scale magnetic field by a turbulent flow driven by a small-scale helical forcing in a low magnetic Prandtl number fluid. We provide an estimate of the dynamo threshold that takes into account the presence of large-scale turbulent fluctuations by considering that the scales of the flow that mostly contribute to the dynamo process are roughly in <span class="hlt">absolute</span> equilibrium. We show that turbulent flows in <span class="hlt">absolute</span> equilibrium do generate dynamos and we compare their growth rates to their laminar counterparts. Finally, we show that the back reaction of the growing magnetic field modifies the statistical properties of turbulent flow by suppressing its kinetic helicity at large magnetic Reynolds number.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1995RScI...66.1247S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1995RScI...66.1247S"><span id="translatedtitle"><span class="hlt">Absolute</span> calibration of TFTR helium proportional countersa)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Strachan, J. D.; Barnes, Cris W.; Diesso, M.; Jassby, D.; Johnson, L.; Loughlin, M.; McCauley, S.; Munsat, T.; Roquemore, A. L.</p> <p>1995-02-01</p> <p>The TFTR helium proportional counters are located in the central five (5) channels of the TFTR multichannel neutron collimator. These detectors were <span class="hlt">absolutely</span> calibrated using a 14 MeV neutron generator positioned at the horizontal midplane of the TFTR vacuum vessel. The neutron generator position was scanned in centimeter steps to determine the collimator aperture width to 14 MeV neutrons and the <span class="hlt">absolute</span> sensitivity of each channel. Neutron profiles were measured for TFTR plasmas with time resolution between 5 and 50 ms depending upon count rates. The He detectors were used to measure the burnup of 1 MeV tritons in deuterium plasmas, the transport of tritium in trace tritium experiments, and the residual tritium levels in plasmas following 50:50 DT experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/25423049','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/25423049"><span id="translatedtitle">Probing <span class="hlt">absolute</span> spin polarization at the nanoscale.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Eltschka, Matthias; Jäck, Berthold; Assig, Maximilian; Kondrashov, Oleg V; Skvortsov, Mikhail A; Etzkorn, Markus; Ast, Christian R; Kern, Klaus</p> <p>2014-12-10</p> <p>Probing <span class="hlt">absolute</span> values of spin polarization at the nanoscale offers insight into the fundamental mechanisms of spin-dependent transport. Employing the Zeeman splitting in superconducting tips (Meservey-Tedrow-Fulde effect), we introduce a novel spin-polarized scanning tunneling microscopy that combines the probing capability of the <span class="hlt">absolute</span> values of spin polarization with precise control at the atomic scale. We utilize our novel approach to measure the locally resolved spin polarization of magnetic Co nanoislands on Cu(111). We find that the spin polarization is enhanced by 65% when increasing the width of the tunnel barrier by only 2.3 Å due to the different decay of the electron orbitals into vacuum. PMID:25423049</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhyA..407...15O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhyA..407...15O"><span id="translatedtitle">An <span class="hlt">absolute</span> measure for a key currency</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Oya, Shunsuke; Aihara, Kazuyuki; Hirata, Yoshito</p> <p></p> <p>It is generally considered that the US dollar and the euro are the key currencies in the world and in Europe, respectively. However, there is no <span class="hlt">absolute</span> general measure for a key currency. Here, we investigate the 24-hour periodicity of foreign exchange markets using a recurrence plot, and define an <span class="hlt">absolute</span> measure for a key currency based on the strength of the periodicity. Moreover, we analyze the time evolution of this measure. The results show that the credibility of the US dollar has not decreased significantly since the Lehman shock, when the Lehman Brothers bankrupted and influenced the economic markets, and has increased even relatively better than that of the euro and that of the Japanese yen.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120011123','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120011123"><span id="translatedtitle">From Hubble's NGSL to <span class="hlt">Absolute</span> Fluxes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Heap, Sara R.; Lindler, Don</p> <p>2012-01-01</p> <p>Hubble's Next Generation Spectral Library (NGSL) consists of R-l000 spectra of 374 stars of assorted temperature, gravity, and metallicity. Each spectrum covers the wavelength range, 0.18-1.00 microns. The library can be viewed and/or downloaded from the website, http://archive.stsci.edu/prepds/stisngsll. Stars in the NGSL are now being used as <span class="hlt">absolute</span> flux standards at ground-based observatories. However, the uncertainty in the <span class="hlt">absolute</span> flux is about 2%, which does not meet the requirements of dark-energy surveys. We are therefore developing an observing procedure that should yield fluxes with uncertainties less than 1 % and will take part in an HST proposal to observe up to 15 stars using this new procedure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3515307','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3515307"><span id="translatedtitle">Redetermination and <span class="hlt">absolute</span> configuration of (+)-7-epiclusianone</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Christian, Omar E.; Fronczek, Frank R.; Ky, Khoa; Pradhan, Shreedu; Manandhar, Anjela; Richmond, Cecilia</p> <p>2012-01-01</p> <p>The <span class="hlt">absolute</span> configuration of 3-benzoyl-4-hy­droxy-6,6-dimethyl-1,5,7-tris­(3-methyl­but-2-en­yl)bicyclo­[3.3.1]non-3-ene-2,9-dione, C33H42O4, isolated from Hypericum hypericoides, has been determined. The previous study [Xiao et al. (2007 ▶). J. Nat. Prod. 70, 1779–1782] gave only the established relative configuration. The three stereogenic centers are now established as 1R, 5R and 7S on the basis of the refinement of the Flack <span class="hlt">absolute</span> structure parameter against Cu Kα data and correspond to a specific rotation of [α]D 20 = +66°. The enol–hy­droxy group forms an intra­molecular O—H⋯O hydrogen bond to close an S(6) ring. PMID:23284527</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22218280','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22218280"><span id="translatedtitle"><span class="hlt">Absolute</span> and relative dosimetry for ELIMED</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Cirrone, G. A. P.; Schillaci, F.; Scuderi, V.; Cuttone, G.; Candiano, G.; Musumarra, A.; Pisciotta, P.; Romano, F.; Carpinelli, M.; Presti, D. Lo; Raffaele, L.; Tramontana, A.; Cirio, R.; Sacchi, R.; Monaco, V.; Marchetto, F.; Giordanengo, S.</p> <p>2013-07-26</p> <p>The definition of detectors, methods and procedures for the <span class="hlt">absolute</span> and relative dosimetry of laser-driven proton beams is a crucial step toward the clinical use of this new kind of beams. Hence, one of the ELIMED task, will be the definition of procedures aiming to obtain an <span class="hlt">absolute</span> dose measure at the end of the transport beamline with an accuracy as close as possible to the one required for clinical applications (i.e. of the order of 5% or less). Relative dosimetry procedures must be established, as well: they are necessary in order to determine and verify the beam dose distributions and to monitor the beam fluence and the energetic spectra during irradiations. Radiochromic films, CR39, Faraday Cup, Secondary Emission Monitor (SEM) and transmission ionization chamber will be considered, designed and studied in order to perform a fully dosimetric characterization of the ELIMED proton beam.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/73021','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/73021"><span id="translatedtitle"><span class="hlt">Absolute</span> calibration of TFTR helium proportional counters</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Strachan, J.D.; Diesso, M.; Jassby, D.; Johnson, L.; McCauley, S.; Munsat, T.; Roquemore, A.L.; Barnes, C.W. |; Loughlin, M. |</p> <p>1995-06-01</p> <p>The TFTR helium proportional counters are located in the central five (5) channels of the TFTR multichannel neutron collimator. These detectors were <span class="hlt">absolutely</span> calibrated using a 14 MeV neutron generator positioned at the horizontal midplane of the TFTR vacuum vessel. The neutron generator position was scanned in centimeter steps to determine the collimator aperture width to 14 MeV neutrons and the <span class="hlt">absolute</span> sensitivity of each channel. Neutron profiles were measured for TFTR plasmas with time resolution between 5 msec and 50 msec depending upon count rates. The He detectors were used to measure the burnup of 1 MeV tritons in deuterium plasmas, the transport of tritium in trace tritium experiments, and the residual tritium levels in plasmas following 50:50 DT experiments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFMIN51B0405A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFMIN51B0405A"><span id="translatedtitle">The Global Multi-Resolution <span class="hlt">Topography</span> (GMRT) Synthesis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arko, R.; Ryan, W.; Carbotte, S.; Melkonian, A.; Coplan, J.; O'Hara, S.; Chayes, D.; Weissel, R.; Goodwillie, A.; Ferrini, V.; Stroker, K.; Virden, W.</p> <p>2007-12-01</p> <p>Topographic maps provide a backdrop for research in nearly every earth science discipline. There is particular demand for bathymetry data in the ocean basins, where existing coverage is sparse. Ships and submersibles worldwide are rapidly acquiring large volumes of new data with modern swath mapping systems. The science community is best served by a global <span class="hlt">topography</span> compilation that is easily accessible, up-to-date, and delivers data in the highest possible (i.e. native) resolution. To meet this need, the NSF-supported Marine Geoscience Data System (MGDS; www.marine-geo.org) has partnered with the National Geophysical Data Center (NGDC; www.ngdc.noaa.gov) to produce the Global Multi-Resolution <span class="hlt">Topography</span> (GMRT) synthesis - a continuously updated digital elevation model that is accessible through Open Geospatial Consortium (OGC; www.opengeospatial.org) Web services. GMRT had its genesis in 1992 with the NSF RIDGE Multibeam Synthesis (RMBS); later grew to include the Antarctic Multibeam Synthesis (AMBS); expanded again to include the NSF Ridge 2000 and MARGINS programs; and finally emerged as a global compilation in 2005 with the NSF Legacy of Ocean Exploration (LOE) project. The LOE project forged a permanent partnership between MGDS and NGDC, in which swath bathymetry data sets are routinely published and exchanged via the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH; www.openarchives.org). GMRT includes both color-shaded relief images and underlying elevation values at ten different resolutions as high as 100m. New data are edited, gridded, and tiled using tools originally developed by William Haxby at Lamont-Doherty Earth Observatory. Global and regional data sources include the NASA Shuttle Radar <span class="hlt">Topography</span> Mission (SRTM; http://www.jpl.nasa.gov/srtm/); Smith & Sandwell Satellite Predicted Bathymetry (http://topex.ucsd.edu/marine_topo/); SCAR Subglacial Topographic Model of the Antarctic (BEDMAP; http://www.antarctica.ac.uk/bedmap/); and International Bathymetric Chart of the Arctic Ocean (IBCAO; http://www.ngdc.noaa.gov/mgg/bathymetry/arctic/). Local data sources include high-resolution bathymetry swaths and grids from over 210 research cruises, submersible dives, and related compilations to date. GMRT is accessible via a OGC Web Map Service (WMS) which offers <span class="hlt">dynamic</span> resolution and on-the-fly map re- projection. A growing number of commercial and open-source clients support OGC protocols, including recent versions of Google Earth and Google Maps which now support WMS natively. GMRT is incorporated as a primary basemap in science Web portals and geobrowsers including EarthChem (www.earthchem.org) and GeoMapApp (www.geomapapp.org), which also serves the underlying elevation values. Future development work will include extension of GMRT to higher resolutions; addition of the International Bathymetric Chart of the Southern Ocean (IBCSO; www.ibcso.org) and the improved SRTM V2; and deployment of new OGC services including a Web Coverage Service (WCS) and Web Terrain Service (WTS).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26280315','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26280315"><span id="translatedtitle">Relative errors can cue <span class="hlt">absolute</span> visuomotor mappings.