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Sample records for aligned currents facs

  1. Field-aligned currents onboard the Intercosmos Bulgaria-1300 satellite in comparison with modeled FAC

    NASA Astrophysics Data System (ADS)

    Danov, Dimitar

    2008-02-01

    The statistical field-aligned current (FAC) distribution has been demonstrated by [Iijima, T., Potemra, T.A., 1976. The amplitude distribution of field-aligned currents at northern high latitudes observed by Triad. Journal of Geophysical Research 81(13), 2165-2174] and many other authors. The large-scale (LS) FACs have been described by different empirical/statistical models [Feldstein, Ya. I., Levitin, A.E., 1986. Solar wind control of electric fields and currents in the ionosphere. Journal of Geomagnetism and Geoelectricity 38, 1143; Papitashvili, V.O., Rich, F.J., Heinemann, M.A., Hairston, M.R., 1999. Parameterization of the Defense Meteorological Satellite Program ionospheric electrostatic potentials by the interplanetary magnetic field strength and direction. Journal of Geophysical Research 104, 177-184; Papitashvili, V.O., Christiansen, F., Neubert, T., 2002. A new model of field-aligned currents derived from high-precision satellite magnetic field data. Geophysical Research Letters, 29(14), 1683, doi:10.1029/2001GL014207; Tsyganenko, N.A., 2001. A model of the near magnetosphere with a dawn-dusk asymetry (I. Mathematical structure). Journal of Geophysical Research 107(A8), doi:10.1029/2001JA000219; Weimer, D.R., 1996a. A new model for prediction of ionospheric electric potentials as a function of the IMF. In: Snowmass'96 Online Poster Session; Weimer, D.R., 1996b. Substorm influence on the ionospheric convection patterns. In: Snowmass'96 Online Poster Session; Weimer, D.R., 2001. Maps of ionospheric field-aligned currents as a function of the interplanetary magnetic field derived from Dynamic Explorer 2 data. Journal of Geophysical Research 106, 12,889-12,902; Weimer, D.R., 2005. Improved ionospheric electrodynamic models and application to calculating Joule heating rates. Journal of Geophysical Research 110, A05306, doi:10.1029/2004JA010884]. In the present work, we compare two cases of LS FAC obtained from magnetic field measurements onboard the

  2. Generation of field-aligned current (FAC) and convection through the formation of pressure regimes: Correction for the concept of Dungey's convection

    NASA Astrophysics Data System (ADS)

    Tanaka, T.; Watanabe, M.; Den, M.; Fujita, S.; Ebihara, Y.; Kikuchi, T.; Hashimoto, K. K.; Kataoka, R.

    2016-09-01

    In this paper, we try to elucidate the generation mechanism of the field-aligned current (FAC) and coexisting convection. From the comparison between the theoretical prediction and the state of numerical solution from the high-resolution global simulation, we obtain the following conclusions about the distribution of dynamo, the magnetic field structure along the flow path that diverges Poynting flux, and energy conversion promoting the generation of electromagnetic energy. The dynamo for the region 1 FAC, which is in the high-latitude-side cusp-mantle region, has a structure in which magnetic field is compressed along the convection path by the slow mode motion. The dynamo for the region 2 FAC is in the ring current region at the inner edge of the plasma sheet, and has a structure in which magnetic field is curved outward along the convection path. Under these structures, electromagnetic energy is generated from the work done by pressure gradient force, in both dynamos for the region 1 and region 2 FACs. In these generation processes of the FACs, the excitation of convection and the formation of pressure regimes occur as interdependent processes. This structure leads to a modification in the way of understanding the Dungey's convection. Generation of the FAC through the formation of pressure regimes is essential even for the case of substorm onset.

  3. Properties and behaviour of FAC currents in the inner magnetosphere

    NASA Astrophysics Data System (ADS)

    Yang, Junying; Dunlop, Malcolm; Yang, Yanyan; Xiong, Chao; Lühr, Hermann; Cao, Jinbin; Li, Liuyuan; Ma, Yuduan; Shen, Chao

    2017-04-01

    Cusp, region 1 and 2, and other large scale field-aligned currents (FACs), are sampled in situ by both the four Cluster spacecraft and by the three Swarm spacecraft at different altitudes, separated by a few to several Earth radii, and sometimes simultaneously. Here, the capability of Swarm-Cluster coordination for probing the behaviour of the field aligned currents (FACs) at medium and low orbits is explored. Joint signatures of R1 and R2 FACs (as well as cusp, R0 and NBZ currents) can be found and compared in terms of the magnetic signatures, using multi-spacecraft analysis where possible. Using the Swarm configuration, statistical correlation analysis of the local time variation of R1/R2 FACs can be shown and compared to standard MVA analysis. For context, we identify the associated auroral boundaries through application of a method to determine the FAC intensity gradients in order to interpret and resolve the R1 and R2 FACs. We also explore the relation of R2 FACs to the ring current properties measured in situ.

  4. Study of field-aligned current (FAC), interplanetary electric field component (Ey), interplanetary magnetic field component (Bz), and northward (x) and eastward (y) components of geomagnetic field during supersubstorm

    NASA Astrophysics Data System (ADS)

    Adhikari, Binod; Dahal, Subodh; Chapagain, Narayan P.

    2017-05-01

    A dominant process by which energy and momentum are transported from the magnetosphere to the ionosphere is known as field-aligned current (FAC). It is enhanced during magnetic reconnection and explosive energy release at a substorm. In this paper, we studied FAC, interplanetary electric field component (Ey), interplanetary magnetic field component (Bz), and northward (x) and eastward (y) components of geomagnetic field during three events of supersubstorm occurred on 24 November 2001, 21 January 2005, and 24 August 2005. Large-scale FAC, supposed to be produced during supersubstorm (SSS), has potentiality to cause blackout on Earth. We examined temporal variations of the x and y components of high-latitude geomagnetic field during SSS, which is attributed to the FACs. We shall report the characteristics of high-latitude northward and eastward components of geomagnetic field variation during the growth phase of SSS by the implementation of discrete wavelet transform (DWT) and cross-correlation analysis. Among three examples of SSS events, the highest peak value of FAC was estimated to be 19 μAm-2. This is shore up with the prediction made by Parks (1991) and Stasiewicz et al. (1998) that the FACs may vary from a few tens to several hundred μAm-2. Although this peak value of FACs for SSS event is much higher than the average FACs associated with regular substorms or magnetic storms, it is expedient and can be expect for SSS events which might be due to very high density solar wind plasma parcels (PPs) triggering the SSS events. In all events, during growth phase, the FAC increases to extremely high level and the geomagnetic northward component decreases to extremely low level. This represents a strong positive correlation between FAC and geomagnetic northward component. The DWT analysis accounts that the highest amplitude of the wavelet coefficients indicates singularities present in FAC during SSS event. But the amplitude of squared wavelet coefficient is found

  5. Relationships between Geomagnetic Induced Currents and Field Aligned Currents

    NASA Astrophysics Data System (ADS)

    Waters, C. L.; Barnett, R.; Anderson, B. J.; Gjerloev, J. W.; Korth, H.; Barnes, R. J.

    2015-12-01

    Geomagnetic Induced Currents (GICs) appear in the ground due to time varying magnetic fields that occur during periods of enhanced geomagnetic activity. The resultant time varying electric fields at Earth's surface drive very low frequency, currents through electricity supply transformers which reduces transforming capacity. In extreme cases, electricity supply grids can collapse as multiple transformers are affected. GICs have larger magnitudes at auroral latitudes and should be related to the field aligned current (FAC) and auroral ionosphere currents systems. At ground locations under the regions between upward and downward FACs, the GIC related fields show a direct relationship with the time derivative of the FACs. This allows a conversion factor between FAC and GIC magnitudes. Examples of the relationship between FAC and GIC related fields are presented using data derived from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) and SuperMAG.

  6. Coordinated Coverage of the Ring Current, Cusp and Adjacent FACs with Cluster and Swarm

    NASA Astrophysics Data System (ADS)

    Xiong, C.; Dunlop, M. W.; Bogdanova, Y.; Yang, J.; Yang, Y.; Shen, C.; Luhr, H.; Olsen, N.; Zhang, Q. H.; Ritter, P.; Kauristie, K.; Masson, A.; Haagmans, R.

    2014-12-01

    We explore the capability of Swarm-Cluster coordination for probing the behavior of the ring current (RC), field aligned currents (FAC) and cusp currents at medium and low orbits. The RC and connecting R2 FACs influence the geomagnetic field at low Earth orbit (LEO) and are sampled in situ by the four Cluster spacecraft every perigee pass. Coordination of the configuration of the three Swarm spacecraft with the constellation of the four Cluster spacecraft has been planned through joint operations; providing a set of distributed, multi-point measurements covering this region. A particularly close coordination of all spacecraft has been achieved during the start of the Swarm operations. We show preliminary study of the morphology and influence of the ring current from the in-situ RC and associated FACs determined directly from the 4-spacecraft Cluster perigee observations. We report here preliminary results of joint science targets, including coordinated cusp encounters; the comparative significance of the connecting R2 FACs, and the use and application of new analysis techniques derived from the calculation of curl B and magnetic gradients to compare estimates of the current distributions. For context, we will report on the coordination of Champ and Cluster data to interpret and resolve the R1 and R2 FACs using Champ derived models of the associated auroral boundaries.

  7. Field-Aligned Current Systems at Mercury

    NASA Astrophysics Data System (ADS)

    Heyner, Daniel; Exner, Willi

    2017-04-01

    Mercury exhibits a very dynamic magnetosphere, which is partially due to strong dayside reconnection and fast magnetospheric convection. It has been shown that dayside reconnection occurs even on low magnetic shear angles across the magnetopause. This drives quasi-steady region 1 field-aligned currents (FAC) that are observable in in-situ MESSENGER data. Here, the structure of the Hermean FAC-system is discussed and compared to the terrestrial counterpart. Due to the lack of a significant ionosphere at Mercury, it has to be examined how much of the poloidal FAC is reflected back to the magnetosphere, closed via toroidal currents in the planetary interior or via Pedersen currents in the tenuous exosphere. This investigation gives insights into the planetary conductivity structure as well as the exospheric plasma densities. Furthermore, it will be examined how much the only partially developed ring current at Mercury produces possible region 2 FAC signatures. We conclude with requirements to simulations that are needed to forecast the FAC structure on the southern hemisphere that will be closely studied with the upcoming BepiColombo mission.

  8. The detailed spatial structure of field-aligned currents comprising the substorm current wedge

    NASA Astrophysics Data System (ADS)

    Murphy, Kyle R.; Mann, Ian R.; Rae, I. Jonathan; Waters, Colin L.; Frey, Harald U.; Kale, Andy; Singer, Howard J.; Anderson, Brian J.; Korth, Haje

    2013-12-01

    We present a comprehensive two-dimensional view of the field-aligned currents (FACs) during the late growth and expansion phases for three isolated substorms utilizing in situ observations from the Active Magnetosphere and Planetary Electrodynamics Response Experiment and from ground-based magnetometer and optical instrumentation from the Canadian Array for Realtime Investigations of Magnetic Activity and Time History of Events and Macroscale Interactions during Substorms ground-based arrays. We demonstrate that the structure of FACs formed during the expansion phase and associated with the substorm current wedge is significantly more complex than a simple equivalent line current model comprising a downward FAC in the east and upward FAC in the west. This two-dimensional view demonstrates that azimuthal bands of upward and downward FACs with periodic structuring in latitude form across midnight and can span up to 8 h of magnetic local time. However, when averaged over latitude, the overall longitudinal structure of the net FACs resembles the simpler equivalent line current description of the substorm current wedge (SCW). In addition, we demonstrate that the upward FAC elements of the structured SCW are spatially very well correlated with discrete aurora during the substorm expansion phase and that discrete changes in the FAC topology are observed in the late growth phase prior to auroral substorm expansion phase onset. These observations have important implications for determining how the magnetosphere and ionosphere couple during the late growth phase and expansion phase, as well as providing important constraints on the magnetospheric generator of the FACs comprising the SCW.

  9. Swarm Observations of Field-Aligned Currents: Case Studies

    NASA Astrophysics Data System (ADS)

    Le, G.; Chi, P. J.; Gjerloev, J. W.; Stolle, C.; Luhr, H.; Park, J.; Rauberg, J.

    2014-12-01

    In this paper, we report the results of a few case studies of multi-point magnetic field measurements of field-aligned currents (FACs) from Swarm constellation mission to understand their temporal and spatial characteristics. During the commissioning phase, the three Swarm spacecraft were in an identical polar orbit with a string-of-pearl configuration with small separations. During the science operational phase (since April, 2014), the three spacecraft were placed in slightly different polar orbits: one spacecraft in a higher altitude orbit (507km x 512km) and two side-by-side in lower altitude orbits (459km x 462km). We analyze a few FAC events in both orbital phases and during periods of active geomagnetic conditions. The multi-point observations enable us to examine the FACs' temporal evolution and separate their temporal and spatial variations.

  10. Swarm Observations of Field Aligned Currents during Geomagnetic Storms

    NASA Astrophysics Data System (ADS)

    Le, G.; Luhr, H.; Anderson, B. J.; Strangeway, R. J.; Russell, C. T.; Slavin, J. A.; Bromund, K. R.; Plaschke, F.; Magnes, W.; Fischer, D.; Nakamura, R.; Leinweber, H. K.; Torbert, R. B.; Le Contel, O.; Oliveira, D. M.; Raeder, J.; Kepko, L.

    2015-12-01

    Field-aligned currents connect the Earth's magnetosphere to the high latitude ionosphere, and provide a main channel for energy transfer from the magnetosphere to the ionosphere. They are driven by solar wind-magnetosphere interactions and respond dynamically to changes in the solar wind and interplanetary magnetic field. Enhanced interaction during geomagnetic storms significantly intensifies their strength and variability. In this paper, we review our recent observations of field-aligned currents (FACs) during geomagnetic storms using observations from polar orbiting Swarm constellation as well as the Active Magnetosphere and Polar Electrodynamics Response Experiment (AMPERE). Both temporal resolutions and spatial coverage of these observations provide new insights in understanding the FACs and the magnetosphere-ionosphere coupling. We will discuss their spatial and temporal evolutions, ionospheric closure currents, and hemispheric asymmetry during storms.

  11. Field-aligned Currents on Board of Intercosmos Bulgaria-1300 Satellite in Comparison with Modelled Large-scale Currents

    NASA Astrophysics Data System (ADS)

    Danov, D.; Koleva, R.

    2007-08-01

    The large-scale field-aligned currents (FACs) are well examined experimentally and described by different models, but the small scale FACs are less investigated and there exists a controversy about their intensity and dimensions. A possible source for the discrepancy is the assumption of infinite homogeneous current sheet which allowed their deriving from one-satellite measurements. We present a new method for identification of finite size current sheets, which we applied to derive FACs from magnetic field measurements aboard the INTERCOSMOS BULGARIA-1300 satellite. Then we compare one case of FAC, detected on 22 August 1981, with empirical (Tsyganenko 2001) and a magneto-hydrodynamic Block-Adaptive-Tree-Solar-wind-Roe-Upwind-Scheme (BATS-R-US) model of large-scale currents. We discuss the possible reasons for the observed discrepancy between the measured and modelled FACs.

  12. A High-resolution Model of Field-aligned Currents Through Empirical Orthogonal Functions Analysis (MFACE)

    NASA Technical Reports Server (NTRS)

    He, Maosheng; Vogt, Joachim; Luehr, Hermann; Sorbalo, Eugen; Blagau, Adrian; Le, Guan; Lu, Gang

    2012-01-01

    Ten years of CHAMP magnetic field measurements are integrated into MFACE, a model of field-aligned currents (FACs) using empirical orthogonal functions (EOFs). EOF1 gives the basic Region-1/Region-2 pattern varying mainly with the interplanetary magnetic field Bz component. EOF2 captures separately the cusp current signature and By-related variability. Compared to existing models, MFACE yields significantly better spatial resolution, reproduces typically observed FAC thickness and intensity, improves on the magnetic local time (MLT) distribution, and gives the seasonal dependence of FAC latitudes and the NBZ current signature. MFACE further reveals systematic dependences on By, including 1) Region-1/Region-2 topology modifications around noon; 2) imbalance between upward and downward maximum current density; 3) MLT location of the Harang discontinuity. Furthermore, our procedure allows quantifying response times of FACs to solar wind driving at the bow shock nose: we obtain 20 minutes and 35-40 minutes lags for the FAC density and latitude, respectively.

  13. Variations of thermal electron energy distribution associated with field-aligned currents

    SciTech Connect

    Oyama, Kohichiro ); Fukunishi, Hiroshi ); Abe, Takumi; Okuzawa, Takashi; Fujii, Ryoichi

    1991-02-01

    Relationships between thermal electrons and field aligned currents (FACs) in the auroral region have been investigated using data simultaneously obtained from the Thermal Electron Detector (TED) and the fluxgate magnetometer both onboard the EXOS-D satellite. Several features resulted from the observations are summarized as; (1) At altitudes from 300 to 1,800km, electron temperature in the upward FAC region is higher than that of the neighboring no FAC region by the increment {Delta}T=1,100-9,500K, while the temperature is lower in the downward FAC region by the decrement {minus}{Delta}T=500-1,500K. (2) The electron temperature increase in the upward-current region grows with an increase of the FAC density. (3) The thermal electrons do not have Maxwell distribution in the upward-current region at altitudes higher than about 2,000km.

  14. Field-aligned currents and large-scale magnetospheric electric fields

    NASA Technical Reports Server (NTRS)

    Dangelo, N.

    1979-01-01

    The existence of field-aligned currents (FAC) at northern and southern high latitudes was confirmed by a number of observations, most clearly by experiments on the TRIAD and ISIS 2 satellites. The high-latitude FAC system is used to relate what is presently known about the large-scale pattern of high-latitude ionospheric electric fields and their relation to solar wind parameters. Recently a simplified model was presented for polar cap electric fields. The model is of considerable help in visualizing the large-scale features of FAC systems. A summary of the FAC observations is given. The simplified model is used to visualize how the FAC systems are driven by their generators.

  15. Lobe cell convection and field-aligned currents poleward of the region 1 current system

    NASA Astrophysics Data System (ADS)

    Eriksson, S.; Bonnell, J. W.; Blomberg, L. G.; Ergun, R. E.; Marklund, G. T.; Carlson, C. W.

    2002-08-01

    We present a case and statistical study of plasma convection in the Northern Hemisphere during summer conditions using electric field, magnetic field, and particle data taken during dawn-dusk directed orbits of the FAST satellite. To our knowledge, this set provides the most comprehensive combination of data as yet presented in support of lobe cell convection from an ionospheric perspective this far from the noon sector. In particular, we study the current systems and convection patterns for all passes in July 1997 that show evidence for six large-scale field-aligned currents (FACs) rather than the usual system of four FACs associated with the region 1/region 2 current systems. A total of 71 passes out of 232 in the study had the extra pair of FACs. The extra pair of FACs in 30 of the 71 cases lies either on the dawnside or on the duskside of the noon-midnight meridian, and their position is strongly correlated with the polarity of the IMF By (negative and positive, respectively). This is consistent with the IMF dependence of a three-cell convection pattern of coexisting merging, viscous, and lobe-type convection cells. The occurrence of the asymmetric FAC pair was also strongly linked to conditions of IMF |By/Bz| > 1. The extra pair of FACs in these cases was clearly associated with the lobe cell of the three-cell convection system. The remaining 41 cases had the pair of FACs straddling the noon-midnight meridian. The extra pair of FACs was often (20 cases out of 30) observed at magnetic local times more than three hours away from noon, rather than being confined to regions near noon and the typical location of the cusp. Such a current system consisting of a pair of FACs poleward of the nearest region 1 current is consistent with the IMF By-dependent global MHD model developed by Ogino et al. [1986] for southward IMF conditions, as well as with other magnetospheric and ionospheric convection models that include the effects of merging occuring simultaneously at

  16. Field-Aligned Current at Plasma Sheet Boundary Layers During Storm Time: Cluster Observation

    NASA Astrophysics Data System (ADS)

    Shi, J.; Cheng, Z.; Zhang, T.; Dunlop, M.; Liu, Z.

    2007-05-01

    The magnetic field data from the FGM instruments on board the four Cluster spacecrafts were used to study Field Aligned Current (FAC) at the Plasma Sheet Boundary Layers (PSBLs) with the so called "curlometer technique". We analyzed the date obtained in 2001 in the magnetotail and only two cases were found in the storm time. One (August 17, 2001) occurred from sudden commencement to main phase, and the other (October 1, 2001) lay in the main phase and recovery phase. The relationship between the FAC density and the AE index was studied and the results are shown as follows. (1) In the sudden commencement and the main phase the density of the FAC increases obviously, in the recovery phase the density of the FAC increases slightly. (2) From the sudden commencement to the initial stage of the main phase the FAC increases with decreasing AE index and decreases with increasing AE index. From the late stage of the main phase to initial stage of the recovery phase, the FAC increases with increasing AE index and decreases with decreasing AE index. In the late stage of the recovery phase the disturbance of the FAC is not so violent, so that the FAC varying with the AE index is not very obvious.

  17. Observation of a Unipolar Field-aligned Current System Associated With IMF By-triggered Theta Auroras

    NASA Astrophysics Data System (ADS)

    Hairston, M. R.; Watanabe, M.

    2016-12-01

    We investigate the existence of a specific field-aligned current (FAC) system predicted by numerical magnetohydrodynamic simulations in a past study. The FAC system is expected to occur when a drifting theta aurora is formed in response to a stepwise transition of interplanetary magnetic field (IMF) By during strongly northward IMF periods. When the IMF By changes from positive to negative, a crossbar forms in the Northern Hemisphere that moves dawnward, while in the Southern Hemisphere the crossbar moves in the opposite direction. The crossbar motion reverses when the IMF By changes from negative to positive. The FAC system appears on the trailing side of the drifting crossbar of the theta aurora as it moves either dawnward or duskward. When the theta aurora is drifting dawnward, the FACs flow into the ionosphere. The FAC polarity reverses when the theta aurora is drifting duskward. Using low-altitude satellite data, we confirmed the real existence of the above model-predicted FAC system.

  18. Localized field-aligned currents in the polar cap associated with airglow patches

    NASA Astrophysics Data System (ADS)

    Zou, Ying; Nishimura, Yukitoshi; Burchill, Johnathan K.; Knudsen, David J.; Lyons, Larry R.; Shiokawa, Kazuo; Buchert, Stephan; Chen, Steve; Nicolls, Michael J.; Ruohoniemi, J. Michael; McWilliams, Kathryn A.; Nishitani, Nozomu

    2016-10-01

    Airglow patches have been recently associated with channels of enhanced antisunward ionospheric flows propagating across the polar cap from the dayside to nightside auroral ovals. However, how these flows maintain their localized nature without diffusing away remains unsolved. We examine whether patches and collocated flows are associated with localized field-aligned currents (FACs) in the polar cap by using coordinated observations of the Swarm spacecraft, a polar cap all-sky imager, and Super Dual Auroral Radar Network (SuperDARN) radars. We commonly (66% of cases) identify substantial FAC enhancements around patches, particularly near the patches' leading edge and center, in contrast to what is seen in the otherwise quiet polar cap. These FACs have densities of 0.1-0.2 μA/m-2 and have a distribution of width peaking at 75 km. They can be approximated as infinite current sheets that are orientated roughly parallel to patches. They usually exhibit a Region 1 sense, i.e., a downward FAC lying eastward of an upward FAC. With the addition of Resolute Bay Incoherent Scatter radar data, we find that the FACs can close through Pedersen currents in the ionosphere, consistent with the locally enhanced dawn-dusk electric field across the patch. Our results suggest that ionospheric polar cap flow channels are imposed by structures in the magnetospheric lobe via FACs, and thus manifest mesoscale magnetosphere-ionosphere coupling embedded in large-scale convection.

  19. Field-aligned current signatures during the March 13-14, 1989, great magnetic storm

    SciTech Connect

    Fujii, R. ); Fukunishi, H. ); Kokubun, S. ); Sugiura, M. ); Tohyama, F. ); Hayakawa, H.; Tsuruda, K. ); Okada, T. )

    1992-07-01

    Characteristics of field-aligned currents (FACs) in the evening and morning regions during the March 13-14, 1989, great magnetic storm have been determined using magnetic and electric field data obtained from the EXOS D spacecraft. This storm began with an SSC at 0128 UT on March 13, and the second SSC occurred at 0747 UT on the same day. The storm continued until March 14. The equatorward boundary of the FAC region began to move equatorward right after the first SSC in both the evening and morning sectors, but the poleward boundary did not immediately respond to the SSC. The equatorward boundary of the FAC system reached as low as below 48{degree} invariant latitude, which corresponds to L = 2.2, and the latitudinal width of the FAC region increased greatly, particularly in the morning sector ({approximately}33{degree} in invariant latitude). In the evening sector the conventional current system characterized by a pair of upward region 1 and downward region 2 FACs changed into complicated patterns consisting of many pairs of upward and downward FACs with the development of the storm, particularly around 22 UT on March 13 when an intense eastward electrojet was observed as low as 50{degree} invariant latitude on the ground. In the morning sector an additional large-scale upward FAC was observed poleward of the conventional downward region 1 and upward region 2 FAC system throughout the storm. In addition, a pair of FACs with a narrow latitudinal width ({approximately}1.5{degree}) was observed at the poleward boundary of the extra upward FAC.

  20. Comparison of field-aligned currents at ionospheric and magnetospheric altitudes

    NASA Technical Reports Server (NTRS)

    Spence, H. E.; Kivelson, M. G.; Walker, R. J.

    1988-01-01

    Using the empirical terrestrial magnetospheric magnetic field models of Tsyganenko and Usmanov (1982) and Tsyganenko (1987) the average field-aligned currents (FACs) in the magnetosphere were determined as a function of the Kp index. Three major model FAC systems were identified, namely, the dayside region 1, the nightside region 1, and the nightside polar cap. The models provide information about the sources of the current systems. Mapped ionospheric model FACs are compared with low-altitude measurements obtained by the spacecraft. It is found that low-altitude data can reveal either classic region 1/2 or more highly structured FAC patterns. Therefore, statistical results either obtained from observations or inferred from models are expected to be averages over temporally and spatially shifting patterns.

  1. Space Technology 5 observations of auroral field-aligned currents

    NASA Astrophysics Data System (ADS)

    Slavin, James

    During its three month long technology validation mission, Space Technology 5 (ST-5) returned high quality multi-point measurements of the near-Earth magnetic field. Its three micro-satellites were launched into a 300 x 4500 km, dawn - dusk, sun synchronous orbit (inclination = 105.6o) orbit with a period of 138 min by a Pegasus launch vehicle on March 22, 2006. The spacecraft were maintained in a "pearls on a sting" constellation with controlled spacings ranging from just over 5000 km down to under 50 km. The individual micro-satellites were 48 cm tall octagons with diameters of 50 cm. They were spin-stabilized at approximately 20 rpm at deployment and slowly spun-down to about 15 rpm by the end of the mission. Each spacecraft carried a miniature tri-axial fluxgate magnetometer (MAG) provided by the University of California at Los Angeles mounted at the end of a ultra-low mass 72 cm boom. These data allow, for the first time, the separation of temporal and spatial variations in field-aligned current (FAC) perturbations measured in low-Earth orbit on time scales of 10 sec to 10 min. The constellation measurements are used to directly determine field-aligned current sheet motion, thickness, and current density. Two multi-point methods for the inference of FAC current density that have not previously been possible in low-Earth orbit are demonstrated: 1) the "standard method," based upon s/c velocity, but corrected for FAC current sheet motion, and 2) the "gradiometer method" which uses simultaneous magnetic field measurements at two points with known separation. Future studies will apply these methods to the entire ST-5 data set and expand to include horizontal ionospheric currents, ULF waves and geomagnetic field gradient analyses.

  2. Space Technology 5 Observations of Auroral Field-Aligned Currents

    NASA Technical Reports Server (NTRS)

    Slavin, James

    2008-01-01

    During its three month long technology validation mission, Space Technology 5 (ST-5) returned high quality multi-point measurements of the near-Earth magnetic field. Its three micro-satellites were launched into a 300 x 4500 km, dawn - dusk, sun synchronous orbit (inclination = 105.60) orbit with a period of 138 min by a Pegasus launch vehicle on March 22, 2006. The spacecraft were maintained in a "pearls on a sting" constellation with controlled spacings ranging from just over 5000 km down to under 50 km. The individual micro-satellites were 48 cm tall octagons with diameters of 50 cm. They were spin-stabilized at approximately 20 rpm at deployment and slowly spun-down to about 15 rpm by the end of the mission. Each spacecraft carried a miniature tri-axial fluxgate magnetometer (MAG) provided by the University of California at Los Angeles mounted at the end of a ultra-low mass 72 cm boom. These data allow, for the first time, the separation of temporal and spatial variations in field-aligned current (FAC) perturbations measured in low-Earth orbit on time scales of 10 sec to 10 min. The constellation measurements are used to directly determine field-aligned current sheet motion, thickness. and current density. Two multi-point methods for the inference of FAC current density that have not previously been possible in low-Earth orbit are demonstrated: 1) the -standard method." based upon s/c velocity, but corrected for FAC current sheet motion. and 2) the "gradiometer method" which uses simultaneous magnetic field measurements at two points with known separation. Future studies will apply these methods to the entire ST-5 data sct and expand to include horizontal ionospheric currents. ULF waves and geomagnetic field gradient analyses.

  3. Four large-scale field-aligned current systems in the dayside high-latitude region

    SciTech Connect

    Ohtani, S.; Potemra, T.A.; Newell, P.T.

    1995-01-01

    A system of four current sheets of large-scale field-aligned currents (FACs) was discovered in the data set of simultaneous Viking and DMSP-F7 crossings of the dayside high-latitude region. This paper reports four examples of this system that were observed in the prenoon sector. The flow polarities of FACs are upward, downward, upward, and downward, from equatorward to poleward. The lowest-latitude upward current is flowing mostly in the CPS precipitation region, often overlapping with the BPS at its poleward edge, and is interpreted as a region 2 current. The pair of downward and upward FACs in the middle of the structure are collocated with structured electron precipitation. The precipitation of high-energy (>1 keV) electrons is more intense in the lower-latitude downward current sheet. The highest-latitude downward flowing current sheet is located in a weak, low-energy particle precipitation region, suggesting that this current is flowing on open field lines. Simultaneous observations in the postnoon local time sector reveal the standard three-sheet structure of FACs, sometimes described as region 2, region 1, and mantle (referred to the midday region 0) currents. A high correlation was found between the occurrence of the four FAC sheet structure and negative interplanetary magnetic field (IMF) B{sub Y}. The authors discuss the FAC structure in terms of three types of convection cells: the merging, viscous, and lobe cells. During strongly negative IMF B{sub Y}, two convection reversals exist in the prenoon sector; one is inside the viscous cell, and the other is between the viscous cell and the lobe cell. This structure of convection flow is supported by the Viking electric field and auroral UV image data. Based on the convection pattern, the four FAC sheet structure is interpreted as the latitudinal overlap of midday and morning FAC systems. 47 refs., 12 figs., 1 tab.

  4. Field-aligned currents distribution as derived from the Swarm satellite constellation

    NASA Astrophysics Data System (ADS)

    Luhr, H.; Kervalishvili, G.; Rauberg, J.; Michaelis, I.

    2015-12-01

    The seminal studies of Iijima and Potemra have outlined the major distribution features of field-aligned currents (FACs) in a local time versus magnetic latitude frame. The related plot showing the Region 1 and 2 FAC belts has been the reference in many studies as the baseline configuration during the past decades. What did we learn more since then? ESA's constellation mission Swarm provides the opportunity to derive more reliable FAC estimates from multi-satellite magnetic field measurements. We make use of the Swarm A/C satellite pair, which flies side-by-side at a separation of 1.4° in longitude. By considering along-track differences over 5 s the four readings at the corners of an almost symmetrical quad are used for calculating the mean vertical current density flowing through the encircled area. FACs are estimated by mapping the vertical current component onto the field direction. Within the auroral oval current estimates from single and dual-satellite solutions agree generally well. Significant differences are frequently observed in the polar cap. Here underlying assumptions for single-satellite solutions are obviously not well satisfied. Another characteristic derived from the multi-satellite observations: FACs can be divided into two classes. For scale sizes up to some ten kilometers rapid temporal variations are observed. These FACs are related to kinetic Alfvén waves. The other class with scale lengths of more than 150 km can be regarded as stationary current systems lasting for more than a minute.

  5. Filamentary field-aligned currents at the polar cap region during northward interplanetary magnetic field derived with the Swarm constellation

    NASA Astrophysics Data System (ADS)

    Lühr, Hermann; Huang, Tao; Wing, Simon; Kervalishvili, Guram; Rauberg, Jan; Korth, Haje

    2016-10-01

    ESA's Swarm constellation mission makes it possible for the first time to determine field-aligned currents (FACs) in the ionosphere uniquely. In particular at high latitudes, the dual-satellite approach can reliably detect some FAC structures which are missed by the traditional single-satellite technique. These FAC events occur preferentially poleward of the auroral oval and during times of northward interplanetary magnetic field (IMF) orientation. Most events appear on the nightside. They are not related to the typical FAC structures poleward of the cusp, commonly termed NBZ. Simultaneously observed precipitating particle spectrograms and auroral images from Defense Meteorological Satellite Program (DMSP) satellites are consistent with the detected FACs and indicate that they occur on closed field lines mostly adjacent to the auroral oval. We suggest that the FACs are associated with Sun-aligned filamentary auroral arcs. Here we introduce in an initial study features of the high-latitude FAC structures which have been observed during the early phase of the Swarm mission. A more systematic survey over longer times is required to fully characterize the so far undetected field aligned currents.

  6. Effect of Interhemispheric Field-Aligned Currents on Region-1 Currents

    NASA Technical Reports Server (NTRS)

    Lyatsky, Sonya; Lyatsky, Wladislaw; Khazanov, George V.

    2015-01-01

    An asymmetry in ionospheric conductivity between two hemispheres results in the formation of additional, interhemispheric field-aligned currents flowing between conjugate ionospheres within two auroral zones. These interhemispheric currents are especially significant during summer-winter conditions when there is a significant asymmetry in ionospheric conductivity in two hemispheres. In such conditions, these currents may be comparable in magnitude with the Region 1 field-aligned currents. In this case, the R1 current is the sum of two FACs: one is going from to the solar wind, and another is flowing between conjugate ionospheres. These interhemispheric currents can also cause the formation of auroras extended along the nightside polar cap boundary, which may be related to the so-called double auroral oval. In this study, we present the results of analytical and numerical solutions for the interhemispheric currents and their effect on the Region 1 currents.

  7. DMSP F7 observations of a substorm field-aligned current

    NASA Technical Reports Server (NTRS)

    Lopez, R. E.; Spence, H. E.; Meng, C.-I.

    1991-01-01

    Observations are described of a substorm field-aligned current (FAC) system traversed by the DMSP F7 spacecraft just after 0300 UT on April 25, 1985. It is shown that the substorm FAC portion of the current system was located equatorward of the boundary between open and closed field lines. The equatorward boundary of the substorm FAC into the magnetotail was mapped using the Tsyganenko (1987) model, showing that the boundary corresponds to 6.9 earth radii. The result is consistent with the suggestion of Akasofu (1972) and Lopez and Lui (1990) that the region of substorm initiation lies relatively close to the earth and the concept that an essential feature of substorms is the disruption and diversion of the near-earth current sheet.

  8. Space Technology 5 Multi-Point Field-Aligned Current Measurements (Invited)

    NASA Astrophysics Data System (ADS)

    Slavin, J. A.; Le, G.; Gjerloev, J. W.

    2013-12-01

    NASA's Space Technology 5 (ST 5) microsatellite constellation technology mission was launched by a Pegasus launch vehicle on March 22, 2006. The three small (48 cm tall, 50 cm diameter, 25 kg mass, spin stabilized at 20 rpm) satellites were placid in a 300 x 4500 km, dawn to dusk, sun synchronous orbit (inclination = 105.6 deg) orbit with a period of 138 min. They were maintained in this 'pearls on a sting' formation with inter-satellite spacings ranging from over 5000 km to under 50 km. Each satellite carried a miniature tri-axial fluxgate magnetometer (MAG) provided by the University of California at Los Angeles. Field aligned currents (FACs) form in response to the stress exerted on the magnetosphere by the solar wind and act as the primary mechanism for dissipating solar wind energy into the ionosphere and upper atmosphere during the solar wind magnetosphere ionosphere coupling process. ST 5 returned the first direct, simultaneous, multipoint measurements of FAC motion, thickness, and temporal variability. Current density was measured using both 1) the 'standard method' based upon s/c velocity, but corrected for FAC current sheet motion, with the assumption of a time-stationary current density profile, and 2) for the first time at low altitudes, the 'gradiometer method' which uses simultaneous magnetic field measurements at two points with known separation. Here we review the ST 5 scientific results concerning FACs and discuss their implications for future investigations of field aligned currents systems using distributed systems of spaceborne magnetometers.

  9. Influences of the interplanetary magnetic field clock angle and cone angle on the field-aligned currents in the magnetotail

    NASA Astrophysics Data System (ADS)

    Cheng, Z. W.; Shi, J. K.; Dunlop, M.; Liu, Z. X.

    2013-10-01

    The influences of the interplanetary magnetic field (IMF) cone angle θ and clock angle ϕ on the field-aligned currents (FACs) at the plasma sheet boundary layers (PSBLs) have been investigated using Cluster Data. The FAC occurrence increases monotonically with IMF cone angle and has two peaks at -90° and +110° clock angle, respectively. The peak at +110° is distinctly larger than that at -90°. Overall, there are more FACs between 0° < ϕ < 180°, indicating that FACs occurrence is closely associated with duskward IMF. More FACs occur when 90° < |ϕ| < 180°, implying that FAC is closely associated with southward IMF. The large FAC densities occur when 60° < |ϕ| < 120°. The density also has two peaks and the peak at +90° clock angle (duskward IMF) is larger than that at -90° (dawnward IMF). These results indicate that the IMF influence on the FACs is from all IMF components and not only from a single component.

  10. Alfven Wave Reflection Model of Field-Aligned Currents at Mercury

    NASA Technical Reports Server (NTRS)

    Lyatsky, Wladislaw; Khazanov, George V.; Slavin, James

    2010-01-01

    An Alfven Wave Reflection (AWR) model is proposed that provides closure for strong field-aligned currents (FACs) driven by the magnetopause reconnection in the magnetospheres of planets having no significant ionospheric and surface electrical conductance. The model is based on properties of the Alfven waves, generated at high altitudes and reflected from the low-conductivity surface of the planet. When magnetospheric convection is very slow, the incident and reflected Alfven waves propagate along approximately the same path. In this case, the net field-aligned currents will be small. However, as the convection speed increases. the reflected wave is displaced relatively to the incident wave so that the incident and reflected waves no longer compensate each other. In this case, the net field-aligned current may be large despite the lack of significant ionospheric and surface conductivity. Our estimate shows that for typical solar wind conditions at Mercury, the magnitude of Region 1-type FACs in Mercury's magnetosphere may reach hundreds of kilo-Amperes. This AWR model of field-aligned currents may provide a solution to the long-standing problem of the closure of FACs in the Mercury's magnetosphere. c2009 Elsevier Inc. All rights reserved.

  11. Alfven Wave Reflection Model of Field-Aligned Currents at Mercury

    NASA Technical Reports Server (NTRS)

    Lyatsky, Wladislaw; Khazanov, George V.; Slavin, James

    2010-01-01

    An Alfven Wave Reflection (AWR) model is proposed that provides closure for strong field-aligned currents (FACs) driven by the magnetopause reconnection in the magnetospheres of planets having no significant ionospheric and surface electrical conductance. The model is based on properties of the Alfven waves, generated at high altitudes and reflected from the low-conductivity surface of the planet. When magnetospheric convection is very slow, the incident and reflected Alfven waves propagate along approximately the same path. In this case, the net field-aligned currents will be small. However, as the convection speed increases. the reflected wave is displaced relatively to the incident wave so that the incident and reflected waves no longer compensate each other. In this case, the net field-aligned current may be large despite the lack of significant ionospheric and surface conductivity. Our estimate shows that for typical solar wind conditions at Mercury, the magnitude of Region 1-type FACs in Mercury's magnetosphere may reach hundreds of kilo-Amperes. This AWR model of field-aligned currents may provide a solution to the long-standing problem of the closure of FACs in the Mercury's magnetosphere. c2009 Elsevier Inc. All rights reserved.

  12. Plasma Sheet Response to the Ionosphere's Demand for Field-Aligned Current

    NASA Astrophysics Data System (ADS)

    Coroniti, F. V.; Pritchett, P. L.

    2007-12-01

    Magnetospheric convection electric fields and plasma stresses are transmitted to the ionosphere by Alfvén wave electric fields and field-aligned currents (FACs). The closure of the FACs by ionospheric Hall and Pedersen currents drives the ionospheric convection system. However, the ionospheric system does not necessarily mesh smoothly with the magnetospheric drivers, and the magnetosphere must respond by altering its convection and plasma stress configuration, thereby creating self-consistent closure paths for the complete coupled system of currents and electric potentials. Three-dimensional particle-in-cell plasma kinetic simulations are used to determine the plasma sheet response to various current systems imposed as boundary conditions at the near-Earth boundary. These systems consist of separate downward and upward tubes of FAC and a substorm current wedge configuration. The results demonstrate that the creation of closure paths for ionospheric FACs can result in large configuration changes within the near-Earth plasma sheet. The plasma sheet is forced to establish polarization electric fields that locally increase the cross-tail current by producing a duskward Hall electron current; this results in the formation of thin (in z), spatially localized (in y) electron-dominated Hall current sheets. The observed complex magnetic field configuration with opposite polarity Bz fields in close proximity separated by electron scale thin current sheets is reminiscent of the turbulent magnetic fields that are observed within the near-Earth current disruption region at substorm breakup [ Lui et al., 1988, 1992].

  13. The interplanetary magnetic field B sub y -dependent field-aligned current in the dayside polar cap under quiet conditions

    SciTech Connect

    Yamauchi, M. Kyoto Univ. ); Araki, T. )

    1989-03-01

    Spatial distribution and temporal variation of the interplanetary magnetic field (IMF) B{sub y}-dependent cusp region field-aligned currents (FACs) during quiet periods were studied by use of magnetic data observed by Magsat. The analysis was made for 11 events (each event lasts more than one and a half days) when the IMF B{sub y} component was steadily large and B{sub x} was relatively small ({vert bar}B{sub z}{vert bar} < {vert bar}B{sub y}{vert bar}). Results of the analysis of total 62 half-day periods for the IMF B{sub y}-dependent cusp region FAC are summarized as follows: (1) the IMF B{sub y}-dependent cusp region FAC is located at around 86{degree}-87{degree} invariant latitude local noon, which is more poleward than the location of the IMF B{sub z}-dependent cusp region FAC; (2) the current density of this FAC is greater than previous studies ({ge} 4 {mu}A/m{sup 2} for IMF B{sub y} = 6 nT); (3) there are two time scales for the IMF B{sub y}-dependent cusp region FAC to appear: the initial rise of the current is on a short time scale, {approximately} 10 min, and it is followed by a gradual increase on a time scale of several hours to a half day; (4) the seasonal change of this FAC is greater than that of the nightside region 1 or region 2 FACs; (5) the IMF B{sub z}-dependent cusp region FAC is not well observed around the cusp when the IMF B{sub y}-dependent cusp region FAC is intense.

  14. The interplanetary magnetic field B[sub y] effects on large-scale field-aligned currents near local noon: Contributions from cusp part and noncusp part

    SciTech Connect

    Yamauchi, M.; Lundin, R.; Woch, J. )

    1993-04-01

    latitudinals develop a model to account for the effect of the interplanetary magnetic field (IMF) B[sub y] component on the dayside field-aligned currents (FACs). As part of the model the FACs are divided into a [open quotes]cusp part[close quotes] and a [open quotes]noncusp part[close quotes]. The authors then propose that the cusp part FACs shift in the longitudinal direction while the noncusplike part FACs shift in both longitudinal and latitudinal directions in response to the y component of the IMF. If combined, it is observed that the noncusp part FAC is found poleward of the cusp part FAC system when the y component of the IMF is large. These two FAC systems flow in the same direction. They reinforce one another, creating a strong FAC, termed the DPY-FAC. The model also predicts that the polewardmost part of the DPY-FAC flows on closed field lines, even in regions conventionally occupied by the polar cap. Results of the model are successfully compared with particle and magnetic field data from Viking missions.

  15. The particle carriers of field-aligned currents in the Earth's magnetotail during a substorm

    NASA Astrophysics Data System (ADS)

    Cheng, Z. W.; Zhang, J. C.; Shi, J. K.; Kistler, L. M.; Dunlop, M.; Dandouras, I.; Fazakerley, A.

    2016-04-01

    Although the particle carriers of field-aligned currents (FACs) in the Earth's magnetotail play an important role in the transfer of momentum and energy between the solar wind, magnetosphere, and ionosphere, the characteristics of the FAC carriers have been poorly understood. Taking advantage of multiinstrument magnetic field and plasma data collected by the four spacecraft of the Cluster constellation as they traversed the northern plasma sheet boundary layer in the magnetotail on 14 September 2004, we identified the species type and energy range of the FAC carriers for the first time. The results indicate that part of tailward FACs is carried by energetic keV ions, which are probably originated from the ionosphere through outflow, and they are not too small (~2 nA/m2) to be ignored. The earthward (tailward) FACs are mainly carried by the dominant tailward (earthward) motion of electrons, and higher-energy electrons (from ~0.5 to 26 keV) are the main carriers.

  16. Complexities of determining the Field-Aligned current density from LEO satellites.

    NASA Astrophysics Data System (ADS)

    Gjerloev, J. W.; Friel, M. M.; Ohtani, S.; Muhleisen, M.; Gjerloev, A. W.; Martin, P.; Barnes, R. J.

    2015-12-01

    We show results from a study of the field-aligned currents (FAC) as derived from SWARM magnetic field perturbations. We calculate the FAC density using four different techniques and explain why they provide different results. Theoretical work, simulations and data are used to show that widely used techniques can provide current density estimates with errors of 1000%. These errors can be explained by spatial gradients in the currents and temporal variability of the currents as well as a breakdown of other fundamental assumptions. We apply the techniques to auroral crossings with THEMIS ASI coverage and use the SWARM magnetic field observations to calculate the current density. Finally, we show how to estimate the errors in the current density calculations.

  17. Four large-scale field-aligned current systmes in the dayside high-latitude region

    NASA Technical Reports Server (NTRS)

    Ohtani, S.; Potemra, T. A.; Newell, P.T.; Zanetti, L. J.; Iijima, T.; Watanabe, M.; Blomberg, L. G.; Elphinstone, R. D.; Murphree, J. S.; Yamauchi, M.

    1995-01-01

    A system of four current sheets of large-scale field-aligned currents (FACs) was discovered in the data set of simultaneous Viking and Defense Meteorological Satellire Program-F7 (DMSP-F7) crossing of the dayside high-latitude region. This paper reports four examples of this system that were observed in the prenoon sector. The flow polarities of FACs are upward, downward, upward, and downward, from equatorward to poleward. The lowest-latitude upward current is flowing mostly in the central plasma sheet (CPS) precipitation region, often overlapping with the boundary plasma sheet (BPS) at its poleward edge, andis interpreted as a region 2 current. The pair of downward and upward FACs in the middle of te structure are collocated with structured electron precipitation. The precipitation of high-energy (greater than 1 keV) electrons is more intense in the lower-latitude downward current sheet. The highest-latitude downward flowing current sheet is located in a weak, low-energy particle precipitation region, suggesting that this current is flowing on open field lines. Simulaneous observations in the postnoon local time sector reveal the standard three-sheet structure of FACs, sometimes described as region 2, region 1, and mantle (referred to the midday region O) currents. A high correlation was found between the occurrence of the four FAC sheet structure and negative interplanetary magnetic field (IMF) B(sub Y). We discuss the FAC structurein terms of three types of convection cells: the merging, viscous, andlobe cells. During strongly negative IMF B(sub Y), two convection reversals exist in the prenoon sector; one is inside the viscous cell, and the other is between the viscous cell and the lobe cell. This structure of convection flow is supported by the Viking electric field and auroral UV image data. Based on the convection pattern, the four FAC sheet structure is interpreted as the latitude overlap of midday and morning FAC systems. We suggest that the for-current

  18. Four large-scale field-aligned current systmes in the dayside high-latitude region

    NASA Technical Reports Server (NTRS)

    Ohtani, S.; Potemra, T. A.; Newell, P.T.; Zanetti, L. J.; Iijima, T.; Watanabe, M.; Blomberg, L. G.; Elphinstone, R. D.; Murphree, J. S.; Yamauchi, M.

    1995-01-01

    A system of four current sheets of large-scale field-aligned currents (FACs) was discovered in the data set of simultaneous Viking and Defense Meteorological Satellire Program-F7 (DMSP-F7) crossing of the dayside high-latitude region. This paper reports four examples of this system that were observed in the prenoon sector. The flow polarities of FACs are upward, downward, upward, and downward, from equatorward to poleward. The lowest-latitude upward current is flowing mostly in the central plasma sheet (CPS) precipitation region, often overlapping with the boundary plasma sheet (BPS) at its poleward edge, andis interpreted as a region 2 current. The pair of downward and upward FACs in the middle of te structure are collocated with structured electron precipitation. The precipitation of high-energy (greater than 1 keV) electrons is more intense in the lower-latitude downward current sheet. The highest-latitude downward flowing current sheet is located in a weak, low-energy particle precipitation region, suggesting that this current is flowing on open field lines. Simulaneous observations in the postnoon local time sector reveal the standard three-sheet structure of FACs, sometimes described as region 2, region 1, and mantle (referred to the midday region O) currents. A high correlation was found between the occurrence of the four FAC sheet structure and negative interplanetary magnetic field (IMF) B(sub Y). We discuss the FAC structurein terms of three types of convection cells: the merging, viscous, andlobe cells. During strongly negative IMF B(sub Y), two convection reversals exist in the prenoon sector; one is inside the viscous cell, and the other is between the viscous cell and the lobe cell. This structure of convection flow is supported by the Viking electric field and auroral UV image data. Based on the convection pattern, the four FAC sheet structure is interpreted as the latitude overlap of midday and morning FAC systems. We suggest that the for-current

  19. Quantitative patterns of large-scale field-aligned currents in the auroral ionosphere

    SciTech Connect

    Foster, J.C.; Fuller-Rowell, T.; Evans, D.S.

    1989-03-01

    Quantitative patterns of the distribution of field-aligned current (FAC) density have been derived from gradients of the average patterns of the Hall and Pedersen currents at high latitudes under the assumption that the total current is divergence-free. The horizontal currents were calculated from empirical convection electric field models, derived from Millstone Hill radar observations, and the ionospheric Hall and Pedersen conductances, based on satellite observations of the precipitating particle energy flux and spectrum and including an average (equinox) solar contribution. These independent empirical models, and the resultant patterns of the field-aligned currents, are keyed to an auroral precipitation index which quantifies the intensity and spatial extent of high-latitude particle precipitation and which is determined from a single satellite crossing of the auroral precipitation pattern. The patterns detail the spatial distribution of the currents as a function of increasing disturbance level. The magnitudes of the total single-hemisphere currents into or out of the ionosphere are closely balanced at each activity level and increase exponentially between 0.1 and 6 MA with increasing values of the precipitation index. The interplanetary magnetic field (IMF) sector dependence of the FAC patterns is investigated for disturbed conditions. A large portion of the FAC pattern is closed by local Pedersen currents (current into the ionosphere is balanced by an equal current out of the ionosphere at that local time). This locally balanced portion of the FAC system is enhanced in the prenoon (postnoon) sector for IMF B/sub v/>+1 nT (B/sub y/<-1 nT). In addition, there are net currents into the ionosphere postnoon and out of the ionosphere in the premidnight sector.

  20. Laboratory simulation of field-aligned currents

    NASA Technical Reports Server (NTRS)

    Wessel, Frank J.; Rostoker, Norman

    1993-01-01

    A summary of progress during the period Apr. 1992 to Mar. 1993 is provided. Objectives of the research are (1) to simulate, via laboratory experiments, the three terms of the field-aligned current equation; (2) to simulate auroral-arc formation processes by configuring the boundary conditions of the experimental chamber and plasma parameters to produce highly localized return currents at the end of a field-aligned current system; and (3) to extrapolate these results, using theoretical and computational techniques, to the problem of magnetospheric-ionospheric coupling and to compare them with published literature signatures of auroral-arc phenomena.

  1. Observations of Field-Aligned Current Spatial and Temporal Variations by Space Technology 5

    NASA Astrophysics Data System (ADS)

    Le, G.; Slavin, J. A.; Strangeway, R. J.; Wang, Y.

    2013-12-01

    In this paper, we report the results of magnetic field measurements of field-aligned currents (FACs) using multi-point magnetic field data from Space Technology 5 (ST-5) mission. ST-5 is a three micro-satellite constellation deployed into a 300 x 4500 km, dawn-dusk, sun synchronous polar orbit. The spacecraft were maintained in a 'pearls on a sting' constellation with controlled spacings ranging from just over 5000 km down to under 50 km. During the three-month mission duration, the constellation mission returned high quality multi-point measurements of the magnetic field through Earth's dynamic ionospheric current systems over a range of inter-satellite spacing. In this study, we use the ST-5 magnetic field measurements to separate spatial and temporal variations of FACs and to quantify the imbalance between the region 1 (R1) and the region 2 (R2) currents.

  2. Global ionospheric current patterns associated with the development of the R1 and R2 FACs deduced by the GEMSIS-POT

    NASA Astrophysics Data System (ADS)

    Nakamizo, A.; Hiraki, Y.; Hori, T.; Seki, K.; Ieda, A.; Tsuji, Y.; Miyoshi, Y.; Ebihara, Y.; Kikuchi, T.