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>van Dam, Loes C J; Ernst, Marc O</p> <p>2015-12-01</p> <p>When repeatedly switching between two visuomotor mappings, e.g. in a reaching or pointing task, adaptation tends to speed up over time. That is, when the error in the feedback corresponds to a mapping switch, fast adaptation occurs. Yet, what is learned, the relative error or the <span class="hlt">absolute</span> mappings? When switching between mappings, errors with a size corresponding to the relative difference between the mappings will occur more often than other large errors. Thus, we could learn to correct more for errors with this familiar size (Error Learning). On the other hand, it has been shown that the human visuomotor system can store several <span class="hlt">absolute</span> visuomotor mappings (Mapping Learning) and can use associated contextual cues to retrieve them. Thus, when contextual information is present, no error feedback is needed to switch between mappings. Using a rapid pointing task, we investigated how these two types of learning may each contribute when repeatedly switching between mappings in the absence of task-irrelevant contextual cues. After training, we examined how participants changed their behaviour when a single error probe indicated either the often-experienced error (Error Learning) or one of the previously experienced <span class="hlt">absolute</span> mappings (Mapping Learning). Results were consistent with Mapping Learning despite the relative nature of the error information in the feedback. This shows that errors in the feedback can have a double role in visuomotor behaviour: they drive the general adaptation process by making corrections possible on subsequent movements, as well as serve as contextual cues that can signal a learned <span class="hlt">absolute</span> mapping. PMID:26280315</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JLTP..151.1055L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JLTP..151.1055L"><span id="translatedtitle">Metallic Magnetic Calorimeters for <span class="hlt">Absolute</span> Activity Measurement</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Loidl, M.; Leblanc, E.; Rodrigues, M.; Bouchard, J.; Censier, B.; Branger, T.; Lacour, D.</p> <p>2008-05-01</p> <p>We present a prototype of metallic magnetic calorimeters that we are developing for <span class="hlt">absolute</span> activity measurements of low energy emitting radionuclides. We give a detailed description of the realization of the prototype, containing an 55Fe source inside the detector absorber. We present the analysis of first data taken with this detector and compare the result of activity measurement with liquid scintillation counting. We also propose some ways for reducing the uncertainty on the activity determination with this new technique.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014Icar..236..169M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014Icar..236..169M"><span id="translatedtitle">Shape, <span class="hlt">topography</span>, gravity anomalies and tidal deformation of Titan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mitri, Giuseppe; Meriggiola, Rachele; Hayes, Alex; Lefevre, Axel; Tobie, Gabriel; Genova, Antonio; Lunine, Jonathan I.; Zebker, Howard</p> <p>2014-07-01</p> <p>Gravity measurements and elevation data from the Cassini mission have been used to create shape, global <span class="hlt">topography</span> and gravity anomaly models of Titan that enable an improved understanding of its outer ice I shell structure. We provide constraints on the averaged ice shell thickness and its long-wavelength lateral variations, as well as the density of the subsurface ocean using gravity anomalies, the tidal Love number k2 measurement and long-wavelength <span class="hlt">topography</span>. We found that Titan’s surface <span class="hlt">topography</span> is consistent with an approximate isostatically compensated ice shell of variable thickness, likely in a thermally conductive or in a subcritical convective state, overlying a relatively dense subsurface ocean.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EOSTr..91Q.416K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EOSTr..91Q.416K"><span id="translatedtitle">Research Spotlight: High-resolution measurements of lunar <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kumar, Mohi; Tretkoff, Ernie</p> <p></p> <p>Selection of landing sites for potential human or robotic lunar missions requires precise knowledge of lunar <span class="hlt">topography</span>. Contributing to that knowledge, Smith et al. present initial observations from the Lunar Orbiter Laser Altimeter (LOLA) on board the Lunar Reconnaissance Orbiter.The LOLA measurements provide a high-resolution global model of lunar <span class="hlt">topography</span> based on more observations and observations with greater accuracy than previous lunar <span class="hlt">topography</span> maps. LOLA also collected high-resolution data on the slope, roughness, and reflectance of the lunar surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9623E..04W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9623E..04W"><span id="translatedtitle"><span class="hlt">Absolute</span> angular encoder based on optical diffraction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Jian; Zhou, Tingting; Yuan, Bo; Wang, Liqiang</p> <p>2015-08-01</p> <p>A new encoding method for <span class="hlt">absolute</span> angular encoder based on optical diffraction was proposed in the present study. In this method, an encoder disc is specially designed that a series of elements are uniformly spaced in one circle and each element is consisted of four diffraction gratings, which are tilted in the directions of 30°, 60°, -60° and -30°, respectively. The disc is illuminated by a coherent light and the diffractive signals are received. The positions of diffractive spots are used for <span class="hlt">absolute</span> encoding and their intensities are for subdivision, which is different from the traditional optical encoder based on transparent/opaque binary principle. Since the track's width in the disc is not limited in the diffraction pattern, it provides a new way to solve the contradiction between the size and resolution, which is good for minimization of encoder. According to the proposed principle, the diffraction pattern disc with a diameter of 40 mm was made by lithography in the glass substrate. A prototype of <span class="hlt">absolute</span> angular encoder with a resolution of 20" was built up. Its maximum error was tested as 78" by comparing with a small angle measuring system based on laser beam deflection.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA02764&hterms=anaglyph&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Danaglyph','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA02764&hterms=anaglyph&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Danaglyph"><span id="translatedtitle">SRTM Anaglyph: Inverted <span class="hlt">Topography</span>, Patagonia, Argentina</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2000-01-01</p> <p><p/> The Meseta de Somuncura is a broad plateau capped by basalt. Near its western edge is evidence of multiple volcanic events and a complex erosion history. Most notable are the long, narrow, and winding lava flows that run across most of the right side of the image. These formed from low-viscosity lava that flowed down gullies over fairly flat terrain. Later, erosion of the landscape continued, and the solidified flows were more resistant than the older surrounding rocks. Consequently, the flows became the ridges we see here. This natural process of converting gullies to ridges is called topographic inversion. See image PIA02755 (upper left corner) for a good example of topographic inversion in its earlier stages.<p/>Other features seen here include numerous and varied closed depressions. The regional drainage is not well integrated, but instead the drainage ends up in salty lakes (dark water, some with bright shores). Wind streaks indicate that winds blow toward the east (right) and blow salt grains off the lake beds when dry. The bowtie pattern in the upper left has resulted from differing grazing practices among fenced fields.<p/>This anaglyph was generated by first draping a Landsat Thematic Mapper image over a topographic map from the Shuttle Radar <span class="hlt">Topography</span> Mission, then producing the two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and the right eye with a blue filter.<p/>Landsat satellites have provided visible light and infrared images of the Earth continuously since 1972. SRTM topographic data match the 30-meter (99-foot) spatial resolution of most Landsat images and provide a valuable complement for studying the historic and growing Landsat data archive. The Landsat 7 Thematic Mapper image used here was provided to the SRTM project by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center,Sioux Falls, South Dakota.<p/>Elevation data used in this image was acquired by the Shuttle Radar <span class="hlt">Topography</span> Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise,Washington, DC.<p/>Size: 21.5 kilometers (13.4 miles) x 27.2 kilometers (16.9 miles) Location: 41.6 deg. South lat., 67.9 deg. West lon. Orientation: North toward upper left Image Data: Landsat band 7 (short infrared) Date Acquired: February 19, 2000 (SRTM), January 22, 2000 (Landsat)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=PIA10143&hterms=Spider&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DSpider','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=PIA10143&hterms=Spider&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DSpider"><span id="translatedtitle">Science in Motion: Isolated Araneiform <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2007-01-01</p> <p><p/> [figure removed for brevity, see original site] Figure 1 <p/> Have you ever found that to describe something you had to go to the dictionary and search for just the right word? <p/> The south polar terrain is so full of unearthly features that we had to visit Mr. Webster to find a suitable term. 'Araneiform' means 'spider-like'. These are channels that are carved in the surface by carbon dioxide gas. We do not have this process on Earth. <p/> The channels are somewhat radially organized (figure 1) and widen and deepen as they converge. In the past we've just refered to them as 'spiders.' 'Isolated araneiform <span class="hlt">topography</span>' means that our features look like spiders that are not in contact with each other. <p/> Observation Geometry Image PSP_003087_0930 was taken by the High Resolution Imaging Science Experiment (HiRISE) camera onboard the Mars Reconnaissance Orbiter spacecraft on 24-Mar-2007. The complete image is centered at -87.1 degrees latitude, 126.3 degrees East longitude. The range to the target site was 244.4 km (152.8 miles). At this distance the image scale is 24.5 cm/pixel (with 1 x 1 binning) so objects 73 cm across are resolved. The image shown here has been map-projected to 25 cm/pixel . The image was taken at a local Mars time of 08:22 PM and the scene is illuminated from the west with a solar incidence angle of 81 degrees, thus the sun was about 9 degrees above the horizon. At a solar longitude of 206.4 degrees, the season on Mars is Northern Autumn.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26538639','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26538639"><span id="translatedtitle">Epithelial <span class="hlt">topography</span> for repetitive tooth formation.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gaete, Marcia; Fons, Juan Manuel; Popa, Elena Mădălina; Chatzeli, Lemonia; Tucker, Abigail S</p> <p>2015-01-01</p> <p>During the formation of repetitive ectodermally derived organs such as mammary glands, lateral line and teeth, the tissue primordium iteratively initiates new structures. In the case of successional molar development, new teeth appear sequentially in the posterior region of the jaw from Sox2(+) cells in association with the posterior aspect of a pre-existing tooth. The sequence of molar development is well known, however, the epithelial <span class="hlt">topography</span> involved in the formation of a new tooth is unclear. Here, we have examined the morphology of the molar dental epithelium and its development at different stages in the mouse in vivo and in molar explants. Using regional lineage tracing we show that within the posterior tail of the first molar the primordium for the second and third molar are organized in a row, with the tail remaining in connection with the surface, where a furrow is observed. The morphology and Sox2 expression of the tail retains characteristics reminiscent of the earlier stages of tooth development, such that position along the A-P axes of the tail correlates with different temporal stages. Sox9, a stem/progenitor cell marker in other organs, is expressed mainly in the suprabasal epithelium complementary with Sox2 expression. This Sox2 and Sox9 expressing molar tail contains actively proliferating cells with mitosis following an apico-basal direction. Snail2, a transcription factor implicated in cell migration, is expressed at high levels in the tip of the molar tail while E-cadherin and laminin are decreased. In conclusion, our studies propose a model in which the epithelium of the molar tail can grow by posterior movement of epithelial cells followed by infolding and stratification involving a population of Sox2(+)/Sox9(+) cells. PMID:26538639</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4736031','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4736031"><span id="translatedtitle">Epithelial <span class="hlt">topography</span> for repetitive tooth formation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gaete, Marcia; Fons, Juan Manuel; Popa, Elena Mădălina; Chatzeli, Lemonia; Tucker, Abigail S.