    2011-12-01

    As part of the GEMSIS project (Geospace Environment Modeling System for Integrated Studies), we have developed a two-dimensional ionospheric global potential solver. There has been considerable research on the mid-and low-latitude ionospheric system driven by neutral wind [e.g., Richmond, 1973]. However, there are few researches on the relationship between the high-latitude system and middle and low latitude system, which is important for the integrated studies of the magnetosphere-inner magnetosphere system coupled through the ionosphere. Our model basically follows a methodology provided by Tsunomura [1999]; it solves the Ohm's law under the thin-shell approximated 2-D ionosphere, with FACs in the polar region and height-integrated ionospheric conductivities. The most important extension from previous studies is that our model covers both hemispheres without a boundary at the equator. The values of Pedersen and Hall conductivities are calculated as exactly as possible with the MSIS-2000, IRI-2007, and IGRF-2005 reference models. In addition, we consider the effect of auroral particle precipitation on conductivities with reference to the empirical models [e.g., Hardy et al., 1987]. Although the FACs and ionospheric conductivity are intrinsically related to each other, we set them a priori at present because there is still no theory describing the development of the FACs-conductivity coupled system self-consistently. By using the solver, we investigate (1) the relationship between the conductivity and electric field in the middle and low latitude ionosphere and (2) how the current density ratio and latitudinal/longitudinal distribution of R1-FAC and R2-FAC affect the electric field distribution and current pattern in the middle and low latitude ionosphere. Here, FACs are distributed with reference to the empirical model by Hori et al. [in preparation] and the location of the conductivity enhancement associated with auroral activities given by empirical models is

  3. Identifying intervals of temporally invariant field-aligned currents from Swarm: Assessing the validity of single-spacecraft methods

    NASA Astrophysics Data System (ADS)

    Forsyth, C.; Rae, I. J.; Mann, I. R.; Pakhotin, I. P.

    2017-03-01

    Field-aligned currents (FACs) are a fundamental component of coupled solar wind-magnetosphere-ionosphere. By assuming that FACs can be approximated by stationary infinite current sheets that do not change on the spacecraft crossing time, single-spacecraft magnetic field measurements can be used to estimate the currents flowing in space. By combining data from multiple spacecraft on similar orbits, these stationarity assumptions can be tested. In this technical report, we present a new technique that combines cross correlation and linear fitting of multiple spacecraft measurements to determine the reliability of the FAC estimates. We show that this technique can identify those intervals in which the currents estimated from single-spacecraft techniques are both well correlated and have similar amplitudes, thus meeting the spatial and temporal stationarity requirements. Using data from European Space Agency's Swarm mission from 2014 to 2015, we show that larger-scale currents (>450 km) are well correlated and have a one-to-one fit up to 50% of the time, whereas small-scale (<50 km) currents show similar amplitudes only 1% of the time despite there being a good correlation 18% of the time. It is thus imperative to examine both the correlation and amplitude of the calculated FACs in order to assess both the validity of the underlying assumptions and hence ultimately the reliability of such single-spacecraft FAC estimates.

  4. Field-aligned currents, convection electric fields, and ULF-ELF waves in the cusp

    NASA Technical Reports Server (NTRS)

    Saflekos, N. A.; Potemra, T. A.; Kintner, P. M., Jr.; Green, J. L.

    1979-01-01

    Nearly simultaneous observations from the Triad and Hawkeye satellites over the Southern Hemisphere, at low altitudes near the noon meridian and close to the usual polar cusp latitudes, show that in and near the polar cusp there exist several relationships between field-aligned currents (FACs), convection electric fields, ULF-ELF magnetic noise, broadband electrostatic noise and interplanetary magnetic fields. The most important findings are (1) the FACs directed into the ionosphere in the noon-to-dusk local time sector and directed away from the ionosphere in the noon-to-dawn local time sector and identified as region-1 permanent FACs (Iijima and Potemra, 1976a) and are located equatorward of the regions of antisunward (westward) convection; (2) the observations are consistent with a two-cell convection pattern symmetric in one case (throat positioned at noon) and asymmetric in another (throat located in a sector on the forenoon side in juxtaposition to the region of strong convection on the afternoon side); and (3) fine-structure FACs are responsible for the generation of ULF-ELF noise in the polar cusp.

  5. Multi-point Magnetic Field Observations of Field-Aligned Currents from Swarm Constellation Mission

    NASA Astrophysics Data System (ADS)

    Le, Guan; Chi, Peter; Lühr, Hermann; Gjerloev, Jesper; Stolle, Claudia; Park, Jaeheung; Rauberg, Jan

    2015-04-01

    In this paper, we report the results of case studies of multi-point magnetic field measurements of field-aligned currents (FACs) from Swarm constellation mission to understand their temporal characteristics and hemispheric asymmetry. For science operations (since April, 2014), the three spacecraft were placed in slightly different polar orbits: Swarm B spacecraft in a higher altitude orbit (507km x 512km) and Swarm A and C side-by-side in lower altitude orbits (459km x 462km). In the beginning of the science operational phase, the longitudinal separations of the orbital planes were small, and Swarm A/C pair and Swarm B were nearly out of phase in the orbit. This unique orbit configuration provides opportunities to study some new features of FACs. Specifically, the Swarm satellites make multiple crossings of a FAC region within a few hours. Such data enable us to study temporal variations in several time scales, from 1 minute up to about 3 hours. Furthermore, the three satellites make nearly simultaneous observations of FACs in northern and southern hemispheres, which provide us an opportunity to study the hemispheric asymmetry.

  6. The Four-Part Field-Aligned Current System in the Ionosphere at Substorm Onset

    NASA Astrophysics Data System (ADS)

    McWilliams, K. A.; Sofko, G. J.; Bristow, W. A.; Hussey, G. C.

    2015-12-01

    Whereas the plasma circulation in the ionosphere is driven by convective drift which is the same for ions and electrons, the magnetospheric plasma circulation includes curvature and gradient drifts, which are charge-dependent. There is even a region of the Neutral Sheet in which the ions, but not the electrons, are "unmagnetized" and where charge separation can occur even for convective drift, which the electrons execute but the ions do not. Due to the charge separations in the magnetosphere, field-aligned currents are generated. The FACs and the associated electric fields play an important role in producing the convection pattern in the ionosphere. Here we argue that there are two pairs of FACs near substorm onset. One pair involves the auroral zone portion of the convection. There, a downward D FAC occurs in the poleward part of the auroral zone and an upward U FAC occurs in the equatorward part. We show that the D-U auroral FAC pair results from the odd situation in the INSh, where the electrons can convect earthward while the unmagnetized ions do not and so remain further tailward of the electrons. The equatorward edge of the auroral zone is marked by a convection reversal, because the auroral zone flows have an eastward velocity component, whereas subauroral flows have a westward component. At the convection reversal, the flow is strictly southward and the electric field strictly westward. The subauroral zone maps out to the outer radiation belt, where the high-energy electrons precipitate tailward of the energetic electron trapping boundary,and high-energy ions precipitate tailward of the energetic ion trapping boundary, the latter being earthward of the former. As a result, another FAC pair forms on field lines in the ORB/subauroral regions. The U FAC of the latter region is adjacent but earthward of the U FAC of the auroral zone pair. The D-U auroral zone pair is poleward of the U-D subauroral (Radiation Belt) pair. Finally, we note that the electric field

  7. ST5 Observations of the Imbalance of Region 1 and 2 Field-Aligned Currents and its Implication to Ionospheric Closure Currents

    NASA Technical Reports Server (NTRS)

    Le, G.

    2008-01-01

    A major unsolved question in the physics of ionosphere-magnetosphere coupling is how field-aligned currents (FACs) close. In order to maintain the divergence free condition, overall downward FACs (carried mainly by upward electrons) must eventually balance the overall upward FACs associated with the precipitating electrons through ionospheric Pedersen currents. Although much of the current closure may take place via local Pedersen currents flowing between Region 1 (R1) and Region 2 (R2) FACs, there is a generally an imbalance, i.e., more currents in R1 than in R2, in total currents between them. The net currents may be closed within R1 via cross-polar cap Pedersen currents. In this study, we use the magnetic field observations from Space Technology 5 mission to quantify the imbalance of R1 and R2 currents. We will determine the net R1-R2 currents under various solar wind conditions and discuss the implication of such imbalance to the ionospheric closure currents.

  8. Field-Aligned Current Reconfiguration and Magnetospheric Response to an Impulse in the Interplanetary Magnetic Field BY Component

    NASA Astrophysics Data System (ADS)

    Wilder, F. D.; Eriksson, S.; Korth, H.; Hairston, M. R.; Baker, J. B.; Heinselman, C. J.

    2013-12-01

    When the interplanetary magnetic field (IMF) is dawnward or duskward, magnetic merging between the IMF and the geomagnetic field occurs near the cusp on the dayside flanks of the magnetosphere. During these intervals, flow channels in the ionosphere with velocities in excess of 2 km/s have been observed, which can deposit large amounts of energy into the high-latitude thermosphere. In this study, we analyze an interval on 5 April 2010 where there was a strong dawnward impulse in the IMF, followed by a gradual decay in IMF magnitude at constant clock angle. Data from the Sondrestrom incoherent scatter radar and the DMSP spacecraft were used to investigate ionospheric convection during this interval, and data from the Active Magnetospheric and Planetary Electrodynamics Response Experiment (AMPERE) were used to investigate the associated Field-Aligned Current (FAC) system. Additionally, data from AMPERE were used to investigate the time response of the dawn-side FAC pair. We find there is a delay of approximately 1.25 hours between the arrival of the dawnward IMF impulse at the magnetopause and strength of the dawnward FAC pair, which is comparable to substorm growth and expansion time scales under southward IMF. Additionally, we find at the time of the peak FAC, there is evidence of a reconfiguring four-sheet FAC system in the morning local time sector of the ionosphere. Additionally, we find an inverse correlation between the dawn FAC strength and both the solar wind Alfvénic Mach number and the SYM-H index. No statistically significant correlation between the FAC strength and the solar wind dynamic pressure was found.

  9. Field-aligned current reconfiguration and magnetospheric response to an impulse in the interplanetary magnetic field BY component

    NASA Astrophysics Data System (ADS)

    Wilder, F. D.; Eriksson, S.; Korth, H.; Baker, J. B. H.; Hairston, M. R.; Heinselman, C.; Anderson, B. J.

    2013-06-01

    the interplanetary magnetic field (IMF) is dawnward or duskward, magnetic merging between the IMF and the geomagnetic field occurs near the cusp on the dayside flanks of the magnetosphere. During these intervals, flow channels in the ionosphere with velocities in excess of 2 km/s have been observed, which can deposit large amounts of energy into the high-latitude thermosphere. In this study, we analyze an interval on 5 April 2010 where there was a strong dawnward impulse in the IMF, followed by a gradual decay in IMF magnitude at constant clock angle. Data from the Sondrestrom incoherent scatter radar and the Defense Meteorological Satellite Program spacecraft were used to investigate ionospheric convection during this interval, and data from the Active Magnetospheric and Planetary Electrodynamics Response Experiment (AMPERE) were used to investigate the associated Field-Aligned Current (FAC) system. Additionally, data from AMPERE were used to investigate the time response of the dawnside FAC pair. We find there is a delay of approximately 1.25 h between the arrival of the dawnward IMF impulse at the magnetopause and strength of the dawnward FAC pair, which is comparable to substorm growth and expansion time scales under southward IMF. Additionally, we find at the time of the peak FAC, there is evidence of a reconfiguring four-sheet FAC system in the morning local time sector of the ionosphere. Additionally, we find an inverse correlation between the dawn FAC strength and both the solar wind Alfvénic Mach number and the SYM-H index. No statistically significant correlation between the FAC strength and the solar wind dynamic pressure was found.

  10. Field-aligned Currents Induced by Electrostatic Polarization at the Ionosphere: Application to the Poleward Boundary Intensification (PBI) of Auroral Emission

    NASA Astrophysics Data System (ADS)

    Ohtani, S.; Yoshikawa, A.

    2016-12-01

    Although the field-aligned currents (Birkeland currents) are generally considered to be driven by magnetospheric processes, it is possible that some field-aligned currents are locally induced in the ionosphere in the presence of sharp conductance gradient. In this presentation we shall discuss the poleward boundary intensification (PBI) of auroral emission as an example effect of such electrostatic polarization. The observations show that the PBIs are very often preceded by the fast polar cap convection approaching the nightside auroral oval. We propose that the ionospheric currents driven by the associated electric field diverges/converges at the poleward boundary of the auroral oval as the background ionospheric conductance changes sharply in space, and they close with field-aligned currents. The associated upward field-aligned current is accompanied by electron precipitation, which may cause auroral emission as observed as PBIs. We test this idea by modeling the ionosphere as a slab-shaped enhancement of conductance and the polar cap flow channel as a pair of upward and downward FACs. The results show that (i) a pair of upward and downward FACs is induced at the poleward boundary when the front of the polar cap flow channel approaches the auroral oval; (ii) the upward FAC extends westward much wider in longitude than the flow channel; (iii) the peak FAC density is significantly larger than the incident FAC; and (iv) the induced upward and downward FACs are distributed almost symmetrically in longitude, indicating that the Pedersen polarization dominates the Hall polarization. These results are consistent with some general characteristics of PBIs, which are rather difficult to explain if the PBIs are the ionospheric manefestation of distant reconnection as often suggested.

  11. Alfven Wave - DC Dualism in Description of Stationary Field-Aligned Currents

    NASA Technical Reports Server (NTRS)

    Khazanov, George V.

    2009-01-01

    In many cases, the field-aligned currents (FACs) in the Earth's magnetosphere and heliosphere may be described in terms of both DC currents and the currents of a propagating Alfven wave. The simplest example is when a propagating Alfven wave transports a potential hop along the magnetic fieid: between the source of the wave and its front, the problem is well stationary and includes the stationary field-aligned currents, transporting the electric charges along the magnetic field, which may be described as a DC problem, and only at the front of the wave there are the polarization (inertial) currents, closing across the magnetic field. In some cases, the Alfven wave approach brings better understanding to many problems. We will consider here the results of the applications of this approach to two long-staying problems: the effect of saturation of the transpolar voltage in the Earth's magnetosphere, and the experimentally-observed existence of the strong field-aligned currents in the subtle Mercury's magnetosphere which is not able tc close the measured field-aligned currents.

  12. Alfven Wave - DC Dualism in Description of Stationary Field-Aligned Currents

    NASA Technical Reports Server (NTRS)

    Khazanov, George V.

    2009-01-01

    In many cases, the field-aligned currents (FACs) in the Earth's magnetosphere and heliosphere may be described in terms of both DC currents and the currents of a propagating Alfven wave. The simplest example is when a propagating Alfven wave transports a potential hop along the magnetic fieid: between the source of the wave and its front, the problem is well stationary and includes the stationary field-aligned currents, transporting the electric charges along the magnetic field, which may be described as a DC problem, and only at the front of the wave there are the polarization (inertial) currents, closing across the magnetic field. In some cases, the Alfven wave approach brings better understanding to many problems. We will consider here the results of the applications of this approach to two long-staying problems: the effect of saturation of the transpolar voltage in the Earth's magnetosphere, and the experimentally-observed existence of the strong field-aligned currents in the subtle Mercury's magnetosphere which is not able tc close the measured field-aligned currents.

  13. Alfvenic Generation of Field-Aligned Currents and Displacement Currents in the M-I Coupling System and the Formation of Discrete Auroral Arcs

    NASA Astrophysics Data System (ADS)

    Song, Y.; Lysak, R. L.

    2016-12-01

    In previous theories (e.g., Hasegawa and Sato, 1979; Sato and Iijima, 1979; Vasyliunas, 1984), field-aligned current (FAC) generation is derived from current continuity assumption plus the force balance between the Lorentz force and other forces in the MHD momentum equation. These theories suggest that the FAC is generated by other forces, such as the inertia and/or pressure gradients. In fact, the FAC cannot be generated by these forces. From Maxwell's equations, FAC generation is associated with enhanced sheared magnetic fields and free magnetic energy where a dynamo action and Alfven waves are needed to generate and transport free magnetic energy. It is obvious that the mechanism of FAC generation cannot be given by analyzing a local force balance. We propose that FACs are generated by Alfvenic interactions in the M-I coupling driven system. From a full set of the dynamical equations, we have found that the generation of the total FAC (J||total ) is associated with spatial gradients of the parallel vorticity, where J||total=J||+J||D, and J||D=(1/4∏)(∂E||/∂t) is the displacement current, which describes E|| generation (Song and Lysak, 2006). The J||total generation is a dynamo process associated with the increase of the azimuthal magnetic flux caused by the axial torque acting on FAC flux tubes. Although the magnitude of the J||D is often very small relative to J||, neglecting this term, we cannot find the mechanism of the E|| generation. When the plasma density is low J||D becomes important relative to the current. We will demonstrate how the generation of E|| and the formation of auroral arcs can redistribute perpendicular mechanical and magnetic stresses which can cause a sudden and violent tail energy release and enhance the total FAC leading to the substorm auroral poleward expansion. We will also show how the nonlinear interaction of incident and reflected Alfven wave packets in the auroral acceleration region can produce quasi-stationary non

  14. Mesoscale Magnetosphere-Ionosphere Coupling along Open Magnetic Field Lines Associated with Airglow Patches: Field-aligned Currents and Precipitation

    NASA Astrophysics Data System (ADS)

    Zou, Y.; Nishimura, Y.; Lyons, L. R.; Shiokawa, K.; Burchill, J. K.; Knudsen, D. J.; Buchert, S. C.; Chen, S.; Nicolls, M. J.; Ruohoniemi, J. M.; McWilliams, K. A.; Nishitani, N.

    2016-12-01

    Although airglow patches are traditionally regarded as high-density plasma unrelated to local field-aligned currents (FACs) and precipitation, past observations were limited to storm-time conditions. Recent non-storm time observations show patches to be associated with azimuthally narrow ionospheric fast flow channels that substantially contribute to plasma transportation across the polar cap and connect dayside and nightside explosive disturbances. We examine whether non-storm time patches are related also to localized polar cap FACs and precipitation using Swarm- and FAST-imager-radar conjunctions. In Swarm data, we commonly (66%) identify substantial magnetic perturbations indicating FAC enhancements around patches. These FACs have substantial densities (0.1-0.2 μA/m-2) and can be approximated as infinite current sheets (typically 75 km wide) orientated roughly parallel to patches. They usually exhibit a Region-1 sense, i.e. a downward FAC lying eastward of an upward FAC, and can close through Pedersen currents in the ionosphere, implying that the locally enhanced dawn-dusk electric field across the patch is imposed by processes in the magnetosphere. In FAST data, we identify localized precipitation that is enhanced within patches in comparison to weak polar rain outside patches. The precipitation consists of structured or diffuse soft electron fluxes. While the latter resembles polar rain only with higher fluxes, the former consists of discrete fluxes enhanced by 1-2 orders of magnitude from several to several hundred eV. Although the precipitation is not a major contributor to patch ionization, it implies that newly reconnected flux tubes that retain electrons of magnetosheath origin can rapidly traverse the polar cap from the dayside. Therefore non-storm time patches should be regarded as part of a localized magnetosphere-ionosphere coupling system along open magnetic field lines, and their transpolar evolution as a reflection of reconnected flux tubes

  15. Relation of field-aligned currents measured by AMPERE project to solar wind and substorms

    NASA Astrophysics Data System (ADS)

    McPherron, R. L.; Anderson, B. J.; Chu, X.

    2016-12-01

    Magnetic perturbations measured in the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) by the Iridium constellation of spacecraft have been processed to obtain the time history of field-aligned currents (FAC) connecting the magnetosphere to the ionosphere. We find that the strength of these currents is closely related to the strength of the solar wind driver defined as a running average of the previous three hours of the optimum AL (auroral lower) coupling function. The relation is well represented by a saturation model I = A*S*Ss/(S+Ss) with I the current strength in mega Amps, S the driver strength in mV/m, Ss the saturation value of 7.78 mV/m, and A = 2.55 scales the relation to units of current. We also find that in general the upward current on the nightside increases with each substorm expansion onset defined by a combination of the SuperMag SML (SuperMag AL) and midlatitude positive bay (MPB) onset lists. A superposed epoch analysis using 700 onsets in 2010 shows the following: solar wind coupling peaks at expansion onset; dayside outward current starts to increase one hour before onset while nightside outward current starts suddenly at onset; nightside outward current reaches a peak at 28 minutes as do SML and MPB indices; FAC, SML, and MPB respectively take 1, 2, and 3 hours to decay to background. The data indicate that the substorm current wedge is superposed on a pre-existing field-aligned current system and that the location and properties of the current wedge can be studied with the AMPERE data.

  16. Contribution of Field-Aligned Currents to the Variations of Mid-Latitude Magnetic Field on the Ground: Dayside and Nightside are Compared.

    NASA Astrophysics Data System (ADS)

    Dubyagin, S.; Ganushkina, N. Y.

    2015-12-01

    Field-aligned currents (FACs) are believed to be the main contributors to the asymmetric variation of the magnetic field on the ground at mid-latitudes during geomagnetic storms. However, the contribution from the ionospheric currents can interfere with that from FACs on the dayside where ionospheric conductivity is higher and not concentrated along the auroral oval. We present the results of the comparison of the contribution from the large-scale FAC system with the observations at the mid-latitude observatories during 12 geomagnetic storms. The contribution from the FAC system is estimated using the 10 min resolution data of AMPERE system which provides 2D map of the FAC flowing in and out of the ionosphere reconstructed from the measurements onboard of ~70 Irridium satellites . To estimate the magnetic effect of FAC system, we performed Biot-Savart integration of these currents along IGRF field from the equator to the earth center. Although in reality the FACs close via ionosphere, we generally obtain a good quantitative agreement with observations at the ground observatories on the nighside. On the other hand the agreement is much worse on the dayside. The correlation coefficient between the D-component of the magnetic field measured on the ground and that computed using Biot-Savart integration varies between ~0.65 (21-03h MLT) and < 0.1 (12-18h MLT). In addition, we discuss the closure paths of the large scale FACs during storm periods and the sources of the north-south asymmetry of the ground magnetic field at mid-latitudes.

  17. A comparison of small-scale magnetic fluctuations in the Region 1 and 2 field-aligned current systems

    NASA Astrophysics Data System (ADS)

    Wu, J.; Bryant, M. S.; Ridley, C. G.; Shen, Y.; Yang, L.; Clausen, L. B. N.; McWilliams, K. A.; Murphy, K. R.; Mann, I. R.; Ozeke, L. G.; Korth, H.; Anderson, B. J.; Waters, C. L.

    2017-03-01

    By determining the location and size of the Region 1 (R1) and Region 2 (R2) large-scale field-aligned currents (FACs) from Active Magnetosphere and Planetary Electrodynamics Response Experiment data, we are able to study the small-scale magnetic fluctuations observed by the Swarm satellites embedded within the large-scale FACs. A statistical comparison of R1 and R2 high-frequency fluctuations is presented in terms of different solar wind conditions and geomagnetic activities. We find that (1) the amplitude of high-frequency fluctuations in both R1 and R2 increases as the large-scale R1 and R2 FACs intensify; (2) high-frequency fluctuations in R1 peak near dayside dawn and dusk, while those in R2 peak around noon; (3) the location of the largest high-frequency fluctuations in R1 shifts in local time in response to IMF By, indicating a connection between the R1 fluctuation and the driving solar wind most likely explained by magnetic reconnection; and (4) high-frequency fluctuations in R2 are enhanced in a small region near local noon and respond clearly to nightside drivers, as characterized by the auroral electrojet index. Our analysis shows that the intensity of R1 and R2 high-frequency magnetic fluctuations is directly connected to the intensity of FACs, which implies that the magnetic fluctuations are closely related to the magnetospheric processes that drive them.

  18. Polar cap field-aligned currents for southward interplanetary magnetic fields

    SciTech Connect

    Xu, D.; Kivelson, M.G.

    1994-04-01

    It has been common to suppose that polar region field-aligned currents for southward interplanetary magnetic fields (IMF) consist of two parts: region 1 and region 2 currents. It is often suggested that both of these current systems flow on closed field lines. In this pilot study the limited data available from the ISIS 2 satellite are used to examine region 1 currents with the objective of establishing whether or not they can exist partially on open field lines (i.e., inside the polar caps) for southward IMF. Magnetic field perturbations were used to identify the field-aligned currents (FACs). The absence of {ge}keV electrons but the presence of {le}200 eV electrons in the polar cap or background polar rain is considered as the signature of open field lines. On some passes, region 1 sense FACs appear to be composed of two parts. The poleward part of the current signature is accompanied by electron fluxes at energies {le}200 eV or occasionally by fluxes at background levels while the equatorward part of the interval is accompanied by electron fluxes at energies both {le}200 eV and {ge}keV. On other passes, region 1 sense currents are accompanied by both {le}200 eV and {ge}keV electron fluxes during the entire pass. The authors propose that region 1 sense FACs flow on both closed and open field lines for the first situation and on closed field lines for the second situation. In seeking to understand why region 1 currents sometimes flow only on closed field lines and sometimes flow on open as well as closed field lines, the authors suggest a control by the IMF B{sub y}. The IMF B{sub y} may also shift the region 1 currents on open field lines to one side (dawn or dusk) of the polar cap like the convection cells. Such a shift provides a consistent model of the data taken on the dayside and the authors discuss why night side observations may be different. 47 refs., 6 figs., 1 tab.

  19. A Science Mission for QSAT Project: Study of FACs in the Polar and Equatorial Regions

    NASA Astrophysics Data System (ADS)

    Fujimoto, Akiko; Ueno, Tamiki; Yumoto, Kiyohumi

    2009-04-01

    Kyushu University, Kyushu Institute of Technology and Fukuoka Institute of Technology are now designing, developing and building a micro-satellite called “QSAT”. The primary objective of QSAT is understanding the mechanism of spacecraft charging, which can be achieved with the onboard magnetometer, high-frequency probe (HP) and Langmuir probe (LP). The magnetometer measures the magnetic field variations caused by field-aligned currents (FACs) in the polar and equatorial regions. Polar FACs are well understood, while equatorial FACs are not. The science goals are as follows: (1) to better understand FACs in the polar region, (2) to compare the FACs observed in orbit with ground-based MAGDAS observations, (3) to investigate spatial distribution of FACs in the equatorial region. FACs play a crucial role in the coupling between solar wind, magnetosphere and ionosphere in terms of energy transfer. Also if we understand the relationship between the space and ground-based FACs data, then we can conduct long-term study on the solar wind-magnetosphere-ionosphere coupling in the future by mainly using data from ground-based magnetometer arrays.

  20. Sources of field-aligned currents in the auroral plasma

    SciTech Connect

    Marshall, J.A.; Burch, J.L. ); Kan, J.R. ); Reiff, P.H. ); Slavin, J.A. )

    1991-01-01

    Data from the Dynamics Explorer 1 High Altitude Plasma Instrument (HAPI) and magnetometer are used to investigate the sources of field-aligned currents in the nightside auroral zone. It is found that the formula developed by S. Knight predicts the field-aligned current density fairly accurately in regions where a significant potential drop can be inferred from the HAPI data; there are, however, regions in which the proportionality between potential drop and field-aligned current does not hold. In particular, the authors note occurrences of strong upward field-aligned current associated not with inverted-V events but instead with suprathermal bursts. In addition, upward field-aligned currents are often observed to peak near the edges of inverted-V events, rather than in the center as would be predicted by Knight.

  1. Sources of field-aligned currents in the auroral plasma

    NASA Astrophysics Data System (ADS)

    Marshall, J. A.; Burch, J. L.; Kan, J. R.; Reiff, P. H.; Slavin, J. A.

    1991-01-01

    Data from the Dynamics Explorer 1 High Altitude Plasma Instrument (HAPI) and magnetometer are used to investigate the sources of field-aligned currents in the nightside auroral zone. It is found that the formula developed by S. Knight predicts the field-aligned current density fairly accurately in regions where a significant potential drop can be inferred from the HAPI data; there are, however, regions in which the proportionality between potential drop and field-aligned current does not hold. In particular, occurrences of strong upward field-aligned current associated not with inverted-V events but instead with suprathermal bursts are noted. In addition, upward field-aligned currents are often observed to peak near the edges of inverted-V events, rather than in the center as would be predicted by Knight.

  2. Business-IT Alignment: A Current-State Evaluation of Strategic Alignment within the Hospital Organization

    ERIC Educational Resources Information Center

    Evers, Kevin W.

    2010-01-01

    More than thirty years of research has shown that the practical value of business-IT alignment is significant and that its importance derives from strategic impact on business outcomes. The purpose of this exploratory study is to identify the current-state of business-IT alignment maturity within the hospital organization. Data for this study was…

  3. Business-IT Alignment: A Current-State Evaluation of Strategic Alignment within the Hospital Organization

    ERIC Educational Resources Information Center

    Evers, Kevin W.

    2010-01-01

    More than thirty years of research has shown that the practical value of business-IT alignment is significant and that its importance derives from strategic impact on business outcomes. The purpose of this exploratory study is to identify the current-state of business-IT alignment maturity within the hospital organization. Data for this study was…

  4. Field aligned current observations in the polar cusp ionosphere

    NASA Technical Reports Server (NTRS)

    Ledley, B. G.; Farthing, W. H.

    1973-01-01

    Vector magnetic field measurements made during a sounding rocket flight in the polar cusp ionosphere show field fluctuations in the lower F-region which are interpreted as being caused by the payload's passage through a structured field aligned current system. The field aligned currents have a characteristic horizontal scale size of one kilometer. Analysis of one large field fluctuation gives a current density of 0.0001 amp/m sq.

  5. Field-aligned currents and large scale magnetospheric electric fields

    NASA Technical Reports Server (NTRS)

    Dangelo, N.

    1980-01-01

    D'Angelo's model of polar cap electric fields (1977) was used to visualize how high-latitude field-aligned currents are driven by the solar wind generator. The region 1 and region 2 currents of Iijima and Potemra (1976) and the cusp field-aligned currents of Wilhjelm et al. (1978) and McDiarmid et al. (1978) are apparently driven by different generators, although in both cases the solar wind is their ultimate source.

  6. The Poleward Boundary Intensification (PBI) of Auroral Emission: Its Dynamics and Associated Field-aligned Current System

    NASA Astrophysics Data System (ADS)

    Ohtani, S.; Motoba, T.; Gjerloev, J. W.

    2016-12-01

    The poleward boundary intensification (PBI) of aurora emission is often addressed in terms of distant reconnection. Recently, however, Ohtani and Yoshikawa [2016] proposed that the PBIs, at least at the initial stage of their formation, are actually the effect of ionospheric polarization in the presence of the enhanced convection in the polar cap and conductance gradient at the poleward boundary of the auroral oval. Whereas the ionospheric polarization itself is a transient process, it is known that the PBIs occasionally extend longitudinally suggesting that a 3D current system forms subsequently, which electrodynamically couples the magnetosphere and ionosphere. In the present study we observationally examine the associated field-aligned current (FAC) observed by the SWARM satellites and compare its characteristics with ground all-sky images. It is found that complex signatures of FACs as suggested by magnetic disturbances reflect the spatial structure of aurora (e.g., location and orientation), whereas the overall motion of PBIs is well explained in terms of the background convection suggested by the FAC distribution. We shall discuss the implications of these results for the responsible evolution process of the PBIs.

  7. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2017-04-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org. Copyright © 2017. Published by Elsevier Inc.

  8. PC-FACS.

    PubMed

    Davis, Mellar P

    2017-07-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org. Copyright © 2017. Published by Elsevier Inc.

  9. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2016-11-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org. Copyright © 2016. Published by Elsevier Inc.

  10. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2016-07-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org. Copyright © 2016. Published by Elsevier Inc.

  11. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2016-10-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org. Copyright © 2016. Published by Elsevier Inc.

  12. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2017-05-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org. Copyright © 2017. Published by Elsevier Inc.

  13. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2016-12-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org. Copyright © 2016. Published by Elsevier Inc.

  14. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2017-03-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org. Copyright © 2017. Published by Elsevier Inc.

  15. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2017-02-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org. Copyright © 2016. Published by Elsevier Inc.

  16. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2016-06-01

    PC-FACS(FastArticleCriticalSummaries for Clinicians inPalliativeCare) provides hospice and palliative care clinicians with concise summaries of the most important findings from more than 100 medical and scientific journals. If you have colleagues who would benefit from receiving PC-FACS, please encourage them to join the AAHPM at aahpm.org. Comments from readers are welcomed at pc-facs@aahpm.org. Copyright © 2016. Published by Elsevier Inc.

  17. Detecting Field-Aligned Current Signatures Using MAVEN Observations

    NASA Astrophysics Data System (ADS)

    Hanley, K.; Brain, D.; Weber, T. D.

    2016-12-01

    Currents aligned with magnetic field lines have been observed on multiple planets, including Mars, Mercury, Earth, Saturn, and Jupiter. As documented by Mars Global Surveyor, field-aligned currents occur at Mars near regions of moderate or strong crustal magnetic fields. These currents, identified by the magnetic field perturbations they cause, indicate the acceleration of charged particles toward the Martian atmosphere, which may result in atmospheric heating, ionization, and discrete aurora observed at ultraviolet wavelengths. It is likely that charged particles are removed from the atmosphere via these currents in magnetic cusp regions. At present, the locations and conditions for which field-aligned current systems can occur at Mars are not well understood. We use magnetic field measurements collected by MAVEN between December 2014 and September 2015 to investigate the incidence of low-altitude field-aligned currents on the nightside of the planet in regions of strong crustal fields. These currents have been found to cause perturbations in the magnetic field at magnitudes of 5 nT. We have automated the detection process in order to facilitate future study of field-aligned currents using MAVEN data. First, low-frequency signals caused by spacecraft motion are removed from the data, revealing short-term (1-5 seconds) perturbations. The disturbances due to field-aligned currents are recorded by finding areas where the filtered data exceeds a threshold value for multiple seconds. Current events are then mapped to the planet's surface. We report on the geographic distribution of field-aligned current signatures, as well as their distributions with respect to local time.

  18. Alfvénic field-aligned currents, ion upflow and electron precipitation during large geomagnetic storms

    NASA Astrophysics Data System (ADS)

    Hatch, Spencer; LaBelle, James; Chaston, Christopher

    2016-04-01

    We present four years of FAST observations of Alfvénic field-aligned currents (FACs) in the Northern Hemisphere coincident with 40 moderate (Dst < -50 nT) to very large geomagnetic storms. Superposed epoch analysis of Alfvénic activity of storm periods demonstrate a sharp increase in the probability of AlfvÉn wave occurrence just after storm commencement, and analysis based on storm phase shows that the probability of Alfvén wave occurrence increases by more than a factor of 5 on both dayside and nightside. Additionally, recently reported Van Allen Probes measurements in the magnetosphere imply a region (˜60-68 degrees invariant latitude) in the nightside ionosphere where Alfvén waves are statistically likely to be observed during storm main phase; we report statistical observations during main phase showing that this region instead corresponds to both intense electron precipitation (>10 mW m-2) and strong upflowing ion number flux (> 108 cm^{-2 s-1), while observed Alfvénic FAC occurrence rates are diminished relative to Van Allen Probes measurements. FAST observations also indicate that the most intense electron precipitation associated with Alfvénic FACs occurs pre-midnight during storm recovery phase.

  19. Quasiperiodic field-aligned current dynamics associated with auroral undulations during a substorm recovery

    NASA Astrophysics Data System (ADS)

    Bunescu, C.; Marghitu, O.; Vogt, J.; Constantinescu, D.; Partamies, N.

    2017-03-01

    A substorm recovery event in the early morning sector is explored by means of ground and spacecraft data. The ground data are provided by stations of the MIRACLE network, in northern Scandinavia and Svalbard, while spacecraft data are observed by the Cluster satellites, toward the end of the recovery phase. Additional information is provided by the Fast Auroral SnapshoT (FAST) satellite, conjugate to Cluster 3 (C3). A prominent signature in the Cluster data is the low-frequency oscillations of the perturbation magnetic field, in the Pc5 range, interpreted in terms of a motion of quasi-stationary mesoscale field-aligned currents (FACs). Ground magnetic pulsations in the Ps6 range suggest that the Cluster observations are the high-altitude counterpart of the drifting auroral undulations, whose features thus can be explored closely. While multiscale minimum variance analysis provides information on the planarity, orientation, and scale of the FAC structures, the conjugate data from FAST and from the ground stations can be used to resolve also the azimuthal motion. A noteworthy feature of this event, revealed by the Cluster observations, is the apparent relaxation of the twisted magnetic flux tubes, from a sequence of 2-D current filaments to an undulated current sheet, on a timescale of about 10 min. This timescale appears to be consistent with the drift mirror instability in the inner magnetosphere, mapping to the equatorward side of the oval, or the Kelvin-Helmholtz instability related to bursty bulk flows farther downtail, mapping to the poleward side of the oval. However, more work is needed and a better event statistics, to confirm these tentative mechanisms as sources of Ω-like auroral undulations during late substorm recovery.

  20. Simultaneous particle and field observations of field-aligned currents

    NASA Technical Reports Server (NTRS)

    Berko, F. W.; Hoffman, R. A.; Burton, R. K.; Holzer, R. E.

    1973-01-01

    Simultaneous measurements of low energy precipitating electrons and magnetic fluctuations from the low altitude polar orbiting satellite OGO-4 have been compared. Analysis of the two sets of experimental data for isolated events led to the classification of high latitude field-aligned currents as purely temporal or purely spatial variations. Magnetic field disturbances calculated using these simple current models and the measured particle fluxes were in good agreement with measured field values. While fluxes of greater than 1 keV electrons are detected primarily on the nightside, magnetometer disturbances indicative of field-aligned currents were seen at all local times, both in the visual auroral regions and dayside polar cusp. Thus electrons with energies less than approximately 1 keV are the prime charge carriers in high latitude dayside field-aligned currents. The satellite measurements are in good agreement with previously measured field-aligned current values and with values predicted from several models involving magnetospheric field-aligned currents.

  1. Changes in Magnetosphere-Ionosphere Coupling and FACs Associated with Substorm Onset (Invited)

    NASA Astrophysics Data System (ADS)

    Murphy, K. R.; Mann, I. R.; Rae, I. J.; Waters, C. L.; Anderson, B. J.; Korth, H.; Milling, D. K.; Singer, H. J.; Frey, H. U.

    2013-12-01

    Field aligned currents (FACs) are crucial for the communication of information between the ionosphere and magnetosphere. Utilising in-situ observations from the Iridium constellation and Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) we provide detailed observations of the FAC topology through the substorm growth and expansion phases. In particular, for an isolated substorm on 16 February 2010 we demonstrate a clear and localized reduction in the FACs at least 6 minutes prior to auroral onset. A new auroral arc forms in the region of reduced FAC on closed field lines and initially expands azimuthally in wave like fashion. This newly formed arc continues to brighten and expands poleward signifying the start of the substorm expansion phase. We argue that the change in FACs observed prior to onset is the result of a change in the magnetosphere-ionosphere (M-I) coupling in a region local to the subsequent auroral onset. Such a change implies an important role for M-I coupling in destabilising the near-Earth tail during magnetospheric substorms and perhaps more importantly in selecting the location in the ionosphere where auroral onset begins. Further, we provide, a comprehensive in-situ two-dimensional view of the FAC topology associated with the substorm current wedge and westward traveling surge during the substorm expansion phase. We demonstrate that these current structures, when integrated with latitude to produce a net FAC as a function of MLT, have the same structure as the equivalent line current system comprising the SCW. Moreover, regions of upward FAC are associated with discrete auroral forms during the substorm expansion phase.

  2. Simultaneous prenoon and postnoon observations of three field-aligned current systems from Viking and DMSP-F7

    NASA Technical Reports Server (NTRS)

    Ohtani, S.; Potemra, T. A.; Newell, P. T.; Zanetti, L. J.; Iijima, T.; Watanabe, M.; Yamauchi, M.; Elphinstone, R. D.; De La Beauijardie, O.; Blomberg, L. G.

    1995-01-01

    The spatial structure of dayside large-scale field-aligned current (FAC) systems is examined by using Viking and Defense Meteorological Satellite Program-F7 (DMSP-F7) data. We focus on four events in which the satellites simultaneously observed postnoon and prenoon three FAC systems: the region 2, the region 1, and the mantle (referred to as midday region O) systems, from equatorward to poleward. These events provide the most solid evidence to date that the midday region O system is a separate and unique FAC system, and is not an extension of the region 1 system from other local times. The events are examined comprehensively by making use of a mulit-instrumental data set, which includes magnetic field, particle flux, electric field, auroral UV image data from the satellites, and the Sondrestrom convection data. The results are summarized as follows: (1) Region 2 currents flow mostly in the central plasma sheet (CPS) precipitation region, often overlapping with the boundary plasma sheet (BPD) at their poleward edge. (2) The region 1 system is located in the core part of the auroral oval and is confined in a relatively narrow range in latitude which includes the convection reversal. The low-latitude boundary layer, possibly including the outer part of the plasma sheet, and the external cusp are the major source regions of dayside region 1 currents. (2) Midday region O currents flow on open field lines and are collocated with the shear of antisunward convection flows with velocites decreasing poleward. On the basis of these results we support the view that both prenoon and postnoon current systems consist of the three-sheet structure when the disctortion ofthe convection pattern associated with interplanetary magnetic field (IMF) B(sub Y) is small and both morningside and eveningside convection cells are crescent-shaped. We also propose that the midday region O and a part of the region 1 systems are closely coupled to the same source.

  3. Simultaneous prenoon and postnoon observations of three field-aligned current systems from Viking and DMSP-F7

    NASA Technical Reports Server (NTRS)

    Ohtani, S.; Potemra, T. A.; Newell, P. T.; Zanetti, L. J.; Iijima, T.; Watanabe, M.; Yamauchi, M.; Elphinstone, R. D.; De La Beauijardie, O.; Blomberg, L. G.

    1995-01-01

    The spatial structure of dayside large-scale field-aligned current (FAC) systems is examined by using Viking and Defense Meteorological Satellite Program-F7 (DMSP-F7) data. We focus on four events in which the satellites simultaneously observed postnoon and prenoon three FAC systems: the region 2, the region 1, and the mantle (referred to as midday region O) systems, from equatorward to poleward. These events provide the most solid evidence to date that the midday region O system is a separate and unique FAC system, and is not an extension of the region 1 system from other local times. The events are examined comprehensively by making use of a mulit-instrumental data set, which includes magnetic field, particle flux, electric field, auroral UV image data from the satellites, and the Sondrestrom convection data. The results are summarized as follows: (1) Region 2 currents flow mostly in the central plasma sheet (CPS) precipitation region, often overlapping with the boundary plasma sheet (BPD) at their poleward edge. (2) The region 1 system is located in the core part of the auroral oval and is confined in a relatively narrow range in latitude which includes the convection reversal. The low-latitude boundary layer, possibly including the outer part of the plasma sheet, and the external cusp are the major source regions of dayside region 1 currents. (2) Midday region O currents flow on open field lines and are collocated with the shear of antisunward convection flows with velocites decreasing poleward. On the basis of these results we support the view that both prenoon and postnoon current systems consist of the three-sheet structure when the disctortion ofthe convection pattern associated with interplanetary magnetic field (IMF) B(sub Y) is small and both morningside and eveningside convection cells are crescent-shaped. We also propose that the midday region O and a part of the region 1 systems are closely coupled to the same source.

  4. Simultaneous prenoon and postnoon observations of three field-aligned current systems from Viking and DMSP-F7

    SciTech Connect

    Ohtani, S.; Potemra, A.; Newell, P.T.; Zanetti, L.J.; Iijima, T.; Watanbe, M.; Yamauchi, M.; Elphinstone, R.D.; Beaujardiere, O. de la; Blomberg, L.G.

    1995-01-01

    The spatial structure of dayside large-scale field-aligned current (FAC) systems is examined by using VIking and DMSP-F7 data. The authors focus on four events in which the satellite simultaneously observed postnoon and prenoon three FAC systems: the region 2, the region 1, and the mantle (referred to as midday region 0) systems, from equatorward to poleward. These events provide the most solid evidence to date that the midday region 0 system is a separate and unique FAC system, and is not an extension of the region 1 system from other local times. The events are examined comprehensively by making use of a multi-instrument data set, which includes magnetic field, particle flux, electric field, auroral UV image data from the satellites, and the Sondrestrom convection data. The results are summarized as follows: (1) Region 2 currents flow mostly in the CPS precipitation region, often overlapping with the BPS at their poleward edge. (2) The region 1 system is located in the core part of the auroral oval and is confined in a relatively narrow range in latitude which includes the convection reversal. The low-latitude boundary layer, possibly including the outer part of the plasma sheet, and the external cusp are the major source regions of dayside region 1 currents. (3) Midday region 0 currents flow on open field lines and are collocated with the shear of antisunward convection flows with velocities decreasing poleward. On the basis of these results the authors support the view that both prenoon and postnoon current systems consist of the three-sheet structure when the distortion of the convection pattern associated with interplanetary magnetic field (IMF) B{sub y} is small and both morningside and eveningside convection cells are crescent-shaped. They also propose that the midday region 0 and a part of the region 1 systems are closely coupled to the same source. 57 refs., 16 figs., 1 tab.

  5. Field-aligned currents and ionospheric electric fields

    NASA Technical Reports Server (NTRS)

    Yasuhara, F.; Akasofu, S.-I.

    1977-01-01

    It is shown that the observed distribution of the ionospheric electric field can be deduced from an equation combining Ohm's law with the current continuity equation by using the 'observed' distribution of field-aligned currents as the boundary condition for two models of the ionosphere. The first model has one conductive annular ring representing the quiet-time auroral precipitation belt; the second has two conductive annular rings that simulate the discrete and diffuse auroral regions. An analysis is performed to determine how well the electric-field distribution can be reproduced. The results indicate that the first model reproduces the Sq(p)-type distribution, the second model reproduces reasonably well a substorm-type potential and ionospheric current patterns together with the Harang discontinuity, and that the distribution of field-aligned currents is the same for both models.

  6. Generation of field-aligned current in the auroral zone

    NASA Technical Reports Server (NTRS)

    Okuda, Hideo

    1991-01-01

    Generation of a magnetic field-aligned current in the auroral zone connecting the magnetospheric and ionospheric plasmas has been studied by means of a three dimensional particle simulation model. The model is of a magnetostatic variety appropriate for a low beta plasma in which the high frequency transverse displacement current has been eliminated. The simulation model is highly elongated along the magnetic field lines in order to model a highly elongated flux tube in the auroral zone. An enhanced field-aligned current was generated by injection of a magnetospheric plasma across the auroral zone magnetic field at the center of the model. Such a plasma injection may correspond to a plasmoid injection at the geomagnetic tail associated with magnetic reconnection during a substorm or a transverse plasma flow along the low latitude magnetopause boundary layer. The results of the simulations show that the field-aligned current can be enhanced over the thermal current by a factor of 5 - 10 via such injection. Associated with the enhanced current are the electrostatic ion cyclotron waves and shear Alfven waves excited in the auroral zone.

  7. Net field-aligned currents observed by Triad

    NASA Technical Reports Server (NTRS)

    Sugiura, M.; Potemra, T. A.

    1975-01-01

    From the Triad magnetometer observation of a step-like level shift in the east-west component of the magnetic field at 800 km altitude, the existence of a net current flowing into or away from the ionosphere in a current layer was inferred. The current direction is toward the ionosphere on the morning side and away from it on the afternoon side. The field aligned currents observed by Triad are considered as being an important element in the electro-dynamical coupling between the distant magnetosphere and the ionosphere. The current density integrated over the thickness of the layer increases with increasing magnetic activity, but the relation between the current density and Kp in individual cases is not a simple linear relation. An extrapolation of the statistical relation to Kp = 0 indicates existence of a sheet current of order 0.1 amp/m even at extremely quiet times. During periods of higher magnetic activity an integrated current of approximately 1 amp/m and average current density of order 0.000001 amp/sq m are observed. The location and the latitudinal width of the field aligned current layer carrying the net current very roughly agree with those of the region of high electron intensities in the trapping boundary.

  8. A New DMSP Magnetometer & Auroral Boundary Dataset and Estimates of Field Aligned Currents in Dynamic Auroral Boundary Coordinates.

    PubMed

    Kilcommons, Liam M; Redmon, Robert J; Knipp, Delores J

    2017-08-01

    We have developed a method for reprocessing the multi-decadal, multi-spacecraft Defense Meteorological Satellite Program Magnetometer (DMSP SSM) dataset and have applied it to fifteen spacecraft-years of data (DMSP Flight 16-18, 2010-2014). This Level-2 dataset improves on other available SSM datasets with recalculated spacecraft locations and magnetic perturbations, artifact signal removal, representations of the observations in geomagnetic coordinates, and in-situ auroral boundaries. Spacecraft locations have been recalculated using ground-tracking information. Magnetic perturbations (measured field minus modeled main-field) are recomputed. The updated locations ensure the appropriate model field is used. We characterize and remove a slow-varying signal in the magnetic field measurements. This signal is a combination of ring current and measurement artifacts. A final artifact remains after processing: step-discontinuities in the baseline caused by activation/deactivation of spacecraft electronics. Using coincident data from the DMSP precipitating electrons and ions instrument (SSJ4/5), we detect the in-situ auroral boundaries with an improvement to the Redmon et al. [2010] algorithm. We embed the location of the aurora and an accompanying figure of merit in the Level-2 SSM data product. Finally, we demonstrate the potential of this new dataset by estimating field-aligned current (FAC) density using the Minimum Variance Analysis (MVA) technique. The FAC estimates are then expressed in dynamic auroral boundary coordinates using the SSJ-derived boundaries, demonstrating a dawn-dusk asymmetry in average FAC location relative to the equatorward edge of the aurora. The new SSM dataset is now available in several public repositories.

  9. PC-FACS.

    PubMed

    Abernethy, Amy P

    2012-03-01

    PC-FACS (Fast Article Critical Summaries for Clinicians in Palliative Care), an electronic publication of the American Academy of Hospice and Palliative Medicine, provides palliative care clinicians with concise summaries of the most important findings from more than 50 medical and scientific journals. Each month, structured summaries and insightful commentaries on 6-10 articles help palliative care clinicians stay on top of the research that is critical to contemporary practice. PC-FACS is free to AAHPM members and members can earn up to 3 CME credits quarterly. Following are excerpts from recent issues, and comments from readers are welcomed at resources@aahpm.org.

  10. PC-FACS.

    PubMed

    Zhukovsky, Donna S

    2012-04-01

    PC-FACS (Fast Article Critical Summaries for Clinicians in Palliative Care), an electronic publication of the American Academy of Hospice and Palliative Medicine, provides palliative care clinicians with concise summaries of the most important findings from more than 50 medical and scientific journals. Each month, structured summaries and insightful commentaries on 6-10 articles help palliative care clinicians stay on top of the research that is critical to contemporary practice. PC-FACS is free to AAHPM members. Following are excerpts from recent issues, and comments from readers are welcomed at resources@aahpm.org.

  11. SuperDARN-derived plasma convection: Comparison with other data and application to field-aligned current measurements

    NASA Astrophysics Data System (ADS)

    Xu, Liang

    In this thesis, several aspects of the SuperDARN HF radar observations at high latitudes are investigated in cooperation with measurements performed by three other instruments, the Sondrestrom incoherent scatter radar, the ion drift meter onboard of the DMSP satellite and the CADI ionosonde. The first issue under investigation was consistency of plasma convection data provided by these instruments. First, routine measurements by the Goose Bay and Stokkseyri SuperDARN radar pair ("merge" velocity estimates) were compared with the Sondrestrom incoherent scatter radar data. Three different levels of assessment were used; by looking at the line-of-sight velocities, by comparing the SuperDARN vectors and corresponding Sondrestrom line-of-sight velocities and by comparing the end products of the instruments, the convection maps. All three comparisons showed overall reasonable agreement of the convection measurements though the data spread was significant and for some points a strong disagreement was obvious. Importantly, the convection map comparison showed a tendency for the SuperDARN velocities to be often less than the Sondrestrom drifts for strong flows (velocities > 1000 m/s) and larger for weak flows (velocities < 500 m/s). The second issue under investigation was the configuration of the ionospheric plasma convection and field-aligned currents (FACs) in the dayside ionosphere at small IMF B2 and By. By merging SuperDARN convection data for a number of events, it was found that convection tends to be compressed to the poleward edge of the polar cap with a noticeable decrease of the flow velociity inside the central polar cap for this condition. Also, for individual events, existence of three sheets of FACs was illustrated. FACs had similar appearance as region 1, region 2, and region 0 currents known from satellite magnetometer observations for the disturbed magnetosphere. Spatially, sheets of region 1 FACs were co-located with a line separating the plasma flow of

  12. Field-aligned current response to solar indices

    NASA Astrophysics Data System (ADS)

    Edwards, Thom R.; Weimer, D. R.; Tobiska, W. K.; Olsen, Nils

    2017-05-01

    Magnetometer data from three satellite missions have been used to analyze and identify the effects of varying solar radiation on the magnitudes and locations of field-aligned currents in the Earth's upper atmosphere. Data from the CHAMP, Ørsted, and Swarm satellite missions have been brought together to provide a database spanning a 15 year period. The extensive time frame has been augmented by data from the ACE satellite, as well as a number of indices of solar radiation. This data set has been sorted by a number of solar wind, interplanetary magnetic field, and solar radiation indices to provide measurements for the field-aligned current structures in both hemispheres for arbitrary seasonal tilts. In addition, routines have been developed to extract the total current for different regions of the current structures, including regions 0, 1, and 2. Results from this study have been used to evaluate the effects of variations in four different solar indices on the total current in different regions of the polar cap. While the solar indices do not have major influence on the total current of the polar cap when compared to solar wind and interplanetary magnetic field parameters, it does appear that there is a nonlinear response to increasing F10.7, M10.7, and S10.7 solar indices. Surprisingly, there appears to be a very linear response as Y10.7 solar index increases.

  13. On the Spatio-Temporal Variability of Field-Aligned Currents Observed with the Swarm Satellite Constellation: Implications for the Energetics of Magnetosphere-Ionosphere Coupling

    NASA Astrophysics Data System (ADS)

    Pakhotin, I.; Mann, I. R.; Forsyth, C.; Rae, J.; Burchill, J. K.; Knudsen, D. J.; Murphy, K. R.; Gjerloev, J. W.; Ozeke, L.; Balasis, G.; Daglis, I. A.