</p> <p>2015-01-01</p> <p>ABSTRACT During the formation of repetitive ectodermally derived organs such as mammary glands, lateral line and teeth, the tissue primordium iteratively initiates new structures. In the case of successional molar development, new teeth appear sequentially in the posterior region of the jaw from Sox2+ cells in association with the posterior aspect of a pre-existing tooth. The sequence of molar development is well known, however, the epithelial <span class="hlt">topography</span> involved in the formation of a new tooth is unclear. Here, we have examined the morphology of the molar dental epithelium and its development at different stages in the mouse in vivo and in molar explants. Using regional lineage tracing we show that within the posterior tail of the first molar the primordium for the second and third molar are organized in a row, with the tail remaining in connection with the surface, where a furrow is observed. The morphology and Sox2 expression of the tail retains characteristics reminiscent of the earlier stages of tooth development, such that position along the A-P axes of the tail correlates with different temporal stages. Sox9, a stem/progenitor cell marker in other organs, is expressed mainly in the suprabasal epithelium complementary with Sox2 expression. This Sox2 and Sox9 expressing molar tail contains actively proliferating cells with mitosis following an apico-basal direction. Snail2, a transcription factor implicated in cell migration, is expressed at high levels in the tip of the molar tail while E-cadherin and laminin are decreased. In conclusion, our studies propose a model in which the epithelium of the molar tail can grow by posterior movement of epithelial cells followed by infolding and stratification involving a population of Sox2+/Sox9+ cells. PMID:26538639</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22093718','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22093718"><span id="translatedtitle"><span class="hlt">Absolutely</span> continuous spectrum implies ballistic transport for quantum particles in a random potential on tree graphs</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Aizenman, Michael; Warzel, Simone</p> <p>2012-09-15</p> <p>We discuss the <span class="hlt">dynamical</span> implications of the recent proof that for a quantum particle in a random potential on a regular tree graph <span class="hlt">absolutely</span> continuous (ac) spectrum occurs non-perturbatively through rare fluctuation-enabled resonances. The main result is spelled in the title.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4191383','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4191383"><span id="translatedtitle"><span class="hlt">Absolute</span> and relative quantification of RNA modifications via biosynthetic isotopomers</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kellner, Stefanie; Ochel, Antonia; Thüring, Kathrin; Spenkuch, Felix; Neumann, Jennifer; Sharma, Sunny; Entian, Karl-Dieter; Schneider, Dirk; Helm, Mark</p> <p>2014-01-01</p> <p>In the resurging field of RNA modifications, quantification is a bottleneck blocking many exciting avenues. With currently over 150 known nucleoside alterations, detection and quantification methods must encompass multiple modifications for a comprehensive profile. LC–MS/MS approaches offer a perspective for comprehensive parallel quantification of all the various modifications found in total RNA of a given organism. By feeding 13C-glucose as sole carbon source, we have generated a stable isotope-labeled internal standard (SIL-IS) for bacterial RNA, which facilitates relative comparison of all modifications. While conventional SIL-IS approaches require the chemical synthesis of single modifications in weighable quantities, this SIL-IS consists of a nucleoside mixture covering all detectable RNA modifications of Escherichia coli, yet in small and initially unknown quantities. For <span class="hlt">absolute</span> in addition to relative quantification, those quantities were determined by a combination of external calibration and sample spiking of the biosynthetic SIL-IS. For each nucleoside, we thus obtained a very robust relative response factor, which permits direct conversion of the MS signal to <span class="hlt">absolute</span> amounts of substance. The application of the validated SIL-IS allowed highly precise quantification with standard deviations <2% during a 12-week period, and a linear <span class="hlt">dynamic</span> range that was extended by two orders of magnitude. PMID:25129236</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/2014765','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/2014765"><span id="translatedtitle"><span class="hlt">Absolute</span> refractory period of human nerve fibres during postnatal myelination.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Duron, B; Khater-Boidin, J</p> <p>1991-01-01</p> <p>In order to study the <span class="hlt">absolute</span> refractory period of a given group of nerve fibres during development we measured <span class="hlt">absolute</span> refractory periods and conduction velocities of motor fibres and the most excitable fibres in the human ulnar nerve of newborns, children and adults. In each group of nerve fibres <span class="hlt">absolute</span> refractory period was not correlated to conduction velocity (i.e. fibre diameters) and was rather constant during development. However, <span class="hlt">absolute</span> refractory period of the most excitable fibres was smaller than <span class="hlt">absolute</span> refractory period of motor fibres independently of the subject's age. Thus, it appears that already at birth, <span class="hlt">absolute</span> refractory period is characteristic for a given group of nerve fibres. PMID:2014765</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/pa0105.photos.141202p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/pa0105.photos.141202p/"><span id="translatedtitle">2. GENERAL VIEW SHOWING RELATION OF BRIDGE TO THE <span class="hlt">TOPOGRAPHY</span> ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>2. GENERAL VIEW SHOWING RELATION OF BRIDGE TO THE <span class="hlt">TOPOGRAPHY</span> OF THE APPROACH ROAD. - Speicher Bridge, Church Road over Tulpehocken Creek between Penn & North Heidelberg Townships, Bernville, Berks County, PA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('//www.loc.gov/pictures/collection/hh/item/wa0270.photos.168461p/','SCIGOV-HHH'); return false;" href="//www.loc.gov/pictures/collection/hh/item/wa0270.photos.168461p/"><span id="translatedtitle">23. SPILLWAY NO. 1 LOWER END <span class="hlt">TOPOGRAPHY</span> AND SECTIONS. ...</span></a></p> <p><a target="_blank" href="http://www.loc.gov/pictures/collection/hh/">Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey</a></p> <p></p> <p></p> <p>23. SPILLWAY NO. 1 - LOWER END <span class="hlt">TOPOGRAPHY</span> AND SECTIONS. February 1934. Reference BS-150. - Cushman No. 1 Hydroelectric Power Plant, Spillway, North Fork of Skokomish River, 5 miles West of Hood Canal, Hoodsport, Mason County, WA</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/26271245','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/26271245"><span id="translatedtitle">Tectonic control on the persistence of glacially sculpted <span class="hlt">topography</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Prasicek, Günther; Larsen, Isaac J; Montgomery, David R</p> <p>2015-01-01</p> <p>One of the most fundamental insights for understanding how landscapes evolve is based on determining the extent to which <span class="hlt">topography</span> was shaped by glaciers or by rivers. More than 10(4) years after the last major glaciation the <span class="hlt">topography</span> of mountain ranges worldwide remains dominated by characteristic glacial landforms such as U-shaped valleys, but an understanding of the persistence of such landforms is lacking. Here we use digital topographic data to analyse valley shapes at sites worldwide to demonstrate that the persistence of U-shaped valleys is controlled by the erosional response to tectonic forcing. Our findings indicate that glacial <span class="hlt">topography</span> in Earth's most rapidly uplifting mountain ranges is rapidly replaced by fluvial <span class="hlt">topography</span> and hence valley forms do not reflect the cumulative action of multiple glacial periods, implying that the classic physiographic signature of glaciated landscapes is best expressed in, and indeed limited by, the extent of relatively low-uplift terrain. PMID:26271245</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3619386','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3619386"><span id="translatedtitle">Engineering microscale <span class="hlt">topographies</span> to control the cell–substrate interface</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nikkhah, Mehdi; Edalat, Faramarz; Manoucheri, Sam; Khademhosseini, Ali</p> <p>2013-01-01</p> <p>Cells in their in vivo microenvironment constantly encounter and respond to a multitude of signals. While the role of biochemical signals has long been appreciated, the importance of biophysical signals has only recently been investigated. Biophysical cues are presented in different forms including <span class="hlt">topography</span> and mechanical stiffness imparted by the extracellular matrix and adjoining cells. Microfabrication technologies have allowed for the generation of biomaterials with microscale <span class="hlt">topographies</span> to study the effect of biophysical cues on cellular function at the cell–substrate interface. <span class="hlt">Topographies</span> of different geometries and with varying microscale dimensions have been used to better understand cell adhesion, migration, and differentiation at the cellular and sub-cellular scales. Furthermore, quantification of cell-generated forces has been illustrated with micropillar <span class="hlt">topographies</span> to shed light on the process of mechanotransduction. In this review, we highlight recent advances made in these areas and how they have been utilized for neural, cardiac, and musculoskeletal tissue engineering application. PMID:22521491</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19890056768&hterms=oceanic+crust&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Doceanic%2Bcrust','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19890056768&hterms=oceanic+crust&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Doceanic%2Bcrust"><span id="translatedtitle">Geoid height versus <span class="hlt">topography</span> for oceanic plateaus and swells</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sandwell, David T.; Mackenzie, Kevin R.</p> <p>1989-01-01</p> <p>Gridded geoid height data (Marsh et al.l, 1986) and gridded bathymetry data (Van Wykhouse, 1973) are used to estimate the average compensation depths of 53 oceanic swells and plateaus. The relationship between geoid height and <span class="hlt">topography</span> is examined using Airy and thermal compensation models. It is shown that geoid height is linearly related to <span class="hlt">topography</span> between wavelengths of 400 and 4000 m as predicted by isostatic compensation models. The geoid/<span class="hlt">topography</span> ratio is dependent on the average depth of compensation. The intermediate geoid/<span class="hlt">topography</span> ratios of most thermal swells are interpreted as a linear combination of the decaying thermal swell signature and that of the persisting Airy-compensated volcanic edifice.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4557346','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4557346"><span id="translatedtitle">Tectonic control on the persistence of glacially sculpted <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Prasicek, Günther; Larsen, Isaac J.; Montgomery, David R.</p> <p>2015-01-01</p> <p>One of the most fundamental insights for understanding how landscapes evolve is based on determining the extent to which <span class="hlt">topography</span> was shaped by glaciers or by rivers. More than 104 years after the last major glaciation the <span class="hlt">topography</span> of mountain ranges worldwide remains dominated by characteristic glacial landforms such as U-shaped valleys, but an understanding of the persistence of such landforms is lacking. Here we use digital topographic data to analyse valley shapes at sites worldwide to demonstrate that the persistence of U-shaped valleys is controlled by the erosional response to tectonic forcing. Our findings indicate that glacial <span class="hlt">topography</span> in Earth's most rapidly uplifting mountain ranges is rapidly replaced by fluvial <span class="hlt">topography</span> and hence valley forms do not reflect the cumulative action of multiple glacial periods, implying that the classic physiographic signature of glaciated landscapes is best expressed in, and indeed limited by, the extent of relatively low-uplift terrain. PMID:26271245</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2731455','PMC'); return false;" href="http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2731455"><span id="translatedtitle">Stimulus control <span class="hlt">topography</span> coherence theory: Foundations and extensions</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>McIlvane, William J.; Dube, William V.