    2016-12-01

    With the advent of the Swarm mission with its multi-satellite capacity, it became possible for the first time to make systematic close separation multi-satellite measurements of the magnetic fields associated with field-aligned currents (FACs) at a 50 Hz cadence using fluxgate magnetometers. Initial studies have revealed an even greater level of detail and complexity and spatio-temporal non-stationarity than previously understood. On inter-satellite separation scales of 10 seconds along-track and <120 km cross-track, the peak-to-peak magnitudes of the small scale and poorly correlated inter-spacecraft magnetic field fluctuations can reach tens to hundreds of nanoteslas. These magnitudes are directly comparable to those associated with larger scale magnetic perturbations such as the global scale Region 1 and 2 FAC systems characterised by Iijima and Potemra 40 years ago. We evaluate the impact of these smaller scale magnetic perturbations relative to the larger scale FAC systems statistically as a function of the total number of FAC crossings observed, and as a function of geomagnetic indices, spatial location, and season. Further case studies incorporating Swarm electric field measurements enable estimates of the Poynting flux associated with the small scale and non-stationary magnetic fields. We interpret the small scale structures as Alfvenic, suggesting that Alfven waves play a much larger and more energetically significant role in magnetosphere-ionosphere coupling than previously thought. We further examine what causes such high variability among low-Earth orbit FAC systems to be observed under some conditions but not in others.

  14. Using AMIENext Patterns Derived from AMPERE Data to Explore Hemispheric Asymmetries in Field Aligned Currents and Magnetic Potential

    NASA Astrophysics Data System (ADS)

    Shi, Y.; Knipp, D. J.; Matsuo, T.; Anderson, B. J.

    2016-12-01

    We report on the inter-hemispheric asymmetries that develop during a quiet time period on June 14, 2011 and an active interval on May 28 2011. Magnetic potential and field-aligned currents (FACs) patterns derived from Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) data using the new AMIENext procedure (Matsuo et al, 2015), allow us to do simultaneous northern/southern hemisphere comparisons. We generate empirical orthogonal functions (EOFs) from the data to describe the primary modes of variability in magnetic potential and field-aligned currents, which helps minimize the impact of difference in data coverage resulting from relative displacement of the geomagnetic pole from geographic poles in the two hemispheres. On the quiet day we observe that when the IMF By and Bz is positive, the expected mirror symmetry in magnetic potential patterns is only partially present (Fig. a and b). More symmetry appears when Bz turns south during the middle of the day (Fig. c and d). We attribute this to seasonal conductivity difference. We also see strong cusp and region 1 current in the sunlit hemisphere while the dark hemisphere lacks clear cusp current throughout the day and lacks symmetric region 1 current for most of the day. Our preliminary result for the active days suggests strong mirror symmetry even under different sunlit conditions. We will show results for solstice and equinox to compare and contrast the hemispheric asymmetries.

  15. Solar cycle dependence of nightside field-aligned currents: Effects of dayside ionospheric conductivity on the solar wind-magnetosphere-ionosphere coupling

    NASA Astrophysics Data System (ADS)

    Ohtani, S.; Wing, S.; Merkin, V. G.; Higuchi, T.

    2014-01-01

    the present study we observationally address the role of ionospheric conductivity in the solar wind-magnetosphere coupling in terms of global field-aligned currents (FACs). Solar EUV irradiance changes during a solar cycle and so does its contribution to the ionospheric conductivity. We statistically examine how, under fixed external conditions, the intensities of the R1 and R2 currents and their demarcation latitude depend on solar activity (F10.7). An emphasis is placed on nightside FACs in the dark hemisphere. The result shows that for fixed ranges of interplanetary electric field, the nightside FACs are more intense for higher solar activity irrespective of their polarities or local times. It is also found that the R1-R2 pair, therefore the auroral oval, moves equatorward as the solar activity increases. For both current intensity and latitude, the dependence on F10.7 is more sensitive at smaller F10.7 and it levels off with increasing F10.7. The intensities of dayside FACs reveal similar F10.7 dependence as expected from the enhancement of the local ionospheric conductance. Interestingly, they also move equatorward with increasing F10.7. It is expected from force balance that as the dayside R1 current becomes more intense with increasing solar activity, the magnetosphere shrinks on the day side and expands on the night side. This configurational change of the magnetosphere presumably affects the energy transport from the solar wind to the magnetosphere, although its details still remain to be understood. We conclude that the ionospheric conductivity plays an active role in the solar wind-magnetosphere-ionosphere coupling.

  16. Effects of Dayside Ionospheric Conductivity on the Solar Wind-Magnetosphere-Ionosphere Coupling: Solar Cycle Dependence of Night-side Field-aligned Currents

    NASA Astrophysics Data System (ADS)

    Ohtani, S.; Higuchi, T.; Wing, S.; Merkin, V. G.

    2014-12-01

    In the present study we observationally address the role of ionospheric conductivity in the solar wind-magnetosphere coupling in terms of global field-aligned currents (FACs). Solar EUV irradiance changes during a solar cycle, and so does its contribution to the ionospheric conductivity. We statistically examine how, under fixed external conditions, the intensities of the R1 and R2 currents and their demarcation latitude depend on solar activity (F10.7). An emphasis is placed on nightside FACs in the dark hemisphere. The result shows that for fixed ranges of interplanetary electric field, the nightside FACs are more intense for higher solar activity irrespective of their polarities or local times. It is also found that the R1-R2 pair, therefore the auroral oval, moves equatorward as the solar activity increases. For both current intensity and latitude, the dependence on F10.7 is more sensitive at smaller F10.7 and it levels off with increasing F10.7. The intensities of dayside FACs reveal similar F10.7 dependence as expected from the enhancement of the local ionospheric conductance. Interestingly, they also move equatorward with increasing solar activity. It is expected from force balance that as the dayside R1 current becomes more intense with increasing solar activity, the magnetosphere shrinks on the day side and expands on the night side. This configurational change of the magnetosphere presumably affects the energy transport from the solar wind to the magnetosphere, although its details still remain to be understood. We conclude that the ionospheric conductivity actively affects the solar wind-magnetosphere-ionosphere coupling.

  17. Terrestrial ionospheric signatures of field-aligned currents

    NASA Technical Reports Server (NTRS)

    Friis-Christensen, E.

    1990-01-01

    The occurrence of traveling field-aligned current filaments and twin-vortex patterns is suggested to be related to sudden changes in solar wind dynamic pressure and/or the IMF. Greenland magnetometer observations of the cleft region magnetic perturbations associated with small-scale twin-vortex patterns show that these events occur on both sides of the magnetic local noon, contradicting Glassmeier at al.'s (1989) statistical analysis of 82 twin-vortex subauroral-latitude events obtained by the Scandinavian Magnetometer Array; the stations are closer to the ionospheric projection of the cleft earlier in magnetic local time, relative to the across-the-cleft-located Greenland stations.

  18. 27 August 2001 substorm: Preonset phenomena, two main onsets, field-aligned current systems, and plasma flow channels in the ionosphere and in the magnetosphere

    NASA Astrophysics Data System (ADS)

    Mishin, V. M.; Mishin, V. V.; Lunyushkin, S. B.; Wang, J. Y.; Moiseev, A. V.

    2017-05-01

    We supplement the results of the 27 August 2001 substorm studied earlier in the series of papers. Described is the plasma flow in the nightside ionosphere from the near-polar region from the polar cap to the auroral oval during the substorm preonset phase and two expansion onsets, EO1 and EO2, produced by reconnection in the closed tail (magnetic reconnection (MR1) and in the open tail lobes (MR2), respectively. We discuss the location of the MR2 region (is it near, middle, and/or distant tail?) and the EO2 trigger mechanism. The upward substorm current wedge field-aligned current (FAC) and the downward FAC in the polar cap dusk sector that were both produced by different types of magnetosphere-ionosphere feedback instability are found to provide the main contribution to the system of FACs during EO1 and EO2. Also, we obtain the estimates for the EO1 and EO2 power and energy. Addressed are the variations in the tail lobe magnetic flux and their (variations) association with EO2. In addition, we describe a 3-D system of mesoscale cells, each of which involves a plasma vortex and a local FAC maximum. The cells of this system in the inner magnetosphere and in the tail lobes intensify one after other within 2 min interval. At last, we substantiate the assumption that the fast plasma flow recorded by the Cluster satellites 7 min prior to EO1 was a bursty bulk flow from the most distant tail.

  19. Three-dimensional structure of ionospheric currents produced by field-aligned currents

    NASA Astrophysics Data System (ADS)

    Takeda, M.

    1982-08-01

    Ionospheric currents caused by field-aligned currents are calculated three-dimensionally under quiet conditions at the equinox, using a magnetic field line coordinate system and with the assumption of infinite parallel conductivity. Input field-aligned currents are assumed to be distributed only in the daytime and the whole system is assumed to be symmetric about the equator. Calculated currents are comparable with those of the ionospheric dynamo in higher latitudes, but much weaker in lower latitudes including the equatorial electrojet region. Hence, if the model is valid these currents may have a considerable effect on the day-to-day variation of Sq currents in higher latitudes, but little effect on those in lower latitudes such as the counter-electrojet.

  20. Asymmetric field-aligned currents in the conjugate hemispheres

    NASA Astrophysics Data System (ADS)

    Reistad, J. P.; Ostgaard, N.; Oksavik, K.; Laundal, K. M.

    2012-12-01

    Earlier studies using simultaneous imaging from space of the Aurora Borealis (Northern Hemisphere) and Aurora Australis (Southern Hemisphere) have revealed that the aurora can experience a high degree of asymmetry between the two hemispheres. Using 19 hours of simultaneous global imaging from both hemispheres (IMAGE satellite in north and Polar satellite in south) in conjunction with the entire IMAGE WIC database, we investigate the importance of various mechanisms thought to generate the asymmetries seen in global imaging. In terms of asymmetric or interhemispheric field-aligned currents, three candidate mechanisms have been suggested: 1) Hemispheric differences in solar wind dynamo efficiency mainly controlled by IMF Bx leading to asymmetric region 1 currents; 2) conductivity differences in conjugate areas; and 3) penetration of IMF By into the closed magnetosphere possibly generating a pair of oppositely directed interhemispheric currents. From the 19 hour conjugate dataset we find that the solar wind dynamo is likely to be the most important controlling mechanism for asymmetric bright aurora in the polar part of the nightside oval. Here we present statistical analyses of candidates 1) and 3). Using the entire IMAGE WIC database, a statistical analysis of the auroral brightness distribution along and across the Northern Hemisphere oval is carried out. For each candidate, two extreme cases (+/- IMF Bx for 1) and +/- IMF By for 3)) are compared during times non-favorable for the other two mechanisms. Our results indicate that solar wind dynamo induced currents play an important role for the nightside auroral brightness in an average sense. Also, signatures of interhemispheric currents due to IMF By penetration are seen in our statistics, although this effect is somehow weaker.

  1. FACS binding assay for analysing GDNF interactions.

    PubMed

    Quintino, Luís; Baudet, Aurélie; Larsson, Jonas; Lundberg, Cecilia

    2013-08-15

    Glial cell-line derived neurotrophic factor (GDNF) is a secreted protein with great therapeutic potential. However, in order to analyse the interactions between GDNF and its receptors, researchers have been mostly dependent of radioactive binding assays. We developed a FACS-based binding assay for GDNF as an alternative to current methods. We demonstrated that the FACS-based assay using TGW cells allowed readily detection of GDNF binding and displacement to endogenous receptors. The dissociation constant and half maximal inhibitory concentration obtained were comparable to other studies using standard binding assays. Overall, this FACS-based, simple to perform and adaptable to high throughput setup, provides a safer and reliable alternative to radioactive methods. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Field Aligned Currents Derived From Pressure Profiles Obtained From TWINS ENA Images for Geomagnetic Storms That Occurred On 01 June 2013 and 17 March 2015.

    NASA Astrophysics Data System (ADS)

    Wood, K.; Perez, J. D.; Goldstein, J.; McComas, D. J.; Valek, P. W.

    2016-12-01

    Field aligned currents (FACs) that flow from the Earth's magnetosphere into the ionosphere are an important coupling mechanism in the interaction of the solar wind with the Earth's magnetosphere and ionosphere. Assuming pressure balance and charge conservation yields an expression for the FACs in terms of plasma pressure gradients and pressure anisotropy. The Two Wide-angle Imaging Neutral Atom Spectrometers (TWINS) mission, the first stereoscopic ENA magnetospheric imager, provides global images of the inner magnetosphere from which ion pressure distributions and pressure anisotropies are obtained. Following the formulations in Vasyliunas (1970), Vasyliunas (1984), and Heinemann (1990), and using results from TWINS observations, we calculate the distributions of field aligned currents for geomagnetic storms on 1 June 2013 and 17 March 2015, in which extended ionospheric precipitation was observed. As previous work has assumed isotropic pressure distributions, we perform calculations both assuming pressure isotropy, and using the pressure anisotropy observed by TWINS, and compare the results from the two storms. References: 1. Vasyliunas, V. M. (1970). Mathematical Models of Magnetospheric Convection and its Coupling to the Ionosphere. Particles and Fields in the Magnetosphere Astrophysics and Space Science Library, 60-71. doi:10.1007/978-94-010-3284-1_6 2. Vasyliunas, V. M. (1984). Fundamentals of current description. Magnetospheric Currents Geophysical Monograph Series, 63-66. doi:10.1029/gm028p0063 3. Heinemann, M. (1990). Representations of currents and magnetic fields in anisotropic magnetohydrostatic plasma. J. Geophys. Res. Journal of Geophysical Research, 95(A6), 7789. doi:10.1029/ja095ia06p07789

  3. A subauroral polarization stream driven by field-aligned currents associated with precipitating energetic ions caused by EMIC waves: A case study

    NASA Astrophysics Data System (ADS)

    Yuan, Zhigang; Xiong, Ying; Qiao, Zheng; Li, Haimeng; Huang, Shiyong; Wang, Dedong; Deng, Xiaohua; Raita, Tero; Wang, Jingfang

    2016-02-01

    During the energetic ion injection event observed by the Los Alamos National Laboratory geosynchronous spacecraft, observations of the NOAA 15 satellite and Finnish network of search coil magnetometers have shown that a sharp enhancement of precipitating ring current (RC) ion flux is contributed to the pitch angle scattering caused by electromagnetic ion cyclotron (EMIC) waves. At subauroral latitudes, lower than the equatorward edge of precipitating electrons from the plasma sheet, the DMSP F13 satellite observed a subauroral polarization stream (SAPS) with a peak velocity of 688 m/s. When passing the region of EMIC waves derived by the Finnish network of search coil magnetometers and NOAA 15 satellite, the DMSP F13 satellite simultaneously observed field-aligned currents (FACs) flowing into the ionosphere and precipitating RC ions in the region of the SAPS. The peak of the SAPS accords to the minimum of the ion density in the region of the SAPS. Our result suggests that loss of RC ions caused by EMIC waves would possibly lead to FACs flowing into the ionosphere and drive the SAPS in the evening sector.

  4. Small-scale field-aligned currents and ionospheric disturbances induced by vertical acoustic resonance during the 2015 eruption of Chile's Calbuco volcano

    NASA Astrophysics Data System (ADS)

    Aoyama, T.; Iyemori, T.; Nakanishi, K.; Nishioka, M.

    2015-12-01

    Wave packet structure of small-scale magnetic fluctuations were observed by SWARM satellites just above the volcano and it's magnetic conjugate point after the eruption of Chile's Calbuco volcano on April 22, 2015. These magnetic fluctuations in low and middle latitudes generated by small-scale field aligned currents (FACs), and have about 10-30 seconds period along the satellites' orbit [Nakanishi et al., 2014] and about 200 (340) seconds temporal scale for meridional (longitudinal) magnetic components [Iyemori et al., 2015]. We also observed ionospheric disturbances and ground geomagnetic fluctuations just after the eruption. The 4-min period oscillations of total electron content (TEC) were observed by GPS receivers near the volcano. The 260 and 215 seconds spectral peaks in D component of ground based geomagnetic observation were found. Such oscillations and spectral peaks didn't exist before the eruption. All of these observations may have the same origin, i.e., vertical acoustic resonance between the ionosphere and the ground. In this presentation, we estimate the propagation velocity of the TEC oscillations and the spatial scale of the disturbance region in the E-layer where the FACs are generated by the ionospheric dynamo.

  5. Dynamics of field-aligned currents reconstructed by the ground-based and satellite data

    NASA Astrophysics Data System (ADS)

    Nikolaeva, V. D.; Kotikov, A. L.; Sergienko, T. I.

    2014-09-01

    Parameters of field-aligned currents reconstructed by ground-based measurements of magnetic field in the Scandinavian countries (IMAGE) and ionospheric conductivity for specific events of the 6 and 8 December 2004 are represented here. Ionospheric conductivity was calculated from precipitating electron flux measured at DMSP-13 satellite and electron density EISCAT incoherent scattering radar direct measurements. There is a high correlation between field-aligned currents, calculated from DMSP-13 satellite data and field-aligned currents calculated from radar measurements for the December 6, 2004 in the presence of developed ionospheric current system. The comparison of field-aligned currents, reconstructed by the proposed method, with the currents calculated by the variation of magnetic field on the DMSP satellites, confirms correctness of the offered algorithm.

  6. Field-aligned current and the auroral electrojets in the post-noon quadrant

    NASA Astrophysics Data System (ADS)

    Rostoker, G.; Mareschal, M.

    1982-11-01

    It is shown that in the post-noon quadrant, the combination of field-aligned currents associated with the eastward auroral electrojet and polar cap currents produces a magnetic field perturbation pattern on the ground and at TRIAD altitude (800 km) in good agreement with observations. This model permits downward net field-aligned current flow across the post-noon sector auroral oval while at the same time replicating the observation of a sharp level shift in the east-west component of the magnetic perturbation field at 800-km altitude attributed, until now, to net upward field-aligned current. These results reconcile the contentions of Hughes and Rostoker (1977, 1979) that there is net downward field-aligned current across the post-noon auroral oval and of Sugiura and Potemra (1976) that the net current flow in the post-noon quadrant is upward.

  7. Current Methods for Automated Filtering of Multiple Sequence Alignments Frequently Worsen Single-Gene Phylogenetic Inference

    PubMed Central

    Tan, Ge; Muffato, Matthieu; Ledergerber, Christian; Herrero, Javier; Goldman, Nick; Gil, Manuel; Dessimoz, Christophe

    2015-01-01

    Phylogenetic inference is generally performed on the basis of multiple sequence alignments (MSA). Because errors in an alignment can lead to errors in tree estimation, there is a strong interest in identifying and removing unreliable parts of the alignment. In recent years several automated filtering approaches have been proposed, but despite their popularity, a systematic and comprehensive comparison of different alignment filtering methods on real data has been lacking. Here, we extend and apply recently introduced phylogenetic tests of alignment accuracy on a large number of gene families and contrast the performance of unfiltered versus filtered alignments in the context of single-gene phylogeny reconstruction. Based on multiple genome-wide empirical and simulated data sets, we show that the trees obtained from filtered MSAs are on average worse than those obtained from unfiltered MSAs. Furthermore, alignment filtering often leads to an increase in the proportion of well-supported branches that are actually wrong. We confirm that our findings hold for a wide range of parameters and methods. Although our results suggest that light filtering (up to 20% of alignment positions) has little impact on tree accuracy and may save some computation time, contrary to widespread practice, we do not generally recommend the use of current alignment filtering methods for phylogenetic inference. By providing a way to rigorously and systematically measure the impact of filtering on alignments, the methodology set forth here will guide the development of better filtering algorithms. PMID:26031838

  8. FACS Sorting Mammary Stem Cells.

    PubMed

    Iriondo, Oihana; Rábano, Miriam; Vivanco, María D M

    2015-01-01

    Fluorescent-activated cell sorting (FACS) represents one of the key techniques that have been used to isolate and characterize stem cells, including cells from the mammary gland. A combination of approaches, including recognition of cell surface antigens and different cellular activities, has facilitated the identification of stem cells from the healthy mammary gland and from breast tumors. In this chapter we describe the protocol to use FACS to separate breast cancer stem cells, but most of the general principles discussed could be applied to sort other types of cells.

  9. Influence of the electron source distribution on field-aligned currents

    NASA Astrophysics Data System (ADS)

    Bruening, K.; Goertz, C. K.

    1985-01-01

    The field-aligned current density above a discrete auroral arc has been deduced from the downward electron flux and magnetic field measurements onboard the rocket Porcupine flight 4. Both measurements show that the field-aligned current density is, in spite of decreasing peak energies towards the edge of the arc, about 4 times higher there than in the center of the arc. This can be explained by using the single particle description for an anisotropic electron source distribution.

  10. Modeling magnetic perturbation fields associated with ionospheric and geomagnetic-field-aligned currents

    NASA Astrophysics Data System (ADS)

    Richmond, A. D.; Maute, A.

    2003-04-01

    The National Center for Atmospheric Research Thermosphere-Ionosphere-Electrodynamics General-Circulation Model calculates ionospheric and geomagnetic-field-aligned electric currents produced by ionospheric wind dynamo action, taking into account magnetospheric sources at high latitudes. The associated magnetic perturbations at the ground and at low-Earth-orbit (LEO) satellite altitudes are calculated by representing the height-integrated horizontal ionospheric current as a current sheet at 110 km, connected to geomagnetic-field-aligned currents flowing into and out of the top. The horizontal sheet current can be divided into two components: a divergence-free equivalent current which, together with the associated induced Earth currents, is responsible for all of the magnetic perturbations below the current sheet, and a divergent (but not irrotational) current that closes the field-aligned currents above. We call the combination of the field-aligned currents and their closing ionospheric currents the ``nonequivalent'' currents. By definition, these produce no magnetic effect at the ground, but they do produce important magnetic effects at LEO altitudes, generally dominating the component of LEO magnetic perturbations perpendicular to the main geomagnetic field. At high magnetic latitudes the nonequivalent LEO magnetic perturbations are largely toroidal, and are associated with the strong field-aligned currents that couple the ionosphere with the outer magnetosphere. At middle and low magnetic latitudes the nonequivalent LEO magnetic perturbations are largely associated with field-aligned currents that flow between the northern and southern hemispheres, and that can produce east-west perturbations of tens of nanoteslas.

  11. Origins of enhanced field-aligned current at the edge of an auroral arc

    NASA Astrophysics Data System (ADS)

    Greenspan, M. E.

    1989-09-01

    Consideration is given to observations showing that the upward field-aligned currents associated with auroral arcs are larger at their edges than within the arcs, focusing on the observations made with the Porcupine F4 rocket (Bruning and Geortz, 1985). It is found that an increase in the altitude of the top of the parallel electric field region does not sufficiently explain the increase in the upward field-aligned current at the edge of the arc crossed by the Porcupine F4. Other explanations are discussed, including the adiabatic acceleration of magnetospheric electrons through a field-aligned electrostatic potential. It is suggested that an increase in the density and/or a decrease in the perpendicular temperature of the magnetospheric electron population at the edge of the arc may explain the observed increase in upward field-aligned current.

  12. The evolution of arguments regarding the existence of field-aligned currents

    NASA Technical Reports Server (NTRS)

    Dessler, A. J.

    1984-01-01

    The present understanding of Birkeland (magnetically-field-aligned) currents was not obtained by a direct, logical course. The story is rather more complex. Starting at the end of the 19th century, the Norwegian scientist Kristian Birkeland laid out a compelling case, supported by both theory and experiment, for the existence of field-aligned currents that cause both the aurora and polar geomagnetic disturbances. Sydney Chapman, the British geophysicist, became the acknowledged leader and opinion maker in the field in the decades following Birkeland's death. Chapman proposed, in contradistinction to Birkeland's ideas, equivalent currents that were restricted to flow in the ionosphere with no vertical or field-aligned components. Birkeland's ideas may have faded completely if it had not been for Hannes Alfven, who became involved well after Chapman's ideas gained predominance. Alfven kept insisting that Birkeland's current system made more sense because field-aligned currents were required to drive most of the ionospheric currents. The author became personally involved when Zmuda et al. (1966) submitted to the Journal of Geophysical Research a paper reporting satellite data showing magnetic disturbances above the ionosphere that were consistent with field-aligned Birkeland currents, but which they did not interpret as being due to such currents.

  13. Field-aligned electric currents and their measurement by the incoherent backscatter technique

    NASA Technical Reports Server (NTRS)

    Bauer, P.; Cole, K. D.; Lejeume, G.

    1975-01-01

    Field aligned electric currents flow in the magnetosphere in many situations of fundamental geophysical interest. It is shown here that the incoherent backscatter technique can be used to measure these currents when the plasma line can be observed. The technique provides a ground based means of measuring these currents which complements the rocket and satellite ones.

  14. Current Methods for Automated Filtering of Multiple Sequence Alignments Frequently Worsen Single-Gene Phylogenetic Inference.

    PubMed

    Tan, Ge; Muffato, Matthieu; Ledergerber, Christian; Herrero, Javier; Goldman, Nick; Gil, Manuel; Dessimoz, Christophe

    2015-09-01

    Phylogenetic inference is generally performed on the basis of multiple sequence alignments (MSA). Because errors in an alignment can lead to errors in tree estimation, there is a strong interest in identifying and removing unreliable parts of the alignment. In recent years several automated filtering approaches have been proposed, but despite their popularity, a systematic and comprehensive comparison of different alignment filtering methods on real data has been lacking. Here, we extend and apply recently introduced phylogenetic tests of alignment accuracy on a large number of gene families and contrast the performance of unfiltered versus filtered alignments in the context of single-gene phylogeny reconstruction. Based on multiple genome-wide empirical and simulated data sets, we show that the trees obtained from filtered MSAs are on average worse than those obtained from unfiltered MSAs. Furthermore, alignment filtering often leads to an increase in the proportion of well-supported branches that are actually wrong. We confirm that our findings hold for a wide range of parameters and methods. Although our results suggest that light filtering (up to 20% of alignment positions) has little impact on tree accuracy and may save some computation time, contrary to widespread practice, we do not generally recommend the use of current alignment filtering methods for phylogenetic inference. By providing a way to rigorously and systematically measure the impact of filtering on alignments, the methodology set forth here will guide the development of better filtering algorithms. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society of Systematic Biologists.

  15. Does FACS perturb gene expression?

    PubMed

    Richardson, Graham M; Lannigan, Joanne; Macara, Ian G

    2015-02-01

    Fluorescence activated cell sorting is the technique most commonly used to separate primary mammary epithelial sub-populations. Many studies incorporate this technique before analyzing gene expression within specific cellular lineages. However, to our knowledge, no one has examined the effects of fluorescence activated cell sorting (FACS) separation on short-term transcriptional profiles. In this study, we isolated a heterogeneous mixture of cells from the mouse mammary gland. To determine the effects of the isolation and separation process on gene expression, we harvested RNA from the cells before enzymatic digestion, following enzymatic digestion, and following a mock FACS sort where the entire cohort of cells was retained. A strict protocol was followed to minimize disruption to the cells, and to ensure that no subpopulations were enriched or lost. Microarray analysis demonstrated that FACS causes minimal disruptions to gene expression patterns, but prior steps in the mammary cell isolation process are followed by upregulation of 18 miRNA's and rapid decreases in their predicted target transcripts. © 2015 International Society for Advancement of Cytometry. © 2015 International Society for Advancement of Cytometry.

  16. A numerical model of ionospheric convection derived from field-alignment currents and the corresponding conductivity

    NASA Astrophysics Data System (ADS)

    Blomberg, L. G.; Marklund, G. T.

    1991-08-01

    A numerical model for the calculation of ionospheric convection patterns from given distributions of field aligned current and ionospheric conductivity is described. The model includes a coupling between the conductivity and the field aligned current. The input contributions, the field aligned current and the conductivity, are parametrized. From the primary model output a number of other quantities can be computed: the potential in the inertial frame, the potential in the magnetospheric equatorial plane, the distribution of ionosheric current, and the Joule heating in the ionosphere. This model was used together with a technique to caculate the high latitude potential distribution prevailing during a particular event by combining information from global auroral images and local measurements of fields and particles. The model potential variation along the satellite orbit was found to be in agreement with that calculated from the measured electric field. The model was also used to study some fundamental properties of the electrodynamics of the high latitude ionosphere.

  17. 76 FR 39260 - Direct Investment Surveys: Alignment of Regulations With Current Practices

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-06

    ... Regulations With Current Practices AGENCY: Bureau of Economic Analysis, Commerce. ACTION: Final rule. SUMMARY... align its regulations for direct investment surveys with current practices. No comments on the proposed... acquired and on the new foreign owner, information on the cost of the investment and source of funding,...

  18. Response of ionospheric field-aligned currents to a sudden increase in the solar wind dynamic pressure: high-resolution LFM simulations and AMPERE observations

    NASA Astrophysics Data System (ADS)

    Merkin, V. G.; Anderson, B. J.; Lyon, J.; Korth, H.; Wiltberger, M. J.

    2012-12-01

    Birkeland currents, i.e., magnetic field-aligned currents linking the magnetosphere and ionosphere, are one of the primary manifestations of solar wind-magnetosphere-ionosphere (SW-M-I) coupling. Until recently, recovering their global morphology and dynamics has only been possible indirectly: either from ground-based magnetometers or from radar observations of ionospheric convection. With the development of the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE), global distributions of the magnetic perturbations associated with the Birkeland currents can be inferred from in-situ measurements by the >70 Iridium satelites located in six, approximately equally-spaced, polar orbit planes. At the same time, recent advances in global magnetohydrodynamic (MHD) modeling of the SW-M-I system have allowed simulations yielding realistic FAC distributions, which compare favorably with AMPERE observations. In this presentation we investigate the response of the magnetosphere-ionosphere system to a sudden increase in the solar wind dynamic pressure as seen in high-resolution Lyon-Fedder-Mobarry (LFM) simulations and AMPERE observations. Both simulations and observations indicate the formation of multiple longitudinally-extended field-aligned current sheets in response to the dynamic pressure jump (arriving at the bow shock at ~15:00 UT, January 24, 2012) and the subsequent propagation of fast-mode waves through the magnetosphere. We analyze the simulation to identify the primary MHD mechanisms of generation of these complex current patterns. By flying virtual satellites through the MHD simulation, we help interpret the observations of the transient currents by fast-moving spacecraft and test quantitatively the simulation predictions of these signatures.

  19. Direct determination of large-scale magnetospheric field-aligned currents with superDARN

    SciTech Connect

    Solfo, G.J.; Greenwald, R.; Bristow, W.

    1995-08-01

    The authors present 2D images of plasma convection velocities in the high latitude F region, measured using a dual radar pair. These maps allow them to calculate the vorticity of the plasma flow. The authors argue that this provides a measure of the field aligned currents in the F regions, in that velocity is equivalent to J{sub m}/{Sigma}{sub p}, where J{sub m} is the magnetospheric component of the field aligned current, and {Sigma}{sub p} is the integrated Pederson conductivity.

  20. Magnetospheric Multiscale Observations of Field-aligned Currents at the Magnetopause

    NASA Astrophysics Data System (ADS)

    Strangeway, R. J.; Russell, C. T.; Zhao, C.; Magnes, W.; Bromund, K. R.; Plaschke, F.; Fischer, D.; Anderson, B. J.; Le, G.; Chutter, M.; Slavin, J. A.; Nakamura, R.; Baumjohann, W.; Paterson, W. R.; Torbert, R. B.; Burch, J. L.

    2016-12-01

    Magnetospheric Multiscale (MMS) has demonstrated that the dayside magnetopause is usually highly structured, with multiple layers. Within these layers currents are observed to be flowing both parallel and perpendicular to the magnetic field. The parallel currents primarily act to bend or shear the magnetic field, while the perpendicular currents mainly change the field strength. We note that within the magnetopause MMS observes current densities that can be of the order of 100s of nAm-2. If these currents were to map to the ionosphere, then they would correspond to field-aligned current densities of the order of 100s of μAm-2, orders of magnitude larger than the observed low altitude field-aligned currents. A survey of several magnetopause crossings shows that the field-aligned currents on the magnetosphere side of the current layers can be flowing either parallel or anti-parallel to the magnetic field. On the magnetospheric side of the magnetopause current layers the plasma flows are generally in the -z direction (in GSM coordinates) for the events studied, suggesting that the observations are to the south of the reconnection site. If the currents were to correspond to Region-1 sense currents flowing into and out of the southern ionosphere, then the polarity of the currents would be ordered by local time, flowing parallel to the local magnetic field on the dusk-side of noon, and anti-parallel on the dawn-side of noon. But the current signatures are mixed, and sometimes the field-aligned currents reverse polarity within one crossing of the magnetopause. The issue is therefore how do we reconcile the local magnetopause field-aligned current signatures with what would be expected for the large-scale Region-1 currents that are typically associated with flow shears introduced through reconnection? Given the strength of the currents and their structure much of the current may be closed locally, with only a residual contributing to the large-scale currents.

  1. Characteristics of ionospheric convection and field-aligned current in the dayside cusp region

    NASA Technical Reports Server (NTRS)

    Lu, G.; Lyons, L. R.; Reiff, P. H.; Denig, W. F.; Beaujardiere, O. De LA; Kroehl, H. W.; Newell, P. T.; Rich, F. J.; Opgenoorth, H.; Persson, M. A. L.

    1995-01-01

    The assimilative mapping of ionospheric electrodynamics (AMIE) technique has been used to estimate global distributions of high-latitude ionospheric convection and field-aligned current by combining data obtained nearly simultaneously both from ground and from space. Therefore, unlike the statistical patterns, the 'snapshot' distributions derived by AMIE allow us to examine in more detail the distinctions between field-aligned current systems associated with separate magnetospheric processes, especially in the dayside cusp region. By comparing the field-aligned current and ionospheric convection patterns with the corresponding spectrograms of precipitating particles, the following signatures have been identified: (1) For the three cases studied, which all had an IMF with negative y and z components, the cusp precipitation was encountered by the DMSP satellites in the postnoon sector in the northern hemisphere and in the prenoon sector in the southern hemisphere. The equatorward part of the cusp in both hemispheres is in the sunward flow region and marks the beginning of the flow rotation from sunward to antisunward. (2) The pair of field-aligned currents near local noon, i.e., the cusp/mantle currents, are coincident with the cusp or mantle particle precipitation. In distinction, the field-aligned currents on the dawnside and duskside, i.e., the normal region 1 currents, are usually associated with the plasma sheet particle precipitation. Thus the cusp/mantle currents are generated on open field lines and the region 1 currents mainly on closed field lines. (3) Topologically, the cusp/mantle currents appear as an expansion of the region 1 currents from the dawnside and duskside and they overlap near local noon. When B(sub y) is negative, in the northern hemisphere the downward field-aligned current is located poleward of the upward current; whereas in the southern hemisphere the upward current is located poleward of the downward current. (4) Under the assumption of

  2. EquiFACS: The Equine Facial Action Coding System

    PubMed Central

    Wathan, Jen; Burrows, Anne M.; Waller, Bridget M.; McComb, Karen

    2015-01-01

    Although previous studies of horses have investigated their facial expressions in specific contexts, e.g. pain, until now there has been no methodology available that documents all the possible facial movements of the horse and provides a way to record all potential facial configurations. This is essential for an objective description of horse facial expressions across a range of contexts that reflect different emotional states. Facial Action Coding Systems (FACS) provide a systematic methodology of identifying and coding facial expressions on the basis of underlying facial musculature and muscle movement. FACS are anatomically based and document all possible facial movements rather than a configuration of movements associated with a particular situation. Consequently, FACS can be applied as a tool for a wide range of research questions. We developed FACS for the domestic horse (Equus caballus) through anatomical investigation of the underlying musculature and subsequent analysis of naturally occurring behaviour captured on high quality video. Discrete facial movements were identified and described in terms of the underlying muscle contractions, in correspondence with previous FACS systems. The reliability of others to be able to learn this system (EquiFACS) and consistently code behavioural sequences was high—and this included people with no previous experience of horses. A wide range of facial movements were identified, including many that are also seen in primates and other domestic animals (dogs and cats). EquiFACS provides a method that can now be used to document the facial movements associated with different social contexts and thus to address questions relevant to understanding social cognition and comparative psychology, as well as informing current veterinary and animal welfare practices. PMID:26244573

  3. Space Technology 5 Multipoint Observations of Temporal and Spatial Variability of Field-Aligned Currents

    NASA Technical Reports Server (NTRS)

    Le, G.; Wang, Y.; Slavin, J. A.; Strangeway, R. L.

    2009-01-01

    Space Technology 5 (ST5) is a constellation mission consisting of three microsatellites. It provides the first multipoint magnetic field measurements in low Earth orbit, which enables us to separate spatial and temporal variations. In this paper, we present a study of the temporal variability of field-aligned currents using the ST5 data. We examine the field-aligned current observations during and after a geomagnetic storm and compare the magnetic field profiles at the three spacecraft. The multipoint data demonstrate that mesoscale current structures, commonly embedded within large-scale current sheets, are very dynamic with highly variable current density and/or polarity in approx.10 min time scales. On the other hand, the data also show that the time scales for the currents to be relatively stable are approx.1 min for mesoscale currents and approx.10 min for large-scale currents. These temporal features are very likely associated with dynamic variations of their charge carriers (mainly electrons) as they respond to the variations of the parallel electric field in auroral acceleration region. The characteristic time scales for the temporal variability of mesoscale field-aligned currents are found to be consistent with those of auroral parallel electric field.

  4. Space Technology 5 Multi-Point Observations of Temporal Variability of Field-Aligned Currents

    NASA Technical Reports Server (NTRS)

    Le, Guan; Wang, Yongli; Slavin, James A.; Strangeway, Robert J.

    2008-01-01

    Space Technology 5 (ST5) is a three micro-satellite constellation deployed into a 300 x 4500 km, dawn-dusk, sun-synchronous polar orbit from March 22 to June 21, 2006, for technology validations. In this paper, we present a study of the temporal variability of field-aligned currents using multi-point magnetic field measurements from ST5. The data demonstrate that meso-scale current structures are commonly embedded within large-scale field-aligned current sheets. The meso-scale current structures are very dynamic with highly variable current density and/or polarity in time scales of approximately 10 min. They exhibit large temporal variations during both quiet and disturbed times in such time scales. On the other hand, the data also shown that the time scales for the currents to be relatively stable are approximately 1 min for meso-scale currents and approximately 10 min for large scale current sheets. These temporal features are obviously associated with dynamic variations of their particle carriers (mainly electrons) as they respond to the variations of the parallel electric field in auroral acceleration region. The characteristic time scales for the temporal variability of meso-scale field-aligned currents are found to be consistent with those of auroral parallel electric field.

  5. Space Technology 5 (ST-5) Observations of Field-Aligned Currents: Temporal Variability

    NASA Technical Reports Server (NTRS)

    Le, Guan

    2010-01-01

    Space Technology 5 (ST-5) is a three micro-satellite constellation deployed into a 300 x 4500 km, dawn-dusk, sun-synchronous polar orbit from March 22 to June 21, 2006, for technology validations. In this paper, we present a study of the temporal variability of field-aligned currents using multi-point magnetic field measurements from STS. The data demonstrate that masoscale current structures are commonly embedded within large-scale field-aligned current sheets. The meso-scale current structures are very dynamic with highly variable current density and/or polarity in time scales of about 10 min. They exhibit large temporal variations during both quiet and disturbed times in such time scales. On the other hand, the data also shown that the time scales for the currents to be relatively stable are about I min for meso-scale currents and about 10 min for large scale current sheets. These temporal features are obviously associated with dynamic variations of their particle carriers (mainly electrons) as they respond to the variations of the parallel electric field in auroral acceleration region. The characteristic time scales for the temporal variability of meso-scale field-aligned currents are found to be consistent with those of auroral parallel electric field.

  6. Space Technology 5 Multi-Point Observations of Temporal Variability of Field-Aligned Currents

    NASA Technical Reports Server (NTRS)

    Le, Guan; Wang, Yongli; Slavin, James A.; Strangeway, Robert J.

    2008-01-01

    Space Technology 5 (ST5) is a three micro-satellite constellation deployed into a 300 x 4500 km, dawn-dusk, sun-synchronous polar orbit from March 22 to June 21, 2006, for technology validations. In this paper, we present a study of the temporal variability of field-aligned currents using multi-point magnetic field measurements from ST5. The data demonstrate that meso-scale current structures are commonly embedded within large-scale field-aligned current sheets. The meso-scale current structures are very dynamic with highly variable current density and/or polarity in time scales of approximately 10 min. They exhibit large temporal variations during both quiet and disturbed times in such time scales. On the other hand, the data also shown that the time scales for the currents to be relatively stable are approximately 1 min for meso-scale currents and approximately 10 min for large scale current sheets. These temporal features are obviously associated with dynamic variations of their particle carriers (mainly electrons) as they respond to the variations of the parallel electric field in auroral acceleration region. The characteristic time scales for the temporal variability of meso-scale field-aligned currents are found to be consistent with those of auroral parallel electric field.

  7. Superposed epoch analysis of vertical ion velocity, electron temperature, field-aligned current, and thermospheric wind in the dayside auroral region as observed by DMSP and CHAMP

    NASA Astrophysics Data System (ADS)

    Kervalishvili, G.; Lühr, H.

    2016-12-01

    This study reports on the results obtained by a superposed epoch analysis (SEA) method applied to the electron temperature, vertical ion velocity, field-aligned current (FAC), and thermospheric zonal wind velocity at high-latitudes in the Northern Hemisphere. The SEA study is performed in a magnetic latitude versus magnetic local time (MLat-MLT) frame. The obtained results are based on observations collected during the years 2001-2005 by the CHAMP and DMSP (F13 and F15) satellites. The dependence on interplanetary magnetic field (IMF) orientations is also investigated using data from the NASA/GSFC's OMNI database. Further, the obtained results are subdivided into three Lloyd seasons of 130 days each, which are defined as follows: local winter (1 January ± 65 days), combined equinoxes (1 April and 1 October ± 32days), and local summer (1 July ± 65 days). A period of 130 days is needed by the CHAMP satellite to pass through all local times. The time and location of the electron temperature peaks from CHAMP measurements near the cusp region are used as the reference parameter for the SEA method to investigate the relationship between the electron temperature and other ionospheric quantities. The SEA derived MLat profiles of the electron temperature show a seasonal dependence, increasing from winter to summer, as expected. But, the temperature rise (difference between the reference temperature peak and the background electron temperature) strongly decreases towards local summer. The SEA derived MLat profiles of the ion vertical velocity at DMSP altitude show the same seasonal behaviour as the electron temperature rice. There exists a clear linear relation between these two variables with a quiet large correlation coefficient value, >0.9. The SEA derived MLat profiles of both, thermospheric zonal wind velocity and FAC, show a clear IMF By orientation dependence for all local seasons. The zonal wind velocity is prominently directed towards west in the MLat-MLT frame

  8. Field-aligned currents observed by the OGO 5 and Triad satellites

    NASA Technical Reports Server (NTRS)

    Sugiura, M.

    1975-01-01

    The existence of field-aligned currents in the polar cap boundary layer as a permanent feature of the magnetosphere is investigated. Magnetic field observations from Triad at 800 km altitude and from OGO 5 in the high-altitude magnetosphere are examined. Results indicate that in the morning half of the boundary layer, currents flow into the ionosphere, and that the current direction is reversed in the afternoon half of the layer. The Triad data further indicate that the net current is a maximum near 1500 MLT and that there may be a secondary maximum during early morning hours. According to the Isis 2 electron observations, the locations of these maximums of field-aligned net current roughly match those of two maximums in the isointensity contours for 150 ev electrons. It is proposed that the polar cap boundary current is driven by a current generator in the magnetotail, or ultimately in the solar wind. It is suggested that the large scale field-aligned currents in the polar cap boundary layer are associated with the dominance of protons on the morning side and of electrons on the afternoon side near the poleward edge of the precipitation zone along the auroral oval.

  9. High-latitude convection patterns for various large-scale field-aligned current configurations

    SciTech Connect

    Blomberg, L.G.; Marklund, G.T. )

    1991-04-01

    The large-scale field-aligned current system for persistent northward interplanetary magnetic field (IMF) is typically different from that for persistent southward IMF. One characteristic difference is that for northward IMF there is often a large-scale field-aligned current system poleward of the main auroral oval. This current system (the NBZ current) typically occupies a large function of the region poleward of the region 1 and 2 currents. The present paper models the high-latitude convection as a function of the large-scale field-aligned currents. In particular, a possible evolution of the convection pattern as the current system changes from a typical configuration for southward IMF to a configuration representing northward IMF (or vice versa) is presented. Depending on additional assumptions, for example about the y-component of the IMF, the convection pattern could either turn directly from a two-cell type to a four-cell type, or a three-cell type pattern could show up as an intermediate state. An interesting although rather surprising result of this study is that different ways of balancing the NBZ currents has a minor influence on the large-scale convection pattern.

  10. Statistical relationship between large-scale upward field-aligned currents and electron precipitation

    NASA Astrophysics Data System (ADS)

    Korth, Haje; Zhang, Yongliang; Anderson, Brian J.; Sotirelis, Thomas; Waters, Colin L.

    2014-08-01

    Simultaneous observations of Birkeland currents by the constellation of Iridium satellites and N2 Lyman-Birge-Hopfield (LBH) auroral emissions measured by the Global Ultraviolet Imager (GUVI) onboard the Thermosphere, Ionosphere, and Mesosphere Energetics and Dynamics (TIMED) satellite are used to establish relationships between large-scale upward field-aligned currents and electron precipitation during stable current configurations. The electron precipitation was inferred from GUVI data using a statistical relationship between LBH intensity and electron energy flux. LBH emissions with >5% contribution from protons, identified by Lyman-alpha intensity, were excluded from the analysis. The Birkeland currents were derived with a spatial resolution of 3° in latitude and 2 h in local time. For southward interplanetary magnetic field (IMF), the electron precipitation occurred primarily within and near large-scale upward currents. The correspondence was less evident for northward IMF, presumably because the spatial variability is large compared to the areas of interest so that the number of events identified is smaller and the derived statistical distributions are less reliable. At dusk, the correlation between upward current and precipitation was especially high, where a larger fraction of the electron precipitation is accelerated downward by a field-aligned potential difference. Unaccelerated electron precipitation dominated in the morning sector, presumably induced by scattering of eastward-drifting energetic electrons into the loss cone through interaction with whistler-mode waves (diffuse precipitation) rather than by field-aligned acceleration. In the upward Region 1 on the dayside, where the electron precipitation is almost exclusively due to field-aligned acceleration, a quadratic relationship between current density and electron energy flux was observed, implying a linear current-voltage relationship in this region. Current density and electron energy flux in

  11. Possibility of Ionospheric Cause of FACs and Convection Field in the Magnetosphere-Ionosphere System: The Harang Reversal, Premidnight Upward-FAC, and the Ionospheric Hall Polarization Field

    NASA Astrophysics Data System (ADS)

    Nakamizo, A.; Yoshikawa, A.

    2016-12-01

    Whereas it is generally thought that Birkeland Currents (FACs) are generated in the magnetosphere and that the ionospheric convection reflects the magnetospheric convection, we present a possibility that the ionosphere drives FACs and the convection field in the M-I system. We apply this idea to the Harang Reversal (HR) for demonstration. By using an ionospheric potential solver we calculate the electrostatic field for given distributions of FACs and conductance. The result shows that a conspicuous structure resembling HR is generated even for a symmetric distribution of the R1-type FACs and that the Hall polarization field is produced at the equatorward boundary of the auroral region as the primary currents diverge/converge at the conductance gradient there, which causes the potential deformation (HR). Conventionally HR has been considered to be of the magnetospheric origin, and a ring current model actually produces the corresponding structure in the magnetosphere [e.g., Erickson et al., 1991]. Observationally the divE equivalent to HR is consistent with the premidnight upward-FAC seen in Iijima and Potemra's diagram. A recent theoretical study [Ohtani et al., 2016] proposes that HR is a required structure for the interchange stability of the magnetotail in the presence of the R1 and R2-FAC systems including a premidnight upward-FAC. Returning to our result, the important point is that HR is reproduced at the conductance edge by the ionospheric polarization field, for which the primary field originates from the R1-FACs distributed far from that region. We also suggest: (i) In a more realistic finite ΣA, the total ionospheric polarization is partly released by a FAC, which may be a part of the premidnight upward-FAC. (ii) However, existing simulation models do not allow this type of current closure, and accordingly they may enhance the HR structure in the magnetosphere. This discussion should hold generally and would promote the global M-I coupling studies to the

  12. The Extent to Which Dayside Reconnection Drives Field-Aligned Currents During Substorms

    NASA Astrophysics Data System (ADS)

    Forsyth, C.; Shortt, M. W.; Coxon, J.; Rae, J.; Freeman, M. P.; Kalmoni, N. M. E.; Jackman, C. M.; Anderson, B. J.

    2016-12-01

    Field-aligned currents, also known as Birkeland currents, are the agents by which energy and momentum is transferred to the ionosphere from the magnetosphere and solar wind. In order to understand this coupling, it is necessary to analyze the variations in these current systems with respect to the main energy sources of the solar wind and substorms. In this study, we perform a superposed epoch analysis of field-aligned currents determined by the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) project with respect to substorm expansion phase onsets identified using the Substorm Onsets and Phases from Indices of the Electrojet (SOPHIE) technique. We examine the total upward and downward currents separately in the noon, dusk, dawn and midnight sectors. Our results show that the dusk and dawn currents have up to a 66% linear correlated with the dayside reconnection rate estimated from solar wind measurements, whereas the noon and midnight currents are not. The noon currents show little or no variation throughout the substorm cycle. The midnight currents follows the dusk currents up to 20 min before onset, after which the midnight current increases more rapidly and exponentially. At substorm onset, the exponential growth rate increases. While the midnight field-aligned currents grow exponentially after substorm onset, the auroral indices vary with a 1/6th power law. Overall, our results show that the growth and decay rates of the Region 1 and 2 current systems, which are strongest at dawn and dusk, are directly driven by the solar wind, whereas the growth and decay rates of the substorm current system, which are dominant at midnight, act independently of the upstream driver.

  13. Individualized FAC on bottom tab subassemblies to minimize adhesive gap between emitter and optics

    NASA Astrophysics Data System (ADS)

    Sauer, Sebastian; Müller, Tobias; Haag, Sebastian; Beleke, Andreas; Zontar, Daniel; Baum, Christoph; Brecher, Christian

    2017-02-01

    High Power Diode Laser (HPDL) systems with short focal length fast-axis collimators (FAC) require submicron assembly precision. Conventional FAC-Lens assembly processes require adhesive gaps of 50 microns or more in order to compensate for component tolerances (e.g. deviation of back focal length) and previous assembly steps. In order to control volumetric shrinkage of fast-curing UV-adhesives shrinkage compensation is mandatory. The novel approach described in this paper aims to minimize the impact of volumetric shrinkage due to the adhesive gap between HPDL edge emitters and FAC-Lens. Firstly, the FAC is actively aligned to the edge emitter without adhesives or bottom tab. The relative position and orientation of FAC to emitter are measured and stored. Consecutively, an individual subassembly of FAC and bottom tab is assembled on Fraunhofer IPT's mounting station with a precision of +/-1 micron. Translational and lateral offsets can be compensated, so that a narrow and uniform glue gap for the consecutive bonding process of bottom tab to heatsink applies (Figure 4). Accordingly, FAC and bottom tab are mounted to the heatsink without major shrinkage compensation. Fraunhofer IPT's department assembly of optical systems and automation has made several publications regarding active alignment of FAC lenses [SPIE LASE 8241-12], volumetric shrinkage compensation [SPIE LASE 9730-28] and FAC on bottom tab assembly [SPIE LASE 9727-31] in automated production environments. The approach described in this paper combines these and is the logical continuation of that work towards higher quality of HPDLs.

  14. Field-aligned currents in Saturn's northern nightside magnetosphere: Evidence for interhemispheric current flow associated with planetary period oscillations

    NASA Astrophysics Data System (ADS)

    Hunt, G. J.; Cowley, S. W. H.; Provan, G.; Bunce, E. J.; Alexeev, I. I.; Belenkaya, E. S.; Kalegaev, V. V.; Dougherty, M. K.; Coates, A. J.

    2015-09-01

    We investigate the magnetic perturbations associated with field-aligned currents observed on 34 Cassini passes over the premidnight northern auroral region during 2008. These are found to be significantly modulated not only by the northern planetary-period oscillation (PPO) system, similar to the southern currents by the southern PPO system found previously, but also by the southern PPO system as well, thus providing the first clear evidence of PPO-related interhemispheric current flow. The principal field-aligned currents of the two PPO systems are found to be co-located in northern ionospheric colatitude, together with the currents of the PPO-independent (subcorotation) system, located between the vicinity of the open-closed field boundary and field lines mapping to ~9 Saturn radius (Rs) in the equatorial plane. All three systems are of comparable magnitude, ~3 MA in each PPO half-cycle. Smaller PPO-related field-aligned currents of opposite polarity also flow in the interior region, mapping between ~6 and ~9 Rs in the equatorial plane, carrying a current of ~ ±2 MA per half-cycle, which significantly reduce the oscillation amplitudes in the interior region. Within this interior region the amplitudes of the northern and southern oscillations are found to fall continuously with distance along the field lines from the corresponding hemisphere, thus showing the presence of cross-field currents, with the southern oscillations being dominant in the south, and modestly lower in amplitude than the northern oscillations in the north. As in previous studies, no oscillations related to the opposite hemisphere are found on open field lines in either hemisphere.

  15. A numerical model of ionospheric convection derived from field-aligned currents and the corresponding conductivity

    NASA Astrophysics Data System (ADS)

    Blomberg, L. G.; Marklund, G. T.

    1988-03-01

    A numerical model for the calculation of ionospheric convection patterns from given distributions of field-aligned current and ionospheric conductivity is described. The model includes a coupling between the conductivity and the field-aligned current, so that the conductivity peaks in regions of upward current, as usually observed by measurements. The model is very flexible in that the input distributions, the field-aligned current, and the conductivity are parameterized in a convenient way. From the primary model output, namely the ionospheric electrostatic potential (or convection) in the corotating frame, a number of other quantities can be computed. These include: the potential in a Sun-fixed frame (the transformation takes into account the nonalignment of the Earth's magnetic and geographic axes); the potential in the magnetospheric equatorial plane (projected using either a dipole magnetic field model or the Tsyganenko-Usmanov model, and the assumption of vanishing parallel electric field); the distribution of ionospheric (horizontal) current; and Joule heating in the ionosphere. The model was used with input data inferred from satellite measurements to calculate the high-latitude potential distribution prevailing during a particular event. The model potential variation along the satellite orbit is found to be in excellent agreement with the measured electric field.

  16. Temporal variations in a four-sheet field-aligned current system and associated aurorae as observed during a Polar-ground magnetic conjunction in the midmorning sector

    NASA Astrophysics Data System (ADS)

    Farrugia, C. J.; Sandholt, P. E.; Maynard, N. C.; Torbert, R. B.; Ober, D. M.

    2003-06-01

    We relate measurements of temporarily varying field-aligned current systems (FACs) and their associated plasmas made by the Polar spacecraft at midmorning local times and likewise temporarily varying aurorae observed from Svalbard, Norway, when the magnetic footprint of the spacecraft passed across the field-of-view of the ground instruments on 3 December 1997. We combine the in situ observations of plasma and magnetic and electric fields with meridian scanning photometry and all-sky imagery from the ground site. The interplanetary magnetic field (IMF) pointed strongly east (By ≫ 0) and generally south. Descending from ˜7.5 to ˜5.5 RE and heading south, Polar traversed a four-sheet current system: a twin-sheet cusp current system C1-C2, spanning 80.6°-77.7° invariant latitudes (ILT), and then the traditional regions 1 (R1) and 2 (R2) currents, extending from 77.7° to 73.3° ILT. A convection reversal separated the C1-C2 from the R1-R2 FACs. Currents C1 and R2 flow out of the ionosphere, while C2 and R1 flow into the ionosphere. Within C1, Polar observed six bursts of ions of typically magnetosheath energies (≤2 keV) repeating every ˜5 min, accompanied by intensified field-aligned electron beams and magnetic field depressions. Auroral data, acquired later but under very similar IMF conditions and at the same latitudes as when Polar was within C1, suggest auroral forms which are pulsed in both red and green lines with a similar period to the plasma bursts observed earlier at Polar. Within C2, at Polar, the pulsing ceased, but magnetosheath plasma was still present, albeit at diminished intensity. This was in part also a temporal change as the IMF clock angle decreased to ˜60°. Equatorward of the cusp aurora we find a mixing region of magnetosheath and magnetospheric plasmas with spectral characteristics of the boundary plasma sheet (BPS) forming the source of the R1 current. Plasma inhomogeneities and bipolar current elements embedded therein were related

  17. On the dynamical development of the downward field-aligned current in the substorm current wedge

    SciTech Connect

    Pellinen, R.J.; Pulkkinen, T.I.; Huuskonen, A.

    1995-08-01

    We report observations of a substorm event on March 4, 1979, onset at 2236 UT, which confirm the participation of the upward accelerated ionospheric electrons in the substorm current wedge current during the first few minutes after the substorm onset. The slow ions do not contribute much to the downward current immediately after the substorm onset, whereas the precipitating magnetospheric electrons quickly set up the upward current. A scanning photometer was centrally placed at the center of the downward current during the event. The observations suggest that the current was mainly caused by cold ionospheric electrons. 27 refs., 8 figs.

  18. Net ionospheric currents closing field-aligned currents in the auroral region: CHAMP results

    NASA Astrophysics Data System (ADS)

    Zhou, Yun-Liang; Lühr, Hermann

    2017-04-01

    By utilizing the high-resolution and precise vector magnetic field measurements from CHAMP during 2001-2005, the characteristics of the net auroral currents calculated by Ampère's integral law are comprehensively investigated. It is found that the net currents deduced from noon-midnight (dawn-dusk) orbits are directed duskward (antisunward). The intensities of the net currents increase linearly when the merging electric field (Em) is growing, exhibiting maximum values of about 2 (1) MA for the net duskward (antisunward) currents when Em exceeds 4 mV/m. For the first time the seasonal variations of the different net currents are shown. The net currents deduced from full orbits show only little seasonal dependence due to a compensation of the effects between the hemispheres. Conversely, the net currents deduced separately for the two hemispheres exhibit prominent seasonal dependences. For the net duskward currents the amplitudes and slopes of Em dependence are both larger by a factor of about 2 in summer than in winter. The related cross-polar cap Pedersen currents are higher in the sunlit hemisphere due to enhanced conductivity. The summer-time duskward currents are larger in the Northern Hemisphere than in the Southern Hemisphere by a factor of 1.5. Conversely, the net antisunward currents show an opposite seasonal dependence. The ratio of summer to winter intensity amounts to about 0.7. In this case the currents are stronger in the Southern Hemisphere.

  19. High current density and low turn-on field from aligned Cd(OH)2 nanosheets

    NASA Astrophysics Data System (ADS)

    Bagal, Vivekanand S.; Patil, Girish P.; Deore, Amol B.; Baviskar, Prashant K.; Suryawanshi, Sachin R.; More, Mahendra A.; Chavan, Padmakar G.

    2016-04-01

    High current density of 9.8 mA/cm2 was drawn at an applied field of 4.1 V/μm from aligned Cd(OH)2 nanosheets and low turn-on field of 1.4 V/μm was found for the emission current density of 10 μA/cm2. The aligned Cd(OH)2 nanosheets were synthesized by CBD technique on Cadmium foil. To the best of our knowledge this is the first report on the field emission studies of Cd(OH)2 nanosheets. Simple synthesis route coupled with superior field emission properties indicate the possible use of Cd(OH)2 nanosheets for micro/nanoelectronic devices.

  20. Field-aligned currents calculated based on the upgraded Prairie View Magnetosphere- ionosphere Coupling Model

    NASA Astrophysics Data System (ADS)

    Romashets, E.; Huang, T.

    2006-12-01

    Using the experimental magnetic field and the newly defined Eular Potentials, we upgraded Prairie View Magnetosphere-ionosphere Coupling Model that was originally created in the frame of IGRF. The electric fields in the ionosphere and the field-aligned currents in the magnetosphere are calculated with the upgraded magnetosphere-ionosphere coupling model, and a preliminary comparison of the calculations with the measurements from ST5 will be presented.

  1. Properties of net ionospheric currents closing field-aligned currents in the auroral region

    NASA Astrophysics Data System (ADS)

    Lühr, Hermann; Zhou, Yun-Liang

    2017-04-01

    Satellite missions offer the opportunity to deduce the net electric current flowing through the orbital loop. Suzuki and Fukushima [1982] were the first to apply Ampère's integral law to the along-track magnetic field component from the Magsat satellite. By utilizing the vector magnetic field measurements from CHAMP during 2001-2005, the characteristics of the net auroral currents calculated in this way are comprehensively investigated. It is found that the net currents deduced from noon-midnight (dawn-dusk) orbits are directed duskward (anti-sunward). The intensities of the net currents increase linearly when the merging electric field (Em) at the magnetopause is growing, exhibiting values of about 2 (1) MA for the net duskward (anti-sunward) currents when Em exceeds 4 mV/m. For the first time the seasonal variations of the different net currents are derived. The net currents deduced from full orbits show only little seasonal dependence due to a compensation of the effects between the hemispheres. Conversely, the net currents deduced separately for the two hemispheres exhibit prominent seasonal dependences. For the net duskward currents the amplitudes are larger by a factor of about 2 in summer than in winter. The related cross-polar cap Pedersen currents are higher in the sunlit hemisphere due to enhanced conductivity. Conversely, the net anti-sunward currents (mainly Hall currents) show an opposite seasonal dependence. The ratio of summer-to-winter intensity amounts to about 0.6. In this case the conductivity gradient from the auroral oval to the polar cap is of importance, which is larger in winter.

  2. On the relationship between morning sector irregular magnetic pulsations and field aligned currents

    NASA Technical Reports Server (NTRS)

    Engebretson, M. J.; Cahill, L. J., Jr.; Potemra, T. A.; Zanetti, L. J.; Arnoldy, R. L.; Mende, S. B.; Rosenberg, T. J.

    1984-01-01

    For three magnetically disturbed days in early 1980, data from south polar masses of the Magsat satellite are compared with data from search coil magnetometer, riometer, and photometer instrumentation at Siple, Antarctica. It is found that during each Magsat polar pass in the morning sector, the level of Pi 1 activity correlates well with the intensities of three-dimensional current systems. Fine structure is often observed in the field-aligned currents during periods of intense Pi activity. Among the Birkeland currents are 2-s to 10-s (16-80 km) structured perturbations; these are evident in the transverse components of the field and are thought to indicate filamentary currents. Pi 1 amplitudes are found to be considerably larger when region 2 Birkeland currents are overhead than when they are not. In one case, detailed features are identified in the high-resolution Magsat magnetic field data that may be current fluctuations related to asymmetric Pi 1.

  3. Relationships between field-aligned currents, electric fields and particle precipitation as observed by dynamics Explorer-2

    NASA Technical Reports Server (NTRS)

    Sugiura, M.; Iyemori, T.; Hoffman, R. A.; Maynard, N. C.; Burch, J. L.; Winningham, J. D.

    1983-01-01

    The relationships between field-aligned currents, electric fields, and particle fluxes are determined using observations from the polar orbiting low-altitude satellite Dynamics Explorer-2. It is shown that the north-south electric field and the east-west magnetic field components are usually highly correlated in the field-aligned current regions. This proportionality observationally proves that the field-aligned current equals the divergence of the height-integrated ionospheric Pedersen current in the meridional plane to a high degree of approximation. As a general rule, in the evening sector the upward field-aligned currents flow in the boundary plasma sheet region and the downward currents flow in the central plasma sheet region. The current densities determined independently from the plasma and magnetic field measurements are compared. Although the current densities deduced from the two methods are in general agreement, the degree and extent of the agreement vary in individual cases.

  4. Relationships between field-aligned currents, electric fields, and particle precipitation as observed by Dynamics Explorer-2

    NASA Technical Reports Server (NTRS)

    Sugiura, M.; Iyemori, T.; Hoffman, R. A.; Maynard, N. C.; Burch, J. L.; Winningham, J. D.

    1984-01-01

    The relationships between field-aligned currents, electric fields, and particle fluxes are determined using observations from the polar orbiting low-altitude satellite Dynamics Explorer-2. It is shown that the north-south electric field and the east-west magnetic field components are usually highly correlated in the field-aligned current regions. This proportionality observationally proves that the field-aligned current equals the divergence of the height-integrated ionospheric Pedersen current in the meridional plane to a high degree of approximation. As a general rule, in the evening sector the upward field-aligned currents flow in the boundary plasma sheet region and the downward currents flow in the central plasma sheet region. The current densities determined independently from the plasma and magnetic field measurements are compared. Although the current densities deduced from the two methods are in general agreement, the degree and extent of the agreement vary in individual cases.

  5. Dynamics of the field-aligned current distribution during a magnetic storm: AMPERE

    NASA Astrophysics Data System (ADS)

    Vassiliadis, D.; Tepke, B. P.

    2015-12-01

    Field-aligned current density in the ionosphere can be used to identify the location and intensity of solar wind-magnetosphere-ionosphere coupling, and help identify the large-scale processes that contribute to this coupling. The Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) mission effectively provides high-resolution spatial and temporal measurements of the radial current during magnetic storms. These in situ measurements are complementary to magnetic remote sensing from the ground using magnetometer arrays. Here we examine two storms, on May 29, 2010 and August 5, 2011, using AMPERE and solar wind data. We identify the regions whose radial current density has the greatest correlation with solar wind coupling functions and individual magnetic and plasma variables. We develop a statistical model of the radial current density from the magnetospheric and solar wind data which is then used to represent regions of outflowing and inflowing current in the two hemispheres. While the model is limited in representing high spatial resolution, time series of regional and global field-aligned current are reproduced with relatively large correlation coefficients (0.70-0.90) in each event.

  6. Field-aligned currents observed in the vicinity of a moving auroral arc

    NASA Astrophysics Data System (ADS)

    Goertz, C. K.; Bruening, K.

    1984-09-01

    The sounding rocket Porcupine F4 was launched into an auroral arc and the field aligned currents were independently deduced from magnetic field measurements; the horizontal current deduced from the electric field measurements and height integrated conductivity calculations; and measurements of electron fluxes. Above the arc the different methods agree. The magnetosphere acts as generator and the ionosphere as load. North of the arc, the first two methods disagree, possibly due to an Alfven wave carrying the observed magnetic field perturbation. The energy flow is out of the ionosphere. Here the ionosphere acts as generator and the magnetosphere as load.

  7. Field-aligned currents observed in the vicinity of a moving auroral arc

    NASA Technical Reports Server (NTRS)

    Goertz, C. K.; Bruening, K.

    1984-01-01

    The sounding rocket Porcupine F4 was launched into an auroral arc and the field aligned currents were independently deduced from magnetic field measurements; the horizontal current deduced from the electric field measurements and height integrated conductivity calculations; and measurements of electron fluxes. Above the arc the different methods agree. The magnetosphere acts as generator and the ionosphere as load. North of the arc, the first two methods disagree, possibly due to an Alfven wave carrying the observed magnetic field perturbation. The energy flow is out of the ionosphere. Here the ionosphere acts as generator and the magnetosphere as load.

  8. Field-Aligned and Ionospheric Current Contributions to Ground Magnetic Perturbations

    NASA Astrophysics Data System (ADS)

    Connors, M. G.; McPherron, R. L.; Anderson, B. J.; Korth, H.; Russell, C. T.; Chu, X.

    2014-12-01

    AMPERE data provides global space-derived radial electric currents on temporal and spatial scales suited to studying magnetic fields at ULF frequencies. It responds little to ionspheric currents, which dominate ground-based measurements, so that AMPERE and ground datasets complement each other to give a comprehensive view of near-Earth electric currents. Connors et al. (GRL, 2014) found that a three-dimensional current system slightly modified from the original substorm current wedge (SCW) concept of McPherron et al. (JGR, 1973) represented substorm midnight sector perturbations well both in the auroral and subauroral regions, if a current equivalent to that found by integrating AMPERE downward current was used, located where clear SCW signatures were indicated by AMPERE, and featuring an ionospheric electrojet. The AMPERE upward current was found to exceed that in the SCW, at least in part since the evening sector electrojet fed into it. We extend these results with a more detailed accounting of field-aligned and ionospheric currents throughout the active period (including growth phase). Ionospheric currents for the study are obtained from ground perturbations through optimization of a simple forward model over regions or on a meridian chain. We also investigate the degree to which subauroral perturbations may be directly calculated from AMPERE results. We further find that auroral zone currents may be very localized, to the extent that the entire SCW ionospheric current flows in a very restricted latitudinal range near onset, possibly corresponding to a single auroral arc.

  9. Field-Aligned Currents in Saturn's Southern Nightside Magnetosphere: Sub-Corotation and Planetary Period Oscillation Currents

    NASA Astrophysics Data System (ADS)

    Hunt, G. J.; Cowley, S. W. H.; Provan, G.; Bunce, E. J.; Alexeev, I. I.; Belenkaya, E. S.; Kalegaev, V. V.; Dougherty, M. K.; Coates, A. J.

    2014-12-01

    We have investigated azimuthal magnetic field data showing the presence of field-aligned current sheets on 31 similar Cassini passes during the 2008 interval of near polar orbits across Saturn's southern post-midnight auroral region at radial distances ~3-5 RS. The currents are found to be strongly modulated in magnitude, form, and position by the phase of the southern planetary period oscillations (PPOs). We separate currents independent of PPO phase from PPO-related currents, by exploiting the expected anti-symmetry of the latter with respect to PPO phase. The PPO-independent current system is thought to be associated mainly with sub-corotation of magnetospheric plasma, and consists of a weak distributed downward current over the whole polar region, enhanced downward currents in a layer mapping to the outer magnetosphere where the ionospheric conductivity is elevated, and a main upward-directed current layer ~2° wide centered at ~18° co-latitude with respect to the southern pole carrying ~2.5 MA per radian of azimuth. The latter current maps to the main region of the hot plasma in Saturn's magnetosphere and is co-located with Saturn's main UV oval in this hemisphere and local time sector. No major currents are detected mapping to the inner equatorial magnetosphere ~4-8 RS dominated by cool Enceladus plasma. The PPO-related currents map to the inner part of the hot plasma region at ~18°-20° co-latitude, and carry rotating upward and downward currents peaking at ~1.7 MA rad-1. The co-latitude of the current layers is also modulated by 1° amplitude in the PPO cycle, with maximum equatorward and poleward excursions adjacent to maximum upward and downward PPO currents, respectively. It is shown that this phasing requires the current system to be driven upward from the planetary atmosphere rather than downward from the magnetosphere.

  10. Dependence of premidnight field-aligned currents and particle precipitation on solar illumination

    NASA Astrophysics Data System (ADS)

    Ohtani, S.; Wing, S.; Ueno, G.; Higuchi, T.

    2009-12-01

    The present study statistically addresses the dependence of large-scale field-aligned currents (R1/R2) and particle precipitation in the premidnight sector on solar illumination at the ionosphere. The energy flux and average energy of precipitating electrons and ions are examined for downward R2 and upward R1 currents. Results are summarized as follows: (1) The R1 current density is larger in the dark hemisphere, whereas the dependence of R2 density on solar illumination is unclear. (2) For R1 currents the electron energy flux is larger and the average electron energy is higher in the dark hemisphere. (3) For R2 currents, a similar preference for the dark hemisphere is found for the electron energy flux, which, however, is significantly lower than for R1 currents. The average electron energy is similar between the two hemispheres. (4) For both R1 and R2 currents, ion precipitation is more intense and energetic in the dark hemisphere. (5) For a given field-aligned current density, whether R1 or R2 currents, both electron and ion precipitation is more intense and energetic in the dark hemisphere. The Pedersen conductivity is estimated from electron precipitation and solar illumination. The result suggests that in the dark hemisphere the absence of solar illumination is often overcompensated by more intense and energetic electron precipitation. The interhemispheric difference in electron acceleration may be interpreted in terms of plasma density in the acceleration region, which is known to be significantly lower in the dark hemisphere, and therefore electrons need to be more accelerated along the field line to carry imposed currents.

  11. Observations of field-aligned currents, waves, and electric fields at substorm onset

    NASA Technical Reports Server (NTRS)

    Smits, D. P.; Hughes, W. J.; Cattell, C. A.; Russell, C. T.

    1986-01-01

    Substorm onsets, identified Pi 2 pulsations observed on the Air Force Geophysics Laboratory Magnetometer Network, are studied using magnetometer and electric field data from ISEE 1 as well as magnetometer data from the geosynchronous satellites GOES 2 and 3. The mid-latitude magnetometer data provides the means of both timing and locating the substorm onset so that the spacecraft locations with respect to the substorm current systems are known. During two intervals, each containing several onsets or intensifications, ISEE 1 observed field-aligned current signatures beginning simultaneously with the mid-latitude Pi 2 pulsation. Close to the earth broadband bursts of wave noise were observed in the electric field data whenever field-aligned currents were detected. One onset occurred when ISEE 1 and GOES 2 were on the same field line but in opposite hemispheres. During this onset ISEE 1 and GOES 2 saw magnetic signatures which appear to be due to conjugate field-aligned currents flowing out of the western end of the westward auroral electrojets. The ISEE 1 signature is of a line current moving westward past the spacecraft. During the other interval, ISEE 1 was in the near-tail region near the midnight meridian. Plasma data confirms that the plasma sheet thinned and subsequently expanded at onset. Electric field data shows that the plasma moved in the opposite direction to the plasma sheet boundary as the boundary expanded which implies that there must have been an abundant source of hot plasma present. The plasma motion was towards the center of the plasma sheet and earthwards and consisted of a series of pulses rather than a steady flow.

  12. Saturn's auroral morphology and field-aligned currents during a solar wind compression

    NASA Astrophysics Data System (ADS)

    Badman, S. V.; Provan, G.; Bunce, E. J.; Mitchell, D. G.; Melin, H.; Nichols, J. D.; Jinks, S. L.; Cowley, S. W. H.; Stallard, T.; Radioti, A.; Pryor, W. R.; Kurth, W. S.; Brown, R. H.; Baines, K. H.; Dougherty, M. K.

    2014-04-01

    During the 2013 auroral observing campaign, instruments onboard Cassini and the Hubble Space Telescope observed Saturn's aurora while Cassini traversed the high latitude auroral field lines. Signatures of upward and downward field-aligned currents were detected on the nightside in the magnetic field and plasma measurements. The location of the upward current corresponded to the bright auroral arc seen in the auroral images, and the downward current region was located poleward of the upward current in an aurorally dark region. A solar wind compression region impacted Saturn's magnetosphere at the start of 2013-112 with the following sequence of effects: (1) intensification and extension to lower frequencies of the Saturn Kilometric Radiation; (2) intensification and spatial expansion of the auroral field-aligned current regions; (3) appearance of a localised, intense bulge in the dawnside aurora while the nightside aurora remained fainter and narrow; (4) latitudinal broadening and poleward contraction of the nightside aurora, where the poleward motion in this sector is opposite to that expected from a model of the auroral oval's usual oscillation. These observations are interpreted as the response to tail reconnection events, initially involving Vasyliunas-type reconnection of closed, mass-loaded magnetotail field lines, and then proceeding onto open lobe field lines, causing the contraction of the polar cap region.

  13. Cross-tail current, field-aligned current, and B(y)

    NASA Technical Reports Server (NTRS)

    Kaufmann, Richard L.; Lu, Chen; Larson, Douglas J.

    1994-01-01

    Orbits of individual charged particles were traced in a one-dimensional magnetic field model that included a uniform cross-tail component B(sub yo). The effects of B(sub yo) on the cross-tail current distribution j(sub y)(z), the average cross-tail drift velocity(nu(sub y)z), and the average pitch angle change(delta alpha) experienced during current sheet encounters were calculated. The addition of a B(sub yo) that exceeded several tenths of one nanotesla completely eliminated all resonance effects for odd-N orbits. An odd-N resonance involves ions that enter and exit the current sheet on the same side. Pitch angles of nearly all such ions changed substantially during a typical current sheet interaction, and there was no region of large cross-tail drift velocity in the presence of a modest B(sub yo). the addition of a very large B(sub yo) guide field in the direction that enhances the natural drift produces a large j(y) and small (Delta alpha) for ions with all energies. The addition of a modest B(sub yo) had less effect near even-N resonances. In this case, ions in a small energy range were found to undergo so little change in pitch angle that particles which originated in the ionosphere would pass through the current sheet and return to the conjugate ionosphere. Finally, the cross-tail drift of ions from regions dominated by stochastic orbits to regions dominated by either resonant or guiding center orbits was considered. The ion drift speed changed substantially during such transitions. The accompanying electrons obey the guiding center equations, so electron drift is more uniform. Any difference between gradients in the fluxes associated with electron and ion drifts requires the presence of a Birkeland current in order to maintain charge neutrality. This plasma sheet region therefore serves as a current generator. The analysis predicts that the resulting Birkeland current connects to the lowest altitude equatorial regions in which ions drift to or from a point

  14. Field-aligned current associated with a distorted two-cell convection pattern during northward interplanetary magnetic field

    NASA Technical Reports Server (NTRS)

    Zhu, L.; Schunk, R. W.; Sojka, J. J.

    1991-01-01

    The influence of the ionospheric conductance on the field-aligned current associated with a distorted two-cell convection pattern during northward IMF was investigated using the Heppner-Maynard (1987) convection model and the Utah State University conductivity model described by Rasmussen and Schunk (1987). Results show that the variation of the ionospheric conductivity distribution can significantly affect the features of the field-aligned current for northward IMF, where matching or mismatching between the conductance gradient and the convection electric field plays a key role. It was found that the increase of the field-aligned current in the polar cap observed during summer is mainly due to the increasing contribution from the Pedersen current, and that the increase of the field-aligned current in both the oval region and the evening-midnight sector during the active aurora period is mainly due to the increasing contribution from the Hall current.

  15. Driven magnetic reconnection in three dimensions - Energy conversion and field-aligned current generation

    NASA Technical Reports Server (NTRS)

    Sato, T.; Walker, R. J.; Ashour-Abdalla, M.

    1984-01-01

    The energy conversion processes occurring in three-dimensional driven reconnection is analyzed. In particular, the energy conversion processes during localized reconnection in a taillike magnetic configuration are studied. It is found that three-dimensional driven reconnection is a powerful energy converter which transforms magnetic energy into plasma bulk flow and thermal energy. Three-dimensional driven reconnection is an even more powerful energy converter than two-dimensional reconnection, because in the three-dimensional case, plasmas were drawn into the reconnection region from the sides as well as from the top and bottom. Field-aligned currents are generated by three-dimensional driven reconnection. The physical mechanism responsible for these currents which flow from the tail toward the ionosphere on the dawnside of the reconnection region and from the ionosphere toward the tail on the duskside is identified. The field-aligned currents form as the neutral sheet current is diverted through the slow shocks which form on the outer edge of the reconnected field lines (outer edge of the plasma sheet).

  16. Field-aligned currents in Saturn's southern nightside magnetosphere: Subcorotation and planetary period oscillation components

    NASA Astrophysics Data System (ADS)

    Hunt, G. J.; Cowley, S. W. H.; Provan, G.; Bunce, E. J.; Alexeev, I. I.; Belenkaya, E. S.; Kalegaev, V. V.; Dougherty, M. K.; Coates, A. J.

    2014-12-01

    We investigate magnetic data showing the presence of field-aligned magnetosphere-ionosphere coupling currents on 31 Cassini passes across Saturn's southern postmidnight auroral region. The currents are strongly modulated in magnitude, form, and position by the phase of the southern planetary period oscillations (PPOs). PPO-independent currents are separated from PPO-related currents using the antisymmetry of the latter with respect to PPO phase. PPO-independent downward currents ~1.1 MA per radian of azimuth flow over the polar open field region indicative of significant plasma subcorotation are enhanced in an outer plasma sheet layer of elevated ionospheric conductivity carrying ~0.8 MA rad-1 and close principally in an upward directed current sheet at ~17°-19° ionospheric colatitude carrying ~2.3 MA rad-1 that maps to the outer hot plasma region in Saturn's magnetosphere (equatorial range ~11-16 Saturn radii (RS)) colocated with the UV oval. Subsidiary downward and upward currents ~0.5 MA rad-1 lie at ~19°-20.5° colatitude mapping to the inner hot plasma region, but no comparable currents are detected at larger colatitudes mapping to the cool plasma regime inside ~8 RS. PPO-related currents at ~17.5°-20° colatitude overlap the main upward and subsidiary downward currents and carry comparable rotating upward and downward currents peaking at ~1.7 MA rad-1. The overall current layer colatitude is also modulated with 1° amplitude in the PPO cycle, maximum equatorward adjacent to the peak upward PPO current and maximum poleward adjacent to peak downward PPO current. This phasing requires the current system to be driven from the planetary atmosphere rather than directly from the magnetosphere.

  17. Macroscopic transport of mega-ampere electron currents in aligned carbon-nanotube arrays.

    PubMed

    Chatterjee, Gourab; Singh, Prashant Kumar; Ahmed, Saima; Robinson, A P L; Lad, Amit D; Mondal, Sudipta; Narayanan, V; Srivastava, Iti; Koratkar, Nikhil; Pasley, John; Sood, A K; Kumar, G Ravindra

    2012-06-08

    We demonstrate that aligned carbon-nanotube arrays are efficient transporters of laser-generated mega-ampere electron currents over distances as large as a millimeter. A direct polarimetric measurement of the temporal and the spatial evolution of the megagauss magnetic fields (as high as 120 MG) at the target rear at an intensity of (10(18)-10(19))  W/cm2 was corroborated by the rear-side hot electron spectra. Simulations show that such high magnetic flux densities can only be generated by a very well collimated fast electron bunch.

  18. Critical currents of aligned grains of Tl-Ba-Ca-Cu-O compounds

    NASA Technical Reports Server (NTRS)

    Fang, M. M.; Finnemore, D. K.; Farrell, D. E.; Bansal, N. R.

    1989-01-01

    A study of irreversibility in the magnetization curves of Tl2Ba2Ca2Cu3O10 and Tl2Ba2Ca1Cu2O8 was undertaken to determine the intragranular critical currents and the effects of flux-creep in grain-aligned samples of these materials. For fields of greater than 0.3 T, and H parallel to c axis, the critical supercurrent falls approximately exponentially with both magnetic field and temperature. Flux-creep is found to be linear in the logarithm of time at low fields over a wide temperature range.

  19. Field-aligned currents and magnetospheric convection - A comparison between MHD simulations and observations

    NASA Technical Reports Server (NTRS)

    Walker, Raymond J.; Ogino, Tatsuki

    1988-01-01

    A time-dependent three-dimensional MHD model was used to investigate the magnetospheric configuration as a function of the interplanetary magnetic field direction when it was in the y-z plane in geocentric solar magnetospheric coordinates. The model results show large global convection cells, tail lobe cells, high-latitude polarcap cells, and low latitude cells. The field-aligned currents generated in the model magnetosphere and the model convection system are compared with observations from low-altitude polar orbiting satellites.

  20. Joule heating and field-aligned currents: Preliminary results from DE-2

    NASA Technical Reports Server (NTRS)

    Sugiura, M.

    1986-01-01

    There are three main processes by which energy is transferred from the magnetosphere to the thermosphere: (1) charge exchange of the ring current particles; (2) precipitation of charged particles; and (3) joule dissipation by the magnetosphere-ionosphere current systems. The importance of this last process has been recognized and the rate of joule heating has been estimated by many workers. Observations of the electric (E) and magnetic (B) fields from Dynamics Explorer Satellite 2 are providing a new set of data on field-aligned currents. One of the remarkable features found in these observations is the high correlation between an orthogonal pair of the E and B field components. In recent years, observational data have accrued concerning the relationship between the interplanetary magnetic field and the size of the polar cap and also about the evolution of a substorm or a magnetic storm. It is suggested that these findings be incorporated in future model calculations.

  1. Saturn's auroral morphology and field-aligned currents during a solar wind compression

    NASA Astrophysics Data System (ADS)

    Badman, S. V.; Provan, G.; Bunce, E. J.; Mitchell, D. G.; Melin, H.; Cowley, S. W. H.; Radioti, A.; Kurth, W. S.; Pryor, W. R.; Nichols, J. D.; Jinks, S. L.; Stallard, T. S.; Brown, R. H.; Baines, K. H.; Dougherty, M. K.

    2016-01-01

    On 21-22 April 2013, during a coordinated auroral observing campaign, instruments onboard Cassini and the Hubble Space Telescope observed Saturn's aurora while Cassini traversed Saturn's high latitude auroral field lines. Signatures of upward and downward field-aligned currents were detected in the nightside magnetosphere in the magnetic field and plasma measurements. The location of the upward current corresponded to the bright ultraviolet auroral arc seen in the auroral images, and the downward current region was located poleward of the upward current in an aurorally dark region. Within the polar cap magnetic field and plasma fluctuations were identified with periods of ∼20 and ∼60 min. The northern and southern auroral ovals were observed to rock in latitude in phase with the respective northern and southern planetary period oscillations. A solar wind compression impacted Saturn's magnetosphere at the start of 22 April 2013, identified by an intensification and extension to lower frequencies of the Saturn kilometric radiation, with the following sequence of effects: (1) intensification of the auroral field-aligned currents; (2) appearance of a localised, intense bulge in the dawnside (04-06 LT) aurora while the midnight sector aurora remained fainter and narrow; and (3) latitudinal broadening and poleward contraction of the nightside aurora, where the poleward motion in this sector is opposite to that expected from a model of the auroral oval's usual oscillation. These observations are interpreted as the response to tail reconnection events, initially involving Vasyliunas-type reconnection of closed mass-loaded magnetotail field lines, and then proceeding onto open lobe field lines, causing the contraction of the polar cap region on the night side.

  2. Validation of a new plasmapause model derived from CHAMP field-aligned current signatures

    NASA Astrophysics Data System (ADS)

    Heilig, Balázs; Darrouzet, Fabien; Vellante, Massimo; Lichtenberger, János; Lühr, Hermann

    2014-05-01

    Recently a new model for the plasmapause location in the equatorial plane was introduced based on magnetic field observations made by the CHAMP satellite in the topside ionosphere (Heilig and Lühr, 2013). Related signals are medium-scale field-aligned currents (MSFAC) (some 10km scale size). An empirical model for the MSFAC boundary was developed as a function of Kp and MLT. The MSFAC model then was compared to in situ plasmapause observations of IMAGE RPI. By considering this systematic displacement resulting from this comparison and by taking into account the diurnal variation and Kp-dependence of the residuals an empirical model of the plasmapause location that is based on MSFAC measurements from CHAMP was constructed. As a first step toward validation of the new plasmapause model we used in-situ (Van Allen Probes/EMFISIS, Cluster/WHISPER) and ground based (EMMA) plasma density observations. Preliminary results show a good agreement in general between the model and observations. Some observed differences stem from the different definitions of the plasmapause. A more detailed validation of the method can take place as soon as SWARM and VAP data become available. Heilig, B., and H. Lühr (2013) New plasmapause model derived from CHAMP field-aligned current signatures, Ann. Geophys., 31, 529-539, doi:10.5194/angeo-31-529-2013

  3. Studies of Westward Electrojets and Field-Aligned Currents in the Magnetotail during Substorms: Implications for Magnetic Field Models

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Our studies elucidated the relationship between the auroral arcs and magnetotail phenomena. One paper examined particle energization in the source region of the field-aligned currents that intensify at substorm onset when the arc brightens to form the westward electrojet. A second paper examined the relationship between the precipitating particles in the arcs, the location of the westward electrojet, and magnetospheric source regions. Two earlier papers also investigated the roles that field aligned currents and particle acceleration have during substorms.

  4. Time-dependent modeling of field-aligned current-generated ion transients in the polar wind

    NASA Technical Reports Server (NTRS)

    Gombosi, T. I.; Nagy, A. F.

    1989-01-01

    The time evolution of field-aligned current-generated transient features in the high-latitude ionosphere is investigated. Ionospheric return currents generate significant downward heavy ion flows in the topside ionosphere with peak values well exceeding 10 to the 8th sq cm/s. When the return current ceases, the polar ionosphere rapidly returns to its previous equilibrium state. During the recovery phase of the return current event, an upward propagating heavy ion transient is formed, which is mainly characterized by a relatively short O(+) upwelling event. On the other hand, the H(+) escape flux remains relatively constant (within 10-20 percent) during field-aligned current events. It is also found that upward currents generate a transient heavy ion outflow, which exceeds the ambient H(+) escape flux by a factor of 3 to 5, depending on the duration and strength of the field-aligned current event.

  5. Observations of field-aligned currents, particles, and plasma drift in the polar cusps near solstice

    NASA Technical Reports Server (NTRS)

    Bythrow, P. F.; Potemra, T. A.; Hoffman, R. A.

    1982-01-01

    Magnetic perturbations observed by the TRIAD magnetometer within two hours of an AE-C spacecraft pass provide field-aligned current data, from the same local time in the northern hemisphere, for a study of the polar cusp. The AE-C spinning mode has allowed the use of the Z-axis magnetometer for Birkeland current observations, in conjunction with particle and drift measurements. The average B(z) were found to be 1.9 nT and -1.1 nT during the first two hourly intervals on January 15, 1977. Measurements from the low energy electron experiment revealed intense fluxes of soft, cusp-like 100 eV Maxwellian electrons throughout the prenoon polar cap. The upward directed current can be identified as the dominant cusp current appropriate for B(y) values lower than zero, while the downward directed current, which has the appropriate sign of a dayside region 1 current, is observed to lie entirely within a westerly, antisunward-convecting plasma.

  6. Terminator field-aligned current system: A new finding from model-assimilated data set (MADS)

    NASA Astrophysics Data System (ADS)

    Zhu, L.; Schunk, R. W.; Scherliess, L.; Sojka, J. J.; Gardner, L. C.; Eccles, J. V.; Rice, D.

    2013-12-01

    Physics-based data assimilation models have been recognized by the space science community as the most accurate approach to specify and forecast the space weather of the solar-terrestrial environment. The model-assimilated data sets (MADS) produced by these models constitute an internally consistent time series of global three-dimensional fields whose accuracy can be estimated. Because of its internal consistency of physics and completeness of descriptions on the status of global systems, the MADS has also been a powerful tool to identify the systematic errors in measurements, reveal the missing physics in physical models, and discover the important dynamical physical processes that are inadequately observed or missed by measurements due to observational limitations. In the past years, we developed a data assimilation model for the high-latitude ionospheric plasma dynamics and electrodynamics. With a set of physical models, an ensemble Kalman filter, and the ingestion of data from multiple observations, the data assimilation model can produce a self-consistent time-series of the complete descriptions of the global high-latitude ionosphere, which includes the convection electric field, horizontal and field-aligned currents, conductivity, as well as 3-D plasma densities and temperatures, In this presentation, we will show a new field-aligned current system discovered from the analysis of the MADS produced by our data assimilation model. This new current system appears and develops near the ionospheric terminator. The dynamical features of this current system will be described and its connection to the active role of the ionosphere in the M-I coupling will be discussed.

  7. 2 CFR 200.36 - Federal Audit Clearinghouse (FAC).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 2 Grants and Agreements 1 2014-01-01 2014-01-01 false Federal Audit Clearinghouse (FAC). 200.36... Clearinghouse (FAC). FAC means the clearinghouse designated by OMB as the repository of record where non-Federal... part. The mailing address of the FAC is Federal Audit Clearinghouse, Bureau of the Census, 1201 E. 10th...

  8. Transient, small-scale field-aligned currents in the plasma sheet boundary layer during storm time substorms

    NASA Astrophysics Data System (ADS)

    Nakamura, R.; Sergeev, V. A.; Baumjohann, W.; Plaschke, F.; Magnes, W.; Fischer, D.; Varsani, A.; Schmid, D.; Nakamura, T. K. M.; Russell, C. T.; Strangeway, R. J.; Leinweber, H. K.; Le, G.; Bromund, K. R.; Pollock, C. J.; Giles, B. L.; Dorelli, J. C.; Gershman, D. J.; Paterson, W.; Avanov, L. A.; Fuselier, S. A.; Genestreti, K.; Burch, J. L.; Torbert, R. B.; Chutter, M.; Argall, M. R.; Anderson, B. J.; Lindqvist, P.-A.; Marklund, G. T.; Khotyaintsev, Y. V.; Mauk, B. H.; Cohen, I. J.; Baker, D. N.; Jaynes, A. N.; Ergun, R. E.; Singer, H. J.; Slavin, J. A.; Kepko, E. L.; Moore, T. E.; Lavraud, B.; Coffey, V.; Saito, Y.

    2016-05-01

    We report on field-aligned current observations by the four Magnetospheric Multiscale (MMS) spacecraft near the plasma sheet boundary layer (PSBL) during two major substorms on 23 June 2015. Small-scale field-aligned currents were found embedded in fluctuating PSBL flux tubes near the separatrix region. We resolve, for the first time, short-lived earthward (downward) intense field-aligned current sheets with thicknesses of a few tens of kilometers, which are well below the ion scale, on flux tubes moving equatorward/earthward during outward plasma sheet expansion. They coincide with upward field-aligned electron beams with energies of a few hundred eV. These electrons are most likely due to acceleration associated with a reconnection jet or high-energy ion beam-produced disturbances. The observations highlight coupling of multiscale processes in PSBL as a consequence of magnetotail reconnection.

  9. Transient, Small-Scale Field-Aligned Currents in the Plasma Sheet Boundary Layer During Storm Time Substorms

    NASA Technical Reports Server (NTRS)

    Nakamura, R.; Sergeev, V. A.; Baumjohann, W.; Plaschke, F.; Magnes, W.; Fischer, D.; Varsani, A.; Schmid, D.; Nakamura, T. K. M.; Russell, C. T.; hide

    2016-01-01

    We report on field-aligned current observations by the four Magnetospheric Multiscale (MMS) spacecraft near the plasma sheet boundary layer (PSBL) during two major substorms on 23 June 2015. Small-scale field-aligned currents were found embedded in fluctuating PSBL flux tubes near the Separatrix region. We resolve, for the first time, short-lived earthward (downward) intense field-aligned current sheets with thicknesses of a few tens of kilometers, which are well below the ion scale, on flux tubes moving equatorward earth ward during outward plasma sheet expansion. They coincide with upward field-aligned electron beams with energies of a few hundred eV. These electrons are most likely due to acceleration associated with a reconnection jet or high-energy ion beam-produced disturbances. The observations highlight coupling of multiscale processes in PSBL as a consequence of magnetotail reconnection.

  10. Transient, small-scale field-aligned currents in the plasma sheet boundary layer during storm time substorms.

    PubMed

    Nakamura, R; Sergeev, V A; Baumjohann, W; Plaschke, F; Magnes, W; Fischer, D; Varsani, A; Schmid, D; Nakamura, T K M; Russell, C T; Strangeway, R J; Leinweber, H K; Le, G; Bromund, K R; Pollock, C J; Giles, B L; Dorelli, J C; Gershman, D J; Paterson, W; Avanov, L A; Fuselier, S A; Genestreti, K; Burch, J L; Torbert, R B; Chutter, M; Argall, M R; Anderson, B J; Lindqvist, P-A; Marklund, G T; Khotyaintsev, Y V; Mauk, B H; Cohen, I J; Baker, D N; Jaynes, A N; Ergun, R E; Singer, H J; Slavin, J A; Kepko, E L; Moore, T E; Lavraud, B; Coffey, V; Saito, Y

    2016-05-28

    We report on field-aligned current observations by the four Magnetospheric Multiscale (MMS) spacecraft near the plasma sheet boundary layer (PSBL) during two major substorms on 23 June 2015. Small-scale field-aligned currents were found embedded in fluctuating PSBL flux tubes near the separatrix region. We resolve, for the first time, short-lived earthward (downward) intense field-aligned current sheets with thicknesses of a few tens of kilometers, which are well below the ion scale, on flux tubes moving equatorward/earthward during outward plasma sheet expansion. They coincide with upward field-aligned electron beams with energies of a few hundred eV. These electrons are most likely due to acceleration associated with a reconnection jet or high-energy ion beam-produced disturbances. The observations highlight coupling of multiscale processes in PSBL as a consequence of magnetotail reconnection.

  11. Current mechanism and band alignment of Al (Pt)/HfGdO/Ge capacitors

    NASA Astrophysics Data System (ADS)

    Junjun, Yuan; Zebo, Fang; Yanyan, Zhu; Bo, Yao; Shiyan, Liu; Gang, He; Yongsheng, Tan

    2016-03-01

    HfGdO high-k gate dielectric thin films were deposited on Ge substrates by radio-frequency magnetron sputtering. The current transport properties of Al(Pt)/HfGdO/Ge MOS structures were investigated at room temperature. The results show that the leakage currents are mainly induced by Frenkel-Poole emissions at a low electric field. At a high electric field, Fowler Nordheim tunneling dominates the current. The energy barriers were obtained by analyzing the Fowler Nordheim tunneling characteristics, which are 1.62 eV and 2.77 eV for Al/HfGdO and Pt/HfGdO, respectively. The energy band alignments for metal/HfGdO/Ge capacitors are summarized together with the results of current-voltage and the x-ray photoelectron spectroscopy. Project supported by the Natural Science Foundation of Shanghai (No. 15ZR1418700), the Natural Science Foundation of China (Nos. 51272159, 61405118), and the Natural Science Foundation of Zhejiang (Nos. LY15A040001, LQ13A040004).

  12. Electrode Degradation Study of Vertically Aligned Carbon Nanotubes on a 3D Integrated Current Collector

    SciTech Connect

    Schroeder, Marshall A.; Pearse, Alexander J.; Kozen, Alexander C.; Lee, Sang Bok; Rubloff, Gary W.; Noked, Malachi

    2015-01-01

    Assembling nanostructured materials into rationally designed mesoscale arrays for use as electrodes in electrochemical systems is anticipated to reveal new challenges, particularly concerning new synthesis modes, architecture-related performance limitations, and degradation mechanisms. In this work, we focus on characterizing the degradation of densely packed vertically aligned carbon nanotubes (VACNTs) grown directly on a metallic foam to form a self-supporting, hierarchically porous 3D electrode architecture with an integrated current collector. The degradation pathways of this electrode, observed with microscopy and semi in-situ XPS after cycling as a redox scaffold in aprotic Li—O2 and Li—S batteries, shed new light on important design, performance, and degradation considerations for integrated mesoscale electrode architectures.

  13. A seasonal change in the effect of field-aligned currents at synchronous orbit

    NASA Technical Reports Server (NTRS)

    Mcpherron, R. L.; Barfield, J. N.

    1980-01-01

    The expected signature of substorm field-aligned currents is described for synchronous satellites near 10 deg magnetic latitude. The main effect is a positive D perturbation premidnight and a negative D perturbation postmidnight. This behavior is illustrated for two substorms near the fall equinox. A second pair of substorms taken from winter solstice do not show the expected behavior. The absence of this effect in winter observations is verified statistically by superposed epoch analysis. A simple explanation of this behavior based on the geometry of the plane of magnetic symmetry is presented. During disturbed times at winter solstice a synchronous satellite nominally at 10 deg magnetic latitude is effectively at the magnetic equator. This distortion of the magnetic equator must be considered in future models of the disturbed magnetospheric magnetic field.

  14. Field line twist and field-aligned currents in an axially symmetric equilibrium magnetosphere. [of Uranus

    NASA Technical Reports Server (NTRS)

    Voigt, Gerd-Hannes

    1986-01-01

    Field-aligned Birkeland currents and the angle of the magnetic line twist were calculated for an axially symmetric pole-on magnetosphere (assumed to be in MHD equilibrium). The angle of the field line twist was shown to have a strong radial dependence on the axisymmetric magnetotail as well as on the ionospheric conductivity and the amount of thermal plasma contained in closed magnetotail flux tubes. The field line twist results from the planetary rotation, which leads to the development of a toroidal magnetic B-sub-phi component and to differentially rotating magnetic field lines. It was shown that the time development of the toroidal magnetic B-sub-phi component and the rotation frequency are related through an induction equation.

  15. An MHD simulation of By-dependent magnetospheric convection and field-aligned currents during northward IMF

    NASA Technical Reports Server (NTRS)

    Ogino, T.; Walker, R. J.; Ashour-Abdalla, M.; Dawson, J. M.

    1985-01-01

    A three-dimensional MHD simulation code is used to model the magnetospheric configuration when the IMF has both a northward B(z) component and a B(y) component in the east-west direction. Projections of the plasma pressure, the field-aligned velocity, the field-aligned vorticity, and the field-aligned current along the magnetic field lines into the northern ionosphere are shown and discussed. Cross-sectional patterns of these parameters are shown. The results demonstrate that the B(y) component of the IMF strongly influences the plasma sheet configuration and the magnetospheric convection pattern.

  16. Climatology of the inter-hemispheric field-aligned currents system over the Nigeria ionosphere

    NASA Astrophysics Data System (ADS)

    Bolaji, O. S.; Rabiu, A. B.; Oyeyemi, E. O.; Yumoto, K.

    2012-11-01

    Records of the declination (D) magnetic field data for the year 2009 from the Magnetic Data Acquisition System (MAGDAS) facilities at University of Ilorin were employed for this work. From the minutes value of the D-component, the deduced hourly values of the D-component (Sq(QD)) were used to estimate its diurnal (Sq(D)) values with the most five quietest days identified. The monthly mean (MSq(D)) of the most five quietest days and their seasonal (SSq(D)) variabilities were investigated. The inter-hemispheric field aligned currents (IHFACs) exhibit downward and upward inter-hemispheric field-aligned sheet current that appears as a pair at all local times of the Sq(D), MSq(D), and SSq(D) variations. From these variabilities, the IHFACs were observed to flow from the winter to summer hemisphere during noon and dusk sector and flowing in opposite direction during the dawn sector. The Sq(D) variability patterns that were observed in May, June, August September are gentle compared to the disturbed variabilities in January, February, March and November. The highest positive (˜1.7 arc-min) and negative (˜-2.7 arc min) MSq(D) maxima values were observed in August during the dawn and noon sectors respectively. These values indicated that the IHFACs flow in August is strongly southbound (positive) and northbound (negative) in the dawn and noon sectors respectively. Dusk-side IHFACs as can be observed by MAGDAS are weakly northbound in all the seasons. The direction of IHFACs does not flip at the equinoxes but in June and November and does not become largest at solstices but in August. The IHFACs was observed to exhibit longitudinal variability, which indicated that larger amplitude of winter-to-summer IHFACs is observed to be greater in June solstice (northbound/negative IHFACs) than in the December solstice (southbound/positive IHFACs) during the noon sector.

  17. KINETIC ALFVEN WAVE INSTABILITY DRIVEN BY FIELD-ALIGNED CURRENTS IN SOLAR CORONAL LOOPS

    SciTech Connect

    Chen, L.; Wu, D. J. E-mail: djwu@pmo.ac.cn

    2012-08-01

    Magneto-plasma loops, which trace closed solar magnetic field lines, are the primary structural elements of the solar corona. Kinetic Alfven wave (KAW) can play an important role in inhomogeneous heating of these magneto-plasma structures in the corona. By the use of a low-frequency kinetic dispersion equation, which is presented in this paper and is valid in a finite-{beta} plasma with Q < {beta} < 1 plasma (where {beta} is the kinetic to magnetic pressure ratio and Q = m{sub e} /m{sub i} is the mass ratio of electrons to ions), KAW instability driven by a field-aligned current in the current-carrying loops in the solar corona is investigated. The results show that the KAW instability can occur in wave number regimes 0 < k{sub z} < k{sup c}{sub z} and 0 < k < k{sup c} , and that the critical wave numbers k{sup c}{sub z} and k{sup c} and the growth rate both considerably increase as the drift velocity V{sub D} of the current-carrying electrons increases in the loops. In particular, for typical parameters of the current-carrying loops in the solar corona this instability mechanism results in a high growth rate of KAWs, {omega}{sub i} {approx} 0.01-0.1{omega}{sub ci} {approx} 10{sup 3}-10{sup 4} s{sup -1}. The results are of importance in understanding the physics of the electric current dissipation and plasma heating of the current-carrying loops in the solar corona.

  18. High Latitude Precipitating Energy Flux and Joule Heating During Geomagnetic Storms Determined from AMPERE Field-aligned Currents

    NASA Astrophysics Data System (ADS)

    Robinson, R. M.; Zanetti, L. J.; Anderson, B. J.; Korth, H.; Samara, M.; Michell, R.; Grubbs, G. A., II; Hampton, D. L.; Dropulic, A.

    2016-12-01

    A high latitude conductivity model based on field-aligned currents measured by the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) provides the means for complete specification of electric fields and currents at high latitudes. Based on coordinated measurements made by AMPERE and the Poker Flat Incoherent Scatter Radar, the model determines the most likely value of the ionospheric conductance from the direction, magnitude, and magnetic local time of the field-aligned current. A conductance model driven by field-aligned currents ensures spatial and temporal consistency between the calculated electrodynamic parameters. To validate the results, the Pedersen and Hall conductances were used to calculate the energy flux associated with the energetic particle precipitation. When integrated over the entire hemisphere, the total energy flux compares well with the Hemispheric Power Index derived from the OVATION-PRIME model. The conductances were also combined with the field-aligned currents to calculate the self-consistent electric field, which was then used to compute horizontal currents and Joule heating. The magnetic perturbations derived from the currents replicate most of the variations observed in ground-based magnetograms. The model was used to study high latitude particle precipitation, currents, and Joule heating for 24 magnetic storms. In most cases, the total energy input from precipitating particles and Joule heating exhibits a sharply-peaked maximum at the times of local minima in Dst, suggesting a close coupling between the ring current and the high latitude currents driven by the Region 2 field-aligned currents. The rapid increase and decrease of the high latitude energy deposition suggests an explosive transfer of energy from the magnetosphere to the ionosphere just prior to storm recovery.

  19. Optical Alignment of the JWST ISIM to the OTE Simulator (OSIM): Current Concept and Design Studies

    NASA Technical Reports Server (NTRS)

    Frey, Bradley J.; Davila, Pamela S.; Marsh, James M.; Ohl, Raymond G.; Sullivan, Joseph

    2007-01-01

    The James Webb Space Telescope's (JWST) Integrated Science Instrument Module (ISIM) is the scientific payload of the observatory and contai ns four science instruments. During alignment and test of the integrated ISIM (i.e. ISIM + science instruments) at NASA's Goddard Space Fli ght Center (GSFC), the Optical telescope element SIMulator (OSIM) wil l be used to optically stimulate the science instruments to verify their operation and performance. In this paper we present the design of two cryogenic alignment fixtures that will be used to determine and verify the proper alignment of OSIM to ISIM during testing at GSFC. The se fixtures, the Master Alignment Target Fixture (MATF) and the ISIM Alignment Target Fixture (IATF), will provide continuous, 6 degree of freedom feedback to OSIM during initial ambient alignment as well as during cryogenic vacuum testing.

  20. Transition from Meso-scale to Macro-scale Field-aligned Currents as Observed by Magnetospheric Multiscale

    NASA Astrophysics Data System (ADS)

    Strangeway, Robert J.; Russell, Christopher T.; Zhao, Cong; Wei, Hanying; Magnes, Werner; Bromund, Kenneth R.; Plaschke, Ferdinand; Fischer, David; Anderson, Brian J.; Le, Guan; Kepko, Larry; Chutter, Mark; Slavin, James A.; Nakamura, Rumi; Baumjohann, Wolfgang; Paterson, William R.; Giles, Barbara L.; Torbert, Roy B.; Burch, James L.