</p> <p>2003-01-01</p> <p>Stimulus control <span class="hlt">topography</span> refers to qualitative differences among members of a functional stimulus class. Stimulus control <span class="hlt">topography</span> coherence refers to the degree of concordance between the stimulus properties specified as relevant by the individual arranging a reinforcement contingency (behavior analyst, experimenter, teacher, etc.) and the stimulus properties that come to control the behavior of the organism (experimental subject, student, etc.) that experiences those contingencies. This paper summarizes the rationale for analyses of discrimination learning outcomes in terms of stimulus control <span class="hlt">topography</span> coherence and briefly reviews some of the foundational studies that led to this perspective. We also suggest directions for future research, including pursuit of conceptual and methodological challenges to a complete stimulus control <span class="hlt">topography</span> coherence analysis of processes involved in discriminated and generalized operants. ImagesFigure 3Figure 5 PMID:22478402</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NatCo...6E8028P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NatCo...6E8028P"><span id="translatedtitle">Tectonic control on the persistence of glacially sculpted <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Prasicek, Günther; Larsen, Isaac J.; Montgomery, David R.</p> <p>2015-08-01</p> <p>One of the most fundamental insights for understanding how landscapes evolve is based on determining the extent to which <span class="hlt">topography</span> was shaped by glaciers or by rivers. More than 104 years after the last major glaciation the <span class="hlt">topography</span> of mountain ranges worldwide remains dominated by characteristic glacial landforms such as U-shaped valleys, but an understanding of the persistence of such landforms is lacking. Here we use digital topographic data to analyse valley shapes at sites worldwide to demonstrate that the persistence of U-shaped valleys is controlled by the erosional response to tectonic forcing. Our findings indicate that glacial <span class="hlt">topography</span> in Earth's most rapidly uplifting mountain ranges is rapidly replaced by fluvial <span class="hlt">topography</span> and hence valley forms do not reflect the cumulative action of multiple glacial periods, implying that the classic physiographic signature of glaciated landscapes is best expressed in, and indeed limited by, the extent of relatively low-uplift terrain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19730001883','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19730001883"><span id="translatedtitle">Calculation of irrotational wind pattern with application to Cleveland <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Siegel, R.</p> <p>1972-01-01</p> <p>Small perturbation theory is applied to compute the deflection of the wind blowing across land that has an irregular <span class="hlt">topography</span>. As an illustration, the method is applied first to the flow around a single hill of Gaussian profile. Then calculations are made for the irregular <span class="hlt">topography</span> on the east side of Cleveland where the elevation changes by several hundred feet. It was found that the <span class="hlt">topography</span> produced small wind deflections that would not be of practical importance in air pollution dispersion studies. The calculations were for a neutrally stable atmosphere. Although they are not investigated here, other factors such as thermal stratification of the atmosphere, diurnal variations, and convection currents resulting from the proximity of Lake Erie and the city heat island effect are expected to be more significant than the influence of <span class="hlt">topography</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=306874','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/Publications.htm?seq_no_115=306874"><span id="translatedtitle">Influence of local <span class="hlt">topography</span> on precision irrigation management</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Precision irrigation management is currently accomplished using spatial information about soil properties through soil series maps or electrical conductivity (EC measurements. Crop yield, however, is consistently influenced by local <span class="hlt">topography</span>, both in rain-fed and irrigated environments. Utilizing ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGE....11a5003L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGE....11a5003L"><span id="translatedtitle">Traveltime computation and imaging from rugged <span class="hlt">topography</span> in 3D TTI media</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Shaoyong; Wang, Huazhong; Yang, Qinyong; Fang, Wubao</p> <p>2014-02-01</p> <p>Foothill areas with rugged <span class="hlt">topography</span> are of great potential for oil and gas seismic exploration, but subsurface imaging in these areas is very challenging. Seismic acquisition with larger offset and wider azimuth is necessary for seismic imaging in complex areas. However, the scale anisotropy in this case must be taken into account. To generalize the pre-stack depth migration (PSDM) to 3D transversely isotropic media with vertical symmetry axes (VTI) and tilted symmetry axes (TTI) from rugged <span class="hlt">topography</span>, a new <span class="hlt">dynamic</span> programming approach for the first-arrival traveltime computation method is proposed. The first-arrival time on every uniform mesh point is calculated based on Fermat's principle with simple calculus techniques and a systematic mapping scheme. In order to calculate the minimum traveltime, a set of nonlinear equations is solved on each mesh point, where the group velocity is determined by the group angle. Based on the new first-arrival time calculation method, the corresponding PSDM and migration velocity analysis workflow for 3D anisotropic media from rugged surface is developed. Numerical tests demonstrate that the proposed traveltime calculation method is effective in both VTI and TTI media. The migration results for 3D field data show that it is necessary to choose a smooth datum to remove the high wavenumber move-out components for PSDM with rugged <span class="hlt">topography</span> and take anisotropy into account to achieve better images.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016Geomo.260....4C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016Geomo.260....4C"><span id="translatedtitle">Reproducibility of UAV-based earth <span class="hlt">topography</span> reconstructions based on Structure-from-Motion algorithms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Clapuyt, Francois; Vanacker, Veerle; Van Oost, Kristof</p> <p>2016-05-01</p> <p>Combination of UAV-based aerial pictures and Structure-from-Motion (SfM) algorithm provides an efficient, low-cost and rapid framework for remote sensing and monitoring of <span class="hlt">dynamic</span> natural environments. This methodology is particularly suitable for repeated topographic surveys in remote or poorly accessible areas. However, temporal analysis of landform <span class="hlt">topography</span> requires high accuracy of measurements and reproducibility of the methodology as differencing of digital surface models leads to error propagation. In order to assess the repeatability of the SfM technique, we surveyed a study area characterized by gentle <span class="hlt">topography</span> with an UAV platform equipped with a standard reflex camera, and varied the focal length of the camera and location of georeferencing targets between flights. Comparison of different SfM-derived <span class="hlt">topography</span> datasets shows that precision of measurements is in the order of centimetres for identical replications which highlights the excellent performance of the SfM workflow, all parameters being equal. The precision is one order of magnitude higher for 3D topographic reconstructions involving independent sets of ground control points, which results from the fact that the accuracy of the localisation of ground control points strongly propagates into final results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFMGC33A1249G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFMGC33A1249G"><span id="translatedtitle">Volatility of California Precipitation: Effects of Moisture Supply and <span class="hlt">Topography</span> in a Mediterranean Climate</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gershunov, A.; Kanamaru, H.; Panorska, A.; Cayan, D.</p> <p>2005-12-01</p> <p>California's climate is marked with infrequent but copious precipitation events preferentially enhanced by complex <span class="hlt">topography</span>. In California, the presence or absence of daily precipitation extremes contributes significantly to the annual water supply and largely determines flood risk. We explore the intimate connection between <span class="hlt">topography</span> and the volatility of daily precipitation in California, i.e. the magnitude of extreme events relative to typical amounts. Physical mechanisms producing extreme precipitation amounts will be elucidated with respect to synoptic systems and how they interact with California's topographic features. We will show that volatility is closely linked to the direction of moisture flux in individual storms relative to aspect and slope of major mountain ranges. We will also examine the contribution of daily extremes to total seasonal precipitation in wet and dry years. Parallel investigations will be performed on daily precipitation from station observations and a fine resolution <span class="hlt">dynamical</span> Reanalysis over California. These results will contribute to the understanding of synoptic meteorological conditions that give rise to extreme hydrologic events over California's complex <span class="hlt">topography</span>. The insight applied on climatic timescales to observations and modeling of storm tracks will also advance the conceptual understanding of possible effects of global climate change on California mountain hydrology.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMNS43A1782L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMNS43A1782L"><span id="translatedtitle">Three-dimensional inversion of CSAMT data including <span class="hlt">topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lin, C.; Tan, H.; Tong, T.; Zeng, W.</p> <p>2013-12-01</p> <p>CSAMT is widely used in geothermal prospecting, mineral and petroleum exploration, environmental geophysics and geological engineering. However, few data are collected on the flat surface in the field CSAMT work. Most of CSAMT data are collected in the presence of strong <span class="hlt">topography</span> either at the source position or in the survey area. Large interpretation errors may occur in CSAMT surveys if field distortions caused by the surface <span class="hlt">topography</span> are not considered. Therefore, the CSAMT inversion should consider the topographic effect. In this work we develop a 3D inversion algorithm for inverting CSAMT data with <span class="hlt">topography</span> using conjugate gradient inversion method. In the 3D forward problem, the total electric and magnetic fields is separated into their primary and secondary components to calculate the response from the 3D model with irregular <span class="hlt">topography</span>. 3D rectangular grid with stair-stepped ground-air interface is used to approximate <span class="hlt">topography</span>. The primary electric and magnetic field can be calculated by one-dimensional modeling, using the altitude of the highest point of the <span class="hlt">topography</span> as the altitude of the flat surface. The secondary electric and magnetic field can be calculated using the staggered-grid finite difference method. Then, the apparent resistivity and phase response can be obtained by Cagniard equation. In the 3D inversion problem, conjugate gradient method is used to invert the CSAMT apparent resistivity and phase data including <span class="hlt">topography</span>. The background resistivity is a constant value and the anomalous resistivity is used as the inversion parameter. Only the anomalous resistivity under the surface <span class="hlt">topography</span> is updated in the inversion. Results from the synthetic tests show the validity and stability of the inversion algorithm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010TrSpT...7.Tk23A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010TrSpT...7.Tk23A"><span id="translatedtitle">Preliminary Results of Lunar <span class="hlt">Topography</span> by KAGUYA-LALT Mission</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Araki, Hiroshi; Tazawa, Seiichi; Noda, Hirotomo; Migita, Emiko; Kamiya, Izumi; Kawano, Nobuyuki; Sasaki, Sho</p> <p></p> <p>The Laser Altimeter (LALT) on board the main orbiter of KAGUYA (SELENE) started nominal observation on December 30, 2007 for mapping the lunar <span class="hlt">topography</span>. As of March 31, 2008, LALT has obtained about 6.7 million topographic data and the return rate is 97%. Several qualifications of the data to produce reliable <span class="hlt">topography</span> are now in progress. The present status and preliminary results are reported in this article.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/19523768','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/19523768"><span id="translatedtitle">Phase contrast in Simultaneous <span class="hlt">Topography</span> and Recognition imaging.