    2017-04-01

    The four spacecraft Magnetospheric Multiscale (MMS) mission allows for current densities to be derived from the differences in the magnetic fields as measured at the four spacecraft, a technique that is referred to as a curlometer. The curlometer-derived currents densities at the magnetopause can be very large, of the order of 100s of nA/m2. These current densities are sufficiently large that they are readily observable in the corresponding particle measurements, and the current densities derived from the curlometer and the corresponding particle fluxes are often in close agreement. But there is also a consequence of such large current densities in terms of current closure. In particular, field-aligned currents of this magnitude on closed field lines almost certainly do not propagate to the ionosphere, since the change in flux-tube area is about a factor of 1000. The corresponding current densities would be of the order 100s of μA/m2 if mapped to the ionosphere. In addition, the spatial scale in the ionosphere would only be a few km. However, while the larger density field-aligned currents appear to close locally, lower density field-aligned currents are observed away from the higher density magnetopause-related currents. This suggests that the magnetopause field-aligned currents are meso-scale currents closing locally, which transition to the lower density macro-scale currents associated with the larger scale Region-1 class of currents that are in turn required in order to impose convection on the high latitude polar and auroral-zone ionosphere.

  1. Ion gyroradius effects on Alfvenic field aligned currents and electron energization in planetary magnetospheres.

    NASA Astrophysics Data System (ADS)

    Damiano, P. A.; Johnson, J.; Chaston, C. C.; Fox, W. R., II; Delamere, P. A.; Stauffer, B. H.

    2015-12-01

    Alfvenic current systems are a ubiquitous feature of planetary magnetospheres that can be generated by several mechanisms including the braking of flows (e.g. associated with reconnection at substorm onset) and via moon-planet interactions. The energetic electrons needed to carry the field-aligned currents are generally thought to be accelerated on either electron inertial or ion acoustic gyroradius scale lengths in the limit of inertial and kinetic Alfven waves respectively. Recent 2D dipolar hybrid gyrofluid-kinetic electron simulations of kinetic Alfven waves (Damiano et al., JGR, 2015), associated with the braking of fast flows in the terrestrial magnetotail, have illustrated that hot ion effects can act to limit the extent of the parallel current (all along the field line) from what would be expected in the cold ion limit. This correspondingly affects the characteristics of the electron energization, reducing both the parallel elongation in the electron distribution function associated with electron trapping in the kinetic Alfven wave regime and the extent of high energy tails evident in the inertial Alfven wave region above the ionosphere. In this presentation, we build on these initial simulation results analyzing the characteristics of the parallel current system and electron acceleration (associated with both inertial and kinetic Alfven waves) for a range of wave amplitudes and ratios of the electron to ion temperature. One finding is that for a given ion temperature, increasing wave amplitude recovers some of the features of the electron energization evident in the cold ion limit, but this is modulated by the effect of wave energy dispersion perpendicular to the ambient magnetic field. These results will be summarized and the relevance and extension of this work to consider Alfvenic aurora in the Jupiter magnetosphere (e.g. via either interchange motion or the Io-Jupiter interaction) will also be discussed.

  2. Space Technology 5 (ST-5) Multipoint Observations of Temporal and Spatial Variability of Field-Aligned Currents

    NASA Technical Reports Server (NTRS)

    Le, Guan

    2010-01-01

    Space Technology 5 (ST-5) is a three micro-satellite constellation deployed into a 300 x 4500 km, dawn-dusk, sun-synchronous polar orbit from March 22 to June 21, 2006, for technology validations. In this paper, we present a study of the temporal variability of field-aligned currents using multi-point magnetic field measurements from ST5. The data demonstrate that mesoscale current structures are commonly embedded within large-scale field-aligned current sheets. The meso-scale current structures are very dynamic with highly variable current density and/or polarity in time scales of about 10 min. They exhibit large temporal variations during both quiet and disturbed times in such time scales. On the other hand, the data also shown that the time scales for the currents to be relatively stable are about 1 min for meso-scale currents and about 10 min for large scale current sheets. These temporal features are obviously associated with dynamic variations of their particle carriers (mainly electrons) as they respond to the variations of the parallel electric field in auroral acceleration region. The characteristic time scales for the temporal variability of meso-scale field-aligned currents are found to be consistent with those of auroral parallel electric field.

  3. Space Technology 5 Multi-point Observations of Field-aligned Currents: Temporal Variability of Meso-Scale Structures

    NASA Technical Reports Server (NTRS)

    Le, Guan; Wang, Yongli; Slavin, James A.; Strangeway, Robert J.

    2007-01-01

    Space Technology 5 (ST5) is a three micro-satellite constellation deployed into a 300 x 4500 km, dawn-dusk, sun-synchronous polar orbit from March 22 to June 21, 2006, for technology validations. In this paper, we present a study of the temporal variability of field-aligned currents using multi-point magnetic field measurements from ST5. The data demonstrate that meso-scale current structures are commonly embedded within large-scale field-aligned current sheets. The meso-scale current structures are very dynamic with highly variable current density and/or polarity in time scales of - 10 min. They exhibit large temporal variations during both quiet and disturbed times in such time scales. On the other hand, the data also shown that the time scales for the currents to be relatively stable are approx. 1 min for meso-scale currents and approx. 10 min for large scale current sheets. These temporal features are obviously associated with dynamic variations of their particle carriers (mainly electrons) as they respond to the variations of the parallel electric field in auroral acceleration region. The characteristic time scales for the temporal variability of meso-scale field-aligned currents are found to be consistent with those of auroral parallel electric field.

  4. Space Technology 5 Multi-point Observations of Field-aligned Currents: Temporal Variability of Meso-Scale Structures

    NASA Technical Reports Server (NTRS)

    Le, Guan; Wang, Yongli; Slavin, James A.; Strangeway, Robert J.

    2007-01-01

    Space Technology 5 (ST5) is a three micro-satellite constellation deployed into a 300 x 4500 km, dawn-dusk, sun-synchronous polar orbit from March 22 to June 21, 2006, for technology validations. In this paper, we present a study of the temporal variability of field-aligned currents using multi-point magnetic field measurements from ST5. The data demonstrate that meso-scale current structures are commonly embedded within large-scale field-aligned current sheets. The meso-scale current structures are very dynamic with highly variable current density and/or polarity in time scales of - 10 min. They exhibit large temporal variations during both quiet and disturbed times in such time scales. On the other hand, the data also shown that the time scales for the currents to be relatively stable are approx. 1 min for meso-scale currents and approx. 10 min for large scale current sheets. These temporal features are obviously associated with dynamic variations of their particle carriers (mainly electrons) as they respond to the variations of the parallel electric field in auroral acceleration region. The characteristic time scales for the temporal variability of meso-scale field-aligned currents are found to be consistent with those of auroral parallel electric field.

  5. Alternating current impedance spectroscopic analysis of biofunctionalized vertically-aligned silica nanospring surface for biosensor applications

    NASA Astrophysics Data System (ADS)

    Timalsina, Yukta P.

    In this dissertation, a process of vertically-aligned (silica) nanosprings (VANS) based biosensor development is presented. Alternating current (AC) impedance spectroscopy has been used to analyze sensor response as a function of saline phosphate (SP) buffer and biological solutions. The sensor is a parallel plate capacitor consisting of two glass substrates coated with indium tin oxide (ITO), where the VANS [or randomly-aligned nanosprings (RANS)] grown on one substrate serve as the dielectric spacer layer. The response of a VANS device as a function of ionic concentration in SP buffer was examined and an equivalent circuit model was developed. The results demonstrated that VANS sensors exhibited greater sensitivity to the changes in SP concentration relative to the ITO sensors, which serve as controls. The biofunctionalized VANS surface via physisorption and the cross-linker method demonstrates the repeatability, specificity, and selectivity of the binding. The physisorption of biotinylated immunoglobulin G (B-IgG) onto the VANS surface simplifies the whole sensing procedure for the detection of glucose oxidase, since the avidin-conjugated glucose oxidase (Av-GOx) can directly be immobilized on the B-IgG. The cross linker method involves the covalent attachment of antibodies onto the functionalized VANS surface via imine bond. The experiments revealed that the VANS sensor response is solely the result of the interaction of target molecule i.e. mouse IgG with the probe layer, i.e. goat antimouse IgG (GalphaM IgG). It was determined that VANS-based sensors exhibit a greater magnitude of change between successive bio-layers relative to the controls above 100 Hz, which indicates that the addition of biomolecules inhibits the diffusion of ions and changes the effective dielectric response of the VANS via biomolecular polarization. The study of ionic transport in nanosprings suggested that conductance follows a scaling law. It was demonstrated that a VANS-based device

  6. Superposed epoch analysis of vertical plasma flow and its relationship with FACs as observed by DMSP and CHAMP: IMF By and Bx dependence

    NASA Astrophysics Data System (ADS)

    Kervalishvili, Guram; Lühr, Hermann

    2016-04-01

    This study presents results of a superposed epoch analysis (SEA) method applied to vertical plasma flow and large-scale field aligned currents (FACs) in the Northern Hemisphere cusp region. Our study is based on DMSP (F13 and F15) and CHAMP satellite observations during the years 2001-2005. Interplanetary magnetic field (IMF) data were taken from the NASA/GSFC's OMNI online database. The dependence on IMF By and Bx component orientation is investigated, while the absolute amplitude of IMF Bz is selected to be less than 2 nT. Seasonal variations are also investigated with seasons defined as follows: local winter (1 January ± 65 days), combined equinoxes (1 April and 1 October ± 32 days), and local summer (1 July ± 65 days). The reference time and location for the SEA method are taken from the vertical ion velocity peaks (> 100 m/s for upflow and <-100 m/s for downflow) detected by DMSP in the northern cusp region. Our analyses were performed in the magnetic latitude (MLat) and local time (MLT) coordinate system. In general the vertical plasma downflow is weaker than the upflow. This product, ion density times velocity, shows no dependence on the IMF By orientation, while its value increases towards local summer. The ion density is low in winter and increases towards local summer, while the vertical velocity is much higher in local winter than during equinoxes or local summer. The event number distribution (in MLat-MLT frame) of vertical ion velocity peaks shows no significant dependence on the given conditions. In case of large-scale FACs a clear dependence on IMF By orientation and local season emerges from SEA analysis. Similarly to the vertical plasma upflow, the amplitude of large-scale FACs is also increasing towards local summer. Large-scale FACs show an IMF By dependent regular pattern for upflow cases and no regular pattern for downflow cases in all considered cases.

  7. Magnetopause Erosion During the 17 March 2015 Magnetic Storm: Combined Field-Aligned Currents, Auroral Oval, and Magnetopause Observations

    NASA Technical Reports Server (NTRS)

    Le, G.; Luehr, H.; Anderson, B. J.; Strangeway, R. J.; Russell, C. T.; Singer, H.; Slavin, J. A.; Zhang, Y.; Huang, T.; Bromund, K.; hide

    2016-01-01

    We present multimission observations of field-aligned currents, auroral oval, and magnetopause crossings during the 17 March 2015 magnetic storm. Dayside reconnection is expected to transport magnetic flux, strengthen field-aligned currents, lead to polar cap expansion and magnetopause erosion. Our multimission observations assemble evidence for all these manifestations. After a prolonged period of strongly southward interplanetary magnetic field, Swarm and AMPERE observe significant intensification of field-aligned currents .The dayside auroral oval, as seen by DMSP, appears as a thin arc associated with ongoing dayside reconnection. Both the field-aligned currents and the auroral arc move equatorward reaching as low as approx. 60 deg. magnetic latitude. Strong magnetopause erosion is evident in the in situ measurements of the magnetopause crossings by GOES 13/15 and MMS. The coordinated Swarm, AMPERE, DMSP, MMS and GOES observations, with both global and in situ coverage of the key regions, provide a clear demonstration of the effects of dayside reconnection on the entire magnetosphere.

  8. Magnetopause erosion during the 17 March 2015 magnetic storm: Combined field-aligned currents, auroral oval, and magnetopause observations

    NASA Astrophysics Data System (ADS)

    Le, G.; Lühr, H.; Anderson, B. J.; Strangeway, R. J.; Russell, C. T.; Singer, H.; Slavin, J. A.; Zhang, Y.; Huang, T.; Bromund, K.; Chi, P. J.; Lu, G.; Fischer, D.; Kepko, E. L.; Leinweber, H. K.; Magnes, W.; Nakamura, R.; Plaschke, F.; Park, J.; Rauberg, J.; Stolle, C.; Torbert, R. B.

    2016-03-01

    We present multimission observations of field-aligned currents, auroral oval, and magnetopause crossings during the 17 March 2015 magnetic storm. Dayside reconnection is expected to transport magnetic flux, strengthen field-aligned currents, lead to polar cap expansion and magnetopause erosion. Our multimission observations assemble evidence for all these manifestations. After a prolonged period of strongly southward interplanetary magnetic field, Swarm and AMPERE observe significant intensification of field-aligned currents. The dayside auroral oval, as seen by DMSP, appears as a thin arc associated with ongoing dayside reconnection. Both the field-aligned currents and the auroral arc move equatorward reaching as low as ~60° magnetic latitude. Strong magnetopause erosion is evident in the in situ measurements of the magnetopause crossings by GOES 13/15 and MMS. The coordinated Swarm, AMPERE, DMSP, MMS and GOES observations, with both global and in situ coverage of the key regions, provide a clear demonstration of the effects of dayside reconnection on the entire magnetosphere.

  9. Euler potentials for two layers with non-constant current densities in the ambient magnetic field aligned to the layers

    NASA Astrophysics Data System (ADS)

    Vandas, Marek; Romashets, Eugene P.

    2016-12-01

    The Euler potentials for two current layers aligned to an ambient homogeneous magnetic field are found. Previous treatment of such a system assumed constant current density in the layers. However, the magnetic field becomes infinite at the edges. The new approach eliminates this inconsistency by introducing an inhomogeneous current density. Euler potentials are constructed semi-analytically for such a system. Charged-particle motion and trapping in it are examined by this representation. Using Euler potentials, the influence of current sheets of zero and non-zero thicknesses on energetic-particle fluxes is investigated, and characteristic flux variations near the sheets are presented. The results can be applied to Birkeland currents.

  10. Microfluidics microFACS for Life Detection

    NASA Technical Reports Server (NTRS)

    Platt, Donald W.; Hoover, Richard B.

    2010-01-01

    A prototype micro-scale Fluorescent Activated Cell Sorter (microFACS) for life detection has been built and is undergoing testing. A functional miniature microfluidics instrument with the ability to remotely distinguish live or dead bacterial cells from abiotic particulates in ice or permafrost of icy bodies of the solar system would be of fundamental value to NASA. The use of molecular probes to obtain the bio-signature of living or dead cells could answer the most fundamental question of Astrobiology: Does life exist beyond Earth? The live-dead fluorescent stains to be used in the microFACS instrument function only with biological cell walls. The detection of the cell membranes of living or dead bacteria (unlike PAH's and many other Biomarkers) would provide convincing evidence of present or past life. This miniature device rapidly examine large numbers of particulates from a polar ice or permafrost sample and distinguish living from dead bacteria cells and biological cells from mineral grains and abiotic particulates and sort the cells and particulates based on a staining system. Any sample found to exhibit fluorescence consistent with living cells could then be used in conjunction with a chiral labeled release experiment or video microscopy system to seek addition evidence for cellular metabolism or motility. Results of preliminary testing and calibration of the microFACS prototype instrument system with pure cultures and enrichment assemblages of microbial extremophiles will be reported.

  11. Kinetic Alfven Waves Carrying Intense Field Aligned Currents: Particle Trapping and Electron Acceleration

    NASA Astrophysics Data System (ADS)

    Rankin, R.; Artemyev, A.

    2015-12-01

    It is now common knowledge that dispersive scale Alfvén waves can drive parallel electron acceleration [Lotko et al., JGR, 1998; Samson et al., Ann. Geophys., 2003; Wygant et al., JGR, 2002] and transverse ion energization in the auroral zone and inner magnetosphere [Johnson and Cheng, JGR, 2001; Chaston et al., 2004]. In this paper we show that relatively low energy electrons (plasma sheet electrons with energies ranging up to ˜100 eV) can be accelerated very efficiently as they interact nonlinearly with kinetic Alfvén waves (KAWs) that carry intense field aligned currents from the equatorial plane toward the ionosphere in the inner magnetosphere. We propose a theoretical model describing electron trapping into an effective wave potential generated by parallel wave electric fields (with perpendicular wavelengths on the order of the ion gyro-radius) and the mirror force acting on electrons as they propagate along geomagnetic field lines. We demonstrate that waves with an electric potential amplitude between ~100 - 400 V can trap and accelerate electrons to energies approaching several keVs. Trapping acceleration corresponds to conservation of the electron magnetic moment and, thus, results in a significant decrease of the electron equatorial pitch-angle with time. Analytical and numerical estimates of the maximum energy and probability of trapping are presented. We discuss the application of the proposed model in light of recent observations of electromagnetic fluctuations in the inner magnetosphere that are present during periods of strong geomagnetic activity [Chaston et al., GRL, 2014; Califf et al., JGR, 2015].

  12. Alternating current impedance spectroscopic analysis of biofunctionalized vertically-aligned silica nanospring surface for biosensor applications

    NASA Astrophysics Data System (ADS)

    Timalsina, Yukta P.; Branen, Joshua; Aston, D. Eric; Noren, Kenneth; Corti, Giancarlo; Schumacher, Randi; McIlroy, David N.

    2011-07-01

    In this study, alternating current impedance spectroscopic analysis of the biofunctionalization process of a vertically-aligned (silica) nanosprings (VANS) surface is presented. The VANS surface is functionalized with a biotinylated immunoglobulin G (B-IgG) layer formed by physisorption of B-IgG from the solution phase. Bovine serum albumin passivation of the B-IgG layer reduces additional surface adsorption by blocking the potential sites of weak bond formation via electrostatic and hydrophobic interactions. As avidin acts as a receptor of biotinylated compounds, avidin conjugated glucose oxidase (Av-GOx) binds to the B-IgG layer via biotin. This avidin-biotin bond is a stable bond with high association affinity (Ka = 1015 M-1) that withstands wide variations in chemistry and pH. An IgG layer without biotin shows no binding to the Av-GOx, indicating that bonding is through the avidin-biotin interaction. Finally, fluoroscein iso-thiocyanate (FITC) labeled biotinylated bovine serum albumin (B-BSA) added to the Av-GOx surface is used to fluorescently label Av-GOx for fluorescent measurements that allow for the correlation of surface binding with impedance measurements. Modeling of impedance spectra measured after the addition of each biological solution indicates that the bimolecular layers behave as insulating layers. The impedance spectra for the VANS-based sensor are compared to simple parallel capacitor sensors, sans VANS, and serve as controls. VANS-based sensors exhibit a greater magnitude of change between successive bio-layers relative to the controls below 10 kHz. Changes in the magnitudes of the components of the VANS equivalent circuit indicate that the addition of biological layers changes the effective dielectric response of the VANS via the impediment of ionic motion and biomolecule polarization.

  13. A Comprehensive Benchmark Study of Multiple Sequence Alignment Methods: Current Challenges and Future Perspectives

    PubMed Central

    Thompson, Julie D.; Linard, Benjamin; Lecompte, Odile; Poch, Olivier

    2011-01-01

    Multiple comparison or alignmentof protein sequences has become a fundamental tool in many different domains in modern molecular biology, from evolutionary studies to prediction of 2D/3D structure, molecular function and inter-molecular interactions etc. By placing the sequence in the framework of the overall family, multiple alignments can be used to identify conserved features and to highlight differences or specificities. In this paper, we describe a comprehensive evaluation of many of the most popular methods for multiple sequence alignment (MSA), based on a new benchmark test set. The benchmark is designed to represent typical problems encountered when aligning the large protein sequence sets that result from today's high throughput biotechnologies. We show that alignmentmethods have significantly progressed and can now identify most of the shared sequence features that determine the broad molecular function(s) of a protein family, even for divergent sequences. However,we have identified a number of important challenges. First, the locally conserved regions, that reflect functional specificities or that modulate a protein's function in a given cellular context,are less well aligned. Second, motifs in natively disordered regions are often misaligned. Third, the badly predicted or fragmentary protein sequences, which make up a large proportion of today's databases, lead to a significant number of alignment errors. Based on this study, we demonstrate that the existing MSA methods can be exploited in combination to improve alignment accuracy, although novel approaches will still be needed to fully explore the most difficult regions. We then propose knowledge-enabled, dynamic solutions that will hopefully pave the way to enhanced alignment construction and exploitation in future evolutionary systems biology studies. PMID:21483869

  14. Comparison of auroral ionospheric and field-aligned currents derived from Swarm and ground magnetic field measurements

    NASA Astrophysics Data System (ADS)

    Juusola, L.; Kauristie, K.; Vanhamäki, H.; Aikio, A.; Kamp, M.

    2016-09-01

    Derivation of the auroral ionospheric currents from magnetic field measurements can produce drastically different results depending on the data and method used. We have cross tested several methods for obtaining instantaneous field-aligned and horizontal currents from Swarm satellite and International Monitor for Auroral Geomagnetic Effects (IMAGE) ground magnetic field measurements. We found that Swarm can yield latitude profiles of the east-west component of the divergence-free current density at most at ˜200 km resolution, typically resolving the electrojets. The north-south divergence-free component, on the other hand, is not always well reproduced due to the small longitudinal distance between the side-by-side flying satellite pair. Swarm can yield the field-aligned and curl-free current density at a wider range of latitude resolutions (˜7.5-200 km) than the divergence-free current density. While 7.5 km is suitable for comparison with auroras, 200 km typically resolves the Regions 1 and 2 field-aligned currents. IMAGE can yield maps of the divergence-free current density at ˜50 km resolution. Induced telluric currents should be accounted for in the derivation. Not accounting for them in the Swarm analysis, however, does not appear to introduce significant errors. Ionospheric conductances can be estimated by combining the total horizontal current density, consisting of the curl-free and divergence-free components, with the electric field measurements. Our results indicate that Swarm can only yield these at ˜200 km scale size when there is no significant dependence on longitude. However, combining the divergence-free current from IMAGE with the curl-free current and electric field from Swarm could yield conductance maps at ˜50 km resolution.

  15. Dynamics of debye-scale nonstationary plasma structures in the region of auroral field-aligned currents

    NASA Astrophysics Data System (ADS)

    Bespalov, P. A.; Mizonova, V. G.

    2017-01-01

    We consider the formation of small-scale nonstationary plasma structures in the region of relatively strong field-aligned electric currents. The formation of these structures has been shown to be associated with the density instability developed when the current velocity exceeds a critical value. The conditions for the development of this instability can be most favorable in the region of low-density plasma. Numerical calculations have been performed for the initial nonlinear stage of the structure development. The main parameters of the structure, i.e., the times of its formation and destruction, spatial scales, and electric field, have been estimated. The features of the structures are consistent with the existing data from space experiments in the region of auroral field-aligned currents of the Earth.

  16. The Dependence of the Strength and Thickness of Field-Aligned Currents on Solar Wind and Ionospheric Parameters

    SciTech Connect

    Johnson, Jay R.; Wing, Simon

    2014-08-01

    Sheared plasma flows at the low-latitude boundary layer correlate well with early afternoon auroral arcs and eld-aligned currents [Sonnerup, 1980; Lundin and Evans, 1985]. We present a simple analytic model that relates solar wind and ionospheric parameters to the strength and thickness of field-aligned currents in a region of sheared velocity, such as the low latitude boundary layer. We compare the predictions of the model with DMSP observations and nd remarkably good scaling of the currents with solar wind and ionospheric parameters. The sheared boundary layer thickness is inferred to be around 3000km consistent with observational studies. The analytic model provides a simple way to organize data and to infer boundary layer structures from ionospheric data.

  17. Space Technology 5 (ST-5) Observations of the Imbalance of Region 1 and 2 Field-Aligned Currents

    NASA Technical Reports Server (NTRS)

    Le, Guan

    2010-01-01

    Space Technology 5 (ST-5) is a three micro-satellite constellation deployed into a 300 x 4500 km, dawn-dusk, sun-synchronous polar orbit from March 22 to June 21, 2006, for technology validations. In this study, we use the in-situ magnetic field observations from Space Technology 5 mission to quantify the imbalance of Region 1 (R1) and Region 2 (R2) currents. During the three-month duration of the ST5 mission, geomagnetic conditions range from quiet to moderately active. We find that the R1 current intensity is consistently stronger than the R2 current intensity both for the dawnside and the duskside large-scale field-aligned current system. The net currents flowing into (out of) the ionosphere in the dawnside (duskside) are in the order of 5% of the total RI currents. We also find that the net currents flowing into or out of the ionosphere are controlled by the solar wind-magnetosphere interaction in the same way as the field-aligned currents themselves are. Since the net currents due to the imbalance of the R1 and R2 currents require that their closure currents flow across the polar cap from dawn to dusk as Pedersen currents, our results indicate that the total amount of the cross-polar cap Pedersen currents is in the order of approx. 0.1 MA. This study, although with a very limited dataset, is one of the first attempts to quantify the cross-polar cap Pedersen currents. Given the importance of the Joule heating due to Pedersen currents to the high-latitude ionospheric electrodynamics, quantifying the cross-polar cap Pedersen currents and associated Joule heating is needed for developing models of the magnetosphere-ionosphere coupling.

  18. Strong IMF By-Related Plasma Convection in the Ionosphere and Cusp Field-Aligned Currents Under Northward IMF Conditions

    NASA Technical Reports Server (NTRS)

    Le, G.; Lu, G.; Strangeway, R. J.; Pfaff, R. F., Jr.; Vondrak, Richard R. (Technical Monitor)

    2001-01-01

    We present in this paper an investigation of IMF-By related plasma convection and cusp field-aligned currents using FAST data and AMIE model during a prolonged interval with large positive IMF By and northward Bz conditions (By/Bz much greater than 1). Using the FAST single trajectory observations to validate the global convection patterns at key times and key locations, we have demonstrated that the AMIE procedure provides a reasonably good description of plasma circulations in the ionosphere during this interval. Our results show that the plasma convection in the ionosphere is consistent with the anti-parallel merging model. When the IMF has a strongly positive By component under northward conditions, we find that the global plasma convection forms two cells oriented nearly along the Sun-earth line in the ionosphere. In the northern hemisphere, the dayside cell has clockwise convection mainly circulating within the polar cap on open field lines. A second cell with counterclockwise convection is located in the nightside circulating across the polar cap boundary, The observed two-cell convection pattern appears to be driven by the reconnection along the anti-parallel merging lines poleward of the cusp extending toward the dusk side when IMF By/Bz much greater than 1. The magnetic tension force on the newly reconnected field lines drives the plasma to move from dusk to dawn in the polar cusp region near the polar cap boundary. The field-aligned currents in the cusp region flow downward into the ionosphere. The return field-aligned currents extend into the polar cap in the center of the dayside convection cell. The field-aligned currents are closed through the Peterson currents in the ionosphere, which flow poleward from the polar cap boundary along the electric field direction.

  19. 3D model of small-scale density cavities in the auroral magnetosphere with field-aligned current

    NASA Astrophysics Data System (ADS)

    Bespalov, P. A.; Misonova, V. G.; Savina, O. N.

    2016-09-01

    We propose a 3D model of small-scale density cavities stimulated by an auroral field-aligned current and an oscillating field-aligned current of kinetic Alfvén waves. It is shown that when the field-aligned current increases so that the electron drift velocity exceeds a value of the order of the electron thermal velocity, the plasma becomes unstable to the formation of cavities with low density and strong electric field. The condition of instability is associated with the value of the background magnetic field. In the case of a relatively weak magnetic field (where the electron gyro-radius is greater than the ion acoustic wavelength), the current instability can lead to the formation of one-dimensional cavities along the magnetic field. In the case of a stronger magnetic field (where the ion acoustic wavelength is greater than the electron gyro-radius, but still is less than the ion gyro-radius), the instability can lead to the formation of 3D density cavities. In this case, the spatial scales of the cavity, both along and across the background magnetic field, can be comparable, and at the earlier stage of the cavity formation they are of the order of the ion acoustic wavelength. Rarefactions of the cavity density are accompanied by an increase in the electric field and are limited by the pressure of bipolar electric fields that occur within them. The estimates of typical density cavity characteristics and the results of numerical solutions agree with known experimental data: small-scale structures with a sufficiently strong electric field are observed in the auroral regions with strong field-aligned current.

  20. Small spatial scale field aligned currents in middle and low latitudes as observed by the CHAMP satellite and verification of their current circuit model

    NASA Astrophysics Data System (ADS)

    Nakanishi, K.; Iyemori, T.; Luhr, H.

    2013-12-01

    The magnetic field observation by the CHAMP satellite shows the global and frequent appearance of small scale (1-5 nT) magnetic fluctuations with period around a few tens seconds along the satellites. They have the following characteristics. 1. The signal is perpendicular to the geomagnetic main field, and the amplitude of the zonal component is larger than that of the meridional component. 2. Around the dip equator, as the latitude becomes lower, the period and amplitudes of the two components perpendicular to the main field respectively tend to become longer and smaller (to nearly zero on the dip equator). 3. The amplitude of the magnetic fluctuations on the dayside is larger than that on the night side by around one order in magnitude, which highly correlates to the electric conductivity of the ionospheric dynamo layer. 4. The amplitude shows symmetry about the magnetic dip equator which indicates a magnetic conjugacy to a certain extent. 5. The amplitude shows almost no dependence on the solar wind parameters such as the IMF cone angle nor the solar wind speed, which strongly suggests no association with the Pc3 micro pulsation. 6. The amplitude also shows almost no dependence on the geomagnetic activity. 7. The amplitude has a clear seasonal dependence with topographical characteristics. They can be interpreted as the spatial structure of small scale field-aligned currents generated by the ionospheric dynamo driven by atmospheric gravity waves propagating from the lower atmosphere. The mechanism is the following; first, the gravity waves generated by the lower atmospheric disturbance propagate to the ionosphere; the neutral winds oscillate, cause ionospheric dynamo and Pedersen and Hall currents flow; because the dynamo region is finite, the currents cause polarized electric fields; and the polarized electric fields propagate along the geomagnetic filed as Alfven waves accompanied by field-aligned currents, at the same time, the ionospheric currents divert to

  1. Future Aeronautical Communication System (FACS): Report

    NASA Astrophysics Data System (ADS)

    Hof, H. J.

    1985-06-01

    The feasibility of a FACS design, particularly with regard to application possibilities of satellites, was investigated. It was assumed that communication between airborne stations and air traffic control centers is exclusively possible via satellites using mainly voice communication (possibly completed by data communication). It is concluded that integration possibilities of satellites are mainly limited by the airborne antenna chosen. As a solution, phase steered microstrip antenna arrays are presented. However, the use of these antennas is limited to large (long-distance) aircraft. For operational feasibility, it is concluded that communication should take place in the high frequency band.

  2. ST5 Observations of the Imbalance of Region 1 and 2 Field-Aligned Currents and its Implication to the Cross-Polar Cap Pedersen Currents

    NASA Technical Reports Server (NTRS)

    Le, Guan; Slavin, J. A.; Strangeway, Robert

    2010-01-01

    In this study, we use the in-situ magnetic field observations from Space Technology 5 mission to quantify the imbalance of Region 1 (R1) and Region 2 (R2) currents. During the three-month duration of the ST5 mission, geomagnetic conditions range from quiet to moderately active. We find that the R1 current intensity is consistently stronger than the R2 current intensity both for the dawnside and the duskside large-scale field-aligned current system. The net currents flowing into (out of) the ionosphere in the dawnside (duskside) are in the order of 5% of the total R1 currents. We also find that the net currents flowing into or out of the ionosphere are controlled by the solar windmagnetosphere interaction in the same way as the field-aligned currents themselves are. Since the net currents due to the imbalance of the R1 and R2 currents require that their closure currents flow across the polar cap from dawn to dusk as Pedersen currents, our results indicate that the total amount of the cross-polar cap Pedersen currents is in the order of approximately 0.1 MA. This study, although with a very limited dataset, is one of the first attempts to quantify the cross-polar cap Pedersen currents. Given the importance of the Joule heating due to Pedersen currents to the high-latitude ionospheric electrodynamics, quantifying the cross-polar cap Pedersen currents and associated Joule heating is needed for developing models of the magnetosphere-ionosphere coupling.

  3. ST5 Observations of the Imbalance of Region 1 and 2 Field-Aligned Currents and Its Implication to the Cross-Polar Cap Pedersen Currents

    NASA Technical Reports Server (NTRS)

    Le, Guan; Slavin, J. A.; Strangeway, Robert

    2011-01-01

    In this study, we use the in-situ magnetic field observations from Space Technology 5 mission to quantify the imbalance of Region 1 (R1) and Region 2 (R2) currents. During the three-month duration of the ST5 mission, geomagnetic conditions range from quiet to moderately active. We find that the R1 current intensity is consistently stronger than the R2 current intensity both for the dawnside and the duskside large-scale field-aligned current system. The net currents flowing into (out of) the ionosphere in the dawnside (duskside) are in the order of 5% of the total R1 currents. We also find that the net currents flowing into or out of the ionosphere are controlled by the solar wind-magnetosphere interaction in the same way as the field-aligned currents themselves are. Since the net currents due to the imbalance of the R1 and R2 currents require that their closure currents flow across the polar cap from dawn to dusk as Pedersen currents, our results indicate that the total amount of the cross-polar cap Pedersen currents is in the order of 0.1 MA. This study, although with a very limited dataset, is one of the first attempts to quantify the cross-polar cap Pedersen currents. Given the importance of the Joule heating due to Pedersen currents to the high-latitude ionospheric electrodynamics, quantifying the cross-polar cap Pedersen currents and associated Joule heating is needed for developing models of the magnetosphere-ionosphere coupling.

  4. Quasi-steady current sheet structures with field-aligned flow

    NASA Technical Reports Server (NTRS)

    Birn, J.

    1992-01-01

    The paper discusses the characteristics of quasi-steady plasma and field structures with field-aligned flow. Explicit solutions are developed for modeling the compressible flow around a plasmoid in the distant magnetotail. The expected and observed plasmoid signatures are found. Field signatures outside the plasmoid are typically those of encounters of traveling compression region: a north-south signature of Bz accompanied by an enhancement of Bx.

  5. Effects of field-aligned potential drops on region-2 currents, shielding, and the decoupling of magnetospheric and ionospheric flows

    NASA Astrophysics Data System (ADS)

    Wolf, R.; Sazykin, S. Y.

    2013-12-01

    It is technically difficult to include field-aligned potential drops in simulations of inner-magnetospheric electric fields, because the potential drops are most important in thin, intense sheets of Birkeland current, which are hard to resolve accurately on a large-scale grid. However, we have found a highly idealized situation that can be treated almost completely analytically, with the numerical work confined to solving a 1D differential equation. The calculation is set up as follows: (i) in the zero-order configuration, the inner edge of the plasma-sheet ions is circular, and the ions near the inner edge all gradient/curvature-drift west at the same angular rate; (ii) the convection potential is a small perturbation, in the sense that ExB drift near the inner edge is slow compared to gradient/curvature drift; (iii) the field-aligned potential drop is proportional to the density of field-aligned current; (iv) we look for steady-state solutions. The results indicate that the field-aligned potential drop has the following effects: (i) it decreases the total region-2 current but spreads it out in latitude; (ii) it reduces the efficiency with which the inner edge shields the inner magnetosphere from magnetospheric convection; (iii) it causes particles on the magnetospheric portions of field lines near the inner edge to ExB drift zonally at different rates than particles in the topside ionosphere. Results from these quasi-analytic calculations will be compared with compared with Rice Convection Model simulations of the same idealized physical situation.

  6. AMPERE observations of the Birkeland currents associated with substorms and comparison with simple electrodynamic modelling

    NASA Astrophysics Data System (ADS)

    Milan, S. E.; Coxon, J. C.; Clausen, L. B. N.; Korth, H.; Anderson, B. J.

    2014-04-01

    We present observations of the global terrestrial Birkeland field-aligned current (FAC) pattern observed by the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) during a sequence of substorms. The observations show that the region 1 and 2 current systems move to lower latitudes during the substorm growth phase and retreat to higher latitudes following substorm expansion phase onset. We interpret these observations within the framework of the expanding/contracting polar cap paradigm. This links expansion of the polar cap and equatorward motion of the auroras and FAC systems to the action of magnetopause reconnection increasing the open magnetic flux content of the magnetosphere.

  7. Avoiding Tokamak Disruptions by Applying Static Magnetic Fields That Align Locked Modes with Stabilizing Wave-Driven Currents.

    PubMed

    Volpe, F A; Hyatt, A; La Haye, R J; Lanctot, M J; Lohr, J; Prater, R; Strait, E J; Welander, A

    2015-10-23

    Nonrotating ("locked") magnetic islands often lead to complete losses of confinement in tokamak plasmas, called major disruptions. Here locked islands were suppressed for the first time, by a combination of applied three-dimensional magnetic fields and injected millimeter waves. The applied fields were used to control the phase of locking and so align the island O point with the region where the injected waves generated noninductive currents. This resulted in stabilization of the locked island, disruption avoidance, recovery of high confinement, and high pressure, in accordance with the expected dependencies upon wave power and relative phase between the O point and driven current.

  8. Spatial relationships between region 2 field-aligned currents and electron and ion precipitation in the evening sector

    NASA Technical Reports Server (NTRS)

    Fujii, R.; Hoffman, R. A.; Sugiura, M.

    1990-01-01

    The equatorward cutoff of ion and electron precipitation in relation to the evening region 2 field-aligned current during isolated substorms has been investigated using the magnetic field and plasma data obtained from the Dynamics Explorer 2 satellite. The equatorward boundaries of the region 2 currents relative to those of central plasma sheet (CPS) electron precipitation are determined predominantly by magnetic local time and subsequently change with substorm phases. With approaching midnight, the equatorward boundary of CPS electron precipitation extends toward and eventually equatorward of that of the region 2 current. On the other hand, the equatorward boundary of the region 2 current coincides well with that of 10-20 keV ion precipitation during the whole course of substorms. It is proposed that these ions originate in the so-called Alfven layer and that the location of this inner boundary determines the lower latitude boundary of the region 2 current.

  9. Direct current injection and thermocapillary flow for purification of aligned arrays of single-walled carbon nanotubes

    SciTech Connect

    Xie, Xu; Islam, Ahmad E.; Seabron, Eric; Dunham, Simon N.; Du, Frank; Lin, Jonathan; Wilson, William L.; Rogers, John A.; Wahab, Muhammad A.; Alam, Muhammad A.; Li, Yuhang; Tomic, Bojan; Huang, Jiyuan; Burns, Branden; Song, Jizhou; Huang, Yonggang

    2015-04-07

    Aligned arrays of semiconducting single-walled carbon nanotubes (s-SWNTs) represent ideal configurations for use of this class of material in high performance electronics. Development of means for removing the metallic SWNTs (m-SWNTs) in as-grown arrays represents an essential challenge. Here, we introduce a simple scheme that achieves this type of purification using direct, selective current injection through interdigitated electrodes into the m-SWNTs, to allow their complete removal using processes of thermocapillarity and dry etching. Experiments and numerical simulations establish the fundamental aspects that lead to selectivity in this process, thereby setting design rules for optimization. Single-step purification of arrays that include thousands of SWNTs demonstrates the effectiveness and simplicity of the procedures. The result is a practical route to large-area aligned arrays of purely s-SWNTs with low-cost experimental setups.

  10. Current products and practices: curriculum development in orthodontic specialist registrar training: can orthodontics achieve constructive alignment?

    PubMed

    Chadwick, S M

    2004-09-01

    This paper aims to encourage a debate on the learning outcomes that have been developed for orthodontic specialist education. In outcome-based education the learning outcomes are clearly defined. They determine curriculum content and its organization, the teaching and learning approaches, the assessment techniques and hope to focus the minds of the students on ensuring all the learning outcomes are met. In Orthodontic Specialist Registrar training, whether constructive alignment can be achieved depends on the relationship between these aspects of the education process and the various bodies responsible for their delivery in the UK.

  11. Nanofabrication of arrays of silicon field emitters with vertical silicon nanowire current limiters and self-aligned gates

    NASA Astrophysics Data System (ADS)

    Guerrera, S. A.; Akinwande, A. I.

    2016-07-01

    We developed a fabrication process for embedding a dense array (108 cm-2) of high-aspect-ratio silicon nanowires (200 nm diameter and 10 μm tall) in a dielectric matrix and then structured/exposed the tips of the nanowires to form self-aligned gate field emitter arrays using chemical mechanical polishing (CMP). Using this structure, we demonstrated a high current density (100 A cm-2), uniform, and long lifetime (>100 h) silicon field emitter array architecture in which the current emitted by each tip is regulated by the silicon nanowire current limiter connected in series with the tip. Using the current voltage characteristics and with the aid of numerical device models, we estimated the tip radius of our field emission arrays to be ≈4.8 nm, as consistent with the tip radius measured using a scanning electron microscope (SEM).

  12. The evolution of high-latitude field-aligned currents and magnetospheric dynamics in response to solar wind drivers

    NASA Astrophysics Data System (ADS)

    Bogdanova, Yulia; Vennerstrøm, Susanne; Wild, James; Korth, Haje; Lühr, Hermann; Wing, Simon; Pitout, Frederic

    2016-04-01

    While the statistical behaviour of the solar wind-magnetosphere-ionosphere system is well defined by the Dungey cycle, questions remain on the behaviour of this coupled system during extreme conditions, for example during magnetic storms or periods with long lasting northward IMF, and on how, and how fast, the system reacts to abrupt changes in the solar wind driver. Field-aligned currents play a crucial role in the dynamics of this coupled system as they provide connectivity between different regions and act as channels for energy and momentum transfer. These currents have been investigated in the last decade thanks to observations from low-orbiting satellites, such as CHAMP, Ørsted, DMSP, and the Iridium constellation. However, many previous studies concentrated on the statistical behavior of the current systems or measurements from individual observatories. In this paper we will employ data from Swarm, AMPERE, DMSP, Cluster, SuperDARN and SuperMAG to perform a multi-point study of high-latitude field-aligned current systems evolution and properties and magnetospheric dynamics in response to the solar wind driver, concentrating on the intervals of changes in the IMF orientation and extreme IMF and solar wind conditions.

  13. Fibro/Adipogenic Progenitors (FAPs): Isolation by FACS and Culture.

    PubMed

    Low, Marcela; Eisner, Christine; Rossi, Fabio

    2017-01-01

    Fibro/adipogenic progenitors (FAPs ) are tissue-resident mesenchymal stromal cells (MSCs). Current literature supports a role for these cells in the homeostasis and repair of multiple tissues suggesting that FAPs may have extensive therapeutic potential in the treatment of numerous diseases. In this context, it is crucial to establish efficient and reproducible procedures to purify FAP populations from various tissues. Here, we describe a protocol for the isolation and cell culture of FAPs from murine skeletal muscle using fluorescence -activated cell sorting (FACS), which is particularly useful for experiments where high cell purity is an essential requirement. Identification, isolation, and cell culture of FAPs represent powerful tools that will help us to understand the role of these cells in different conditions and facilitate the development of safe and effective new treatments for diseases.

  14. PSBL filed-aligned plasma structures related to auroras

    NASA Astrophysics Data System (ADS)

    Koleva, Rositza; Zelenyi, Lev; Grigorenko, Elena; Sauvaud, Jean-André

    The plasma sheet boundary layer (PSBL) is characterised by field-aligned high-velocity ion beams and it is naturally to expect field-aligned currents (FAC) associated with them. Recent statistical analysis revealed two different types of ion beams. The first type (further - Type I) are collimated in energy, accompanied by isotropic electrons and no FACs or FACs of very small current density are registered with them. Type II are powerful field-aligned ion beams with large parallel temperatures streaming along with anisotropic electron fluxes, the distributions of the latter bear the signature of a separatrix. The electrons produce a pair of FACs: at the lobeward edge directed earthward, and inside PSBL - tailward. Two different acceleration mechanisms were suggested: Type I ion beams, observed under quiet or slightly disturbed conditions, are accelerated in spatially localized resonant sources located in the current sheet in the region of closed magnetic field lines and rather far from the distant X-line; Type II ion beams, observed under active conditions, are accelerated in the vicinity of a near-Earth X-line. To prove this hypothesis we studied the auroral and ground based events related to 364 CLUSTER observations of PSBL ion beams. The auroral and ground manifestations were investigated using POLAR and IMAGE UV images and magnetograms of appropriate ground stations. As a rule in cases of Type I ion beams CLUSTER footprints are in the region of soft diffuse precipitation, poleward of the region of discreet auroral forms, and the magnetograms exhibit no or small variations in the horizontal magnetic field component. In cases of Type II beams (with currents), CLUSTER footprints are located adjacent to the brightest auroral spot and the magnetograms exhibit large negative variations of the horizontal magnetic field component. However, in considerable number of cases PSBL currents are observed under quiet or slightly disturbed conditions. CLUSTER spectrograms for

  15. FACS selection of valuable mutant mouse round spermatids and strain rescue via round spermatid injection.

    PubMed

    Zhu, Lian; Zhou, Wei; Kong, Peng-Cheng; Wang, Mei-Shan; Zhu, Yan; Feng, Li-Xin; Chen, Xue-Jin; Jiang, Man-Xi

    2015-06-01

    Round spermatid injection (ROSI) into mammalian oocytes can result in the development of viable embryos and offspring. One current limitation to this technique is the identification of suitable round spermatids. In the current paper, round spermatids were selected from testicular cells with phase contrast microscopy (PCM) and fluorescence-activated cell sorting (FACS), and ROSI was performed in two strains of mice. The rates of fertilization, embryonic development and offspring achieved were the same in all strains. Significantly, round spermatids selected by PCM and FACS were effectively used to rescue the infertile Pten-null mouse. The current results indicate that FACS selection of round spermatids can not only provide high-purity and viable round spermatids for use in ROSI, but also has no harmful effects on the developmental capacity of subsequently fertilized embryos. It was concluded that round spermatids selected by FACS are useful for mouse strain rederivation and rescue of infertile males; ROSI should be considered as a powerful addition to the armamentarium of assisted reproduction techniques applicable in the mouse.

  16. Critical current, film thickness and grain alignment for spray-pyrolyzed films of TlBa 2Ca 2Cu 3O x

    NASA Astrophysics Data System (ADS)

    Specht, E. D.; Goyal, A.; Kroeger, D. M.; Mogro-Campero, A.; Bednarczyk, P. J.; Tkaczyk, J. E.; DeLuca, J. A.

    1996-02-01

    X-ray diffraction rocking curves are used to measure the c axis alignment of TlBa 2Ca 2Cu 3O x films grown on polycrystalline substrates with thickness varying from 3 to 10.5 μm. Films thicker than 3 μm are found to contain two layers: a well aligned (3.5° FWHM) bottom layer, and a poorly aligned (greater than 12° FWHM) top layer. Azimuthal scans show that the component with good long-range out-of-plane alignment retains its characteristic colony microstructure of local in-plane alignment as film thickness increases. The length dependence of the critical current density may be accounted for by assuming that all the supercurrent is carried by the well-aligned component.

  17. The impact of intrinsic alignment on current and future cosmic shear surveys

    NASA Astrophysics Data System (ADS)

    Krause, Elisabeth; Eifler, Tim; Blazek, Jonathan

    2016-02-01

    Intrinsic alignment (IA) of source galaxies is one of the major astrophysical systematics for weak lensing surveys. Several IA models have been proposed and their impact on cosmological constraints has been examined using the Fisher information matrix in conjunction with approximate, Gaussian covariances. This paper presents the first forecasts of the impact of IA on cosmic shear measurements for future surveys using simulated likelihood analyses and covariances that include higher order moments of the density field. We consider a range of possible IA scenarios and test mitigation schemes which parametrize IA by the fraction of red galaxies, normalization, luminosity and redshift dependence of the IA signal. Compared to previous studies, we find smaller biases in time-dependent dark energy models if IA is ignored in the analysis. The amplitude and significance of these biases vary as a function of survey properties (depth, statistical uncertainties), luminosity function and IA scenario. Due to its small statistical errors and relatively shallow depth, Euclid is significantly impacted by IA. Large Synoptic Survey Telescope (LSST) and Wide-Field Infrared Survey Telescope (WFIRST) benefit from increased survey depth, while larger statistical errors for Dark Energy Survey (DES) decrease IA's relative impact on cosmological parameters. The proposed IA mitigation scheme removes parameter biases for DES, LSST and WFIRST even if the shape of the IA power spectrum is only poorly known; successful IA mitigation for Euclid requires more prior information. We explore several alternative IA mitigation strategies for Euclid; in the absence of alignment of blue galaxies we recommend the exclusion of red (IA-contaminated) galaxies in cosmic shear analyses.

  18. Correlation between magnetic and electric field perturbations in the field-aligned current regions deduced from DE 2 observations

    NASA Technical Reports Server (NTRS)

    Ishii, M.; Sugiura, M.; Iyemori, T.; Slavin, J. A.

    1992-01-01

    The satellite-observed high correlations between magnetic and electric field perturbations in the high-latitude field-aligned current regions are investigated by examining the dependence of the relationship between Delta-B and E on spatial scale, using the electric and magnetic field data obtained by DE 2 in the polar regions. The results are compared with the Pedersen conductivity inferred from the international reference ionosphere model and the Alfven wave velocity calculated from the in situ ion density and magnetic field measurements.

  19. Proteomics of FACS-sorted heterogeneous Corynebacterium glutamicum populations.

    PubMed

    Harst, Andreas; Albaum, Stefan P; Bojarzyn, Tanja; Trötschel, Christian; Poetsch, Ansgar

    2017-05-08

    The metabolic status of individual cells in microbial cultures can differ, being relevant for biotechnology, environmental and medical microbiology. However, it is hardly understood in molecular detail due to limitations of current analytical tools. Here, we demonstrate that FACS in combination with proteomics can be used to sort and analyze cell populations based on their metabolic state. A previously established GFP reporter system was used to detect and sort single Corynebacterium glutamicum cells based on the concentration of branched chain amino acids (BCAA) using FACS. A proteomics workflow optimized for small cell numbers was used to quantitatively compare proteomes of a ΔaceE mutant, lacking functional pyruvate dehydrogenase (PD), and the wild type. About 800 proteins could be quantified from 1,000,000 cells. In the ΔaceE mutant BCAA production was coordinated with upregulation of the glyoxylate cycle and TCA cycle to counter the lack of acetyl CoA resulting from the deletion of aceE. Metabolic pathways in C. glutamicum WT and ΔaceE, devoid of functional pyruvate dehydrogenase, were compared to understand proteome changes that contribute to the high production of branched chain amino acids (BCAA) in the ΔaceE strain. The data complements previous metabolome studies and corroborates the role of malate provided by the glyoxylate cycle and increased activity of glycolysis and pyruvate carboxylase reaction to replenish the TCA cycle. A slight increase in acetohydroxyacid synthase (ILV subunit B) substantiates the previously reported increased pyruvate pool in C. glutamicumΔaceE, and the benefit of additional ilv gene cluster overexpression for BCAA production. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Magnetosphere-ionosphere-thermosphere coupling: Effect of neutral winds on energy transfer and field-aligned current

    SciTech Connect

    Lu, G.; Richmond, A.D.; Emery, B.A.

    1995-10-01

    The assimilative mapping of ionospheric electrodynamics (AMIE) algorithm has been applied to derive the realistic time-dependent large-scale global distributions of the ionospheric convection and particle precipitation during a recent Geospace Environment Modeling (GEM) campaign period: March 28-29, 1992. The AMIE outputs are then used as the inputs of the National Center for Atmospheric Research thermosphere-ionosphere general circulation model to estimate the electrodynamic quantities in the ionosphere and thermosphere. It is found that the magnetospheric electromagnetic energy dissipated in the high-latitude ionosphere is mainly converted into Joule heating, with only a small fraction (6%) going to acceleration of thermospheric neutral winds. This study also reveals that the thermospheric winds can have significant influence on the ionospheric electrodynamics. On the average for these 2 days, the neutral winds have approximately a 28% negative effect on Joule heating and approximately a 27% negative effect on field-aligned currents. The field-aligned currents driven by the neutral wind flow in the opposite direction to those driven by the plasma convection. On the average, the global electromagnetic energy input is about 4 times larger than the particle energy input. 65 refs., 10 figs.

  1. Enhanced critical-current in P-doped BaFe2As2 thin films on metal substrates arising from poorly aligned grain boundaries

    PubMed Central

    Sato, Hikaru; Hiramatsu, Hidenori; Kamiya, Toshio; Hosono, Hideo

    2016-01-01

    Thin films of the iron-based superconductor BaFe2(As1−xPx)2 (Ba122:P) were fabricated on polycrystalline metal-tape substrates with two kinds of in-plane grain boundary alignments (well aligned (4°) and poorly aligned (8°)) by pulsed laser deposition. The poorly aligned substrate is not applicable to cuprate-coated conductors because the in-plane alignment >4° results in exponential decay of the critical current density (Jc). The Ba122:P film exhibited higher Jc at 4 K when grown on the poorly aligned substrate than on the well-aligned substrate even though the crystallinity was poorer. It was revealed that the misorientation angles of the poorly aligned samples were less than 6°, which are less than the critical angle of an iron-based superconductor, cobalt-doped BaFe2As2 (~9°), and the observed strong pinning in the Ba122:P is attributed to the high-density grain boundaries with the misorientation angles smaller than the critical angle. This result reveals a distinct advantage over cuprate-coated conductors because well-aligned metal-tape substrates are not necessary for practical applications of the iron-based superconductors. PMID:27833118

  2. Murine Dermal Fibroblast Isolation by FACS.

    PubMed

    Walmsley, Graham G; Maan, Zeshaan N; Hu, Michael S; Atashroo, David A; Whittam, Alexander J; Duscher, Dominik; Tevlin, Ruth; Marecic, Owen; Lorenz, H Peter; Gurtner, Geoffrey C; Longaker, Michael T

    2016-01-07

    Fibroblasts are the principle cell type responsible for secreting extracellular matrix and are a critical component of many organs and tissues. Fibroblast physiology and pathology underlie a spectrum of clinical entities, including fibroses in multiple organs, hypertrophic scarring following burns, loss of cardiac function following ischemia, and the formation of cancer stroma. However, fibroblasts remain a poorly characterized type of cell, largely due to their inherent heterogeneity. Existing methods for the isolation of fibroblasts require time in cell culture that profoundly influences cell phenotype and behavior. Consequently, many studies investigating fibroblast biology rely upon in vitro manipulation and do not accurately capture fibroblast behavior in vivo. To overcome this problem, we developed a FACS-based protocol for the isolation of fibroblasts from the dorsal skin of adult mice that does not require cell culture, thereby preserving the physiologic transcriptional and proteomic profile of each cell. Our strategy allows for exclusion of non-mesenchymal lineages via a lineage negative gate (Lin(-)) rather than a positive selection strategy to avoid pre-selection or enrichment of a subpopulation of fibroblasts expressing specific surface markers and be as inclusive as possible across this heterogeneous cell type.