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fuss, M C; Sahagún, E; Köber, M; Briones, F; Luna, M; Sáenz, J J</p> <p>2009-08-01</p> <p>The operation of a force microscope in Simultaneous <span class="hlt">Topography</span> and Recognition (TREC) imaging mode is analyzed by means of numerical simulations. Both <span class="hlt">topography</span> and recognition signals are analyzed by using a worm-like chain force as the specific interaction between the functionalized tip probe and the sample. The special feedback mechanism in this mode is shown to couple the phase signal to the presence of molecular recognition interactions even in absence of dissipation. PMID:19523768</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/22340200','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/22340200"><span id="translatedtitle">THE <span class="hlt">ABSOLUTE</span> CALIBRATION OF THE EUV IMAGING SPECTROMETER ON HINODE</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Warren, Harry P.; Ugarte-Urra, Ignacio; Landi, Enrico</p> <p>2014-07-01</p> <p>We investigate the <span class="hlt">absolute</span> calibration of the EUV Imaging Spectrometer (EIS) on Hinode by comparing EIS full-disk mosaics with irradiance observations from the EUV Variability Experiment on the Solar <span class="hlt">Dynamics</span> Observatory. We also use extended observations of the quiet corona above the limb combined with a simple differential emission measure model to establish new effective area curves that incorporate information from the most recent atomic physics calculations. We find that changes to the EIS instrument sensitivity are a complex function of both time and wavelength. We find that the sensitivity is decaying exponentially with time and that the decay constants vary with wavelength. The EIS short wavelength channel shows significantly longer decay times than the long wavelength channel.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA.....4032H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA.....4032H"><span id="translatedtitle">Isidis Basin, Mars: Geology and <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hiesinger, H.; Head, J. W., III</p> <p>2003-04-01</p> <p>Building on Bridges et al. [2003, JGR 108], we are currently studying the general geologic history and evolution of the Isidis basin based on topographic and imaging data obtained by orbiting spacecraft such as Mars Global Surveyor (MGS) and Mars Odyssey. This study complements our recently completed analyses on Syrtis Major to the west [Hiesinger and Head, 2002, LPSC 1063] and the transition between Syrtis Major and Isidis [Ivanov and Head, 2002, LPSC 1341]. We are interested in a number of scientific questions, for example, what are the characteristics of the Isidis rim and what caused its present morphology? What is the role and fate of volatiles in the Isidis basin and what are the characteristics of the uppermost surface layer? Does the floor of the Isidis basin primarily consist of volcanic plains as indicated by wrinkle ridges and cone-like features, material deposited by a catastrophic collapse of the rim as proposed by Tanaka et al. [2000, GRL 29], or of sediments deposited in an ocean as suggested by Parker et al. [1989, Icarus 82]? What is the stratigraphy of the deposits within the Isidis basin and what processes were responsible for its present appearance? For our study we used MOLA <span class="hlt">topography</span> data with a spatial resolution of 128 pixel/deg. The data allowed us to obtain a detailed view of the Isidis basin, its structure, stratigraphy, geologic history and its evolution. Our preliminary investigation let us conclude that (1) the basin floor is tilted towards the southwest with about 0.015 degree, (2) there are 2 types of ridges within the Isidis basin, (3) ridges of the thumbprint terrain are ~10-50 m high, less than ~5-7 km wide, and occur at narrowly constrained elevations of ~-3600 to -3700 m, (4) these ridges occur only within the innermost ring structure and most of them are not exposed at the lowest elevations, (5) wrinkle ridges are ~75-100 m high, less than ~70 km wide, hundreds of kilometers long and occur over a wide range of elevations, (6) the rim of Isidis exhibits a wide range of elevations of ~7500-8000 m. The floor of the Isidis basin has been chosen by the European Space Agency (ESA) as the landing site for the first European lander on Mars, named Beagle, and is under consideration as a potential landing site for one of the NASA MER rovers. While Beagle will investigate the characteristics of the uppermost surface layers, the Mars Express spacecraft will orbit the planet to acquire global high-resolution remote sensing data and to ensure data downlink from the lander to Earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20040073468&hterms=Alpine+Rivers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DAlpine%2BRivers','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20040073468&hterms=Alpine+Rivers&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DAlpine%2BRivers"><span id="translatedtitle">Evolution of <span class="hlt">Topography</span> in Glaciated Mountain Ranges</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Brocklehurst, Simon H.</p> <p>2002-01-01</p> <p>This thesis examines the response of alpine landscapes to the onset of glaciation. The basic approach is to compare fluvial and glacial laudscapes, since it is the change from the former to the latter that accompanies climatic cooling. This allows a detailed evaluation of hypotheses relating climate change to tectonic processes in glaciated mountain belts. Fieldwork was carried out in the eastern Sierra Nevada, California, and the Sangre de Cristo Range, Colorado, alongside digital elevation model analyses in the western US, the Southern Alps of New Zealand, and the Himalaya of northwestern Pakistan. hypothesis is overstated in its appeal to glacial erosion as a major source of relief production and subsequent peak uplift. Glaciers in the eastern Sierra Nevada and the western Sangre de Cristos have redistributed relief, but have produced only modest relief by enlarging drainage basins at the expense of low-relief <span class="hlt">topography</span>. Glaciers have lowered valley floors and ridgelines by similar amounts, limiting the amount of "missing mass' that can be generated, and causing a decrease in drainage basin relief. The principal response of glaciated landscapes to rapid rock uplift is the development of towering cirque headwalls. This represents considerable relief production, but is not caused by glacial erosion alone. Large valley glaciers can maintain their low gradient regardless of uplift rate, which supports the "glacial buzzsaw" hypothesis. However, the inability of glaciers to erode steep hillslopes as rapidly can cause mean elevations to rise. Cosmogenic isotope dating is used to show that (i) where plucking is active, the last major glaciation removed sufficient material to reset the cosmogenic clock; and (ii) former glacial valley floors now stranded near the crest of the Sierra Nevada are at varying stages of abandonment, suggesting a cycle of drainage reorganiszation and relief inversion due to glacial erosion similar to that observed in river networks. Glaciated landscapes are quite distinct from their fluvial counterparts in both landforms and processes. Given the scarcity of purely fluvial, active mountain ranges, it is essential that glacial erosion be considered amongst the processes sculpting active orogenic belts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130009037','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130009037"><span id="translatedtitle">Shuttle <span class="hlt">Topography</span> Data Inform Solar Power Analysis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p></p> <p>2013-01-01</p> <p>The next time you flip on a light switch, there s a chance that you could be benefitting from data originally acquired during the Space Shuttle Program. An effort spearheaded by Jet Propulsion Laboratory (JPL) and the National Geospatial-Intelligence Agency (NGA) in 2000 put together the first near-global elevation map of the Earth ever assembled, which has found use in everything from 3D terrain maps to models that inform solar power production. For the project, called the Shuttle Radar <span class="hlt">Topography</span> Mission (SRTM), engineers at JPL designed a 60-meter mast that was fitted onto Shuttle Endeavour. Once deployed in space, an antenna attached to the end of the mast worked in combination with another antenna on the shuttle to simultaneously collect data from two perspectives. Just as having two eyes makes depth perception possible, the SRTM data sets could be combined to form an accurate picture of the Earth s surface elevations, the first hight-detail, near-global elevation map ever assembled. What made SRTM unique was not just its surface mapping capabilities but the completeness of the data it acquired. Over the course of 11 days, the shuttle orbited the Earth nearly 180 times, covering everything between the 60deg north and 54deg south latitudes, or roughly 80 percent of the world s total landmass. Of that targeted land area, 95 percent was mapped at least twice, and 24 percent was mapped at least four times. Following several years of processing, NASA released the data to the public in partnership with NGA. Robert Crippen, a member of the SRTM science team, says that the data have proven useful in a variety of fields. "Satellites have produced vast amounts of remote sensing data, which over the years have been mostly two-dimensional. But the Earth s surface is three-dimensional. Detailed topographic data give us the means to visualize and analyze remote sensing data in their natural three-dimensional structure, facilitating a greater understanding of the features and processes taking place on Earth."</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20020006041&hterms=Psychophysics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DPsychophysics','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20020006041&hterms=Psychophysics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DPsychophysics"><span id="translatedtitle">Gravitational Acceleration as a Cue for <span class="hlt">Absolute</span> Size and Distance</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hecht, Heiko; Kaiser, Mary K.; Banks, Martin S.; Hart, Sandra G. (Technical Monitor)</p> <p>1994-01-01</p> <p>When an object's motion is influenced by gravity, such as the rise and fall of a thrown ball, the vertical component of acceleration is roughly constant at 9.8 m/sec2. In principle, an observer could use this information to estimate the <span class="hlt">absolute</span> size and distance of the object (Saxberg, 1987a; Watson, Banks, von Hofsten, & Royden, 1992). In three experiments, we examined the ability to utilize the size and distance information provided by gravitational acceleration. Observers viewed computer simulations of an object rising and falling on a trajectory parallel to the gravitational vector. The simulated objects were three balls of different diameters presented across a wide range of simulated distances. Observers were asked to identify which ball was presented and the distance at which it was presented. The results of Experiment 1 showed that size and distance judgments were significantly better than chance, but not as accurate as expected if the information contained in the <span class="hlt">dynamics</span> of free fall were used fully utilized. The results of Experiment 2 showed that acceleration information is used, but that observers can also make use of velocity information. Finally, the results of Experiment 3 showed that observers can use projected size information, but that their size and distance judgments are much more accurate when motion information is present as well. These results show that observers can use the information in the <span class="hlt">dynamics</span> of free fall to estimate <span class="hlt">absolute</span> size and distance, but their estimates are not as accurate as they could be if the information were used effectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.3989M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.3989M"><span id="translatedtitle">Comparison of soil moisture <span class="hlt">dynamics</span> across different land covers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mittelbach, Heidi; Henschel, Florian; Seneviratne, Sonia I.</p> <p>2013-04-01</p> <p>The spatial and temporal variability of soil moisture and its dependency on local or regional scale characteristics, such as soil texture, land cover and <span class="hlt">topography</span> as well as weather and climate anomalies, is a fundamental feature for environmental applications. In a recent study based on a network of grassland stations in Switzerland (Mittelbach and Seneviratne 2012), it was shown that the spatio-temporal variability of <span class="hlt">absolute</span> soil moisture is clearly distinct from the spatio-temporal variability of temporal soil moisture anomalies, and that regional-scale patterns of soil moisture <span class="hlt">dynamics</span> could clearly be identified at the scale of Switzerland. However, it has not yet been investigated whether these conclusions apply across land cover types. In the current study, we investigate differences in soil moisture <span class="hlt">dynamics</span> at paired grassland-forest sites and their dependency either on <span class="hlt">dynamic</span> or static site properties. The analysis is based on three-year continuous soil moisture measurements at three paired grassland and nearby forest sites of the SwissSMEX (http://www.iac.ethz.ch/url/research/SwissSMEX) soil moisture network. The three paired sites are located in different climatic regions of Switzerland. They are characterized by similar meteorological conditions but within the pairs differences in <span class="hlt">topography</span> (elevation, slope, aspect) and soil properties are found. At all sites continuous measurements of soil moisture are available in four different depths, from 5 cm to 50 cm. The analyses of daily mean soil moisture at the single depths and integrated over the 50 cm soil column reveal different behaviour with respect to <span class="hlt">absolute</span> soil moisture levels and temporal soil moisture <span class="hlt">dynamics</span> between grassland and forest sites during the whole three-year period. Focusing on the recession of soil moisture during precipitation-free periods, a seasonal dependency is observed with strongest recession in summer for both land covers. However, a different behaviour is found in spring and autumn. While stronger recession is found over grassland in spring, the forest sites indicate stronger recession in autumn, with most pronounced differences at deeper depths. This investigation thus suggests that differences in soil moisture <span class="hlt">dynamics</span> across land cover types depend on the <span class="hlt">dynamics</span> of the vegetation cover and less on static site properties. Reference: Mittelbach, H., and S.I. Seneviratne, 2012: A new perspective on the spatio-temporal variability of soil moisture: temporal <span class="hlt">dynamics</span> versus time invariant contributions. Hydrol. Earth Syst. Sci., 16, 2169-2179.