  3. FACS Analysis of Memory T Lymphocytes.

    PubMed

    Lugli, Enrico; Zanon, Veronica; Mavilio, Domenico; Roberto, Alessandra

    2017-01-01

    Flow cytometry is a powerful and robust technology for detecting and monitoring multiple markers at the level of single cells. Since its early development, flow cytometry has been used to assess heterogeneity in a cell suspension. Over the years, the increasing number of parameters that could be included in a single assay combined with physical separation by fluorescence-activated cell sorting (FACS) revealed that the T cell compartment is extremely heterogenous in terms of phenotypic diversity, functional capacity, and transcriptional regulation. While naïve T cells are fairly homogenous, diversity becomes extreme in the antigen-experienced memory compartment. The precise identification of memory subsets by the simultaneous analysis of multiple markers by flow cytometry is key not only to basic science but also for the correct immunomonitoring of patients undergoing immunotherapy or for T cell-based therapeutic approaches. In this chapter, we provide guidelines to optimize complex flow cytometry panels, to achieve correct fluorescence compensation and determine positivity for a given antigen. Correct selection of reagents and their validation is essential to the success of the assay. Despite having been developed for the identification of human naïve and memory T cell subsets, the concepts illustrated here can be applied to any experiment aiming to investigate n parameters by flow cytometry.

  4. The dynamics of region 1 field-aligned currents during periods of dayside and nightside reconnection

    NASA Astrophysics Data System (ADS)

    Clausen, L. B. N.; Ruohoniemi, J. M.; Baker, J. B. H.; Milan, S. E.; Coxon, J.; Anderson, B. J.

    2015-12-01

    We use current density data from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) to identify the location of maximum region 1 current at all magnetic local times. We term this location the R1 oval. Comparing the R1 oval location with particle precipitation boundaries identified in DMSP data, we find that the R1 oval is located on average within 1° of particle signatures associated with the open/closed field line boundary (OCB) across dayside and nightside MLTs. We hence conclude that the R1 oval can be used as a proxy for the location of the OCB. Studying the amount of magnetic flux enclosed by the R1 oval during the substorm cycle, we find that the R1 oval flux is well organized by it: during the growth phase the R1 oval location moves equatorward as the amount of magnetic flux increases whereas after substorm expansion phase onset significant flux closure occurs as the R1 current location retreats to higher latitudes. For about 15 minutes after expansion phase onset the amount of open magnetic flux continues to increase indicating that dayside reconnection dominates over nightside reconnection. In the current density data we find evidence of the substorm current wedge and also show that the dayside R1 currents are stronger than their nightside counterpart during the substorm growth phase whereas after expansion phase onset the nightside R1 currents dominate. Our observations of the current distribution and OCB movement during the substorm cycle are in excellent agreement with the expanding/contracting polar cap paradigm.

  5. A fast alignment method for breast MRI follow-up studies using automated breast segmentation and current-prior registration

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Strehlow, Jan; Rühaak, Jan; Weiler, Florian; Diez, Yago; Gubern-Merida, Albert; Diekmann, Susanne; Laue, Hendrik; Hahn, Horst K.

    2015-03-01

    In breast cancer screening for high-risk women, follow-up magnetic resonance images (MRI) are acquired with a time interval ranging from several months up to a few years. Prior MRI studies may provide additional clinical value when examining the current one and thus have the potential to increase sensitivity and specificity of screening. To build a spatial correlation between suspicious findings in both current and prior studies, a reliable alignment method between follow-up studies is desirable. However, long time interval, different scanners and imaging protocols, and varying breast compression can result in a large deformation, which challenges the registration process. In this work, we present a fast and robust spatial alignment framework, which combines automated breast segmentation and current-prior registration techniques in a multi-level fashion. First, fully automatic breast segmentation is applied to extract the breast masks that are used to obtain an initial affine transform. Then, a non-rigid registration algorithm using normalized gradient fields as similarity measure together with curvature regularization is applied. A total of 29 subjects and 58 breast MR images were collected for performance assessment. To evaluate the global registration accuracy, the volume overlap and boundary surface distance metrics are calculated, resulting in an average Dice Similarity Coefficient (DSC) of 0.96 and root mean square distance (RMSD) of 1.64 mm. In addition, to measure local registration accuracy, for each subject a radiologist annotated 10 pairs of markers in the current and prior studies representing corresponding anatomical locations. The average distance error of marker pairs dropped from 67.37 mm to 10.86 mm after applying registration.

  6. A three-dimensional MHD simulation of the interaction of the solar wind with the earth's magnetosphere - The generation of field-aligned currents

    NASA Technical Reports Server (NTRS)

    Ogino, T.

    1986-01-01

    The time-dependent interaction of the solar wind with the earth's magnetosphere is simulated using a three-dimensional MHD model. The bow shock, magnetopause, magnetotail, and plasma sheet of the magnetosphere and Birkeland field-aligned currents that are dependent on the polarity of the z component of the IMF are produced. Twin convection cells and a dawn to dusk electric potential of 30-100 kV are detected at the equator in the magnetosphere. Four types of field-aligned currents are observed: region 1, region 2, dayside magnetopause currents in the dayside cusp region, and the dayside cusp currents for southward IMF. Region 1 and 2 field-aligned currents generated for all IMF conditions are 0.6-1.0 x 10 to the 6th A and 0.15-0.61 x 10 to the 6th A, respectively. The relationship between region 1 currents and field-aligned vorticity, and region 2 currents and pressure gradients are studied. The simulated data are compared with a theoretical analysis of the field-aligned currents and good correlation is observed.

  7. Investigation of sounding rocket observations of field-aligned currents and electron temperature

    NASA Astrophysics Data System (ADS)

    Cohen, I. J.; Lessard, M.; Zettergren, M. D.; Moen, J.; Lynch, K. A.; Heavisides, J. M.

    2014-12-01

    Strangeway et al. [2005] and other authors have concluded that the establishment of the ambipolar field by the deposition of energy from soft electron precipitation is a significant driver of type-2 ion upflows. Likewise, Clemmons et al. [2008] and Zhang et al. [2012] proposed processes by which soft electron precipitation may play a role in heating neutrals and contribute to neutral upwelling. In both situations the thermal ionospheric electron population plays a crucial role in both generation of the ambipolar field and in collisional energy exchange with the atmosphere through a variety of processes. In this study we examine the dynamics of the electron population, specifically the temperature, in a slightly different context - focusing on the auroral downward current region (DCR). In many cases auroral DCRs may be depleted of plasma, which sets up interesting conditions involving thermoelectric heat fluxes (which flow upward - in the opposite direction from the current), adiabatic expansion due to the high (upward) speed of the electrons carrying the downward current, heat exchange from ions which have elevated temperatures due to frictional heating, and direct frictional heating of the electrons. A detailed understanding of the electron temperature in auroral DCRs is necessary to make quantitative statements about recombination, upflow, cavitation and a host of other processes relevant to ion outflow. In this study, we compare in situ rocket observations of electron temperature, density, and current densities with predictions from the Zettergren and Semeter [2012] model in an attempt to better understand the dynamics and relationships between these parameters in DCRs.

  8. Alignment validation

    SciTech Connect

    ALICE; ATLAS; CMS; LHCb; Golling, Tobias

    2008-09-06

    The four experiments, ALICE, ATLAS, CMS and LHCb are currently under constructionat CERN. They will study the products of proton-proton collisions at the Large Hadron Collider. All experiments are equipped with sophisticated tracking systems, unprecedented in size and complexity. Full exploitation of both the inner detector andthe muon system requires an accurate alignment of all detector elements. Alignmentinformation is deduced from dedicated hardware alignment systems and the reconstruction of charged particles. However, the system is degenerate which means the data is insufficient to constrain all alignment degrees of freedom, so the techniques are prone to converging on wrong geometries. This deficiency necessitates validation and monitoring of the alignment. An exhaustive discussion of means to validate is subject to this document, including examples and plans from all four LHC experiments, as well as other high energy experiments.

  9. Artificial riboswitch selection: A FACS-based approach.

    PubMed

    Ghazi, Zohaib; Fowler, Casey C; Li, Yingfu

    2014-01-01

    Riboswitches have a number of characteristics that make them ideal regulatory elements for a wide range of synthetic biology applications. To maximize their utility, methods are required to create custom riboswitches de novo or to modify existing riboswitches to suit specific experimental needs. This chapter describes such a method, which exploits fluorescence-activated cell sorting (FACS) to quickly and efficiently sort through large libraries of riboswitch-like sequences to identify those with the desired activity. Suggestions for the experimental setup are provided, along with detailed protocols for testing and optimizing FACS conditions FACS selection steps, and follow-up assays to identify and characterize individual riboswitches.

  10. High Current Emission from Patterned Aligned Carbon Nanotubes Fabricated by Plasma-Enhanced Chemical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Cui, Linfan; Chen, Jiangtao; Yang, Bingjun; Jiao, Tifeng

    2015-12-01

    Vertically, carbon nanotube (CNT) arrays were successfully fabricated on hexagon patterned Si substrates through radio frequency plasma-enhanced chemical vapor deposition using gas mixtures of acetylene (C2H2) and hydrogen (H2) with Fe/Al2O3 catalysts. The CNTs were found to be graphitized with multi-walled structures. Different H2/C2H2 gas flow rate ratio was used to investigate the effect on CNT growth, and the field emission properties were optimized. The CNT emitters exhibited excellent field emission performance (the turn-on and threshold fields were 2.1 and 2.4 V/μm, respectively). The largest emission current could reach 70 mA/cm2. The emission current was stable, and no obvious deterioration was observed during the long-term stability test of 50 h. The results were relevant for practical applications based on CNTs.

  11. High Current Emission from Patterned Aligned Carbon Nanotubes Fabricated by Plasma-Enhanced Chemical Vapor Deposition.

    PubMed

    Cui, Linfan; Chen, Jiangtao; Yang, Bingjun; Jiao, Tifeng

    2015-12-01

    Vertically, carbon nanotube (CNT) arrays were successfully fabricated on hexagon patterned Si substrates through radio frequency plasma-enhanced chemical vapor deposition using gas mixtures of acetylene (C2H2) and hydrogen (H2) with Fe/Al2O3 catalysts. The CNTs were found to be graphitized with multi-walled structures. Different H2/C2H2 gas flow rate ratio was used to investigate the effect on CNT growth, and the field emission properties were optimized. The CNT emitters exhibited excellent field emission performance (the turn-on and threshold fields were 2.1 and 2.4 V/μm, respectively). The largest emission current could reach 70 mA/cm(2). The emission current was stable, and no obvious deterioration was observed during the long-term stability test of 50 h. The results were relevant for practical applications based on CNTs.

  12. Onset of Antarctic Circumpolar Current 30 million years ago as Tasmanian Gateway aligned with westerlies

    NASA Astrophysics Data System (ADS)

    Scher, Howie D.; Whittaker, Joanne M.; Williams, Simon E.; Latimer, Jennifer C.; Kordesch, Wendy E. C.; Delaney, Margaret L.

    2015-07-01

    Earth's mightiest ocean current, the Antarctic Circumpolar Current (ACC), regulates the exchange of heat and carbon between the ocean and the atmosphere, and influences vertical ocean structure, deep-water production and the global distribution of nutrients and chemical tracers. The eastward-flowing ACC occupies a unique circumglobal pathway in the Southern Ocean that was enabled by the tectonic opening of key oceanic gateways during the break-up of Gondwana (for example, by the opening of the Tasmanian Gateway, which connects the Indian and Pacific oceans). Although the ACC is a key component of Earth's present and past climate system, the timing of the appearance of diagnostic features of the ACC (for example, low zonal gradients in water-mass tracer fields) is poorly known and represents a fundamental gap in our understanding of Earth history. Here we show, using geophysically determined positions of continent-ocean boundaries, that the deep Tasmanian Gateway opened 33.5 +/- 1.5 million years ago (the errors indicate uncertainty in the boundary positions). Following this opening, sediments from Indian and Pacific cores recorded Pacific-type neodymium isotope ratios, revealing deep westward flow equivalent to the present-day Antarctic Slope Current. We observe onset of the ACC at around 30 million years ago, when Southern Ocean neodymium isotopes record a permanent shift to modern Indian-Atlantic ratios. Our reconstructions of ocean circulation show that massive reorganization and homogenization of Southern Ocean water masses coincided with migration of the northern margin of the Tasmanian Gateway into the mid-latitude westerly wind band, which we reconstruct at 64° S, near to the northern margin. Onset of the ACC about 30 million years ago coincided with major changes in global ocean circulation and probably contributed to the lower atmospheric carbon dioxide levels that appear after this time.

  13. Onset of Antarctic Circumpolar Current 30 million years ago as Tasmanian Gateway aligned with westerlies.

    PubMed

    Scher, Howie D; Whittaker, Joanne M; Williams, Simon E; Latimer, Jennifer C; Kordesch, Wendy E C; Delaney, Margaret L

    2015-07-30

    Earth's mightiest ocean current, the Antarctic Circumpolar Current (ACC), regulates the exchange of heat and carbon between the ocean and the atmosphere, and influences vertical ocean structure, deep-water production and the global distribution of nutrients and chemical tracers. The eastward-flowing ACC occupies a unique circumglobal pathway in the Southern Ocean that was enabled by the tectonic opening of key oceanic gateways during the break-up of Gondwana (for example, by the opening of the Tasmanian Gateway, which connects the Indian and Pacific oceans). Although the ACC is a key component of Earth's present and past climate system, the timing of the appearance of diagnostic features of the ACC (for example, low zonal gradients in water-mass tracer fields) is poorly known and represents a fundamental gap in our understanding of Earth history. Here we show, using geophysically determined positions of continent-ocean boundaries, that the deep Tasmanian Gateway opened 33.5 ± 1.5 million years ago (the errors indicate uncertainty in the boundary positions). Following this opening, sediments from Indian and Pacific cores recorded Pacific-type neodymium isotope ratios, revealing deep westward flow equivalent to the present-day Antarctic Slope Current. We observe onset of the ACC at around 30 million years ago, when Southern Ocean neodymium isotopes record a permanent shift to modern Indian-Atlantic ratios. Our reconstructions of ocean circulation show that massive reorganization and homogenization of Southern Ocean water masses coincided with migration of the northern margin of the Tasmanian Gateway into the mid-latitude westerly wind band, which we reconstruct at 64° S, near to the northern margin. Onset of the ACC about 30 million years ago coincided with major changes in global ocean circulation and probably contributed to the lower atmospheric carbon dioxide levels that appear after this time.

  14. Interplanetary magnetic field control of mantle precipitation and associated field-aligned currents

    NASA Technical Reports Server (NTRS)

    Xu, Dingan; Kivelson, Margaret G.; Walker, Ray J.; Newell, Patrick T.; Meng, C.-I.

    1995-01-01

    Dayside reconnection, which is particularly effective for a southward interplanetary magnetic field (IMF), allows magnetosheath particles to enter the magnetosphere where they form the plasma mantle. The motions of the reconnected flux tube produce convective flows in the ionosphere. It is known that the convection patterns in the polar cap are skewed to the dawnside for a positive IMF B(sub y) (or duskside for a negative IMF B(sub y)) in the northern polar cap. Correspondingly, one would expect to find asymmetric distributions of mantle particle precipitation, but previous results have been unclear. In this paper the correlation between B(sub y) and the distribution of mantle particle precipitation is studied for steady IMF conditions with southward IMF. Ion and electron data from the Defense Meteorological Satellite Program (DMSP) F6 and F7 satellites are used to identify the mantle region and IMP 8 is used as a solar wind monitor to characterize the IMF. We study the local time extension of mantle precipitation in the prenoon and postnoon regions. We find that, in accordance with theoretical expectations for a positive (negative) IMF B(sub y), mantle particle precipitation mainly appears in the prenoon region of the northern (southern) hemisphere. The mantle particle precipitation can extend to as early as 0600 magnetic local time (MLT) in the prenoon region but extends over a smaller local time region in the postnoon sector (we did not find mantle plasma beyond 1600 MLT in our data set although coverage is scant in this area). Magnetometer data from F7 are used to determine whether part of the region 1 current flows on open field lines. We find that at times part of the region 1 sense current extends into the region of mantle particle precipitation, and is therefore on open field lines. In other cases, region 1 currents are absent on open field lines. Most of the observed features can be readily interpreted in terms of the open magnetosphere model.

  15. Interplanetary magnetic field control of mantle precipitation and associated field-aligned currents

    NASA Technical Reports Server (NTRS)

    Xu, Dingan; Kivelson, Margaret G.; Walker, Ray J.; Newell, Patrick T.; Meng, C.-I.

    1995-01-01

    Dayside reconnection, which is particularly effective for a southward interplanetary magnetic field (IMF), allows magnetosheath particles to enter the magnetosphere where they form the plasma mantle. The motions of the reconnected flux tube produce convective flows in the ionosphere. It is known that the convection patterns in the polar cap are skewed to the dawnside for a positive IMF B(sub y) (or duskside for a negative IMF B(sub y)) in the northern polar cap. Correspondingly, one would expect to find asymmetric distributions of mantle particle precipitation, but previous results have been unclear. In this paper the correlation between B(sub y) and the distribution of mantle particle precipitation is studied for steady IMF conditions with southward IMF. Ion and electron data from the Defense Meteorological Satellite Program (DMSP) F6 and F7 satellites are used to identify the mantle region and IMP 8 is used as a solar wind monitor to characterize the IMF. We study the local time extension of mantle precipitation in the prenoon and postnoon regions. We find that, in accordance with theoretical expectations for a positive (negative) IMF B(sub y), mantle particle precipitation mainly appears in the prenoon region of the northern (southern) hemisphere. The mantle particle precipitation can extend to as early as 0600 magnetic local time (MLT) in the prenoon region but extends over a smaller local time region in the postnoon sector (we did not find mantle plasma beyond 1600 MLT in our data set although coverage is scant in this area). Magnetometer data from F7 are used to determine whether part of the region 1 current flows on open field lines. We find that at times part of the region 1 sense current extends into the region of mantle particle precipitation, and is therefore on open field lines. In other cases, region 1 currents are absent on open field lines. Most of the observed features can be readily interpreted in terms of the open magnetosphere model.

  16. Small-scale field-aligned currents caused by tropical cyclones as observed by the SWARM satellites above the ionosphere

    NASA Astrophysics Data System (ADS)

    Aoyama, T.; Iyemori, T.; Nakanishi, K.

    2014-12-01

    We present case studies of small-scale magnetic fluctuations above typhoons, hurricanes and cyclones as observed by the swarm constellation. It is reported lately that AGWs(atmospheric gravity waves) generated by meteorological phenomena in the troposphere such as typhoons and tornadoes, large earthquakes and volcanic eruptions propagate to the mesosphere and thermosphere. We observe them in various forms(e.g. airglows, ionospheric disturbances and TEC variations). We are proposing the following model. AGWs caused by atmospheric disturbances in the troposphere propagate to the ionospheric E-layer, drive dynamo action and generate field-aligned currents. The satellites observe magnetic fluctuations above the ionosphere. In this presentation, we focus on cases of tropical cyclone(hurricanes in North America, typhoons in North-West Pacific).

  17. Field-aligned currents observed by MMS in the near-Earth plasma sheet during large-scale substorm dipolarizations.

    NASA Astrophysics Data System (ADS)

    Nakamura, Rumi; Nagai, Tsugunobu; Giles, Barbara; Le Contel, Olivier; Stawarz, Julia; Khotyaintsev, Yuri; Artemyev, Anton

    2017-04-01

    During substorms significant energy conversion has been reported to take place at the sharp dipolarization front in the flow braking region where the probability of observing bursty bulk flows (BBFs) significantly drops. On 10 August 2016, MMS traversed the pre-midnight near-Earth plasma sheet when dipolarization disturbances were detected in an extended nightside local time region by Cluster, Geotail, GOES 13, 14 and 15, and the Van Allen Probes. In an expanding plasma sheet during the dipolarization, MMS detected sub-ion scale field-aligned current layers that are propagating both Earthward (equatorward) as well as tailward (outward). These multi-scale multi-point observations enable a unique investigation of both the meso-scale evolution of the disturbances and the detailed kinetic structures of the fronts and boundaries relevant to the dipolarizations.

  18. Electric fields and field-aligned currents in polar regions of the solar corona: 3-D MHD consideration

    NASA Technical Reports Server (NTRS)

    Pisanko, Yu. V.

    1995-01-01

    The calculation of the solar rotation electro-dynamical effects in the near-the-Sun solar wind seems more convenient from the non-inertial corotating reference frame. This implies some modification of the 3-D MHD equations generally on the base of the General Theory of Relativity. The paper deals with the search of stationary (in corotating non-inertial reference frame) solutions of the modified 3-D MHD equations for the in near-the-Sun high latitude sub-alfvenic solar wind. The solution is obtained requiring electric fields and field-aligned electric currents in the high latitude near-the-Sun solar wind. Various scenario are explored self-consistently via a number of numerical experiments. The analogy with the high latitude Earth's magnetosphere is used for the interpretation of the results. Possible observational manifestations are discussed.

  19. Identifications of the polar cap boundary and the auroral belt in the high altitude magnetosphere: A model for field aligned currents

    NASA Technical Reports Server (NTRS)

    Sugiura, M.

    1974-01-01

    Using the OGO-5 fluxgate magnetometer data, the polar cap boundary is identified in the high altitude magnetosphere by a sudden transition from a dipolar field to a more tail like configuration. The basic pattern of the magnetic field variations observed during the satellite's traversal of the auroral belt is presented. This pattern shows the existence of a field aligned current layer on the equator side of the polar cap boundary. Currents flow in the opposite directions in the two field aligned current layers. The current directions in these layers as observed by OGO-5 in the high-altitude magnetosphere are the same as those observed at low altitudes by the polar orbiting TRIAD satellite. The magnetic field in the region where the lower latitude field aligned current layer is situated is essentially meridional. Thus the equatorial current closure of this current system must be via the equatorial current sheet. The two field aligned current systems, one at the polar cap boundary and the other on the low latitude side of the auroral belt, are coupled through the Pedersen current in the ionosphere.

  20. Field-aligned currents in Saturn's magnetosphere: Local time dependence of southern summer currents in the dawn sector between midnight and noon

    NASA Astrophysics Data System (ADS)

    Hunt, G. J.; Cowley, S. W. H.; Provan, G.; Bunce, E. J.; Alexeev, I. I.; Belenkaya, E. S.; Kalegaev, V. V.; Dougherty, M. K.; Coates, A. J.

    2016-08-01

    We examine and compare the magnetic field perturbations associated with field-aligned ionosphere-magnetosphere coupling currents at Saturn, observed by the Cassini spacecraft during two sequences of highly inclined orbits in 2006/2007 and 2008 under late southern summer conditions. These sequences explore the southern currents in the dawn-noon and midnight sectors, respectively, thus allowing investigation of possible origins of the local time (LT) asymmetry in auroral Saturn kilometric radiation (SKR) emissions, which peak in power at ~8 h LT in the dawn-noon sector. We first show that the dawn-noon field data generally have the same four-sheet current structure as found previously in the midnight data and that both are similarly modulated by "planetary period oscillation" (PPO) currents. We then separate the averaged PPO-independent (e.g., subcorotation) and PPO-related currents for both LT sectors by using the current system symmetry properties. Surprisingly, we find that the PPO-independent currents are essentially identical within uncertainties in the dawn-dusk and midnight sectors, thus providing no explanation for the LT dependence of the SKR emissions. The main PPO-related currents are, however, found to be slightly stronger and narrower in latitudinal width at dawn-noon than at midnight, leading to estimated precipitating electron powers, and hence emissions, that are on average a factor of ~1.3 larger at dawn-noon than at midnight, inadequate to account for the observed LT asymmetry in SKR power by a factor of ~2.7. Some other factors must also be involved, such as a LT asymmetry in the hot magnetospheric auroral source electron population.

  1. Field-aligned currents in Saturn's magnetosphere: Local time dependence of southern summer currents in the dawn sector between midnight and noon

    NASA Astrophysics Data System (ADS)

    Hunt, G. J.; Cowley, S. W. H.; Provan, G.; Bunce, E. J.; Belenkaya, E. S.; Alexeev, I. I.; Kalegaev, V. V.; Dougherty, M. K.; Coates, A. J.

    2016-12-01

    We examine and compare the magnetic field perturbations associated with field-aligned ionosphere-magnetosphere coupling currents at Saturn, observed by the Cassini spacecraft during two sequences of highly inclined orbits in 2006/7 and 2008 under late southern summer conditions. These sequences explore the southern currents in the dawn-noon and midnight sectors, respectively. This allows investigation of possible origins of the local time (LT) asymmetry in auroral Saturn kilometric radiation (SKR) emissions, which peak in power at 8 h LT in the dawn-noon sector. We first show that the dawn-noon field data generally have the same four-sheet current structure as found previously in the midnight data, and that both are similarly modulated by "planetary period oscillation" (PPO) currents, these being associated with the 10.7 h magnetic field oscillations observed throughout Saturn's magnetosphere. We then separate the averaged PPO-independent (e.g., subcorotation) and PPO-related currents for both LT sectors using the latter current system symmetry properties. Surprisingly, we find that the PPO-independent currents are essentially identical within uncertainties in the dawn-dusk and midnight sectors, thus providing no explanation for the LT dependence of the SKR emissions. The main PPO-related currents are, however, found to be slightly stronger and narrower in latitudinal width at dawn-noon than at midnight, leading to estimated precipitating electron powers, and hence emissions, that are on average a factor of 1.3 larger at dawn-noon than at midnight, inadequate to account for the observed LT asymmetry in SKR power by a factor of 2.7. Some other factor must also be involved, such as a LT asymmetry in the hot magnetospheric auroral source electron population.

  2. A New Generation of Comfort Care Order Sets: Aligning Protocols with Current Principles.

    PubMed

    Bender, Melissa A; Hurd, Caroline; Solvang, Nicole; Colagrossi, Kathy; Matsuwaka, Diane; Curtis, J Randall

    2017-09-01

    There are few published comfort care order sets for end-of-life symptom management, contributing to variability in treatment of common symptoms. At our academic medical centers, we have observed that rapid titration of opioid infusions using our original comfort care order set's titration algorithm causes increased discomfort from opioid toxicity. The aim of this study was to describe the process and outcomes of a multiyear revision of a standardized comfort care order set for clinicians to treat end-of-life symptoms in hospitalized patients. Our revision process included interdisciplinary group meetings, literature review and expert consultation, beta testing protocols with end users, and soliciting feedback from key committees at our institutions. We focused on opioid dosing and embedding treatment algorithms and guidelines within the order set for clinicians. The study was conducted at two large academic medical centers. We developed and implemented a comfort care order set with opioid dosing that reflects current pharmacologic principles and expert recommendations. Educational tools and reference materials are embedded within the order set in the electronic medical record. There are prompts for improved collaboration between ordering clinicians, nurses, and palliative care. We successfully developed a new comfort care order set at our institutions that can serve as a resource for others. Further evaluation of this order set is needed.

  3. Structure of High Latitude Currents in Magnetosphere-Ionosphere Models

    NASA Astrophysics Data System (ADS)

    Wiltberger, M.; Rigler, E. J.; Merkin, V.; Lyon, J. G.

    2017-03-01

    Using three resolutions of the Lyon-Fedder-Mobarry global magnetosphere-ionosphere model (LFM) and the Weimer 2005 empirical model we examine the structure of the high latitude field-aligned current patterns. Each resolution was run for the entire Whole Heliosphere Interval which contained two high speed solar wind streams and modest interplanetary magnetic field strengths. Average states of the field-aligned current (FAC) patterns for 8 interplanetary magnetic field clock angle directions are computed using data from these runs. Generally speaking the patterns obtained agree well with results obtained from the Weimer 2005 computing using the solar wind and IMF conditions that correspond to each bin. As the simulation resolution increases the currents become more intense and narrow. A machine learning analysis of the FAC patterns shows that the ratio of Region 1 (R1) to Region 2 (R2) currents decreases as the simulation resolution increases. This brings the simulation results into better agreement with observational predictions and the Weimer 2005 model results. The increase in R2 current strengths also results in the cross polar cap potential (CPCP) pattern being concentrated in higher latitudes. Current-voltage relationships between the R1 and CPCP are quite similar at the higher resolution indicating the simulation is converging on a common solution. We conclude that LFM simulations are capable of reproducing the statistical features of FAC patterns.

  4. Structure of high latitude currents in magnetosphere-ionosphere models

    NASA Astrophysics Data System (ADS)

    Wiltberger, M. J.; Lyon, J.; Merkin, V. G.; Rigler, E. J.

    2016-12-01

    Using three resolutions of the Lyon-Fedder-Mobarry global magnetosphere-ionosphere model (LFM) and the Weimer 2005 empirical model the structure of the high latitude field-aligned current patterns is examined. Each LFM resolution was run for the entire Whole Heliosphere Interval (WHI), which contained two high-speed solar wind streams and modest interplanetary magnetic field strengths. Average states of the field-aligned current (FAC) patterns for 8 interplanetary magnetic field clock angle directions are computed using data from these runs. Generally speaking the patterns obtained agree well with results from the Weimer 2005 computed using the solar wind and IMF conditions that correspond to each bin. As the simulation resolution increases the currents become more intense and confined. A machine learning analysis of the FAC patterns shows that the ratio of Region 1 (R1) to Region 2 (R2) currents decreases as the simulation resolution increases. This brings the simulation results into better agreement with observational predictions and the Weimer 2005 model results. The increase in R2 current strengths in the model also results in a better shielding of mid- and low-latitude ionosphere from the polar cap convection, also in agreement with observations. Current-voltage relationships between the R1 strength and the cross-polar cap potential (CPCP) are quite similar at the higher resolutions indicating the simulation is converging on a common solution. We conclude that LFM simulations are capable of reproducing the statistical features of FAC patterns.

  5. A nonstationary large-scale structure of the ionospheric plasma in the region of field-aligned current outflow

    NASA Astrophysics Data System (ADS)

    Kropotkin, A. P.; Mart'ianov, S. A.

    1989-12-01

    The appearance of an auroral cavity in the ionosphere in the FAC outflow region is examined. Collisionless effects connected with the formation of electrostatic potential jumps lead to the formation of a sharp boundary dividing the regions of cold ionospheric plasma and hot rarefied magnetospheric plasma. A gasdynamic description of the further evolution of the structure in the direction longitudinal with respect to the magnetic field is presented. This evolution consists in the formation of a collection of different types of discontinuities in relative motion.

  6. Three-dimensional MHD simulation of the interaction of the solar wind with the earth's magnetosphere: The generation of field-aligned currents

    SciTech Connect

    Ogino, T.

    1986-06-01

    A global computer simulation of the interaction of the solar wind with the earth's magnetosphere was executed by using a three-dimensional magnetohydrodynamic model. As a result, we were able to reproduce quasi-steady-state magnetospheric configurations and a Birkeland field-aligned current system which depend on the polarity of the z-italic component of the interplanetary magnetic field (IMF). Twin convection cells and a dawn to dusk electric potential of 30--100 kV appeared at the equator in the magnetosphere. Four types of field-aligned currents were observed. Region 1 and 2 field-aligned currents generated for all IMF conditions were 0.6--1.0 x 10/sup 6/ A and 0.15--0.61 x 10/sup 6/ A, respectively, in the total current. Region 1 currents at high latitudes are generated from the field-aligned vorticity at the flanks through a viscous interaction and are strengthened by a twisting of open magnetic field lines in the tail region for southward IMF. On the other hand, the low-latitude region 2 currents probably are generated mainly from the inner pressure gradient of the plasma sheet. The region 1 current obtained from the simulation was in good agreement with an estimate from our theoretical analysis of the localized Alfve-acute-accentn mode. The other two types of field-aligned currents are the dayside magnetopause currents in the dayside cusp region, which increase for northward IMF, and the dayside cusp currents for southward IMF. The cusp currents are associated with a twisting of open magnetic field lines in the magnetopause region.

  7. FACS purification of Drosophila larval Neuroblasts for next generation sequencing

    PubMed Central

    Conder, Ryan; Schmauss, Gerald; Knoblich, Juergen A.

    2014-01-01

    Elegant tools are available for the genetic analysis of neural stem cell lineages in Drosophila, but a methodology for purifying stem cells and their differentiated progeny for transcriptome analysis is currently missing. Previous attempts to overcome this problem either involved using RNA isolated from whole larval brain tissue or co-transcriptional in vivo mRNA tagging. As both methods have limited cell type specificity, we developed a protocol for the isolation of Drosophila neural stem cells (neuroblasts, NBs) and their differentiated sibling cells by FACS. We dissected larval brains from fly strains expressing GFP under the control of a NB lineage-specific GAL4 line. Upon dissociation, we made use of differences in GFP intensity and cell size to separate NBs and neurons. The resulting cell populations are over 98% pure and can readily be used for live imaging or gene expression analysis. Our method is optimized for neural stem cells, but it can also be applied to other Drosophila cell types. Primary cell suspensions and sorted cell populations can be obtained within 1 d; material for deep-sequencing library preparation can be obtained within 4 d. PMID:23660757

  8. Confirmation of Small Scale Field-Aligned Currents in Middle and Low Latitudes and an Estimation of Their Typical Period of Temporal Variation

    NASA Astrophysics Data System (ADS)

    Iyemori, T.; Nakanishi, K.; Aoyama, T.; Luhr, H.; Nose, M.; Koyama, Y.; Yokoyama, Y.

    2014-12-01

    From the analysis of the data obtained by the Oersted and CHAMP satellites, we found that the small-scale magnetic fluctuations with amplitude about a few nT or less having apparent period along the satellite orbit about 10-30 seconds exist almost always. From their statistical characteristics, we suppose that their origin is in the lower atmosphere (Nakanishi et al., 2014). In this paper, we present a clear evidence that the magnetic fluctuations are the spatial structures of small scale field-aligned currents along satellite orbit. By using the data obtained during initial one month when the SWARM-A and SWARM-B were flying on almost the same orbit with gradually increasing separation, we try to estimate the temporal scale of variation of the field-aligned currents. We compare the period with the possible magnetic signature of the field-aligned current system observed on the ground.

  9. 48 CFR 301.603-72 - FAC-C and HHS SAC certification requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false FAC-C and HHS SAC... Responsibilities 301.603-72 FAC-C and HHS SAC certification requirements. (a) The FAC-C certification program is... thereunder are not required to re-take training courses, but shall follow FAC-C training requirements when...

  10. 48 CFR 301.603-72 - FAC-C and HHS SAC certification requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 4 2012-10-01 2012-10-01 false FAC-C and HHS SAC... Responsibilities 301.603-72 FAC-C and HHS SAC certification requirements. (a) The FAC-C certification program is... thereunder are not required to re-take training courses, but shall follow FAC-C training requirements when...

  11. 48 CFR 301.603-72 - FAC-C and HHS SAC certification requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 4 2013-10-01 2013-10-01 false FAC-C and HHS SAC... Responsibilities 301.603-72 FAC-C and HHS SAC certification requirements. (a) The FAC-C certification program is... thereunder are not required to re-take training courses, but shall follow FAC-C training requirements when...

  12. 48 CFR 301.607-75 - Maintenance of FAC-P/PM certification.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 4 2012-10-01 2012-10-01 false Maintenance of FAC-P/PM... 301.607-75 Maintenance of FAC-P/PM certification. (a) FAC-P/PM certification lasts for 2 years. To maintain FAC-P/PM certification, HHS Program and Project Managers are required to earn 80 CLPs of skills...

  13. 48 CFR 301.607-75 - Maintenance of FAC-P/PM certification.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 4 2014-10-01 2014-10-01 false Maintenance of FAC-P/PM... 301.607-75 Maintenance of FAC-P/PM certification. (a) FAC-P/PM certification lasts for 2 years. To maintain FAC-P/PM certification, HHS Program and Project Managers are required to earn 80 CLPs of skills...

  14. 48 CFR 301.603-72 - FAC-C and HHS SAC certification requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false FAC-C and HHS SAC... Responsibilities 301.603-72 FAC-C and HHS SAC certification requirements. (a) The FAC-C certification program is... thereunder are not required to re-take training courses, but shall follow FAC-C training requirements when...

  15. 48 CFR 301.603-72 - FAC-C and HHS SAC certification requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 4 2014-10-01 2014-10-01 false FAC-C and HHS SAC... Responsibilities 301.603-72 FAC-C and HHS SAC certification requirements. (a) The FAC-C certification program is... thereunder are not required to re-take training courses, but shall follow FAC-C training requirements when...

  16. 48 CFR 301.607-75 - Maintenance of FAC-P/PM certification.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 4 2013-10-01 2013-10-01 false Maintenance of FAC-P/PM... 301.607-75 Maintenance of FAC-P/PM certification. (a) FAC-P/PM certification lasts for 2 years. To maintain FAC-P/PM certification, HHS Program and Project Managers are required to earn 80 CLPs of skills...

  17. 48 CFR 301.607-75 - Maintenance of FAC-P/PM certification.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Maintenance of FAC-P/PM... 301.607-75 Maintenance of FAC-P/PM certification. (a) FAC-P/PM certification lasts for 2 years. To maintain FAC-P/PM certification, HHS Program and Project Managers are required to earn 80 CLPs of skills...

  18. By-controlled convection and field-aligned currents near midnight auroral oval for northward interplanetary magnetic field

    NASA Technical Reports Server (NTRS)

    Taguchi, S.; Sugiura, M.; Iyemori, T.; Winningham, J. D.; Slavin, J. A.

    1994-01-01

    Using the Dynamics Explorer (DE) 2 magnetic and electric field and plasma data, B(sub y)- controlled convection and field-aligned currents in the midnight sector for northward interplanetary magnetic field (IMF) are examined. The results of an analysis of the electric field data show that when IMF is stable and when its magnitude is large, a coherent B(sub y)-controlled convection exists near the midnight auroral oval in the ionosphere having adequate conductivities. When B(sub y) is negative, the convection consists of a westward (eastward) plasma flow at the lower latitudes and an eastward (westward) plasma flow at the higher latitudes in the midnight sector in the northern (southern) ionosphere. When B(sub y) is positive, the flow directions are reversed. The distribution of the field-aligned currents associated with the B(sub y)-controlled convection, in most cases, shows a three-sheet structure. In accordance with the convection the directions of the three sheets are dependent on the sign of B(sub y). The location of disappearance of the precipitating intense electrons having energies of a few keV is close to the convection reversal surface. However, the more detailed relationship between the electron precipitation boundary and the convection reversal surface depends on the case. In some cases the precipitating electrons extend beyond the convection reversal surface, and in others the poleward boundary terminates at a latitude lower than the reversal surface. Previous studies suggest that the poleward boundary of the electrons having energies of a few keV is not necessarily coincident with an open/closed bounary. Thus the open/closed boundary may be at a latitude higher than the poleward boundary of the electron precipitation, or it may be at a latitude lower than the poleward boundary of the electron precipitation. We discuss relationships between the open/closed boundary and the convection reversal surface. When as a possible choice we adopt a view that the

  19. Obtaining genomes from uncultivated environmental microorganisms using FACS-based single-cell genomics.

    PubMed

    Rinke, Christian; Lee, Janey; Nath, Nandita; Goudeau, Danielle; Thompson, Brian; Poulton, Nicole; Dmitrieff, Elizabeth; Malmstrom, Rex; Stepanauskas, Ramunas; Woyke, Tanja

    2014-05-01

    Single-cell genomics is a powerful tool for exploring the genetic makeup of environmental microorganisms, the vast majority of which are difficult, if not impossible, to cultivate with current approaches. Here we present a comprehensive protocol for obtaining genomes from uncultivated environmental microbes via high-throughput single-cell isolation by FACS. The protocol encompasses the preservation and pretreatment of differing environmental samples, followed by the physical separation, lysis, whole-genome amplification and 16S rRNA-based identification of individual bacterial and archaeal cells. The described procedure can be performed with standard molecular biology equipment and a FACS machine. It takes <12 h of bench time over a 4-d time period, and it generates up to 1 μg of genomic DNA from an individual microbial cell, which is suitable for downstream applications such as PCR amplification and shotgun sequencing. The completeness of the recovered genomes varies, with an average of ∼50%.

  20. FACS-style detection for real-time cell viscoelastic cytometry.

    PubMed

    Kasukurti, A; Eggleton, C D; Desai, S A; Marr, D W M

    Cell mechanical properties have been established as a label-free biophysical marker of cell viability and health; however, real-time methods with significant throughput for accurately and non-destructively measuring these properties remain widely unavailable. Without appropriate labels for use with fluorescence activated cell sorters (FACS), easily implemented real-time technology for tracking cell-level mechanical properties remains a current need. Employing modulated optical forces and enabled by a low-dimensional FACS-style detection method introduced here, we present a viscoelasticity cytometer (VC) capable of real-time and continuous measurements. We demonstrate the utility of this approach by tracking the high-frequency cell physical properties of populations of chemically-modified cells at rates of ~ 1 s(-1) and explain observations within the context of a simple theoretical model.

  1. Principal component analysis of Birkeland currents determined by the Active Magnetosphere and Planetary Electrodynamics Response Experiment

    NASA Astrophysics Data System (ADS)

    Milan, S. E.; Carter, J. A.; Korth, H.; Anderson, B. J.

    2015-12-01

    Principal component analysis is performed on Birkeland or field-aligned current (FAC) measurements from the Active Magnetosphere and Planetary Electrodynamics Response Experiment. Principal component analysis (PCA) identifies the patterns in the FACs that respond coherently to different aspects of geomagnetic activity. The regions 1 and 2 current system is shown to be the most reproducible feature of the currents, followed by cusp currents associated with magnetic tension forces on newly reconnected field lines. The cusp currents are strongly modulated by season, indicating that their strength is regulated by the ionospheric conductance at the foot of the field lines. PCA does not identify a pattern that is clearly characteristic of a substorm current wedge. Rather, a superposed epoch analysis of the currents associated with substorms demonstrates that there is not a single mode of response, but a complicated and subtle mixture of different patterns.

  2. Principle Component Analysis of Birkeland Currents Determined by the Active Magnetosphere and Planetary Electrodynamics Response Experiment

    NASA Astrophysics Data System (ADS)

    Milan, S. E.; Carter, J. A.; Korth, H.; Anderson, B. J.

    2015-12-01

    Principle Component Analysis is performed on northern and southern hemisphere Birkeland or field-aligned current (FAC) measurements from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE). PCA identifies the patterns in the FACs that respond coherently to different aspects of geomagnetic activity. The region 1 and 2 current system is shown to be the most reproducible feature of the currents, followed by cusp currents associated with magnetic tension forces on newly-reconnected field lines. The cusp currents are strongly modulated by season, indicating that their strength is regulated by the ionospheric conductance at the foot of the field lines. PCA does not identify a pattern that is clearly characteristic of a substorm current wedge. Rather, a superposed epoch analysis of the currents associated with substorms demonstrates that there is not a single mode of response, but a complicated and subtle mixture of different patterns. Other interhemispheric differences are discussed.

  3. Investigation of the Influence of Magnetospheric Sources of Field-Aligned Currents on the Equatorial Electric Fields

    NASA Astrophysics Data System (ADS)

    Beloushko, Konstantin; Knyazeva, Mariya

    The urgency of studying electrodynamic processes related to the influence of spatial and temporal heterogeneities of the electromagnetic field in the Earth's upper atmosphere to the functioning of modern technological systems , satellite navigation systems , radio propagation Fundamentally new is the use of various third-party electrodynamic models in the total open loop model of the atmosphere based on the Upper Atmosphere Model (UAM) [1,2]. Performing calculations on model UAM using different spatial and temporal distributions of field-aligned currents and brands Lukianova and Papitashvili. A comparison of model results with data Jicamarca Incoherent Scatter Radar (Peru). References begin{enumerate} Namgaladze A.A., Korenkov Yu.N., Klimenko V.V., Karpov I.V., Bessarab F.S., Surotkin V.A., Gluschenko T.A., Naumova N.M. Global model of the thermosphere-ionosphere-protonosphere system. Pure and Applied Geophysics. № 2/3, 127, 219-254, 1988. Namgaladze A.A., Martynenko O.V., Namgaladze A.N. Global model of the upper atmosphere with variable latitudinal steps of numerical integration, IUGG XXI General Assembly, Boulder, 1995, Abstracts, GAB41F-6, B150, 1995, and (in Russian) Geamagn. Aeron., 36, 89-95, 1996a.

  4. Subauroral polarization stream on the outer boundary of the ring current during an energetic ion injection event

    NASA Astrophysics Data System (ADS)

    Yuan, Zhigang; Qiao, Zheng; Li, Haimeng; Huang, Shiyong; Wang, Dedong; Yu, Xiongdong; Yu, Tao