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20140005478&hterms=climate+change&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dclimate%2Bchange','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20140005478&hterms=climate+change&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3Dclimate%2Bchange"><span id="translatedtitle">Achieving Climate Change <span class="hlt">Absolute</span> Accuracy in Orbit</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wielicki, Bruce A.; Young, D. F.; Mlynczak, M. G.; Thome, K. J; Leroy, S.; Corliss, J.; Anderson, J. G.; Ao, C. O.; Bantges, R.; Best, F.; Bowman, K.; Brindley, H.; Butler, J. J.; Collins, W.; Dykema, J. A.; Doelling, D. R.; Feldman, D. R.; Fox, N.; Huang, X.; Holz, R.; Huang, Y.; Jennings, D.; Jin, Z.; Johnson, D. G.; Jucks, K.; Kato, S.; Kratz, D. P.; Liu, X.; Lukashin, C.; Mannucci, A. J.; Phojanamongkolkij, N.; Roithmayr, C. M.; Sandford, S.; Taylor, P. C.; Xiong, X.</p> <p>2013-01-01</p> <p>The Climate <span class="hlt">Absolute</span> Radiance and Refractivity Observatory (CLARREO) mission will provide a calibration laboratory in orbit for the purpose of accurately measuring and attributing climate change. CLARREO measurements establish new climate change benchmarks with high <span class="hlt">absolute</span> radiometric accuracy and high statistical confidence across a wide range of essential climate variables. CLARREO's inherently high <span class="hlt">absolute</span> accuracy will be verified and traceable on orbit to Système Internationale (SI) units. The benchmarks established by CLARREO will be critical for assessing changes in the Earth system and climate model predictive capabilities for decades into the future as society works to meet the challenge of optimizing strategies for mitigating and adapting to climate change. The CLARREO benchmarks are derived from measurements of the Earth's thermal infrared spectrum (5-50 micron), the spectrum of solar radiation reflected by the Earth and its atmosphere (320-2300 nm), and radio occultation refractivity from which accurate temperature profiles are derived. The mission has the ability to provide new spectral fingerprints of climate change, as well as to provide the first orbiting radiometer with accuracy sufficient to serve as the reference transfer standard for other space sensors, in essence serving as a "NIST [National Institute of Standards and Technology] in orbit." CLARREO will greatly improve the accuracy and relevance of a wide range of space-borne instruments for decadal climate change. Finally, CLARREO has developed new metrics and methods for determining the accuracy requirements of climate observations for a wide range of climate variables and uncertainty sources. These methods should be useful for improving our understanding of observing requirements for most climate change observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20070032798&hterms=Eis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DEis','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20070032798&hterms=Eis&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3DEis"><span id="translatedtitle"><span class="hlt">Absolute</span> Radiometric Calibration of EUNIS-06</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Thomas, R. J.; Rabin, D. M.; Kent, B. J.; Paustian, W.</p> <p>2007-01-01</p> <p>The Extreme-Ultraviolet Normal-Incidence Spectrometer (EUNIS) is a soundingrocket payload that obtains imaged high-resolution spectra of individual solar features, providing information about the Sun's corona and upper transition region. Shortly after its successful initial flight last year, a complete end-to-end calibration was carried out to determine the instrument's <span class="hlt">absolute</span> radiometric response over its Longwave bandpass of 300 - 370A. The measurements were done at the Rutherford-Appleton Laboratory (RAL) in England, using the same vacuum facility and EUV radiation source used in the pre-flight calibrations of both SOHO/CDS and Hinode/EIS, as well as in three post-flight calibrations of our SERTS sounding rocket payload, the precursor to EUNIS. The unique radiation source provided by the Physikalisch-Technische Bundesanstalt (PTB) had been calibrated to an <span class="hlt">absolute</span> accuracy of 7% (l-sigma) at 12 wavelengths covering our bandpass directly against the Berlin electron storage ring BESSY, which is itself a primary radiometric source standard. Scans of the EUNIS aperture were made to determine the instrument's <span class="hlt">absolute</span> spectral sensitivity to +- 25%, considering all sources of error, and demonstrate that EUNIS-06 was the most sensitive solar E W spectrometer yet flown. The results will be matched against prior calibrations which relied on combining measurements of individual optical components, and on comparisons with theoretically predicted 'insensitive' line ratios. Coordinated observations were made during the EUNIS-06 flight by SOHO/CDS and EIT that will allow re-calibrations of those instruments as well. In addition, future EUNIS flights will provide similar calibration updates for TRACE, Hinode/EIS, and STEREO/SECCHI/EUVI.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=20140005478&hterms=fingerprint&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dfingerprint','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=20140005478&hterms=fingerprint&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dfingerprint"><span id="translatedtitle">Achieving Climate Change <span class="hlt">Absolute</span> Accuracy in Orbit</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wielicki, Bruce A.; Young, D. F.; Mlynczak, M. G.; Thome, K. J; Leroy, S.; Corliss, J.; Anderson, J. G.; Ao, C. O.; Bantges, R.; Best, F.; Bowman, K.; Brindley, H.; Butler, J. J.; Collins, W.; Dykema, J. A.; Doelling, D. R.; Feldman, D. R.; Fox, N.; Huang, X.; Holz, R.; Huang, Y.; Jennings, D.; Jin, Z.; Johnson, D. G.; Jucks, K.; Kato, S.; Kratz, D. P.; Liu, X.; Lukashin, C.; Mannucci, A. J.; Phojanamongkolkij, N.; Roithmayr, C. M.; Sandford, S.; Taylor, P. C.; Xiong, X.</p> <p>2013-01-01</p> <p>The Climate <span class="hlt">Absolute</span> Radiance and Refractivity Observatory (CLARREO) mission will provide a calibration laboratory in orbit for the purpose of accurately measuring and attributing climate change. CLARREO measurements establish new climate change benchmarks with high <span class="hlt">absolute</span> radiometric accuracy and high statistical confidence across a wide range of essential climate variables. CLARREO's inherently high <span class="hlt">absolute</span> accuracy will be verified and traceable on orbit to Systme Internationale (SI) units. The benchmarks established by CLARREO will be critical for assessing changes in the Earth system and climate model predictive capabilities for decades into the future as society works to meet the challenge of optimizing strategies for mitigating and adapting to climate change. The CLARREO benchmarks are derived from measurements of the Earth's thermal infrared spectrum (5-50 micron), the spectrum of solar radiation reflected by the Earth and its atmosphere (320-2300 nm), and radio occultation refractivity from which accurate temperature profiles are derived. The mission has the ability to provide new spectral fingerprints of climate change, as well as to provide the first orbiting radiometer with accuracy sufficient to serve as the reference transfer standard for other space sensors, in essence serving as a "NIST [National Institute of Standards and Technology] in orbit." CLARREO will greatly improve the accuracy and relevance of a wide range of space-borne instruments for decadal climate change. Finally, CLARREO has developed new metrics and methods for determining the accuracy requirements of climate observations for a wide range of climate variables and uncertainty sources. These methods should be useful for improving our understanding of observing requirements for most climate change observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AMTD....8.1671M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AMTD....8.1671M"><span id="translatedtitle">A novel approach for <span class="hlt">absolute</span> radar calibration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Merker, C.; Peters, G.; Clemens, M.; Lengfeld, K.; Ament, F.</p> <p>2015-02-01</p> <p>The theoretical framework of a novel approach for <span class="hlt">absolute</span> radar calibration is presented and its potential analysed by means of synthetic data to lay out a solid basis for future practical application. The method presents the advantage of an <span class="hlt">absolute</span> calibration with respect to the directly measured reflectivity, without needing a previously calibrated reference device. It requires a setup comprising three radars: two devices oriented towards each other, measuring reflectivity along the same horizontal beam and operating within a strongly attenuated frequency range (e.g. K or X band) and one vertical reflectivity and drop size distribution (DSD) profiler below this connecting line, which is to be calibrated. The <span class="hlt">absolute</span> determination of the calibration factor is based on attenuation estimates. Using synthetic, smooth and geometrically idealised data calibration is found to perform best using homogeneous precipitation events with rain rates high enough to ensure a distinct attenuation signal (approx. 30 dBZ). Furthermore, the choice of the interval width (in measuring range gates) around the vertically pointing radar, needed for attenuation estimation, is found to have an impact on the calibration results. Further analysis is done by means of synthetic data with realistic, inhomogeneous precipitation fields taken from measurements. A calibration factor is calculated for each considered case using the presented method. Based on the distribution of the calculated calibration factors, the most probable value is determined by estimating the mode of a fitted shifted logarithmic normal distribution function. After filtering the data set with respect to rain rate and inhomogeneity and choosing an appropriate length of the considered attenuation path, the estimated uncertainty of the calibration factor is in the order of 1%. Considering stability and accuracy of the method, an interval of 8 range gates on both sides of the vertically pointing radar is most appropriate for calibration.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9570E..1DS','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9570E..1DS"><span id="translatedtitle">Clock time is <span class="hlt">absolute</span> and universal</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shen, Xinhang</p> <p>2015-09-01</p> <p>A critical error is found in the Special Theory of Relativity (STR): mixing up the concepts of the STR abstract time of a reference frame and the displayed time of a physical clock, which leads to use the properties of the abstract time to predict time dilation on physical clocks and all other physical processes. Actually, a clock can never directly measure the abstract time, but can only record the result of a physical process during a period of the abstract time such as the number of cycles of oscillation which is the multiplication of the abstract time and the frequency of oscillation. After Lorentz Transformation, the abstract time of a reference frame expands by a factor gamma, but the frequency of a clock decreases by the same factor gamma, and the resulting multiplication i.e. the displayed time of a moving clock remains unchanged. That is, the displayed time of any physical clock is an invariant of Lorentz Transformation. The Lorentz invariance of the displayed times of clocks can further prove within the framework of STR our earth based standard physical time is <span class="hlt">absolute</span>, universal and independent of inertial reference frames as confirmed by both the physical fact of the universal synchronization of clocks on the GPS satellites and clocks on the earth, and the theoretical existence of the <span class="hlt">absolute</span> and universal Galilean time in STR which has proved that time dilation and space contraction are pure illusions of STR. The existence of the <span class="hlt">absolute</span> and universal time in STR has directly denied that the reference frame dependent abstract time of STR is the physical time, and therefore, STR is wrong and all its predictions can never happen in the physical world.