    2017-04-01

    Subauroral polarization stream (SAPS) electric field can play an important role in the coupling between the inner magnetosphere and ionosphere; however, the production mechanism of SAPS has not been yet solved. During an energetic ion injection event on 26 March 2004, at latitudes lower than the equatorward boundaries of precipitating plasma sheet electrons and ions, the Defense Meteorological Satellite Program (DMSP) F13 satellite simultaneously observed a strong SAPS with the peak velocity of 1294 m/s and downward flowing field-aligned currents (FACs). Conjugate observations of DMSP F13 and NOAA 15 satellites have shown that FACs flowing into the ionosphere just lie in the outer boundary of the ring current (RC). The downward flowing FACs were observed in a region of positive latitudinal gradients of the ion energy density, implying that the downward flowing FACs are more likely linked to the azimuthal gradient than the radial gradient of the RC ion pressure. Our result demonstrates that RC ion pressure gradients on the outer boundary of the RC in the evening sector during energetic ion injection events can lead to downward flowing FACs so as to cause strong SAPS in condition of low ionospheric conductivities.Plain Language SummaryThis paper provides a good case that the SAPS and <span class="hlt">FAC</span> occurred in the outer boundary of the ring <span class="hlt">current</span> during an energetic ion injection event. Our result demonstrates that RC ion pressure gradients on the outer boundary of the RC in the evening sector during energetic ion injection events can lead to downward flowing <span class="hlt">FACs</span> so as to cause strong SAPS in condition of low ionospheric conductivities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21911005','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21911005"><span><span class="hlt">FACS</span> purification of immunolabeled cell types from adult rat brain.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Guez-Barber, Danielle; Fanous, Sanya; Harvey, Brandon K; Zhang, Yongqing; Lehrmann, Elin; Becker, Kevin G; Picciotto, Marina R; Hope, Bruce T</p> <p>2012-01-15</p> <p>Molecular analysis of brain tissue is greatly complicated by having many different classes of neurons and glia interspersed throughout the brain. Fluorescence-activated cell sorting (<span class="hlt">FACS</span>) has been used to purify selected cell types from brain tissue. However, its use has been limited to brain tissue from embryos or transgenic mice with promoter-driven reporter genes. To overcome these limitations, we developed a <span class="hlt">FACS</span> procedure for dissociating intact cell bodies from adult wild-type rat brains and sorting them using commercially available antibodies against intracellular and extracellular proteins. As an example, we isolated neurons using a NeuN antibody and confirmed their identity using microarray and real time PCR of mRNA from the sorted cells. Our <span class="hlt">FACS</span> procedure allows rapid, high-throughput, quantitative assays of molecular alterations in identified cell types with widespread applications in neuroscience. Published by Elsevier B.V.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3221768','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3221768"><span><span class="hlt">FACS</span> purification of immunolabeled cell types from adult rat brain</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Guez-Barber, Danielle; Fanous, Sanya; Harvey, Brandon K; Zhang, Yongqing; Lehrmann, Elin; Becker, Kevin G; Picciotto, Marina R; Hope, Bruce T</p> <p>2011-01-01</p> <p>Molecular analysis of brain tissue is greatly complicated by having many different classes of neurons and glia interspersed throughout the brain. Fluorescence-activated cell sorting (<span class="hlt">FACS</span>) has been used to purify selected cell types from brain tissue. However, its use has been limited to brain tissue from embryos or transgenic mice with promoter-driven reporter genes. To overcome these limitations, we developed a <span class="hlt">FACS</span> procedure for dissociating intact cell bodies from adult wild-type rat brains and sorting them using commercially available antibodies against intracellular and extracellular proteins. As an example, we isolated neurons using a NeuN antibody and confirmed their identity using microarray and real time PCR of mRNA from the sorted cells. Our <span class="hlt">FACS</span> procedure allows rapid, high-throughput, quantitative assays of molecular alterations in identified cell types with widespread applications in neuroscience. PMID:21911005</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM21C2198B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM21C2198B"><span>Overview of the Cassini In-Situ Observations of Auroral Field-<span class="hlt">Aligned</span> <span class="hlt">Currents</span> During the 2013 Saturn Aurora Campaign</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bunce, E. J.; Badman, S. V.; Cowley, S. W.; Dougherty, M. K.; Gurnett, D. A.; Jinks, S.; Kurth, W. S.; Mitchell, D. G.; Nichols, J. D.; Provan, G.; Pryor, W. R.</p> <p>2013-12-01</p> <p>The Saturn Aurora Campaign 2013 is a coordinated effort to provide a clearer understanding of Saturn's auroral emissions at multiple wavelengths in the upper atmosphere, and their associated magnetospheric signatures and dynamics. Structures such as Corotating Interaction Regions (CIRs) are known to play a significant role in the modulation of Saturn's auroral emissions via abrupt changes in the dynamic pressure associated with forward shocks at the start of the CIR compression regions. Recent observations from the Cassini spacecraft at Saturn have also taught us that the 'magnetosphere oscillations' observed in magnetic field perturbations in the northern and southern hemispheres, which are associated with the SKR modulations in each hemisphere, also significantly modulate the magnetosphere and auroral emissions. Here we present an overview of the in situ magnetosphere measurements during the campaign, along with an overview of the solar wind conditions upstream of Saturn inferred from the Saturn Kilometric Radiation (SKR) emissions. We will discuss evidence of the high-latitude field-<span class="hlt">aligned</span> <span class="hlt">currents</span> and plasma boundaries (e.g. the open-closed field line (or related) boundary) from the magnetic field data, plasma signatures and/or auroral hiss observations (using the Cassini magnetometer-MAG, the Magnetospheric Imaging Instrument-MIMI, and the Radio Plasma Wave Science-RPWS instruments respectively). We will attempt to characterise the morphology and variability (e.g. co-latitude, intensity) of the <span class="hlt">current</span> system(s) from both the knowledge of the northern or southern magnetosphere oscillation phase (according to the location of the spacecraft) and the inferred solar wind conditions. We will compare these results with available IR/UV auroral images from the campaign.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/200117','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/200117"><span>Average pattern of auroral particle precipitation, its associated conductivity and field <span class="hlt">aligned</span> <span class="hlt">currents</span>. (Reannouncement with new availability information)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hardy, D.A.; Gussenhoven, M.S.; Rich, F.J.; Brautigam, D.H.</p> <p>1991-12-31</p> <p>A series of statistical studies has been completed to determine the global pattern of auroral electron and ion precipitation and their resultant Hall and Pedersen conductivities as a function of geomagnetic activity, solar wind velocity, the orientation of the Interplanetary Magnetic Field (IMF) and season. In addition, studies were performed relating these global patterns in particle precipitation to similar global determinations of the average delta beta vector produced by the auroral field <span class="hlt">aligned</span> <span class="hlt">currents</span>. The data for these studies were from instruments flown on the satellites of the Defense Meteorological Satellite Program (DMSP). In all cases the studies were performed by dividing the high latitude region into a series spatial bins in Magnetic Local Time (MLT) and corrected geomagnetic latitude (CGL). One such matrix of spatial bins was created for each different value or range of values of chosen sort parameter. For geomagnetic activity the sort parameter was one of seven levels of Kp. For the IMF and solar wind velocity the sort parameters consisted of 30 paired ranges of the solar wind velocity and the beta z component of the IMF. A rough separation by the IMF beta was performed by using the IMF sector structure and Kp together as the sort parameter. Seasonal separations were made with Kp and for time periods centered on the summer and winter solstices and the equinoxes. In all cases the large DMSP data sets were used to determine the average spectrum of precipitating electrons and ions and the average delta beta vector for each spatial bin and for each sort parameter used. In this paper the authors review the results of these studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/978949','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/978949"><span>Chemometric Analysis of Gas Chromatography – Mass Spectrometry Data using Fast Retention Time <span class="hlt">Alignment</span> via a Total Ion <span class="hlt">Current</span> Shift Function</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nadeau, Jeremy S.; Wright, Bob W.; Synovec, Robert E.</p> <p>2010-04-15</p> <p>A critical comparison of methods for correcting severely retention time shifted gas chromatography-mass spectrometry (GC-MS) data is presented. The method reported herein is an adaptation to the Piecewise <span class="hlt">Alignment</span> Algorithm to quickly <span class="hlt">align</span> severely shifted one-dimensional (1D) total ion <span class="hlt">current</span> (TIC) data, then applying these shifts to broadly <span class="hlt">align</span> all mass channels throughout the separation, referred to as a TIC shift function (SF). The maximum shift varied from (-) 5 s in the beginning of the chromatographic separation to (+) 20 s toward the end of the separation, equivalent to a maximum shift of over 5 peak widths. Implementing the TIC shift function (TIC SF) prior to Fisher Ratio (F-Ratio) feature selection and then principal component analysis (PCA) was found to be a viable approach to classify complex chromatograms, that in this study were obtained from GC-MS separations of three gasoline samples serving as complex test mixtures, referred to as types C, M and S. The reported <span class="hlt">alignment</span> algorithm via the TIC SF approach corrects for large dynamic shifting in the data as well as subtle peak-to-peak shifts. The benefits of the overall TIC SF <span class="hlt">alignment</span> and feature selection approach were quantified using the degree-of-class separation (DCS) metric of the PCA scores plots using the type C and M samples, since they were the most similar, and thus the most challenging samples to properly classify. The DCS values showed an increase from an initial value of essentially zero for the unaligned GC-TIC data to a value of 7.9 following <span class="hlt">alignment</span>; however, the DCS was unchanged by feature selection using F-Ratios for the GC-TIC data. The full mass spectral data provided an increase to a final DCS of 13.7 after <span class="hlt">alignment</span> and two-dimensional (2D) F-Ratio feature selection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JaJAP..47.1901H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JaJAP..47.1901H"><span>Source Driver Channel Reduction Schemes Employing Corresponding Pixel <span class="hlt">Alignments</span> for <span class="hlt">Current</span> Programming Active-Matrix Organic Light-Emitting Diode Displays</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hong, Soon-Kwang; Oh, Du-Hwan; Jeong, Seok-Hee; Park, Young-Ju; Kim, Byeong-Koo; Ha, Yong-Min; Jang, Jin</p> <p>2008-03-01</p> <p>We propose two types of novel scheme for reducing the number of output channels of driver-integrated circuit (D-IC) for the <span class="hlt">current</span> programming compensation pixel structures of active-matrix organic light-emitting diodes (AMOLEDs). One is a 2:1 data demultiplexing technique that can reduce the number of output channels of D-IC by half. The proposed second scheme is a vertically <span class="hlt">aligned</span> red (R), green (G), and blue (B) subpixel scheme instead of a horizontally <span class="hlt">aligned</span> R-G-B subpixel one, which is regarded as the conventional pixel <span class="hlt">alignment</span> scheme. We have also successfully implemented these schemes in a 2.4-in.-sized QCIF + (176 × RGB × 220) AMOLED using p-type excimer laser annealing (ELA) low-temperature polycrystalline silicon (LTPS) technology and evaluated key performance characteristics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ApPhL.109j1901L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ApPhL.109j1901L"><span>Ion-beam-spurted dimethyl-sulfate-doped PEDOT:PSS composite-layer-<span class="hlt">aligning</span> liquid crystal with low residual direct-<span class="hlt">current</span> voltage</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Yang; Lee, Ju Hwan; Seo, Dae-Shik; Li, Xiang-Dan</p> <p>2016-09-01</p> <p>Thin ion-beam (IB)-spurted dimethyl sulfate/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (DMS/PEDOT:PSS) layers with improved electro-optic performance are presented for <span class="hlt">aligning</span> liquid crystals. IB spurting is effective for enhancing the conductivity of such layers, as well as the anchoring energy of the liquid crystals sandwiched between them. Compared with a commercial twisted-nematic cell assembled with polyimide <span class="hlt">alignment</span> layers, the same cell assembled with 3.0-keV IB-spurted DMS/PEDOT:PSS <span class="hlt">alignment</span> layers shows a 38% faster switching and a 93% lower residual direct <span class="hlt">current</span>. The improved electro-optic performance here is likely due to the enhanced electric field effect and the charge-releasing ability of thin IB-spurted DMS/PEDOT:PSS layers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22594287','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22594287"><span>Ion-beam-spurted dimethyl-sulfate-doped PEDOT:PSS composite-layer-<span class="hlt">aligning</span> liquid crystal with low residual direct-<span class="hlt">current</span> voltage</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Liu, Yang; Lee, Ju Hwan; Seo, Dae-Shik; Li, Xiang-Dan</p> <p>2016-09-05</p> <p>Thin ion-beam (IB)-spurted dimethyl sulfate/poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (DMS/PEDOT:PSS) layers with improved electro-optic performance are presented for <span class="hlt">aligning</span> liquid crystals. IB spurting is effective for enhancing the conductivity of such layers, as well as the anchoring energy of the liquid crystals sandwiched between them. Compared with a commercial twisted-nematic cell assembled with polyimide <span class="hlt">alignment</span> layers, the same cell assembled with 3.0-keV IB-spurted DMS/PEDOT:PSS <span class="hlt">alignment</span> layers shows a 38% faster switching and a 93% lower residual direct <span class="hlt">current</span>. The improved electro-optic performance here is likely due to the enhanced electric field effect and the charge-releasing ability of thin IB-spurted DMS/PEDOT:PSS layers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5255923','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5255923"><span>On the influence of localized electric fields and field-<span class="hlt">aligned</span> <span class="hlt">currents</span> associated with polar arcs on the global potential distribution</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Marklund, G.T.; Blomberg, L.G. )</p> <p>1991-08-01</p> <p>The influence of localized field-<span class="hlt">aligned</span> <span class="hlt">current</span>, associated with intense transpolar arcs mostly occurring during periods of northward interplaentary magnetic field (IMF), on the global electrodynamics has been investigated using a numerical simulation model. Idealized field-<span class="hlt">aligned</span> <span class="hlt">current</span> distributions representing both the region 1/2 system of the auroral oval and the transpolar arc as well as a corresponding ionospheric conductivity distribution are fed into the model to calculate the potential distributions. The transpolar arc has been represented by a few alternative field-<span class="hlt">aligned</span> <span class="hlt">current</span> distributions which are different in the way the downward return <span class="hlt">currents</span> are distributed in the ionosphere. If the conductivity of the main auroral oval is comparable to that of the polar arc the dusk cell will have two local potential minima and thus a region of weak antisunward convection in between. Depending on the direction of the polar arc <span class="hlt">current</span> sheets the dawn-dusk electric field will either be reversed (or weakened) or intensified at the location of the transpolar arc. The presence of a reversal depend, however, not only on the relative magnitude between the polar arc <span class="hlt">current</span> sand those of the region 1/2 system but also on the characteristics of the acceleration region and of the conductivity distribution associated with the polar arc. Comparisons are made between the model results and Viking electric field data for a number of polar arc crossings to reveal the most common electrodynamical signatures of these auroral phenomena.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=FACS&pg=3&id=EJ510284','ERIC'); return false;" href="https://eric.ed.gov/?q=FACS&pg=3&id=EJ510284"><span>MAC/<span class="hlt">FAC</span>: A Model of Similarity-Based Retrieval.</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>Forbus, Kenneth D.; And Others</p> <p>1995-01-01</p> <p>Presents MAC/<span class="hlt">FAC</span>, a model of similarity-based retrieval that attempts to capture psychological phenomena; discusses its limitations and extensions, its relationship with other retrieval models, and its placement in the context of other work on the nature of similarity. Examines the utility of the model through psychological experiments and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/15654398','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/15654398"><span>Cationic <span class="hlt">fac</span>-tris(pyrazole) complexes as anion receptors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nieto, Sonia; Pérez, Julio; Riera, Víctor; Miguel, Daniel; Alvarez, Celedonio</p> <p>2005-01-28</p> <p>New receptors <span class="hlt">fac</span>-[Re(CO)3(pz)3]BAr'4 (pz = 3,5-dimethylpyrazole or 3(5)-tert-butylpyrazole, Ar' = 3,5-(CF3)2C6H3), synthesized from [Re(OTf)(CO)5] and the pyrazoles, have been found to show a high affinity for chloride.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=FACS&pg=3&id=EJ510284','ERIC'); return false;" href="http://eric.ed.gov/?q=FACS&pg=3&id=EJ510284"><span>MAC/<span class="hlt">FAC</span>: A Model of Similarity-Based Retrieval.</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>Forbus, Kenneth D.; And Others</p> <p>1995-01-01</p> <p>Presents MAC/<span class="hlt">FAC</span>, a model of similarity-based retrieval that attempts to capture psychological phenomena; discusses its limitations and extensions, its relationship with other retrieval models, and its placement in the context of other work on the nature of similarity. Examines the utility of the model through psychological experiments and…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017EGUGA..19.7228S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017EGUGA..19.7228S"><span>Study on field-<span class="hlt">aligned</span> electrons with Cluster observation in the Earth's cusp</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shi, Jiankui; Torkar, Klaus; Cheng, Zhengwei</p> <p>2017-04-01</p> <p>Cusp region is very important to the solar wind-magnetosphere coupling. The solar wind particles, through the cusp, can directly entry into the magnetosphere and ionosphere, and transport the mass, momentum and energy. The gyrating charged particles with field-<span class="hlt">aligned</span> velocity are significant to perform the transportation. In this study, data from Cluster observation are used to study the characteristics of field-<span class="hlt">aligned</span> electrons (FAE's) including the downward and the upward FAEs in the cusp. We select FAE event to do analysis. The durations of the FAE event covered a wide range from 6 to 475 seconds. The FAE's were found to occur very commonly in a circumpolar zone in the polar region and the MLT and ILAT distributions showed that most of the FAE events were observed around the cusp (70-80°ILAT, 0900-1500MLT). With the FAE flux the contribution of the electrons to the Field-<span class="hlt">Aligned</span> <span class="hlt">Current</span> (<span class="hlt">FAC</span>) is estimated and the result shows that the FAE was the main carrier to the <span class="hlt">FAC</span> in the cusp. The physical mechanisms of the FAE are analyzed, namely that the downward electrons were mainly from the solar wind and the upward electrons may originated from accelerated ionospheric up-flowing electrons or mirrored solar wind electrons. The energy transportation into the magnetosphere by the solar wind electrons through the cusp is also investigated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70184348','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70184348"><span>Structure of high latitude <span class="hlt">currents</span> in global magnetospheric-ionospheric models</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Wiltberger, M; Rigler, E. J.; Merkin, V; Lyon, J. G</p> <p>2016-01-01</p> <p>Using three resolutions of the Lyon-Fedder-Mobarry global magnetosphere-ionosphere model (LFM) and the Weimer 2005 empirical model we examine the structure of the high latitude field-<span class="hlt">aligned</span> <span class="hlt">current</span> patterns. Each resolution was run for the entire Whole Heliosphere Interval which contained two high speed solar wind streams and modest interplanetary magnetic field strengths. Average states of the field-<span class="hlt">aligned</span> <span class="hlt">current</span> (<span class="hlt">FAC</span>) patterns for 8 interplanetary magnetic field clock angle directions are computed using data from these runs. Generally speaking the patterns obtained agree well with results obtained from the Weimer 2005 computing using the solar wind and IMF conditions that correspond to each bin. As the simulation resolution increases the <span class="hlt">currents</span> become more intense and narrow. A machine learning analysis of the <span class="hlt">FAC</span> patterns shows that the ratio of Region 1 (R1) to Region 2 (R2) <span class="hlt">currents</span> decreases as the simulation resolution increases. This brings the simulation results into better agreement with observational predictions and the Weimer 2005 model results. The increase in R2 <span class="hlt">current</span> strengths also results in the cross polar cap potential (CPCP) pattern being concentrated in higher latitudes. <span class="hlt">Current</span>-voltage relationships between the R1 and CPCP are quite similar at the higher resolution indicating the simulation is converging on a common solution. We conclude that LFM simulations are capable of reproducing the statistical features of <span class="hlt">FAC</span> patterns.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Chemical+AND+bonds&pg=6&id=EJ765864','ERIC'); return false;" href="http://eric.ed.gov/?q=Chemical+AND+bonds&pg=6&id=EJ765864"><span>Developing a New Teaching Approach for the Chemical Bonding Concept <span class="hlt">Aligned</span> with <span class="hlt">Current</span> Scientific and Pedagogical Knowledge</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>Nahum, Tami Levy; Mamlok-Naaman, Rachel; Hofstein, Avi; Krajcik, Joseph</p> <p>2007-01-01</p> <p>The traditional pedagogical approach for teaching chemical bonding is often overly simplistic and not <span class="hlt">aligned</span> with the most up-to-date scientific models. As a result, high-school students around the world lack fundamental understanding of chemical bonding. In order to improve students' understanding of this concept, it was essential to propose a…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=association&pg=3&id=EJ1098841','ERIC'); return false;" href="https://eric.ed.gov/?q=association&pg=3&id=EJ1098841"><span>Statistical Association: <span class="hlt">Alignment</span> of <span class="hlt">Current</span> U.S. High School Textbooks with the Common Core State Standards for 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>Tran, Dung</p> <p>2016-01-01</p> <p>This study examined the <span class="hlt">alignment</span> of three selected U.S. high school textbooks series with the Common Core State Standards for Mathematics (CCSSM) regarding the treatment of statistical association. A framework grounded in the literature for inclusion and exclusion of reasoning about association topics was developed, and textbook entries were…</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://eric.ed.gov/?q=alignment+AND+problem&pg=2&id=EJ1098841','ERIC'); return false;" href="http://eric.ed.gov/?q=alignment+AND+problem&pg=2&id=EJ1098841"><span>Statistical Association: <span class="hlt">Alignment</span> of <span class="hlt">Current</span> U.S. High School Textbooks with the Common Core State Standards for 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>Tran, Dung</p> <p>2016-01-01</p> <p>This study examined the <span class="hlt">alignment</span> of three selected U.S. high school textbooks series with the Common Core State Standards for Mathematics (CCSSM) regarding the treatment of statistical association. A framework grounded in the literature for inclusion and exclusion of reasoning about association topics was developed, and textbook entries were…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=Chemical+AND+bonds&pg=7&id=EJ765864','ERIC'); return false;" href="https://eric.ed.gov/?q=Chemical+AND+bonds&pg=7&id=EJ765864"><span>Developing a New Teaching Approach for the Chemical Bonding Concept <span class="hlt">Aligned</span> with <span class="hlt">Current</span> Scientific and Pedagogical Knowledge</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>Nahum, Tami Levy; Mamlok-Naaman, Rachel; Hofstein, Avi; Krajcik, Joseph</p> <p>2007-01-01</p> <p>The traditional pedagogical approach for teaching chemical bonding is often overly simplistic and not <span class="hlt">aligned</span> with the most up-to-date scientific models. As a result, high-school students around the world lack fundamental understanding of chemical bonding. In order to improve students' understanding of this concept, it was essential to propose a…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25450793','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25450793"><span><span class="hlt">FACS</span> separation of non-compromised forensically relevant biological mixtures.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Verdon, Timothy J; Mitchell, R John; Chen, Weisan; Xiao, Kun; van Oorschot, Roland A H</p> <p>2015-01-01</p> <p>Although focusing attention on the statistical analysis of complex mixture profiles is important, the forensic science community will also benefit from directing research to improving the reduction of the incidence of mixtures before DNA extraction. This preliminary study analysed the use of fluorescence assisted cell sorting (<span class="hlt">FACS</span>) for separation of cellular mixtures before DNA extraction, specifically mixtures of relatively fresh blood and saliva from two donors, prepared in 14 different mixture ratios. Improvements in the number of detectable alleles from the targeted cell type and overall profile quality were seen when compared to the results from unseparated samples. STRmix calculations revealed increases in likelihood ratios after separation, demonstrating the potential for higher probative values to be obtained from forensically relevant mixtures after subjecting them to <span class="hlt">FACS</span> than from unsorted samples. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17458461','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17458461"><span>Sensitivity analysis and evaluation of Micro<span class="hlt">Fac</span>PM: a microscale motor vehicle emission factor model for particulate matter emissions.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Singh, Rakesh B; Huber, Alan H; Braddock, James N</p> <p>2007-04-01</p> <p>A microscale emission factor model (Micro<span class="hlt">Fac</span>PM) for predicting real-time site-specific motor vehicle particulate matter emissions was presented in the companion paper titled "Development of a Microscale Emission Factor Model for Particulate Matter (Micro<span class="hlt">Fac</span>PM) for Predicting Real-Time Motor Vehicle Emissions". The emission rates discussed are in mass per unit distance with the model providing estimates of fine particulate matter (PM2.5) and coarse particulate matter. This paper complements the companion paper by presenting a sensitivity analysis of the model to input variables and evaluation model outputs using data from limited field studies. The sensitivity analysis has shown that Micro<span class="hlt">Fac</span>PM emission estimates are very sensitive to vehicle fleet composition, speed, and the percentage of high-emitting vehicles. The vehicle fleet composition can affect fleet emission rates from 8 mg/mi to 1215 mg/mi; an increase of 5% in the smoking (high-emitting) <span class="hlt">current</span> average U.S. light-duty vehicle fleet (compared with 0%) increased PM2.5 emission rates by -272% for 2000; and for the <span class="hlt">current</span> U.S. fleet, PM2.5 emission rates are reduced by a factor of -0.64 for speeds >50 miles per hour (mph) relative to a speed of 10 mph. Micro<span class="hlt">Fac</span>PM can also be applied to examine the contribution of emission rates per vehicle class, model year, and sources of PM. The model evaluation is presented for the Tuscarora Mountain Tunnel, Pennsylvania Turnpike, PA, and some limited evaluations at two locations: Sepulveda Tunnel, Los Angeles, CA, and Van Nuys Tunnel, Van Nuys, CA. In general, the performance of Micro<span class="hlt">Fac</span>PM has shown very encouraging results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title48-vol4/pdf/CFR-2013-title48-vol4-sec301-607-76.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title48-vol4/pdf/CFR-2013-title48-vol4-sec301-607-76.pdf"><span>48 CFR 301.607-76 - <span class="hlt">FAC</span>-P/PM application process.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-10-01</p> <p>... 48 Federal Acquisition Regulations System 4 2013-10-01 2013-10-01 false <span class="hlt">FAC</span>-P/PM application... 301.607-76 <span class="hlt">FAC</span>-P/PM application process. The P/PM Handbook contains application procedures and forms...; recertification; and certification waiver. Applicants for HHS <span class="hlt">FAC</span>-P/PM certification actions shall comply with the...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title48-vol4/pdf/CFR-2012-title48-vol4-sec301-607-76.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title48-vol4/pdf/CFR-2012-title48-vol4-sec301-607-76.pdf"><span>48 CFR 301.607-76 - <span class="hlt">FAC</span>-P/PM application process.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-10-01</p> <p>... 48 Federal Acquisition Regulations System 4 2012-10-01 2012-10-01 false <span class="hlt">FAC</span>-P/PM application... 301.607-76 <span class="hlt">FAC</span>-P/PM application process. The P/PM Handbook contains application procedures and forms...; recertification; and certification waiver. Applicants for HHS <span class="hlt">FAC</span>-P/PM certification actions shall comply with the...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title48-vol4/pdf/CFR-2011-title48-vol4-sec301-607-76.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title48-vol4/pdf/CFR-2011-title48-vol4-sec301-607-76.pdf"><span>48 CFR 301.607-76 - <span class="hlt">FAC</span>-P/PM application process.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-10-01</p> <p>... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false <span class="hlt">FAC</span>-P/PM application... 301.607-76 <span class="hlt">FAC</span>-P/PM application process. The P/PM Handbook contains application procedures and forms...; recertification; and certification waiver. Applicants for HHS <span class="hlt">FAC</span>-P/PM certification actions shall comply with the...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title48-vol4/pdf/CFR-2014-title48-vol4-sec301-607-76.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title48-vol4/pdf/CFR-2014-title48-vol4-sec301-607-76.pdf"><span>48 CFR 301.607-76 - <span class="hlt">FAC</span>-P/PM application process.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-10-01</p> <p>... 48 Federal Acquisition Regulations System 4 2014-10-01 2014-10-01 false <span class="hlt">FAC</span>-P/PM application... 301.607-76 <span class="hlt">FAC</span>-P/PM application process. The P/PM Handbook contains application procedures and forms...; recertification; and certification waiver. Applicants for HHS <span class="hlt">FAC</span>-P/PM certification actions shall comply with the...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title48-vol4/pdf/CFR-2010-title48-vol4-sec301-607-76.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title48-vol4/pdf/CFR-2010-title48-vol4-sec301-607-76.pdf"><span>48 CFR 301.607-76 - <span class="hlt">FAC</span>-P/PM application process.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-10-01</p> <p>... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false <span class="hlt">FAC</span>-P/PM application... 301.607-76 <span class="hlt">FAC</span>-P/PM application process. The P/PM Handbook contains application procedures and forms...; recertification; and certification waiver. Applicants for HHS <span class="hlt">FAC</span>-P/PM certification actions shall comply with...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24567215','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24567215"><span>Isolating specific embryonic cells of the sea urchin by <span class="hlt">FACS</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Juliano, Celina; Swartz, S Zachary; Wessel, Gary</p> <p>2014-01-01</p> <p>Isolating cells based on specific gene expression enables a focused biochemical and molecular analysis. While cultured cells and hematopoietic cells, for example, are routinely isolated by fluorescence activated cell sorting (<span class="hlt">FACS</span>), early embryonic cells are a relatively untapped source for <span class="hlt">FACS</span> applications often because the embryos of many animals are quite limiting. Furthermore, many applications require genetic model organisms in which cells can be labeled by fluorescent transgenes, or antibodies against cell surface antigens. Here we define conditions in the sea urchin embryo for isolation of embryonic cells based on expression of specific proteins. We use the sea urchin embryo for which a nearly unlimited supply of embryonic cells is available and demonstrate the conditions for separation of the embryo into single cells, fixation of the cells for antibody penetration into the cells, and conditions for <span class="hlt">FACS</span> of a rare cell type in the embryo. This protocol may be adapted for analysis of mRNA, chromatin, protein, or carbohydrates and depends only on the probe availability for the cell of interest. We anticipate that this protocol will be broadly applicable to embryos of other species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4108900','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4108900"><span>Isolating specific embryonic cells of the sea urchin by <span class="hlt">FACS</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>Juliano, Celina; Swartz, S. Zachary; Wessel, Gary</p> <p>2014-01-01</p> <p>Summary Isolating cells based on specific gene expression enables a focused biochemical and molecular analysis. While cultured cells and hematopoietic cells, for example, are routinely isolated by fluorescence activated cell sorting (<span class="hlt">FACS</span>), early embryonic cells are a relatively untapped source for <span class="hlt">FACS</span> applications often because the embryos of many animals are quite limiting. Furthermore, many applications require genetic model organisms in which cells can be labeled by fluorescent transgenes, or antibodies against cell surface antigens. Here we define conditions in the sea urchin embryo for isolation of embryonic cells based on expression of specific proteins. We use the sea urchin embryo for which a nearly unlimited supply of embryonic cells is available and demonstrate the conditions for separation of the embryo into single cells, fixation of the cells for antibody penetration into the cells, and conditions for <span class="hlt">FACS</span> of a rare cell type in the embryo. This protocol may be adapted for analysis of mRNA, chromatin, protein, or carbohydrates and depends only on the probe availability for the cell of interest. We anticipate that this protocol will be broadly applicable to embryos of other species. PMID:24567215</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090001282','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090001282"><span>On Alfvenic Waves and Stochastic Ion Heating with 1Re Observations of Strong Field-<span class="hlt">aligned</span> <span class="hlt">Currents</span>, Electric Fields, and O+ ions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Coffey, Victoria; Chandler, Michael; Singh, Nagendra</p> <p>2008-01-01</p> <p>The role that the cleft/cusp has in ionosphere/magnetosphere coupling makes it a very dynamic region having similar fundamental processes to those within the auroral regions. With Polar passing through the cusp at 1 Re in the Spring of 1996, we observe a strong correlation between ion heating and broadband ELF (BBELF) emissions. This commonly observed relationship led to the study of the coupling of large field-<span class="hlt">aligned</span> <span class="hlt">currents</span>, burst electric fields, and the thermal O+ ions. We demonstrate the role of these measurements to Alfvenic waves and stochastic ion heating. Finally we will show the properties of the resulting density cavities.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25600485','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25600485"><span>mer and <span class="hlt">fac</span> isomerism in tris chelate diimine metal complexes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dabb, Serin L; Fletcher, Nicholas C</p> <p>2015-03-14</p> <p>In this perspective, we highlight the issue of meridional (mer) and facial (<span class="hlt">fac</span>) orientation of asymmetrical diimines in tris-chelate transition metal complexes. Diimine ligands have long been the workhorse of coordination chemistry, and whilst there are now good strategies to isolate materials where the inherent metal centered chirality is under almost complete control, and systematic methodologies to isolate heteroleptic complexes, the conceptually simple geometrical isomerism has not been widely investigated. In systems where the two donor atoms are significantly different in terms of the σ-donor and π-accepting ability, the <span class="hlt">fac</span> isomer is likely to be the thermodynamic product. For the diimine complexes with two trigonal planar nitrogen atoms there is much more subtlety to the system, and external factors such as the solvent, lattice packing and the various steric considerations play a delicate role in determining the observed and isolable product. In this article we discuss the possibilities to control the isomeric ratio in labile systems, consider the opportunities to separate inert complexes and discuss the observed differences in their spectroscopic properties. Finally we report on the ligand orientation in supramolecular systems where facial coordination leads to simple regular structures such as helicates and tetrahedra, but the ability of the ligand system to adopt a mer orientation enables self-assembled structures of considerable beauty and complexity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27084117','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27084117"><span>The modified <span class="hlt">FACS</span> calcein AM retention assay: A high throughput flow cytometer based method to measure cytotoxicity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gillissen, M A; Yasuda, E; de Jong, G; Levie, S E; Go, D; Spits, H; van Helden, P M; Hazenberg, M D</p> <p>2016-07-01</p> <p><span class="hlt">Current</span> methods to determine cellular cytotoxicity in vitro are hampered by background signals that are caused by auto-fluorescent target and effector cells and by non-specific cell death. We combined and adjusted existing cell viability assays to develop a method that allows for highly reproducible, accurate, single cell analysis by high throughput <span class="hlt">FACS</span>, in which non-specific cell death is corrected for. In this assay the number of living, calcein AM labeled cells that are green fluorescent are quantified by adding a fixed number of unlabeled calibration beads to the analysis. Using this modified <span class="hlt">FACS</span> calcein AM retention method, we found EC50 values to be highly reproducible and considerably lower compared to EC50 values obtained by conventional assays, displaying the high sensitivity of this assay. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26228238','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26228238"><span>The Fear-avoidance Components Scale (<span class="hlt">FACS</span>): Development and Psychometric Evaluation of a New Measure of Pain-related Fear Avoidance.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Neblett, Randy; Mayer, Tom G; Hartzell, Meredith M; Williams, Mark J; Gatchel, Robert J</p> <p>2016-04-01</p> <p>Pain-related fear avoidance (FA), a common problem for patients with painful medical conditions, involves pain-related catastrophizing cognitions, hypervigilance, and avoidance behaviors, which can ultimately lead to decreased functioning, depression, and disability. Several patient-reported instruments have been developed to measure FA, but they have been criticized for limited construct validity, inadequate item specificity, lack of cutoff scores, and missing important FA components. The Fear-Avoidance Components Scale (<span class="hlt">FACS</span>) is a new patient-reported measure designed to comprehensively evaluate FA in patients with painful medical conditions. It combines important components of FA found in prior FA scales, while trying to correct some of their deficiencies, within a framework of the most <span class="hlt">current</span> FA model. Psychometric evaluation of the <span class="hlt">FACS</span> found high internal consistency (α = 0.92) and high test/retest reliability (r = 0.90-0.94, P < 0.01). <span class="hlt">FACS</span> scores differentiated between 2 separate chronic pain patient samples and a nonpatient comparison group. When clinically relevant severity levels were created, <span class="hlt">FACS</span> severity scores were highly associated with FA-related patient-reported psychosocial and objective lifting performance variables. These results suggest that the <span class="hlt">FACS</span> is a psychometrically strong and reliable measure that can help healthcare providers assess FA-related barriers to function and recovery. © 2015 World Institute of Pain.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUSMSM33A..02W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUSMSM33A..02W"><span>The Ionospheric Convection and Birkeland <span class="hlt">Current</span> Response to an Impulse in the Interplanetary Magnetic Field BY Component</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wilder, F. D.; Eriksson, S.; Korth, H.; Baker, J. B.; Hairston, M. R.; Heinselman, C. J.; Anderson, B. J.</p> <p>2013-05-01</p> <p>When the interplanetary magnetic field (IMF) is dawnward or duskward, magnetic merging between the IMF and the geomagnetic field occurs near the cusp on the dayside flanks of the magnetosphere. During these intervals, sunward flow channels on open field lines with velocities in excess of 2 km/s are generated in the polar ionosphere, which can deposit large amounts of energy into the cusp-region thermosphere. In this study, we analyze an interval on 5 April 2010 where there was a strong dawnward impulse in the IMF, followed by a gradual decay in IMF magnitude at constant clock angle. Data from ground based radars and the DMSP spacecraft were assimilated to investigate the global convection pattern during this interval, and data from the Active Magnetospheric and Planetary Electrodynamics Response Experiment (AMPERE) were used to investigate the associated Field-<span class="hlt">Aligned</span> <span class="hlt">Current</span> (<span class="hlt">FAC</span>) system. Additionally, data from AMPERE and the Sondrestrom Incoherent Scatter Radar were used to investigate the time response of the flow channel and its associated <span class="hlt">FAC</span> pair. We find that there is a delay of approximately 1.25 hours between the arrival of the dawnward IMF impulse at the magnetopause and the speed of the flow channel and strength of the <span class="hlt">FACs</span> flanking it. In addition to correlation between the dawnward component of the IMF and the flanking <span class="hlt">FAC</span> strength, we also find that there is inverse correlation between the flanking <span class="hlt">FAC</span> strength and both the SYM-H index and Solar Wind Alfvenic Mach Number. No statistically significant correlation is found between the flanking <span class="hlt">FAC</span> strength and solar wind dynamic pressure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRA..119.9804C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRA..119.9804C"><span>The magnitudes of the regions 1 and 2 Birkeland <span class="hlt">currents</span> observed by AMPERE and their role in solar wind-magnetosphere-ionosphere coupling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Coxon, J. C.; Milan, S. E.; Clausen, L. B. N.; Anderson, B. J.; Korth, H.</p> <p>2014-12-01</p> <p>In this paper we present the first large-scale statistical study of the influence of magnetic reconnection on the magnitude of the regions 1 and 2 Birkeland field-<span class="hlt">aligned</span> <span class="hlt">currents</span> (<span class="hlt">FACs</span>). While previous studies have employed single spacecraft measurements to construct a statistical picture of the location and density of the Birkeland <span class="hlt">currents</span>, it has hitherto been difficult to compare in situ measurements of the solar wind with instantaneous global field-<span class="hlt">aligned</span> <span class="hlt">current</span> measurements. To that end, we utilize the Active Magnetosphere Planetary Electrodynamics Response Experiment (AMPERE), which yields field-<span class="hlt">aligned</span> <span class="hlt">current</span> density in both hemispheres at a cadence of 10 min. We quantify the amount of <span class="hlt">current</span> flowing in the regions 1 (R1) and 2 (R2) <span class="hlt">FACs</span>, and we compare these with the dayside reconnection rate ΦD deduced from interplanetary parameters from the OMNI data set and with the AL index to examine whether magnetic reconnection is responsible for driving <span class="hlt">currents</span> in the coupled magnetosphere-ionosphere system. We find that <span class="hlt">current</span> magnitudes are strongly correlated with both ΦD and AL index. We also find that R1 <span class="hlt">currents</span> tend to be higher than R2 <span class="hlt">currents</span> during periods of magnetic reconnection, suggesting leakage of <span class="hlt">current</span> across the polar cap or an association with the substorm <span class="hlt">current</span> wedge.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=107709','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=107709"><span>The <span class="hlt">fac</span>C Gene of Aspergillus nidulans Encodes an Acetate-Inducible Carnitine Acetyltransferase</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Stemple, Christopher J.; Davis, Meryl A.; Hynes, Michael J.</p> <p>1998-01-01</p> <p>Mutations in the <span class="hlt">fac</span>C gene of Aspergillus nidulans result in an inability to use acetate as a sole carbon source. This gene has been cloned by complementation. The proposed translation product of the <span class="hlt">fac</span>C gene has significant similarity to carnitine acetyltransferases (CAT) from other organisms. Total CAT activity was found to be inducible by acetate and fatty acids and repressed by glucose. Acetate-inducible activity was found to be absent in <span class="hlt">fac</span>C mutants, while fatty acid-inducible activity was absent in an acuJ mutant. Acetate induction of <span class="hlt">fac</span>C expression was dependent on the <span class="hlt">fac</span>B regulatory gene, and an expressed <span class="hlt">Fac</span>B fusion protein was demonstrated to bind to 5′ <span class="hlt">fac</span>C sequences. Carbon catabolite repression of <span class="hlt">fac</span>C expression was affected by mutations in the creA gene and a CreA fusion protein bound to 5′ <span class="hlt">fac</span>C sequences. Mutations in the acuJ gene led to increased acetate induction of <span class="hlt">fac</span>C expression and also of an amdS-lacZ reporter gene, and it is proposed that this results from accumulation of acetate, as well as increased expression of <span class="hlt">fac</span>B. A model is presented in which <span class="hlt">fac</span>C encodes a cytosolic CAT enzyme, while a different CAT enzyme, which is acuJ dependent, is present in peroxisomes and mitochondria, and these activities are required for the movement of acetyl groups between intracellular compartments. PMID:9829933</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Ge%26Ae..55..723B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Ge%26Ae..55..723B"><span>3D model of small-scale density cavern formation in the region of auroral field-<span class="hlt">aligned</span> <span class="hlt">currents</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bespalov, P. A.; Mizonova, V. G.</p> <p>2015-11-01</p> <p>A 3D problem of the formation of small-scale density caverns with a nonstationary electric field in the region of auroral electric <span class="hlt">currents</span> and kinetic Alfvén wave <span class="hlt">currents</span> is considered. It is shown that an excess of the electron <span class="hlt">current</span> velocity over a certain critical value of their thermal velocity is a probable cause of cavern formation. Linear and nonlinear stages of the density cavern formation are considered, and their main parameters are estimated. In the case of comparatively strong magnetic fields, caverns can be formed with comparable longitudinal and transverse (with respect to the magnetic field) scales. The properties of parameters of small-scale density caverns and nonstationary electric field agree with well-known experimental data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.6293I','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.6293I"><span>Ground and CHAMP observations of field-<span class="hlt">aligned</span> <span class="hlt">current</span> circuits generated by lower atmospheric disturbances and expectations to the SWARM to clarify their three dimensional structure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Iyemori, Toshihiko; Nakanishi, Kunihito; Aoyama, Tadashi; Lühr, Hermann</p> <p>2014-05-01</p> <p>Acoustic gravity waves propagated to the ionosphere cause dynamo <span class="hlt">currents</span> in the ionosphere. They divert along geomagnetic field lines of force to another hemisphere accompanying electric field and then flow in the ionosphere of another hemisphere by the electric field forming closed <span class="hlt">current</span> circuits. The oscillating <span class="hlt">current</span> circuits with the period of acoustic waves generate magnetic variations on the ground, and they are observed as long period geomagnetic pulsations. This effect has been detected during big earthquakes, strong typhoons, tornados etc. On a low-altitude satellite orbit, the spatial distribution (i.e., structure) of the <span class="hlt">current</span> circuits along the satellite orbit should be detected as temporal magnetic oscillations, and the effect is confirmed by a CHAMP data analysis. On the spatial structure, in particular, in the longitudinal direction, it has been difficult to examine by a single satellite or from ground magnetic observations. The SWARM satellites will provide an unique opportunity to clarify the three dimensional structure of the field-<span class="hlt">aligned</span> <span class="hlt">current</span> circuits.</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://adsabs.harvard.edu/abs/2015TDR.....6...38A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015TDR.....6...38A"><span>Blend Shape Interpolation and <span class="hlt">FACS</span> for Realistic Avatar</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alkawaz, Mohammed Hazim; Mohamad, Dzulkifli; Basori, Ahmad Hoirul; Saba, Tanzila</p> <p>2015-03-01</p> <p>The quest of developing realistic facial animation is ever-growing. The emergence of sophisticated algorithms, new graphical user interfaces, laser scans and advanced 3D tools imparted further impetus towards the rapid advancement of complex virtual human facial model. Face-to-face communication being the most natural way of human interaction, the facial animation systems became more attractive in the information technology era for sundry applications. The production of computer-animated movies using synthetic actors are still challenging issues. Proposed facial expression carries the signature of happiness, sadness, angry or cheerful, etc. The mood of a particular person in the midst of a large group can immediately be identified via very subtle changes in facial expressions. Facial expressions being very complex as well as important nonverbal communication channel are tricky to synthesize realistically using computer graphics. Computer synthesis of practical facial expressions must deal with the geometric representation of the human face and the control of the facial animation. We developed a new approach by integrating blend shape interpolation (BSI) and facial action coding system (<span class="hlt">FACS</span>) to create a realistic and expressive computer facial animation design. The BSI is used to generate the natural face while the <span class="hlt">FACS</span> is employed to reflect the exact facial muscle movements for four basic natural emotional expressions such as angry, happy, sad and fear with high fidelity. The results in perceiving the realistic facial expression for virtual human emotions based on facial skin color and texture may contribute towards the development of virtual reality and game environment of computer aided graphics animation systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1376858-avoiding-tokamak-disruptions-applying-static-magnetic-fields-align-locked-modes-stabilizing-wave-driven-currents-avoiding-tokamak-disruptions-magnetically-aligning-locked-modes-stabilizing-wave-driven-currents','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1376858-avoiding-tokamak-disruptions-applying-static-magnetic-fields-align-locked-modes-stabilizing-wave-driven-currents-avoiding-tokamak-disruptions-magnetically-aligning-locked-modes-stabilizing-wave-driven-currents"><span>Avoiding Tokamak Disruptions by Applying Static Magnetic Fields That <span class="hlt">Align</span> Locked Modes with Stabilizing Wave-Driven <span class="hlt">Currents</span> [Avoiding Tokamak Disruptions by Magnetically <span class="hlt">Aligning</span> Locked Modes with Stabilizing Wave-Driven <span class="hlt">Currents</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Volpe, F. A.; Hyatt, Alan; La Haye, Robert J.; ...</p> <p>2015-10-19</p> <p>The international ITER tokamak has the objective of demonstrating the scientific feasibility of magnetic confinement fusion as a source of energy. A concern towards the achievement of this goal is represented by major disruptions: complete losses of confinement often initiated by a non-rotating ('locked') magnetic island created by magnetic reconnection. During disruptions, energy and particles accumulated in the plasma volume over many seconds are lost in a few milliseconds and released on the plasma-facing materials. In addition, multi-MA level <span class="hlt">currents</span> flowing in the tokamak plasma for its sustainment and confinement are lost, also in milliseconds, thus terminating the plasma dischargemore » and causing electromagnetic stresses that, if unmitigated, could lead to excessive device wear. Moreover it is shown that magnetic perturbations can be used to avoid disruptions by "guiding" the magnetic island to lock in a position where it is accessible to millimetre wave beams that fully stabilize it.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1376858','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1376858"><span>Avoiding Tokamak Disruptions by Applying Static Magnetic Fields That <span class="hlt">Align</span> Locked Modes with Stabilizing Wave-Driven <span class="hlt">Currents</span> [Avoiding Tokamak Disruptions by Magnetically <span class="hlt">Aligning</span> Locked Modes with Stabilizing Wave-Driven <span class="hlt">Currents</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Volpe, F. A.; Hyatt, Alan; La Haye, Robert J.; Lanctot, Matthew J.; Lohr, John; Prater, Ronald; Strait, Edward J.; Welander, Anders</p> <p>2015-10-19</p> <p>The international ITER tokamak has the objective of demonstrating the scientific feasibility of magnetic confinement fusion as a source of energy. A concern towards the achievement of this goal is represented by major disruptions: complete losses of confinement often initiated by a non-rotating ('locked') magnetic island created by magnetic reconnection. During disruptions, energy and particles accumulated in the plasma volume over many seconds are lost in a few milliseconds and released on the plasma-facing materials. In addition, multi-MA level <span class="hlt">currents</span> flowing in the tokamak plasma for its sustainment and confinement are lost, also in milliseconds, thus terminating the plasma discharge and causing electromagnetic stresses that, if unmitigated, could lead to excessive device wear. Moreover it is shown that magnetic perturbations can be used to avoid disruptions by "guiding" the magnetic island to lock in a position where it is accessible to millimetre wave beams that fully stabilize it.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JPS...351..160W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JPS...351..160W"><span>Super-<span class="hlt">aligned</span> carbon nanotube films with a thin metal coating as highly conductive and ultralight <span class="hlt">current</span> collectors for lithium-ion batteries</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Ke; Wu, Yang; Wu, Hengcai; Luo, Yufeng; Wang, Datao; Jiang, Kaili; Li, Qunqing; Li, Yadong; Fan, Shoushan; Wang, Jiaping</p> <p>2017-05-01</p> <p>Cross-stacked super-<span class="hlt">aligned</span> carbon nanotube (SACNT) films are promising for use as <span class="hlt">current</span> collectors in lithium-ion batteries because of their outstanding capability to decrease the weight and thickness of inactive material and strong adhesion to the electrodes. However, the relatively poor conductivity of SACNT films may limit their application to large-size electrodes or at high <span class="hlt">current</span> rate. Herein, a facile approach is proposed to improve the conductivity of SACNT films by electron-beam deposition of a thin metal film on their surface. Such modification lowers the sheet resistance by three orders of magnitude while keeping the extremely small fraction of SACNT <span class="hlt">current</span> collectors. The metal-coated SACNT films strongly inhibit polarization during the electrochemical reaction, resulting in improved cell performance compared with that of metal and uncoated CNT <span class="hlt">current</span> collectors. The improvement in conductivity and cell performance achieved by this approach is so large that the effect of the increase of inactive material is overwhelmed, leading to increased gravimetric energy density.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JGRA..118.4977M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JGRA..118.4977M"><span>Global evolution of Birkeland <span class="hlt">currents</span> on 10 min timescales: MHD simulations and observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Merkin, V. G.; Anderson, B. J.; Lyon, J. G.; Korth, H.; Wiltberger, M.; Motoba, T.</p> <p>2013-08-01</p> <p>In this paper we compare time-dependent global ionospheric field-<span class="hlt">aligned</span> <span class="hlt">current</span> (<span class="hlt">FAC</span>) patterns on 10 min timescales inferred from the Active Magnetosphere and Polar Electrodynamics Response Experiment (AMPERE) with the high-resolution Lyon-Fedder-Mobarry (LFM) global magnetohydrodynamic (MHD) model. The improved LFM model yields temporally varying <span class="hlt">FAC</span> patterns with a fine structure on the sub-100 km scale. The goal of the study is to explore the responses of observed and simulated <span class="hlt">FAC</span> patterns and underlying magnetic perturbations to a succession of rapid transitions in the solar wind and Interplanetary Magnetic Field (IMF) parameters. To drive the simulations, we use the upstream Wind and Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft measurements recorded on 3 August 2010. For the time interval of interest (˜40 min following the impact of an interplanetary shock), the IMF is characterized by a BZ rotation from southward to northward direction under negative BY conditions. Through this case study analysis, it is found that the simulations have generally reproduced the salient characteristics of both the morphology and dynamics of the AMPERE <span class="hlt">FAC</span> patterns. Due to the high resolution of the global model, the peak <span class="hlt">current</span> densities are found to significantly (by a factor of 2-4) exceed those obtained from AMPERE. As a further quantitative analysis, the low-altitude magnetic perturbations measured by Iridium spacecraft and used to derive the AMPERE 2-D <span class="hlt">FAC</span> patterns are also compared with the magnetic field variations calculated from the simulations. It is found that outside of localized regions of peak <span class="hlt">current</span> densities, which mainly occur on the dayside and can fall between the Iridium tracks, the simulated magnetic perturbations closely follow the Iridium measurements. This demonstrates, in particular, that there is no systematic bias in the simulations to overestimate the magnetic perturbations and corresponding <span class="hlt">FAC</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMSM13F4234H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMSM13F4234H"><span>Cluster Multipoint Observations of the Spatial Structure and Time Development of Auroral Acceleration Region Field-<span class="hlt">aligned</span> <span class="hlt">Current</span> Systems, Potentials, and Plasma</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hull, A. J.; Chaston, C. C.; Fillingim, M. O.; Frey, H. U.; Bonnell, J. W.; Mozer, F.; Goldstein, M. L.</p> <p>2014-12-01</p> <p>The auroral acceleration region is an integral part of the magnetosphere-ionosphere electrodynamic system, and plays a key role in the transport of plasma and energy between Earth and space. This region is embedded with field-<span class="hlt">aligned</span> <span class="hlt">currents</span> that couple the magnetosphere to the ionosphere and is where parallel electric fields form that accelerate plasma to and from these regions. Though considerable progress has been made, the complex interplay between field-<span class="hlt">aligned</span> <span class="hlt">current</span> system formation, the development of parallel electric fields, changes in the plasma constituents, and auroral emissions consequences are not fully understood. The Cluster mission is well suited for studying the structure and dynamics of the auroral acceleration region. Over its lifetime, Cluster has sampled much of this region with closely spaced probes enabling the distinction between temporal effects from spatial variations. Moreover, this data when combined with auroral images from IMAGE or THEMIS GBO-ASI enable an assessment of the auroral emission response to spatial morphology and temporal development of structures seeded in the auroral acceleration region. In this study we present a survey of Cluster multi-point traversals within and just above the auroral acceleration region (≤ 3 Re altitude). In particular we highlight the spatial morphology and developmental sequence of auroral acceleration <span class="hlt">current</span> systems, potentials and plasma constituents, with the aim of identifying controlling factors, and assessing ionospheric consequences under different conditions. Our results suggest that the "Alfvénic" activity may be an important precursor and perhaps may be playing an essential role in the development of "quasi-static" <span class="hlt">current</span> systems during quiet and substorm active times. Such events are generally the result of an injection mediated process at or near the plasma sheet boundary layer, resulting in the local expansion of the plasma sheet. Key features of the conversion from Alfv</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23198533','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23198533"><span>[<span class="hlt">FACS</span>-mQ as a powerful clinical test in the cancer stem cell era].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Takano, Toru; Hidaka, Yoh; Iwatani, Yoshinori</p> <p>2012-08-01</p> <p>Stem cells are pluripotent and self renewing, and possess an ability to differentiate into the various cell types of a particular tissue. In cancer tissues, existence of cells showing biological similarities with stem cells, named cancer stem cells (CSC), are known to regulate the growth of the tissue and determine its prognosis. Stem cells and CSCs usually exist as minor populations of cells in a tissue. Detection and analysis of these cells are usually laborious even using fluorescence activated cell sorting (<span class="hlt">FACS</span>) with the conventional protocols. Considering these drawbacks, we developed a novel analytical method named mRNA quantification after <span class="hlt">FACS</span> (<span class="hlt">FACS</span>-mQ). In <span class="hlt">FACS</span>-mQ, cells are labeled with a fluorescent dye in a manner that minimizes RNA degradation, then cells sorted by <span class="hlt">FACS</span> are examined by analyzing their gene expression profile. We established protocols to obtain single cells from clinical samples for flow cytometry analysis. Further, we performed <span class="hlt">FACS</span>-mQ analysis using fluorescence-labeled antibodies, cRNA probes and locked nucleic acid (LNA) probes. Evident decrease of intracellular RNAs did not observed in <span class="hlt">FACS</span>-mQ using immunocytochemistry. Approximately 60% of intracellular RNA was preserved after in situ hybridization using cRNA probes. These RNAs from a small number of sorted cells were suitable for quantitative analysis to establish gene expression profiles. <span class="hlt">FACS</span>-mQ does not require laborious and time-consuming procedures; thus, it is expected to facilitate research on stem cells or cancer stem cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=228186','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=228186"><span>Increased universality of Lepidopteran elicitor compounds across insects: Identification of fatty acid amino acid conjugates (<span class="hlt">FACs</span>)</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Fatty acid amino acid conjugates (<span class="hlt">FACs</span>) are known elicitors of induced release of volatile compounds in plants that, in turn, attract foraging parasitoids. Since the discovery of volicitin [N-(17-hydroxylinolenoyl)-L-glutamine] in the regurgitant of larval Spodoptera exigua1, a series of related <span class="hlt">FAC</span>...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMSM22A..05F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMSM22A..05F"><span>Electric Field, Field-<span class="hlt">aligned</span> <span class="hlt">Current</span> and Electromagnetic Waves in the Dip Region in front of the Dipolarization Front</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fu, S.; Sun, W.; Zhou, X.; Zhao, D.; Zong, Q.; Yao, Z.; Pu, Z.; Parks, G. K.</p> <p>2015-12-01</p> <p>Dipolarization front (DF) is characterized by a strong increase of magnetic field Bz component often observed before the arrival of high-speed flows in the Earth's plasma sheet. The DF interfaces between the high-speed flowing transient plasma and the ambient plasma. Ahead of the DFs, magnetic field Bz decreases and it is, called the "dip region." However, unlike in the high-speed flow and the ambient plasma which can be described by MHD theory, kinetic effects are important in the dip region because the spatial scale is less than the ion gyroradius. Observation and simulation have demonstrated that the dip region is formed by the reflecting ions at the sharp front. Short lived electromagnetic waves are also observed here generated by the reflected ions. In addition, Hall electric field observed in this region is in the opposite direction of the electric field inside the DF. The dipolarization front and the dip region ahead of it formed a set of <span class="hlt">current</span> systems and they are fundamentally important for understanding the cause of flow braking in the plasma sheet.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24475968','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24475968"><span>A 3.5 V lithium-iodine hybrid redox battery with vertically <span class="hlt">aligned</span> carbon nanotube <span class="hlt">current</span> collector.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhao, Yu; Hong, Misun; Bonnet Mercier, Nadège; Yu, Guihua; Choi, Hee Cheul; Byon, Hye Ryung</p> <p>2014-02-12</p> <p>A lithium-iodine (Li-I2) cell using the triiodide/iodide (I3(-)/I(-)) redox couple in an aqueous cathode has superior gravimetric and volumetric energy densities (∼ 330 W h kg(-1) and ∼ 650 W h L(-1), respectively, from saturated I2 in an aqueous cathode) to the reported aqueous Li-ion batteries and aqueous cathode-type batteries, which provides an opportunity to construct cost-effective and high-performance energy storage. To apply this I3(-)/I(-) aqueous cathode for a portable and compact 3.5 V battery, unlike for grid-scale storage as general target of redox flow batteries, we use a three-dimensional and millimeter thick carbon nanotube <span class="hlt">current</span> collector for the I3(-)/I(-) redox reaction, which can shorten the diffusion length of the redox couple and provide rapid electron transport. These endeavors allow the Li-I2 battery to enlarge its specific capacity, cycling retention, and maintain a stable potential, thereby demonstrating a promising candidate for an environmentally benign and reusable portable battery.