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=233512&keyword=AIDS&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=59788273&CFTOKEN=90617383','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=233512&keyword=AIDS&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=59788273&CFTOKEN=90617383"><span id="translatedtitle">Predicting Maximum Lake Depth from Surrounding <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Lake volume aids understanding of the physical and ecological <span class="hlt">dynamics</span> of lakes, yet is often not readily available. The data needed to calculate lake volume (i.e. bathymetry) are usually only collected on a lake by lake basis and are difficult to obtain across broad regions. ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/15020268','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/15020268"><span id="translatedtitle"><span class="hlt">Absolute</span> calibration of the Auger fluorescence detectors</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Bauleo, P.; Brack, J.; Garrard, L.; Harton, J.; Knapik, R.; Meyhandan, R.; Rovero, A.C.; Tamashiro, A.; Warner, D.</p> <p>2005-07-01</p> <p><span class="hlt">Absolute</span> calibration of the Pierre Auger Observatory fluorescence detectors uses a light source at the telescope aperture. The technique accounts for the combined effects of all detector components in a single measurement. The calibrated 2.5 m diameter light source fills the aperture, providing uniform illumination to each pixel. The known flux from the light source and the response of the acquisition system give the required calibration for each pixel. In the lab, light source uniformity is studied using CCD images and the intensity is measured relative to NIST-calibrated photodiodes. Overall uncertainties are presently 12%, and are dominated by systematics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1989ngs..rept.....P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1989ngs..rept.....P"><span id="translatedtitle">The National Geodetic Survey <span class="hlt">absolute</span> gravity program</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Peter, George; Moose, Robert E.; Wessells, Claude W.</p> <p>1989-03-01</p> <p>The National Geodetic Survey <span class="hlt">absolute</span> gravity program will utilize the high precision afforded by the JILAG-4 instrument to support geodetic and geophysical research, which involves studies of vertical motions, identification and modeling of other temporal variations, and establishment of reference values. The scientific rationale of these objectives is given, the procedures used to collect gravity and environmental data in the field are defined, and the steps necessary to correct and remove unwanted environmental effects are stated. In addition, site selection criteria, methods of concomitant environmental data collection and relative gravity observations, and schedule and logistics are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009acse.book..955S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009acse.book..955S"><span id="translatedtitle"><span class="hlt">Absolute</span> Priority for a Vehicle in VANET</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shirani, Rostam; Hendessi, Faramarz; Montazeri, Mohammad Ali; Sheikh Zefreh, Mohammad</p> <p></p> <p>In today's world, traffic jams waste hundreds of hours of our life. This causes many researchers try to resolve the problem with the idea of Intelligent Transportation System. For some applications like a travelling ambulance, it is important to reduce delay even for a second. In this paper, we propose a completely infrastructure-less approach for finding shortest path and controlling traffic light to provide <span class="hlt">absolute</span> priority for an emergency vehicle. We use the idea of vehicular ad-hoc networking to reduce the imposed travelling time. Then, we simulate our proposed protocol and compare it with a centrally controlled traffic light system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005Natur.436..928R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005Natur.436..928R"><span id="translatedtitle">Brownian motion: <span class="hlt">Absolute</span> negative particle mobility</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ros, Alexandra; Eichhorn, Ralf; Regtmeier, Jan; Duong, Thanh Tu; Reimann, Peter; Anselmetti, Dario</p> <p>2005-08-01</p> <p>Noise effects in technological applications, far from being a nuisance, can be exploited with advantage - for example, unavoidable thermal fluctuations have found application in the transport and sorting of colloidal particles and biomolecules. Here we use a microfluidic system to demonstrate a paradoxical migration mechanism in which particles always move in a direction opposite to the net acting force (`<span class="hlt">absolute</span> negative mobility') as a result of an interplay between thermal noise, a periodic and symmetric microstructure, and a biased alternating-current electric field. This counterintuitive phenomenon could be used for bioanalytical purposes, for example in the separation and fractionation of colloids, biological molecules and cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/16107829','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/16107829"><span id="translatedtitle">Brownian motion: <span class="hlt">absolute</span> negative particle mobility.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ros, Alexandra; Eichhorn, Ralf; Regtmeier, Jan; Duong, Thanh Tu; Reimann, Peter; Anselmetti, Dario</p> <p>2005-08-18</p> <p>Noise effects in technological applications, far from being a nuisance, can be exploited with advantage - for example, unavoidable thermal fluctuations have found application in the transport and sorting of colloidal particles and biomolecules. Here we use a microfluidic system to demonstrate a paradoxical migration mechanism in which particles always move in a direction opposite to the net acting force ('<span class="hlt">absolute</span> negative mobility') as a result of an interplay between thermal noise, a periodic and symmetric microstructure, and a biased alternating-current electric field. This counterintuitive phenomenon could be used for bioanalytical purposes, for example in the separation and fractionation of colloids, biological molecules and cells. PMID:16107829</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1982Natur.296...27B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1982Natur.296...27B"><span id="translatedtitle"><span class="hlt">Absolute</span> configuration of chiral polar crystals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Berkovitch-Yellin, Z.; Addadi, L.; Idelson, M.; Leiserowitz, L.; Lahav, M.</p> <p>1982-03-01</p> <p>A method is described for direct determination of <span class="hlt">absolute</span> configuration of chiral polar crystals, based on changes in crystal habit induced by tailor-made impurities. The method embodies the assignment of the direction of the chiral substrate molecule with respect to the crystal polar axis based on differences in the hemihedral faces of the substrate crystals as grown from solution in the presence and absence of impurities. The molecular packing requirements and the choice of impurities for application of this method in lysine and trans-cinnamoyl alanine are outlined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19900066048&hterms=rings+saturn&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Drings%2Bsaturn','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19900066048&hterms=rings+saturn&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Drings%2Bsaturn"><span id="translatedtitle">An <span class="hlt">absolute</span> radius scale for Saturn's rings</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nicholson, Philip D.; Cooke, Maren L.; Pelton, Emily</p> <p>1990-01-01</p> <p>Radio and stellar occultation observations of Saturn's rings made by the Voyager spacecraft are discussed. The data reveal systematic discrepancies of almost 10 km in some parts of the rings, limiting some of the investigations. A revised solution for Saturn's rotation pole has been proposed which removes the discrepancies between the stellar and radio occultation profiles. Corrections to previously published radii vary from -2 to -10 km for the radio occultation, and +5 to -6 km for the stellar occultation. An examination of spiral density waves in the outer A Ring supports that the revised <span class="hlt">absolute</span> radii are in error by no more than 2 km.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70010730','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70010730"><span id="translatedtitle"><span class="hlt">Absolute</span> method of measuring magnetic susceptibility</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Thorpe, A.; Senftle, F.E.</p> <p>1959-01-01</p> <p>An <span class="hlt">absolute</span> method of standardization and measurement of the magnetic susceptibility of small samples is presented which can be applied to most techniques based on the Faraday method. The fact that the susceptibility is a function of the area under the curve of sample displacement versus distance of the magnet from the sample, offers a simple method of measuring the susceptibility without recourse to a standard sample. Typical results on a few substances are compared with reported values, and an error of less than 2% can be achieved. ?? 1959 The American Institute of Physics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMGC21C..07F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMGC21C..07F"><span id="translatedtitle">Characterization of the DARA solar <span class="hlt">absolute</span> radiometer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Finsterle, W.; Suter, M.; Fehlmann, A.; Kopp, G.</p> <p>2011-12-01</p> <p>The Davos <span class="hlt">Absolute</span> Radiometer (DARA) prototype is an Electrical Substitution Radiometer (ESR) which has been developed as a successor of the PMO6 type on future space missions and ground based TSI measurements. The DARA implements an improved thermal design of the cavity detector and heat sink assembly to minimize air-vacuum differences and to maximize thermal symmetry of measuring and compensating cavity. The DARA also employs an inverted viewing geometry to reduce internal stray light. We will report on the characterization and calibration experiments which were carried out at PMOD/WRC and LASP (TRF).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/21410442','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/biblio/21410442"><span id="translatedtitle">Exploring the Saturation Levels of Stimulated Raman Scattering in the <span class="hlt">Absolute</span> Regime</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Michel, D. T.; Depierreux, S.; Tassin, V.; Stenz, C.; Labaune, C.</p> <p>2010-06-25</p> <p>This Letter reports new experimental results that evidence the transition between the <span class="hlt">absolute</span> and convective growth of stimulated Raman scattering (SRS). Significant reflectivities were observed only when the instability grows in the <span class="hlt">absolute</span> regime. In this case, saturation processes efficiently limit the SRS reflectivity that is shown to scale linearly with the laser intensity, and the electron density and temperature. Such a scaling agrees with the one established by T. Kolber et al.[Phys. Fluids B 5, 138 (1993)] and B Bezzerides et al.[Phys. Rev. Lett. 70, 2569 (1993)], from numerical simulations where the Raman saturation is due to the coupling of electron plasma waves with ion waves <span class="hlt">dynamics</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9204E..08R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9204E..08R"><span id="translatedtitle"><span class="hlt">Absolute</span> height measurement of specular surfaces with modified active fringe reflection photogrammetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ren, Hongyu; Jiang, Xiangqian; Gao, Feng; Zhang, Zonghua</p> <p>2014-07-01</p> <p>Deflectometric methods have been studied for more than a decade for slope measurement of specular freeform surfaces through utilization of the deformation of a sample pattern after reflection from a tested sample surface. Usually, these approaches require two-directional fringe patterns to be projected on a LCD screen or ground glass and require slope integration, which leads to some complexity for the whole measuring process. This paper proposes a new mathematical measurement model for measuring <span class="hlt">topography</span> information of freeform specular surfaces, which integrates a virtual reference specular surface into the method of active fringe reflection photogrammetry and presents a straight-forward relation between height of the tested surface and phase signals. This method only requires one direction of horizontal or vertical sinusoidal fringe patterns to be projected from a LCD screen, resulting in a significant reduction in capture time over established methods. Assuming the whole system has been precalibrated during the measurement process, the fringe patterns are captured separately via the virtual reference and detected freeform surfaces by a CCD camera. The reference phase can be solved according to the spatial geometric relation between the LCD screen and the CCD camera. The captured phases can be unwrapped with a heterodyne technique and optimum frequency selection method. Based on this calculated unwrapped-phase and that proposed mathematical model, <span class="hlt">absolute</span> height of the inspected surface can be computed. Simulated and experimental results show that this methodology can conveniently calculate <span class="hlt">topography</span> information for freeform and structured specular surfaces without integration and reconstruction processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.T54B..05F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.T54B..05F"><span id="translatedtitle">Evolution of the long-wavelength, subduction-driven <span class="hlt">topography</span> of South America since 150 Ma</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Flament, N. E.; Gurnis, M.; Williams, S.; Bower, D. J.; Seton, M.; Müller, D.</p> <p>2014-12-01</p> <p>Subduction to the west of South America spans 6000 km along strike and has been active for over 250 Myr. The influence of the history of subduction on the geodynamics of South America has been profound, driving mountain building and arc volcanism in the Andean Cordillera. Here, we investigate the long-wavelength changes in the <span class="hlt">topography</span> of South America associated with subduction and plate motion and their interplay with the lithospheric deformation associated with the opening of the South Atlantic. We pay particular attention to the topographic expression of flat-lying subduction zones. We develop time-dependent geodynamic models of mantle flow and lithosphere deformation to investigate the evolution of South American <span class="hlt">dynamic</span> and total <span class="hlt">topography</span> since the late Jurassic (150 Ma). Our models are semi-empirical because the computational cost of fully <span class="hlt">dynamic</span>, evolutionary models is still prohibitive. We impose the kinematics of global plate reconstructions with deforming continents in forward global mantle convection models with compositionally distinct crust and continental lithosphere embedded within the thermal lithosphere. The shallow thermal structure of subducting slabs is imposed, allowing us to investigate the evolution of <span class="hlt">dynamic</span> <span class="hlt">topography</span> around flat slab segments in time-dependent models. Multiple cases are used to investigate how the evolution of South American <span class="hlt">dynamic</span> <span class="hlt">topography</span> is influenced by mantle viscosity, the kinematics of the opening of the South Atlantic and alternative scenarios for recent and past flat-slab subduction. We predict that the migration of South America over sinking oceanic lithosphere resulted in continental tilt to the west until ~ 45 Ma, inverting to an eastward tilt thereafter. This first-order result is consistent with the reversal of the drainage of the Amazon River system. We investigate which scenarios of flat-slab subduction since the Eocene are compatible with geological constraints on the evolution of the Solimoes Basin, the Chaco Basin, the Sierras Pampeanas and the Central Patagonian Basin. To broadly constrain mantle viscosity, we compare models to the total subsidence inferred from well data offshore Argentina and Brazil, and to mantle tomography, since the initial and boundary conditions are based on independent plate reconstructions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ncbi.nlm.nih.gov/pubmed/8999781','PUBMED'); return false;" href="http://www.ncbi.nlm.nih.gov/pubmed/8999781"><span id="translatedtitle">Striving for atomic resolution in biomolecular <span class="hlt">topography</span>: the scanning force microscope (SFM).</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Schaper, A; Jovin, T M</p> <p>1996-11-01</p> <p>The invention in 1986 of scanning force microscopy (SFM) provided a new and powerful tool for the investigation of biological structures. SFM yields a three-dimensional view at nanometer resolution of the surface <span class="hlt">topography</span> associated with biological objects. The potential for imaging either macromolecules or biomolecules and cells under native (physiological) conditions is currently being exploited to obtain functional information at the molecular level. In addition, the forces involved in individual bimolecular interactions are being assessed under static and <span class="hlt">dynamic</span> conditions. In this report we focus on the imaging capability of the SFM. The rather broad spectrum of applications represented is intended to orient the prospective user of biological SFM. PMID:8999781</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://ntrs.nasa.gov/search.jsp?R=19720032809&hterms=absolute+stability&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dabsolute%2Bstability','NASA-TRS'); return false;" href="http://ntrs.nasa.gov/search.jsp?R=19720032809&hterms=absolute+stability&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dabsolute%2Bstability"><span id="translatedtitle"><span class="hlt">Absolute</span> stability analysis of attitude control systems for large boosters.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Siljak, D. D.; Seltzer, S. M.</p> <p>1971-01-01</p> <p>A method for performing an <span class="hlt">absolute</span> stability analysis of attitude control systems for large launch vehicles is presented. <span class="hlt">Absolute</span> stability of these systems is shown to be of a limited extent. The regions of <span class="hlt">absolute</span> stability are computed by using a quadratic Liapunov function. The function is chosen to provide additional information about the exponential property of <span class="hlt">absolute</span> stability. A system model is used to illustrate the method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JGRB..121.3081W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JGRB..121.3081W"><span id="translatedtitle">Heat flux and <span class="hlt">topography</span> constraints on thermochemical structure below North China Craton regions and implications for evolution of cratonic lithosphere</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Yongming; Huang, Jinshui; Zhong, Shijie; Chen, Jiaming</p> <p>2016-04-01</p> <p>The eastern North China Craton (NCC) has undergone extensive reactivation during the Mesozoic and Cenozoic, while the western NCC has remained stable throughout its geological history. Geophysical and geochemical observations, including heat flux, surface <span class="hlt">topography</span>, crustal and lithospheric thicknesses, and volcanism, show significant contrast between the eastern and western NCC. These observations provide constraints on thermochemical structure and reactivation process of the eastern NCC, thus helping understand the <span class="hlt">dynamic</span> evolution of cratonic lithosphere. In this study, we determined the residual <span class="hlt">topography</span> for the NCC region by removing crustal contribution to the <span class="hlt">topography</span>. We found that the residual <span class="hlt">topography</span> of the eastern NCC region is generally 0.3-0.9 km higher than the western NCC. We computed a large number of two-dimension thermochemical convection models for gravitational instability of cratonic lithosphere and quantified surface heat flux and <span class="hlt">topography</span> contrasts between stable and destabilized parts of cratonic lithosphere. These models consider different chemical buoyancy (i.e., buoyancy number B) and viscosity for the cratonic lithosphere. Our models suggest that to explain the difference in heat flux (25-30 mW/m2) and residual <span class="hlt">topography</span> (0.3-0.9 km) between the eastern and western NCC regions, the buoyancy number B is required to be ~0.3-0.4. This range of B implies that as much as 50% of the original cratonic lithospheric material remains in the present-day eastern NCC lithosphere and its underlying shallow mantle and that the new lithosphere in the eastern NCC may be a mixture of the relics of old craton materials and the normal mantle.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005JaJAP..44.6304Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005JaJAP..44.6304Y"><span id="translatedtitle">Observation on Effect of Optical Stimulation to Human Using Optical <span class="hlt">Topography</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yanai, Hiro-Fumi; Yorimoto, Akiyoshi; Kubota, Toshio; Fujii, Kan-ichi; Kawaguchi, Fumio; Yamamoto, Etsuji; Ichikawa, Noriyoshi; Koshino, Yoshihumi</p> <p>2005-08-01</p> <p>We have observed the time course features of cerebral response while a subject is performing the visual tracking task or visual tracking plus finger tapping task using Optiocal <span class="hlt">Topography</span> (OT). The distribution maps of both oxygenated and deoxygenated hemoglobins are demonstrated in contrast with the time course diagram. The response of the cerebrum differs, depending on whether the optical stimulation is static or <span class="hlt">dynamic</span>, even when the overall nature of the pattern and intensity of the stimulation is the same. The cerebral response to a <span class="hlt">dynamic</span> optical stimulation is very rapid and clear, and greater in magnitude than that to static optical stimulation, but it is suppressed when an auxiliary finger tapping task is also performed. From these results, it was confirmed that OT is sensitive to both static and <span class="hlt">dynamic</span> optical stimulations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=ponce&pg=4&id=EJ819063','ERIC'); return false;" href="http://eric.ed.gov/?q=ponce&pg=4&id=EJ819063"><span id="translatedtitle">Using, Seeing, Feeling, and Doing <span class="hlt">Absolute</span> Value for Deeper Understanding</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Ponce, Gregorio A.</p> <p>2008-01-01</p> <p>Using sticky notes and number lines, a hands-on activity is shared that anchors initial student thinking about <span class="hlt">absolute</span> value. The initial point of reference should help students successfully evaluate numeric problems involving <span class="hlt">absolute</span> value. They should also be able to solve <span class="hlt">absolute</span> value equations and inequalities that are typically found in…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=zero+AND+point&pg=3&id=EJ920859','ERIC'); return false;" href="http://eric.ed.gov/?q=zero+AND+point&pg=3&id=EJ920859"><span id="translatedtitle">A Conceptual Approach to <span class="hlt">Absolute</span> Value Equations and Inequalities</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Ellis, Mark W.; Bryson, Janet L.</p> <p>2011-01-01</p> <p>The <span class="hlt">absolute</span> value learning objective in high school mathematics requires students to solve far more complex <span class="hlt">absolute</span> value equations and inequalities. When <span class="hlt">absolute</span> value problems become more complex, students often do not have sufficient conceptual understanding to make any sense of what is happening mathematically. The authors suggest that the…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007PhyEd..42..304A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007PhyEd..42..304A"><span id="translatedtitle">Determination of <span class="hlt">absolute</span> zero using a computer-based laboratory</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Amrani, D.</p> <p>2007-05-01</p> <p>We present a simple computer-based laboratory experiment for evaluating <span class="hlt">absolute</span> zero in degrees Celsius, which can be performed in college and undergraduate physical sciences laboratory courses. With a computer, <span class="hlt">absolute</span> zero apparatus can help demonstrators or students to observe the relationship between temperature and pressure and use datalogger software to mathematically extrapolate to find <span class="hlt">absolute</span> zero.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9206E..0ER','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9206E..0ER"><span id="translatedtitle">Experimental results for <span class="hlt">absolute</span> cylindrical wavefront testing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reardon, Patrick J.; Alatawi, Ayshah</p> <p>2014-09-01</p> <p>Applications for Cylindrical and near-cylindrical surfaces are ever-increasing. However, fabrication of high quality cylindrical surfaces is limited by the difficulty of accurate and affordable metrology. <span class="hlt">Absolute</span> testing of such surfaces represents a challenge to the optical testing community as cylindrical reference wavefronts are difficult to produce. In this paper, preliminary results for a new method of <span class="hlt">absolute</span> testing of cylindrical wavefronts are presented. The method is based on the merging of the random ball test method with the fiber optic reference test. The random ball test assumes a large number of interferograms of a good quality sphere with errors that are statistically distributed such that the average of the errors goes to zero. The fiber optic reference test utilizes a specially processed optical fiber to provide a clean high quality reference wave from an incident line focus from the cylindrical wave under test. By taking measurements at different rotation and translations of the fiber, an analogous procedure can be employed to determine the quality of the converging cylindrical wavefront with high accuracy. This paper presents and discusses the results of recent tests of this method using a null optic formed by a COTS cylindrical lens and a free-form polished corrector ele