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21408072','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21408072"><span>A new <span class="hlt">FACS</span> approach isolates hESC derived endoderm using transcription factors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pan, Yuqiong; Ouyang, Zhengqing; Wong, Wing Hung; Baker, Julie C</p> <p>2011-03-09</p> <p>We show that high quality microarray gene expression profiles can be obtained following <span class="hlt">FACS</span> sorting of cells using combinations of transcription factors. We use this transcription factor <span class="hlt">FACS</span> (tf<span class="hlt">FACS</span>) methodology to perform a genomic analysis of hESC-derived endodermal lineages marked by combinations of SOX17, GATA4, and CXCR4, and find that triple positive cells have a much stronger definitive endoderm signature than other combinations of these markers. Additionally, SOX17(+) GATA4(+) cells can be obtained at a much earlier stage of differentiation, prior to expression of CXCR4(+) cells, providing an important new tool to isolate this earlier definitive endoderm subtype. Overall, tf<span class="hlt">FACS</span> represents an advancement in <span class="hlt">FACS</span> technology which broadly crosses multiple disciplines, most notably in regenerative medicine to redefine cellular populations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18033184','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18033184"><span>[Phospho-<span class="hlt">FACS</span>: a powerful tool for exploring intracellular transduction cascades].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gernez, Y; Herzenberg, L A; Herzenberg, L A; Tirouvanziam, R</p> <p>2007-10-01</p> <p><span class="hlt">FACS</span> (fluorescence-activated cell sorting), or flow cytometry, was developed in 1971 by Leonard Herzenberg's team at Stanford University. Under continuous development, this technology enables single-cell multiparametric analysis and sorting, based on physical properties of cells and/or their relative expression levels of specific glycoproteic epitopes and metabolites. Recently, the use of fluorescent antibodies specific for phosphorylated epitopes - or "phospho-epitopes" - within proteins of interest has further extended the range of <span class="hlt">FACS</span> analyses. This new application, dubbed "phospho-<span class="hlt">FACS</span>", has quickly become a tool of choice for delineating intracellular phosphorylation cascades. In both basic research and clinical research, the application of phospho-<span class="hlt">FACS</span> to cellular subsets from blood or the periphery, whether frequent or rare, enables the discovery of pathological biomarkers and therapeutic innovation. Thanks to its rapid implementation and its ability to generate single-cell data, the phospho-<span class="hlt">FACS</span> technique features numerous advantages compared to preexisting analytical methods for intracellular phosphorylation cascades.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/17059489','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/17059489"><span>Fair Access to Care Services (<span class="hlt">FACS</span>): implementation in the mental health context of the UK.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cestari, L; Munroe, M; Evans, S; Smith, A; Huxley, P</p> <p>2006-11-01</p> <p>Since April 2003, all adults requiring social care services must have an assessment to determine their eligibility, which is set within the four-level framework of Fair Access to Care Services [<span class="hlt">FACS</span>; LAC (2002)13]. This paper examines the implementation of <span class="hlt">FACS</span> by community mental health teams in eight sites in mental health partnership trusts, and one in a mental health and social care trust in the UK. Twenty-eight respondents (managers within trusts and social services departments) participated in in-depth qualitative interviews, which were undertaken between August 2004 and February 2005. The interviews covered: consultation with users and partner organisations; training and briefings for staff; <span class="hlt">FACS</span> thresholds; integration of <span class="hlt">FACS</span> and the Care Programme Approach; and the impact of implementing <span class="hlt">FACS</span> on budgetary arrangements between health and social care. Using the framework analysis approach to analyse data, it was found that <span class="hlt">FACS</span> implementation in mental health services has been somewhat haphazard, and has identified real differences between health and social care approaches to eligibility determination, assessment and priorities. In particular, the type and amount of consultation, training and induction into <span class="hlt">FACS</span> was variable, and in some cases, unacceptably poor. While <span class="hlt">FACS</span> may have reduced variability between authorities, the exercise of professional judgement in the operation of <span class="hlt">FACS</span> and the lack of high-quality preventative services remain as potential sources of inequity within the system. The authors conclude that <span class="hlt">FACS</span> has revealed and reinforced a growing separation rather than an integration of mental health and social care ideas and practices, at least in the participating sites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3686919','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3686919"><span>BH3 Profiling in Whole Cells by Fluorimeter or <span class="hlt">FACS</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>Ryan, Jeremy; Letai, Anthony</p> <p>2013-01-01</p> <p>Rapid analysis of a cell's propensity to undergo apoptosis through the mitochondrial pathway is hindered by the complex network of interactions between more than fifteen known members of the BCL2 family that govern the decision to undergo mitochondrial apoptosis, and measurement of protein levels alone fails to account for critical interactions between the proteins. To address this issue, we have developed two functional assays for same-day analysis of cell lines or primary tissue samples. Using defined inputs in the form of peptides derived primarily from the BH3 domains of pro-apoptotic members of the BCL2 family, we invoke a response in the mitochondria in the form of mitochondrial outer membrane permeabilization measured indirectly using potential sensitive dyes. BH3 profiling can be applied to any viable single cell suspension and provides a response from the sum total of all known and unknown interactions within the BCL2 family for each stimulus, and the pattern of response can provide both a cell's propensity towards mitochondrial apoptosis, or ‘priming’, as well as indicate dependencies on specific anti-apoptotic proteins. Described here are optimized conditions for both plate-based and <span class="hlt">FACS</span>-based BH3 profiling for homogeneous and heterogeneous samples. PMID:23607990</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016GSL.....3...12M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016GSL.....3...12M"><span>Relation of the auroral substorm to the substorm <span class="hlt">current</span> wedge</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McPherron, Robert L.; Chu, Xiangning</p> <p>2016-12-01</p> <p>The auroral substorm is an organized sequence of events seen in the aurora near midnight. It is a manifestation of the magnetospheric substorm which is a disturbance of the magnetosphere brought about by the solar wind transfer of magnetic flux from the dayside to the tail lobes and its return through the plasma sheet to the dayside. The most dramatic feature of the auroral substorm is the sudden brightening and poleward expansion of the aurora. Intimately associated with this expansion is a westward electrical <span class="hlt">current</span> flowing across the bulge of expanding aurora. This <span class="hlt">current</span> is fed by a downward field-<span class="hlt">aligned</span> <span class="hlt">current</span> (<span class="hlt">FAC</span>) at its eastern edge and an upward <span class="hlt">current</span> at its western edge. This <span class="hlt">current</span> system is called the substorm <span class="hlt">current</span> wedge (SCW). The SCW forms within a minute of auroral expansion. <span class="hlt">FAC</span> are created by pressure gradients and field line bending from shears in plasma flow. Both of these are the result of pileup and diversion of plasma flows in the near-earth plasma sheet. The origins of these flows are reconnection sites further back in the tail. The auroral expansion can be explained by a combination of a change in field line mapping caused by the substorm <span class="hlt">current</span> wedge and a tailward growth of the outer edge of the pileup region. We illustrate this scenario with a complex substorm and discuss some of the problems associated with this interpretation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1999JaJAP..38.2555N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1999JaJAP..38.2555N"><span>High-<span class="hlt">Current</span> and High-Transconductance Self-<span class="hlt">Aligned</span> P+-GaAs Junction HFET of Complete Enhancement-Mode Operation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nishii, Katsunori; Yokoyama, Mitsuru; Yamamoto, Shinji; Tamura, Akiyoshi; Inoue, Kaoru</p> <p>1999-04-01</p> <p>High-<span class="hlt">current</span> and high-transconductance self-<span class="hlt">aligned</span> p+-GaAs junction HFETs (PJ-HFETs) of a complete enhancement-mode operation have been developed for the first time. Due to the advantages of the p/n junction, the barrier height of 1.12 eV has been obtained. To obtain high activation for the Si implanted epitaxial layers, we optimized theannealing conditions. The 0.8 µm-gate complete enhancement mode PJ-HFET with a large forward gate voltage swing of more than 1.5 V exhibited a K-value of 400 mS/Vmm, a maximum transconductance (gmMAX) of 410 mS/mm and a maximum drain <span class="hlt">current</span> (IMAX) of 380 mA/mm with a threshold voltage (Vth) of 0.2 V. The standard deviation of Vth was 18.4 mV across a 3 inch wafer. Operated with a drain bias of 3.3 V, the PJ-HFET demonstrated a power-added efficiency (PAE) of 39.5% with an adjacent channel leakage ratio (ACPR) of -57.4 dBc at an output power (Pout) of 21.5 dBm and a frequency of 1.9 GHz.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMSM11C..02P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMSM11C..02P"><span>Multi-point Analysis of Electrostatic Solitary Waves and Field <span class="hlt">Aligned</span> Electrons Observed by Cluster in and Near the Auroral <span class="hlt">Current</span> Regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pickett, J. S.; Forsyth, C.; Christopher, I.; Fazakerley, A. N.; Masson, A.; Marklund, G. T.; Georgescu, E.</p> <p>2011-12-01</p> <p>The four Cluster spacecraft have been transiting Earth's mid and upper auroral acceleration region (AAR) during parts of the year since late 2008. The Wideband Data (WBD) plasma wave receiver mounted on all four spacecraft obtains high time resolution, band-limited waveforms over a wide frequency range (100 Hz to 577 kHz). We present observations of Electrostatic Solitary Waves (ESWs) made by the WBD instrument simultaneously on more than one Cluster spacecraft in and near the auroral downward <span class="hlt">current</span> region in the following two frequency bands: 100 Hz to 9.5 kHz and 700 Hz to 77 kHz. We examine and analyze these ESWs for similarities on different spacecraft, and investigate the conclusion, based on single spacecraft FAST satellite data, that fast ESWs (~1 ms duration) in this region are observed in conjunction with modulations in both upgoing and downgoing electrons, suggesting a <span class="hlt">current</span> instability as the mechanism for generation of these ESWs. We also analyze and discuss the very short time duration ESWs (~20-30 microseconds) observed in the upward <span class="hlt">current</span> region by the Cluster spacecraft. Such short time duration ESWs have not been previously reported in this region, although fast ESWs of ~300 microseconds duration have been reported using data from the FAST satellite. The Cluster PEACE electron data in this upward <span class="hlt">current</span> region are examined to determine if there is a correlation of ESW detection with narrow, field-<span class="hlt">aligned</span> downgoing beams as shown by the FAST results, suggesting ESW generation through a beam instability. The electron density and electric field data are also presented for some events in order to place the wave measurements into context with relation to the auroral density cavity and electric field configuration in and near the AAR.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT.......208C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT.......208C"><span>Configuration and Generation of Substorm <span class="hlt">Current</span> Wedge</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chu, Xiangning</p> <p></p> <p>The substorm <span class="hlt">current</span> wedge (SCW), a core element of substorm dynamics coupling the magnetotail to the ionosphere, is crucial in understanding substorms. It has been suggested that the field-<span class="hlt">aligned</span> <span class="hlt">currents</span> (<span class="hlt">FACs</span>) in the SCW are caused by either pressure gradients or flow vortices, or both. Our understanding of <span class="hlt">FAC</span> generations is based predominately on numerical simulations, because it has not been possible to organize spacecraft observations in a coordinate system determined by the SCW. This dissertation develops an empirical inversion model of the <span class="hlt">current</span> wedge and inverts midlatitude magnetometer data to obtain the parameters of the <span class="hlt">current</span> wedge for three solar cycles. This database enables statistical data analysis of spacecraft plasma and magnetic field observations relative to the SCW coordinate. In chapter 2, a new midlatitude positive bay (MPB) index is developed and calculated for three solar cycles of data. The MPB index is processed to determine the substorm onset time, which is shown to correspond to the auroral breakup onset with at most 1-2 minutes difference. Substorm occurrence rate is found to depend on solar wind speed while substorm duration is rather constant, suggesting that substorm process has an intrinsic pattern independent of external driving. In chapter 3, an SCW inversion technique is developed to determine the strength and locations of the <span class="hlt">FACs</span> in an SCW. The inversion parameters for <span class="hlt">FAC</span> strength and location, and ring <span class="hlt">current</span> strength are validated by comparison with other measurements. In chapter 4, the connection between earthward flows and auroral poleward expansion is examined using improved mapping, obtained from a newly-developed dynamic magnetospheric model by superimposing a standard magnetospheric field model with substorm <span class="hlt">current</span> wedge obtained from the inversion technique. It is shown that the ionospheric projection of flows observed at a fixed point in the equatorial plane map to the bright aurora as it expands poleward</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21428502','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21428502"><span>The Norwegian <span class="hlt">Fac</span>̧ade Insulation Study: the efficacy of <span class="hlt">fac</span>̧ade insulation in reducing noise annoyance due to road traffic.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Amundsen, Astrid H; Klæboe, Ronny; Aasvang, Gunn Marit</p> <p>2011-03-01</p> <p>The efficacy of <span class="hlt">fac</span>̧ade insulation in providing an improved indoor noise environment and in reducing indoor noise annoyance was examined in a socio-acoustic before-and-after study with a control group. An average equivalent noise reduction inside the dwellings of 7 dB was obtained from the <span class="hlt">fac</span>̧ade insulation. Whereas 42% of the respondents were highly annoyed in the before-situation, this dropped to 16% in the after study. The conclusion is therefore that the <span class="hlt">fac</span>̧ade insulation provided a substantial improvement in the indoor noise environment. The advantage with respect to indoor noise annoyance, of having the bedroom facing the least noise-exposed side of the dwelling corresponded to a 6 dB noise reduction. The changes in annoyance from noise reduction due to the <span class="hlt">fac</span>̧ade insulation were in accordance with what would be expected from the exposure-response curves obtained in the before-situation. A total of 637 respondents participated in the before-study. Of these, 415 also participated in the after study. Indoor and outdoor noise exposure calculations for each of the dwellings were undertaken before and after the <span class="hlt">fac</span>̧ade insulation was implemented. © 2011 Acoustical Society of America</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM23A2216H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM23A2216H"><span>Time development of high-altitude auroral acceleration region plasma, potentials, and field-<span class="hlt">aligned</span> <span class="hlt">current</span> systems observed by Cluster during a substorm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hull, A. J.; Chaston, C. C.; Fillingim, M. O.; Mozer, F.; Frey, H. U.</p> <p>2013-12-01</p> <p>The auroral acceleration region is an integral link in the chain of events that transpire during substorms, and the <span class="hlt">currents</span>, plasma and electric fields undergo significant changes driven by complex dynamical processes deep in the magnetotail. These auroral acceleration processes in turn accelerate and heat the plasma that ultimately leads to some of the most intense global substorm auroral displays. The complex interplay between field-<span class="hlt">aligned</span> <span class="hlt">current</span> system formation, the development of parallel electric fields, and resultant changes in the plasma constituents that occur during substorms within or just above the auroral acceleration zone remain unclear. We present Cluster multi-point observations within the high-altitude acceleration region (> 3 Re altitude) at key instances during the development of a substorm. Of particular emphasis is on the time-development of the plasma, potentials and <span class="hlt">currents</span> that occur therein with the aim of ascertaining high-altitude drivers of substorm active auroral acceleration processes and auroral emission consequences. Preliminary results show that the initial onset is dominated by Alfvenic activity as evidenced by the sudden occurrence of relatively intense, short-spatial scale Alfvenic <span class="hlt">currents</span> and attendant energy dispersed, counterstreaming electrons poleward of the growth-phase arc. The Alfvenic <span class="hlt">currents</span> are locally planar structures with characteristic thicknesses on the order of a few tens of kilometers. In subsequent passages by the other spacecraft, the plasma sheet region became hotter and thicker via the injection of new hot, dense plasma of magnetospheric origins poleward of the pre-existing growth phase arc. In association with the heating and/or thickening of the plasma sheet, the <span class="hlt">currents</span> appeared to broaden to larger scales as Alfven dominated activity gave way to either inverted-V dominated or mixed inverted-V and Alfvenic behavior depending on location. The transition from Alfven dominated to inverted-V dominated</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('https://www.ncbi.nlm.nih.gov/pubmed/22608400','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22608400"><span>Two-stage bile preparation with acetone for recovery of fluorescent aromatic compounds (<span class="hlt">FACs</span>).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Karami, Ali; Syed, Mohd A; Christianus, Annie; Willett, Kristine L; Mazzeo, Jeffrey R; Courtenay, Simon C</p> <p>2012-07-15</p> <p>In this study we sought to optimize recovery of fluorescent aromatic compounds (<span class="hlt">FACs</span>) from the bile of African catfish (Clarias gariepinus) injected with 10mg/kg benzo[a]pyrene (BaP). Fractions of pooled bile were hydrolyzed, combined with ten volumes of methanol, ethanol, acetonitrile, or acetone, centrifuged and supernatants were analyzed by high-performance liquid chromatography with fluorescent detection (HPLC/FL). As well, to test whether <span class="hlt">FACs</span> were being lost in solids from the centrifugation, pellets were resuspended, hydrolyzed and mixed with six volumes of the organic solvent that produced best <span class="hlt">FAC</span> recovery from the supernatant, and subjected to HPLC/FL. Highest <span class="hlt">FAC</span> concentrations were obtained with 2000μl and 1250μl acetone for supernatants and resuspended pellets respectively. <span class="hlt">FACs</span> concentrations were negatively correlated with biliary protein content but were unaffected by addition of bovine serum albumin (BSA) followed by no incubation indicating that the presence of proteins in the biliary mixture does not simply interfere with detection of <span class="hlt">FACs</span>. In another experiment, efficiency of acetone addition was compared to two different liquid-liquid extractions (L-LEs). Acetone additions provided significantly higher biliary <span class="hlt">FACs</span> than the L-LE methods. The new two-stage bile preparation with acetone is an efficient, inexpensive and easily performed method. Copyright © 2012 Elsevier B.V. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10172768','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10172768"><span><span class="hlt">Alignment</span> of CEBAF cryomodules</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schneider, W.J.; Bisognano, J.J.; Fischer, J.</p> <p>1993-06-01</p> <p>CEBAF, the Continuous Electron Beam Accelerator Facility, when completed, will house a 4 GeV recirculating accelerator. Each of the accelerator`s two linacs contains 160 superconducting radio frequency (SRF) 1497 MHz niobium cavities in 20 cryomodules. <span class="hlt">Alignments</span> of the cavities within the cryomodule with respect to beam axis is critical to achieving the optimum accelerator performance. This paper discusses the rationale for the <span class="hlt">current</span> specification on cavity mechanical <span class="hlt">alignment</span>: 2 mrad (rms) applied to the 0.5 m active length cavities. We describe the tooling that was developed to achieve the tolerance at the time of cavity pair assembly, to preserve and integrate <span class="hlt">alignment</span> during cryomodule assembly, and to translate <span class="hlt">alignment</span> to appropriate installation in the beam line.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/117678','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/117678"><span>Generation mechanisms for magnetosphere-ionosphere <span class="hlt">current</span> systems deduced from a three-dimensional MHD simulation of the solar wind-magnetosphere-ionosphere coupling processes</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Tanaka, T.</p> <p>1995-07-01</p> <p>Mechanisms that generate the field-<span class="hlt">aligned</span> <span class="hlt">current</span> (<span class="hlt">FAC</span>) systems in the magnetosphere-ionosphere coupling scheme by virtue of the solar wind-magnetosphere interaction are investigated with a three-dimensional magnetohydrodynamic (MHD) simulation. As a simulation scheme, the finite volume total variation diminishing (TVD) scheme on an unstructured grid system is employed for precise calculations of the ionospheric region. In the ionosphere, the divergence of the Pederson and Hall <span class="hlt">currents</span> is matched with <span class="hlt">FAC</span>, mainly assuming uniform conductivity. The present calculation reproduces the traditional region 1 and 2 <span class="hlt">currents</span> in the polar ionosphere, for both the northward and southward interplanetary magnetic fields (IMFs). The calculated magnitude of the region 1 <span class="hlt">current</span> becomes large on the dayside, in agreement with observational results. For the northward IMF, NBZ <span class="hlt">currents</span> that dominate the entire polar cap are obtained, with a maximum on the dayside. This <span class="hlt">current</span> is totally absent in the southward IMF result. Corresponding to the <span class="hlt">FACs</span>, the northward IMF results in multicell convection in the polar ionosphere, and the southward IMF results in two-cell convection. On the evening side, the calculated region 1 <span class="hlt">currents</span> flow almost along the field lines away from the Earth toward the magnetospheric low-latitude boundary layer (LLBL), then flow up the magnetopause across the field lines to high latitudes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title48-vol4/pdf/CFR-2012-title48-vol4-sec301-603-74.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title48-vol4/pdf/CFR-2012-title48-vol4-sec301-603-74.pdf"><span>48 CFR 301.603-74 - Requirement for retention of <span class="hlt">FAC</span>-C and HHS SAC certification.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-10-01</p> <p>... of <span class="hlt">FAC</span>-C and HHS SAC certification. 301.603-74 Section 301.603-74 Federal Acquisition Regulations..., Contracting Authority, and Responsibilities 301.603-74 Requirement for retention of <span class="hlt">FAC</span>-C and HHS SAC certification. To maintain <span class="hlt">FAC</span>-C certification, all warranted Contracting Officers, regardless of series, as...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title48-vol4/pdf/CFR-2013-title48-vol4-sec301-603-74.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title48-vol4/pdf/CFR-2013-title48-vol4-sec301-603-74.pdf"><span>48 CFR 301.603-74 - Requirement for retention of <span class="hlt">FAC</span>-C and HHS SAC certification.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-10-01</p> <p>... of <span class="hlt">FAC</span>-C and HHS SAC certification. 301.603-74 Section 301.603-74 Federal Acquisition Regulations..., Contracting Authority, and Responsibilities 301.603-74 Requirement for retention of <span class="hlt">FAC</span>-C and HHS SAC certification. To maintain <span class="hlt">FAC</span>-C certification, all warranted Contracting Officers, regardless of series, as...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title48-vol4/pdf/CFR-2011-title48-vol4-sec301-603-74.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title48-vol4/pdf/CFR-2011-title48-vol4-sec301-603-74.pdf"><span>48 CFR 301.603-74 - Requirement for retention of <span class="hlt">FAC</span>-C and HHS SAC certification.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-10-01</p> <p>... of <span class="hlt">FAC</span>-C and HHS SAC certification. 301.603-74 Section 301.603-74 Federal Acquisition Regulations..., Contracting Authority, and Responsibilities 301.603-74 Requirement for retention of <span class="hlt">FAC</span>-C and HHS SAC certification. To maintain <span class="hlt">FAC</span>-C certification, all warranted Contracting Officers, regardless of series, as...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title48-vol4/pdf/CFR-2010-title48-vol4-sec301-603-74.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title48-vol4/pdf/CFR-2010-title48-vol4-sec301-603-74.pdf"><span>48 CFR 301.603-74 - Requirement for retention of <span class="hlt">FAC</span>-C and HHS SAC certification.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-10-01</p> <p>... of <span class="hlt">FAC</span>-C and HHS SAC certification. 301.603-74 Section 301.603-74 Federal Acquisition Regulations..., Contracting Authority, and Responsibilities 301.603-74 Requirement for retention of <span class="hlt">FAC</span>-C and HHS SAC certification. To maintain <span class="hlt">FAC</span>-C certification, all warranted Contracting Officers, regardless of series, as...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title48-vol4/pdf/CFR-2014-title48-vol4-sec301-603-74.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title48-vol4/pdf/CFR-2014-title48-vol4-sec301-603-74.pdf"><span>48 CFR 301.603-74 - Requirement for retention of <span class="hlt">FAC</span>-C and HHS SAC certification.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-10-01</p> <p>... of <span class="hlt">FAC</span>-C and HHS SAC certification. 301.603-74 Section 301.603-74 Federal Acquisition Regulations..., Contracting Authority, and Responsibilities 301.603-74 Requirement for retention of <span class="hlt">FAC</span>-C and HHS SAC certification. To maintain <span class="hlt">FAC</span>-C certification, all warranted Contracting Officers, regardless of series, as...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19250790','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19250790"><span>Complement dependent cytotoxicity (CDC) activity of a humanized anti Lewis-Y antibody: <span class="hlt">FACS</span>-based assay versus the 'classical' radioactive method -- qualification, comparison and application of the <span class="hlt">FACS</span>-based approach.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nechansky, A; Szolar, O H J; Siegl, P; Zinoecker, I; Halanek, N; Wiederkum, S; Kircheis, R</p> <p>2009-05-01</p> <p>The fully humanized Lewis-Y carbohydrate specific monoclonal antibody (mAb) IGN311 is <span class="hlt">currently</span> tested in a passive immunotherapy approach in a clinical phase I trail and therefore regulatory requirements demand qualified assays for product analysis. To demonstrate the functionality of its Fc-region, the capacity of IGN311 to mediate complement dependent cytotoxicity (CDC) against human breast cancer cells was evaluated. The "classical" radioactive method using chromium-51 and a <span class="hlt">FACS</span>-based assay were established and qualified according to ICH guidelines. Parameters evaluated were specificity, response function, bias, repeatability (intra-day precision), intermediate precision (operator-time different), and linearity (assay range). In the course of a fully nested design, a four-parameter logistic equation was identified as appropriate calibration model for both methods. For the radioactive assay, the bias ranged from -6.1% to -3.6%. The intermediate precision for future means of duplicate measurements revealed values from 12.5% to 15.9% and the total error (beta-expectation tolerance interval) of the method was found to be <40%. For the <span class="hlt">FACS</span>-based assay, the bias ranged from -8.3% to 0.6% and the intermediate precision for future means of duplicate measurements revealed values from 4.2% to 8.0%. The total error of the method was found to be <25%. The presented data demonstrate that the <span class="hlt">FACS</span>-based CDC is more accurate than the radioactive assay. Also, the elimination of radioactivity and the 'real-time' counting of apoptotic cells further justifies the implementation of this method which was subsequently applied for testing the influence of storage at 4 degrees C and 25 degrees C ('stability testing') on the potency of IGN311 drug product. The obtained results demonstrate that the qualified functional assay represents a stability indicating test method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title48-vol4/pdf/CFR-2011-title48-vol4-sec301-607-75.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title48-vol4/pdf/CFR-2011-title48-vol4-sec301-607-75.pdf"><span>48 CFR 301.607-75 - Maintenance of <span class="hlt">FAC</span>-P/PM certification.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-10-01</p> <p>... maintain <span class="hlt">FAC</span>-P/PM certification, HHS Program and Project Managers are required to earn 80 CLPs of skills...) Training activities, such as teaching, self-directed study, and mentoring; (2) Courses completed to achieve...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/863550','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/863550"><span><span class="hlt">Alignment</span> fixture</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Bell, Grover C.; Gibson, O. Theodore</p> <p>1980-01-01</p> <p>A part <span class="hlt">alignment</span> fixture is provided which may be used for precise variable lateral and tilt <span class="hlt">alignment</span> relative to the fixture base of various shaped parts. The fixture may be used as a part holder for machining or inspection of parts or <span class="hlt">alignment</span> of parts during assembly and the like. The fixture includes a precisely machined diameter disc-shaped hub adapted to receive the part to be <span class="hlt">aligned</span>. The hub is nested in a guide plate which is adapted to carry two oppositely disposed pairs of positioning wedges so that the wedges may be reciprocatively positioned by means of respective micrometer screws. The sloping faces of the wedges contact the hub at respective quadrants of the hub periphery. The lateral position of the hub relative to the guide plate is adjusted by positioning the wedges with the associated micrometer screws. The tilt of the part is adjusted relative to a base plate, to which the guide plate is pivotally connected by means of a holding plate. Two pairs of oppositely disposed wedges are mounted for reciprocative lateral positioning by means of separate micrometer screws between flanges of the guide plate and the base plate. Once the wedges are positioned to achieve the proper tilt of the part or hub on which the part is mounted relative to the base plate, the fixture may be bolted to a machining, inspection, or assembly device.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28493128','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28493128"><span>Selection of High-Producing Clones Using <span class="hlt">FACS</span> for CHO Cell Line Development.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gallagher, Clair; Kelly, Paul S</p> <p>2017-01-01</p> <p>Cell line development aims to generate and select clones with desirable characteristics. One of the most important parameters for biopharmaceutical cell selection is cell-specific productivity (Qp) or the quantity of product produced per cell per day. Fluorescence-activated cell sorting (<span class="hlt">FACS</span>) is a powerful, high-throughput technique that facilitates multiparametric characterization and isolation of individual cell clones from heterogeneous populations. Here, we describe a <span class="hlt">FACS</span>-based method for section of high-producing CHO cell clones.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20644514','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20644514"><span>Purification of specific cell population by fluorescence activated cell sorting (<span class="hlt">FACS</span>).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Basu, Sreemanti; Campbell, Hope M; Dittel, Bonnie N; Ray, Avijit</p> <p>2010-07-10</p> <p>Experimental and clinical studies often require highly purified cell populations. <span class="hlt">FACS</span> is a technique of choice to purify cell populations of known phenotype. Other bulk methods of purification include panning, complement depletion and magnetic bead separation. However, <span class="hlt">FACS</span> has several advantages over other available methods. <span class="hlt">FACS</span> is the preferred method when very high purity of the desired population is required, when the target cell population expresses a very low level of the identifying marker or when cell populations require separation based on differential marker density. In addition, <span class="hlt">FACS</span> is the only available purification technique to isolate cells based on internal staining or intracellular protein expression, such as a genetically modified fluorescent protein marker. <span class="hlt">FACS</span> allows the purification of individual cells based on size, granularity and fluorescence. In order to purify cells of interest, they are first stained with fluorescently-tagged monoclonal antibodies (mAb), which recognize specific surface markers on the desired cell population (1). Negative selection of unstained cells is also possible. <span class="hlt">FACS</span> purification requires a flow cytometer with sorting capacity and the appropriate software. For <span class="hlt">FACS</span>, cells in suspension are passed as a stream in droplets with each containing a single cell in front of a laser. The fluorescence detection system detects cells of interest based on predetermined fluorescent parameters of the cells. The instrument applies a charge to the droplet containing a cell of interest and an electrostatic deflection system facilitates collection of the charged droplets into appropriate collection tubes (2). The success of staining and thereby sorting depends largely on the selection of the identifying markers and the choice of mAb. Sorting parameters can be adjusted depending on the requirement of purity and yield. Although <span class="hlt">FACS</span> requires specialized equipment and personnel training, it is the method of choice for isolation of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8241E..0DB','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8241E..0DB"><span>Automated <span class="hlt">alignment</span> of optical components for high-power diode lasers</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Brecher, C.; Pyschny, N.; Haag, S.; Guerrero Lule, V.</p> <p>2012-03-01</p> <p>Despite major progress in developing brilliant laser sources a huge potential for cost reductions can be found in simpler setups and automated assembly processes, especially for large volume applications. In this presentation, a concept for flexible automation in optics assembly is presented which is based on standard micro assembly systems with relatively large workspace and modular micromanipulators to enhance the system with additional degrees of freedom and a very high motion resolution. The core component is a compact flexure-based micromanipulator especially designed for the <span class="hlt">alignment</span> of micro optical components which will be described in detail. The manipulator has been applied in different scenarios to develop and investigate automated <span class="hlt">alignment</span> processes. This paper focuses on the automated <span class="hlt">alignment</span> of fast axis collimation (<span class="hlt">FAC</span>) lenses which is a crucial step during the production of diode lasers. The handling and positioning system, the measuring arrangement for process feedback during active <span class="hlt">alignment</span> as well as the <span class="hlt">alignment</span> strategy will be described. The fine <span class="hlt">alignment</span> of the <span class="hlt">FAC</span> lens is performed with the micromanipulator under concurrent analysis of the far and the near field intensity distribution. An optimization of the image processing chains for the <span class="hlt">alignment</span> of a <span class="hlt">FAC</span> in front of a diode bar led to cycle times of less than 30 seconds. An outlook on other applications and future work regarding the development of automated assembly processes as well as new ideas for flexible assembly systems with desktop robots will close the talk.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015NIMPA.785...40P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015NIMPA.785...40P"><span>The <span class="hlt">alignment</span> strategy of HADES</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pechenova, O.; Pechenov, V.; Galatyuk, T.; Hennino, T.; Holzmann, R.; Kornakov, G.; Markert, J.; Müntz, C.; Salabura, P.; Schmah, A.; Schwab, E.; Stroth, J.</p> <p>2015-06-01</p> <p>The global as well as intrinsic <span class="hlt">alignment</span> of any spectrometer impacts directly on its performance and the quality of the achievable physics results. An overview of the <span class="hlt">current</span> <span class="hlt">alignment</span> procedure of the DiElectron Spectrometer HADES is presented with an emphasis on its main features and its accuracy. The sequence of all steps and procedures is given, including details on photogrammetric and track-based <span class="hlt">alignment</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/4287173','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/4287173"><span><span class="hlt">ALIGNING</span> JIG</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Culver, J.S.; Tunnell, W.C.</p> <p>1958-08-01</p> <p>A jig or device is described for setting or <span class="hlt">aligning</span> an opening in one member relative to another member or structure, with a predetermined offset, or it may be used for measuring the amount of offset with which the parts have previously been sct. This jig comprises two blocks rabbeted to each other, with means for securing thc upper block to the lower block. The upper block has fingers for contacting one of the members to be a1igmed, the lower block is designed to ride in grooves within the reference member, and calibration marks are provided to determine the amount of offset. This jig is specially designed to <span class="hlt">align</span> the collimating slits of a mass spectrometer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1129377','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1129377"><span>Image <span class="hlt">alignment</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Dowell, Larry Jonathan</p> <p>2014-04-22</p> <p>Disclosed is a method and device for <span class="hlt">aligning</span> at least two digital images. An embodiment may use frequency-domain transforms of small tiles created from each image to identify substantially similar, "distinguishing" features within each of the images, and then <span class="hlt">align</span> the images together based on the location of the distinguishing features. To accomplish this, an embodiment may create equal sized tile sub-images for each image. A "key" for each tile may be created by performing a frequency-domain transform calculation on each tile. A information-distance difference between each possible pair of tiles on each image may be calculated to identify distinguishing features. From analysis of the information-distance differences of the pairs of tiles, a subset of tiles with high discrimination metrics in relation to other tiles may be located for each image. The subset of distinguishing tiles for each image may then be compared to locate tiles with substantially similar keys and/or information-distance metrics to other tiles of other images. Once similar tiles are located for each image, the images may be <span class="hlt">aligned</span> in relation to the identified similar tiles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/10175437','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/10175437"><span>RHIC survey and <span class="hlt">alignment</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Karl, F.X.; Anderson, R.R.; Goldman, M.A.; Hemmer, F.M.; Kazmark, D. Jr.; Mroczkowski, T.T.; Roecklien, J.C.</p> <p>1993-07-01</p> <p>The Relativistic Heavy Ion Collider consists of two interlaced plane rings, a pair of mirror-symmetric beam injection arcs, a spatially curved beam transfer line from the Alternating Gradient Synchrotron, and a collection of precisely positioned and <span class="hlt">aligned</span> magnets, on appropriately positioned support stands, threaded on those arcs. RHIC geometry is defined by six beam crossing points exactly in a plane, lying precising at the vertices of a regular hexagon of specified size position and orientation of this hexagon are defined geodetically. Survey control and <span class="hlt">alignment</span> procedures, <span class="hlt">currently</span> in use to construct RHIC, are described.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/993187','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/993187"><span>Fuel Accident Condition Simulator (<span class="hlt">FACS</span>) Furnace for Post-Irradiation Heating Tests of VHTR Fuel Compacts</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Paul A Demkowicz; Paul Demkowicz; David V Laug</p> <p>2010-10-01</p> <p>Abstract –Fuel irradiation testing and post-irradiation examination are <span class="hlt">currently</span> in progress as part of the Next Generation Nuclear Plant Fuels Development and Qualification Program. The PIE campaign will include extensive accident testing of irradiated very high temperature reactor fuel compacts to verify fission product retention characteristics at high temperatures. This work will be carried out at both the Idaho National Laboratory (INL) and the Oak Ridge National Laboratory, beginning with accident tests on irradiated fuel from the AGR-1 experiment in 2010. A new furnace system has been designed, built, and tested at INL to perform high temperature accident tests. The Fuel Accident Condition Simulator furnace system is designed to heat fuel specimens at temperatures up to 2000°C in helium while monitoring the release of volatile fission metals (e.g. Cs, Ag, Sr, Eu, and I) and fission gases (Kr, Xe). Fission gases released from the fuel to the sweep gas are monitored in real time using dual cryogenic traps fitted with high purity germanium detectors. Condensable fission products are collected on a plate attached to a water-cooled cold finger that can be exchanged periodically without interrupting the test. Analysis of fission products on the condensation plates involves dry gamma counting followed by chemical analysis of selected isotopes. This paper will describe design and operational details of the Fuel Accident Condition Simulator (<span class="hlt">FACS</span>) furnace system, as well as preliminary system calibration results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26759932','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26759932"><span>Functional <span class="hlt">Alignment</span> of Metabolic Networks.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Mazza, Arnon; Wagner, Allon; Ruppin, Eytan; Sharan, Roded</p> <p>2016-05-01</p> <p>Network <span class="hlt">alignment</span> has become a standard tool in comparative biology, allowing the inference of protein function, interaction, and orthology. However, <span class="hlt">current</span> <span class="hlt">alignment</span> techniques are based on topological properties of networks and do not take into account their functional implications. Here we propose, for the first time, an algorithm to <span class="hlt">align</span> two metabolic networks by taking advantage of their coupled metabolic models. These models allow us to assess the functional implications of genes or reactions, captured by the metabolic fluxes that are altered following their deletion from the network. Such implications may spread far beyond the region of the network where the gene or reaction lies. We apply our algorithm to <span class="hlt">align</span> metabolic networks from various organisms, ranging from bacteria to humans, showing that our <span class="hlt">alignment</span> can reveal functional orthology relations that are missed by conventional topological <span class="hlt">alignments</span>.</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://hdl.handle.net/2060/19800013893','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19800013893"><span>Onorbit IMU <span class="hlt">alignment</span> error budget</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Corson, R. W.</p> <p>1980-01-01</p> <p>The Star Tracker, Crew Optical <span class="hlt">Alignment</span> Sight (COAS), and Inertial Measurement Unit (IMU) from a complex navigation system with a multitude of error sources were combined. A complete list of the system errors is presented. The errors were combined in a rational way to yield an estimate of the IMU <span class="hlt">alignment</span> accuracy for STS-1. The expected standard deviation in the IMU <span class="hlt">alignment</span> error for STS-1 type <span class="hlt">alignments</span> was determined to be 72 arc seconds per axis for star tracker <span class="hlt">alignments</span> and 188 arc seconds per axis for COAS <span class="hlt">alignments</span>. These estimates are based on <span class="hlt">current</span> knowledge of the star tracker, COAS, IMU, and navigation base error specifications, and were partially verified by preliminary Monte Carlo analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27896722','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27896722"><span>Multiple Sequence <span class="hlt">Alignment</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bawono, Punto; Dijkstra, Maurits; Pirovano, Walter; Feenstra, Anton; Abeln, Sanne; Heringa, Jaap</p> <p>2017-01-01</p> <p>The increasing importance of Next Generation Sequencing (NGS) techniques has highlighted the key role of multiple sequence <span class="hlt">alignment</span> (MSA) in comparative structure and function analysis of biological sequences. MSA often leads to fundamental biological insight into sequence-structure-function relationships of nucleotide or protein sequence families. Significant advances have been achieved in this field, and many useful tools have been developed for constructing <span class="hlt">alignments</span>, although many biological and methodological issues are still open. This chapter first provides some background information and considerations associated with MSA techniques, concentrating on the <span class="hlt">alignment</span> of protein sequences. Then, a practical overview of <span class="hlt">currently</span> available methods and a description of their specific advantages and limitations are given, to serve as a helpful guide or starting point for researchers who aim to construct a reliable MSA.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JGRA..122..194M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JGRA..122..194M"><span>Use of spherical elementary <span class="hlt">currents</span> to map the polar <span class="hlt">current</span> systems associated with the geomagnetic sudden commencements on 2013 and 2015 St. Patrick's Day storms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Marsal, S.; Torta, J. M.; Segarra, A.; Araki, T.</p> <p>2017-01-01</p> <p>Araki's model of geomagnetic sudden commencements (SCs) establishes that the ground magnetic signatures globally observed after the onset produced by an increased solar wind dynamic pressure impacting on the Earth's magnetosphere are caused by the setting up of a system of electric <span class="hlt">currents</span> in the coupled magnetosphere-ionosphere. This <span class="hlt">current</span> system consists of a particular evolving set of magnetopause <span class="hlt">currents</span> closing in the ionosphere through geomagnetic field-<span class="hlt">aligned</span> <span class="hlt">currents</span> (<span class="hlt">FACs</span>) and their induced counterpart. The present paper confirms the starting assumptions of the referred model by use of spherical elementary <span class="hlt">current</span> systems (SECS), namely, the existence of <span class="hlt">FACs</span> reversing polarity during the first couple of minutes of the SC. It is the first time that SECS have been applied to the study of SCs. The method has been fed with data from more than 100 stations of the global network of geomagnetic observatories and variometer sites in the northern hemisphere so as to provide a reliable pattern of the equivalent <span class="hlt">current</span> system flowing at ionospheric heights on the occasion of the SCs associated with the 2013 and 2015 St. Patrick's Day storms. The combined analysis of solar wind data and the synoptic view of the SC <span class="hlt">current</span> patterns provided by SECS allows it to explain some of the differences observed between both events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JGRA..120.4338W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JGRA..120.4338W"><span>The two-way relationship between ionospheric outflow and the ring <span class="hlt">current</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Welling, D. T.; Jordanova, V. K.; Glocer, A.; Toth, G.; Liemohn, M. W.; Weimer, D. R.</p> <p>2015-06-01</p> <p>It is now well established that the ionosphere, because it acts as a significant source of plasma, plays a critical role in ring <span class="hlt">current</span> dynamics. However, because the ring <span class="hlt">current</span> deposits energy into the ionosphere, the inverse may also be true: the ring <span class="hlt">current</span> can play a critical role in the dynamics of ionospheric outflow. This study uses a set of coupled, first-principles-based numerical models to test the dependence of ionospheric outflow on ring <span class="hlt">current</span>-driven region 2 field-<span class="hlt">aligned</span> <span class="hlt">currents</span> (<span class="hlt">FACs</span>). A moderate magnetospheric storm event is modeled with the Space Weather Modeling Framework using a global MHD code (Block Adaptive Tree Solar wind Roe-type Upwind Scheme, BATS-R-US), a polar wind model (Polar Wind Outflow Model), and a bounce-averaged kinetic ring <span class="hlt">current</span> model (ring <span class="hlt">current</span> atmosphere interaction model with self-consistent magnetic field, RAM-SCB). Initially, each code is two-way coupled to all others except for RAM-SCB, which receives inputs from the other models but is not allowed to feed back pressure into the MHD model. The simulation is repeated with pressure coupling activated, which drives strong pressure gradients and region 2 <span class="hlt">FACs</span> in BATS-R-US. It is found that the region 2 <span class="hlt">FACs</span> increase heavy ion outflow by up to 6 times over the noncoupled results. The additional outflow further energizes the ring <span class="hlt">current</span>, establishing an ionosphere-magnetosphere mass feedback loop. This study further demonstrates that ionospheric outflow is not merely a plasma source for the magnetosphere but an integral part in the nonlinear ionosphere-magnetosphere-ring <span class="hlt">current</span> system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/pages/biblio/1215633-two-way-relationship-between-ionospheric-outflow-ring-current','SCIGOV-DOEP'); return false;" href="https://www.osti.gov/pages/biblio/1215633-two-way-relationship-between-ionospheric-outflow-ring-current"><span>The two-way relationship between ionospheric outflow and the ring <span class="hlt">current</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/pages">DOE PAGES</a></p> <p>Welling, Daniel T.; Jordanova, Vania Koleva; Glocer, Alex; ...</p> <p>2015-06-01</p> <p>It is now well established that the ionosphere, because it acts as a significant source of plasma, plays a critical role in ring <span class="hlt">current</span> dynamics. However, because the ring <span class="hlt">current</span> deposits energy into the ionosphere, the inverse may also be true: the ring <span class="hlt">current</span> can play a critical role in the dynamics of ionospheric outflow. This study uses a set of coupled, first-principles-based numerical models to test the dependence of ionospheric outflow on ring <span class="hlt">current</span>-driven region 2 field-<span class="hlt">aligned</span> <span class="hlt">currents</span> (<span class="hlt">FACs</span>). A moderate magnetospheric storm event is modeled with the Space Weather Modeling Framework using a global MHD code (Block Adaptivemore » Tree Solar wind Roe-type Upwind Scheme, BATS-R-US), a polar wind model (Polar Wind Outflow Model), and a bounce-averaged kinetic ring <span class="hlt">current</span> model (ring <span class="hlt">current</span> atmosphere interaction model with self-consistent magnetic field, RAM-SCB). Initially, each code is two-way coupled to all others except for RAM-SCB, which receives inputs from the other models but is not allowed to feed back pressure into the MHD model. The simulation is repeated with pressure coupling activated, which drives strong pressure gradients and region 2 <span class="hlt">FACs</span> in BATS-R-US. It is found that the region 2 <span class="hlt">FACs</span> increase heavy ion outflow by up to 6 times over the non-coupled results. The additional outflow further energizes the ring <span class="hlt">current</span>, establishing an ionosphere-magnetosphere mass feedback loop. This study further demonstrates that ionospheric outflow is not merely a plasma source for the magnetosphere but an integral part in the nonlinear ionosphere-magnetosphere-ring <span class="hlt">current</span> system.« less</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1215633','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1215633"><span>The two-way relationship between ionospheric outflow and the ring <span class="hlt">current</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Welling, Daniel T.; Jordanova, Vania Koleva; Glocer, Alex; Toth, Gabor; Liemohn, Michael W.; Weimer, Dan R.</p> <p>2015-06-01</p> <p>It is now well established that the ionosphere, because it acts as a significant source of plasma, plays a critical role in ring <span class="hlt">current</span> dynamics. However, because the ring <span class="hlt">current</span> deposits energy into the ionosphere, the inverse may also be true: the ring <span class="hlt">current</span> can play a critical role in the dynamics of ionospheric outflow. This study uses a set of coupled, first-principles-based numerical models to test the dependence of ionospheric outflow on ring <span class="hlt">current</span>-driven region 2 field-<span class="hlt">aligned</span> <span class="hlt">currents</span> (<span class="hlt">FACs</span>). A moderate magnetospheric storm event is modeled with the Space Weather Modeling Framework using a global MHD code (Block Adaptive Tree Solar wind Roe-type Upwind Scheme, BATS-R-US), a polar wind model (Polar Wind Outflow Model), and a bounce-averaged kinetic ring <span class="hlt">current</span> model (ring <span class="hlt">current</span> atmosphere interaction model with self-consistent magnetic field, RAM-SCB). Initially, each code is two-way coupled to all others except for RAM-SCB, which receives inputs from the other models but is not allowed to feed back pressure into the MHD model. The simulation is repeated with pressure coupling activated, which drives strong pressure gradients and region 2 <span class="hlt">FACs</span> in BATS-R-US. It is found that the region 2 <span class="hlt">FACs</span> increase heavy ion outflow by up to 6 times over the non-coupled results. The additional outflow further energizes the ring <span class="hlt">current</span>, establishing an ionosphere-magnetosphere mass feedback loop. This study further demonstrates that ionospheric outflow is not merely a plasma source for the magnetosphere but an integral part in the nonlinear ionosphere-magnetosphere-ring <span class="hlt">current</span> system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMSA41B1731T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMSA41B1731T"><span>Temporal and spatial developments of global ionospheric <span class="hlt">current</span> associated with storm-time overshielding</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tsuji, Y.; Shinbori, A.; Nishimura, Y.; Kikuchi, T.; Nagatsuma, T.; Watari, S.</p> <p>2010-12-01</p> <p>During the strong southward interplanetary magnetic field (IMF), the convection electric field originating from the region-1 field-<span class="hlt">aligned</span> <span class="hlt">currents</span> (R1 <span class="hlt">FACs</span>) causes a two-cell ionospheric Hall <span class="hlt">current</span> at high latitudes. The convection electric field penetrates to the magnetic equator, and drives the eastward equatorial electrojet (EEJ). Subsequently, when the southward IMF weakens, the reversed ionospheric <span class="hlt">current</span> in the equatorial ionosphere, called equatorial counter electrojet (CEJ), is driven by the developed shielding electric field originating from the region-2 field-<span class="hlt">aligned</span> <span class="hlt">currents</span> (R2 <span class="hlt">FACs</span>). Its state is called ‘overshielding’ because the shielding electric field overcomes the reduced convection field in lower latitudes of the R2 <span class="hlt">FACs</span> [e.g., Kelley et al., 1979]. However, the temporal and spatial relationship of the global ionospheric <span class="hlt">current</span> system has not been established during the storm-time overshielding yet. In this paper, we investigated magnetic field variations in high-low latitudes in the 21 CEJ events (overshielding events) during storms occurred during a period from 2001 to 2002. In high-middle latitudes during the period, the developed auroral electrojet (AEJ) moved poleward with ~3-8 degrees in magnetic latitude, maintaining the strength. This indicates a contraction of the auroral oval. Subsequently, the strength rapidly decreased without such a poleward shift. This result supports that the overshielding electric field is strengthened by the poleward shift of the R1 <span class="hlt">FACs</span> [Kikuchi et al., 2008]. Moreover, in the 8 of 21 CEJ events, the magnetic field variation in lower latitudes than the AEJ region changed the direction with magnitudes one order smaller than the AEJ. This variation was generated by the ionospheric Hall <span class="hlt">currents</span> associated with the overshielding electric field. We also found that the observed life time of CEJ, about 15-470 min, was either equal to or up to 3.8 times longer than that of the overshielding <span class="hlt">current</span> at the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19068501','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19068501"><span>Validation of ASHA <span class="hlt">FACS</span>-functional assessment of communication skills for Alzheimer disease population.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>de Carvalho, Isabel Albuquerque M; Mansur, Letícia Lessa</p> <p>2008-01-01</p> <p>This study was aimed to validate the American Speech-Language-Hearing Association Functional Assessment of Communication Skills (ASHA <span class="hlt">FACS</span>) for a Brazilian population. The scale was translated and adapted into Portuguese. Thirty-two patients with mild Alzheimer disease (AD), 25 patients with moderate AD, and 51 elderly without dementia were examined with Mini Mental State Examination, Geriatric Depression Scale, and Alzheimer Disease Assessment Scale-cognitive subscale (ADAS-cog). The ASHA <span class="hlt">FACS</span> was answered by their relative/caregiver. The scale's internal consistency, its inter-examiner and intra-examiner's reproducibility, and scale's criterion validity were researched by correlation with ADAS-cog. The sensitivity and specificity were also researched. Statistical analyses indicated that the ASHA <span class="hlt">FACS</span> has excellent internal consistency (Cronbach [alpha]=0.955), test-retest reliability (interclass correlation coefficient=0.995; P<0.001), and inter-examiners (interclass correlation coefficient=0.998; P<0.001). It showed excellent criterion validity when correlated with ADAS-cog. The ASHA <span class="hlt">FACS</span> scale showed good sensitivity (75.0%) and specificity (82.4%) values once it is an ecologic and broad evaluation. The ASHA <span class="hlt">FACS</span> Portuguese version is a valid and reliable instrument to verify communication alterations in AD patients and fills an important gap of efficiency indicators for speech language therapy in our country.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2743057','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2743057"><span>The RNA structure <span class="hlt">alignment</span> ontology</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Brown, James W.; Birmingham, Amanda; Griffiths, Paul E.; Jossinet, Fabrice; Kachouri-Lafond, Rym; Knight, Rob; Lang, B. Franz; Leontis, Neocles; Steger, Gerhard; Stombaugh, Jesse; Westhof, Eric</p> <p>2009-01-01</p> <p>Multiple sequence <span class="hlt">alignments</span> are powerful tools for understanding the structures, functions, and evolutionary histories of linear biological macromolecules (DNA, RNA, and proteins), and for finding homologs in sequence databases. We address several ontological issues related to RNA sequence <span class="hlt">alignments</span> that are informed by structure. Multiple sequence <span class="hlt">alignments</span> are usually shown as two-dimensional (2D) matrices, with rows representing individual sequences, and columns identifying nucleotides from different sequences that correspond structurally, functionally, and/or evolutionarily. However, the requirement that sequences and structures correspond nucleotide-by-nucleotide is unrealistic and hinders representation of important biological relationships. High-throughput sequencing efforts are also rapidly making 2D <span class="hlt">alignments</span> unmanageable because of vertical and horizontal expansion as more sequences are added. Solving the shortcomings of traditional RNA sequence <span class="hlt">alignments</span> requires explicit annotation of the meaning of each relationship within the <span class="hlt">alignment</span>. We introduce the notion of “correspondence,” which is an equivalence relation between RNA elements in sets of sequences as the basis of an RNA <span class="hlt">alignment</span> ontology. The purpose of this ontology is twofold: first, to enable the development of new representations of RNA data and of software tools that resolve the expansion problems with <span class="hlt">current</span> RNA sequence <span class="hlt">alignments</span>, and second, to facilitate the integration of sequence data with secondary and three-dimensional structural information, as well as other experimental information, to create simultaneously more accurate and more exploitable RNA <span class="hlt">alignments</span>. PMID:19622678</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8446E..5XL','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8446E..5XL"><span>MUSE optical <span class="hlt">alignment</span> procedure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Laurent, Florence; Renault, Edgard; Loupias, Magali; Kosmalski, Johan; Anwand, Heiko; Bacon, Roland; Boudon, Didier; Caillier, Patrick; Daguisé, Eric; Dubois, Jean-Pierre; Dupuy, Christophe; Kelz, Andreas; Lizon, Jean-Louis; Nicklas, Harald; Parès, Laurent; Remillieux, Alban; Seifert, Walter; Valentin, Hervé; Xu, Wenli</p> <p>2012-09-01</p> <p>MUSE (Multi Unit Spectroscopic Explorer) is a second generation VLT integral field spectrograph (1x1arcmin² Field of View) developed for the European Southern Observatory (ESO), operating in the visible wavelength range (0.465-0.93 μm). A consortium of seven institutes is <span class="hlt">currently</span> assembling and testing MUSE in the Integration Hall of the Observatoire de Lyon for the Preliminary Acceptance in Europe, scheduled for 2013. MUSE is composed of several subsystems which are under the responsibility of each institute. The Fore Optics derotates and anamorphoses the image at the focal plane. A Splitting and Relay Optics feed the 24 identical Integral Field Units (IFU), that are mounted within a large monolithic instrument mechanical structure. Each IFU incorporates an image slicer, a fully refractive spectrograph with VPH-grating and a detector system connected to a global vacuum and cryogenic system. During 2011, all MUSE subsystems were integrated, <span class="hlt">aligned</span> and tested independently in each institute. After validations, the systems were shipped to the P.I. institute at Lyon and were assembled in the Integration Hall This paper describes the end-to-end optical <span class="hlt">alignment</span> procedure of the MUSE instrument. The design strategy, mixing an optical <span class="hlt">alignment</span> by manufacturing (plug and play approach) and few adjustments on key components, is presented. We depict the <span class="hlt">alignment</span> method for identifying the optical axis using several references located in pupil and image planes. All tools required to perform the global <span class="hlt">alignment</span> between each subsystem are described. The success of this <span class="hlt">alignment</span> approach is demonstrated by the good results for the MUSE image quality. MUSE commissioning at the VLT (Very Large Telescope) is planned for 2013.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19780010161','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19780010161"><span>IUS prerelease <span class="hlt">alignment</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Evans, F. A.</p> <p>1978-01-01</p> <p>Space shuttle orbiter/IUS <span class="hlt">alignment</span> transfer was evaluated. Although the orbiter <span class="hlt">alignment</span> accuracy was originally believed to be the major contributor to the overall <span class="hlt">alignment</span> transfer error, it was shown that orbiter <span class="hlt">alignment</span> accuracy is not a factor affecting IUS <span class="hlt">alignment</span> accuracy, if certain procedures are followed. Results are reported of <span class="hlt">alignment</span> transfer accuracy analysis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/430639','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/430639"><span>Nearly monotonic problems: A key to effective <span class="hlt">FA/C</span> distributed sensor interpretation?</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Carver, N.; Lesser, V.; Whitehair, R.</p> <p>1996-12-31</p> <p>The functionally-accurate, cooperative (<span class="hlt">FA/C</span>) distributed problem-solving paradigm is one approach for organizing distributed problem solving among homogeneous, cooperating agents. A key assumption of the <span class="hlt">FA/C</span> model has been that the agents` local solutions can substitute for the raw data in determining the global solutions. This is not the case in general, however. Does this mean that researchers` intuitions have been wrong and/or that <span class="hlt">FA/C</span> problem solving is not likely to be effective? We suggest that some domains have a characteristic that can account for the success of exchanging mainly local solutions. We call such problems nearly monotonic. This concept is discussed in the context of FA/C-based distributed sensor interpretation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ClinicalTrials.gov/ct2/show/study/NCT02319005','CLINICALTRIALS'); return false;" href="https://ClinicalTrials.gov/ct2/show/study/NCT02319005"><span>ENDEAVOUR: Phase 3 Multicenter Study of Revusiran (ALN-TTRSC) in Patients With Transthyretin (TTR) Mediated Familial Amyloidotic Cardiomyopathy (<span class="hlt">FAC</span>)</span></a></p> <p><a target="_blank" href="http://www.clinicaltrials.gov/ct/screen/SimpleSearch">ClinicalTrials.gov</a></p> <p></p> <p>2017-05-23</p> <p>Transthyretin (TTR) Mediated Familial Amyloidotic Cardiomyopathy (<span class="hlt">FAC</span>); Amyloidosis, Hereditary; Amyloid Neuropathies, Familial; Amyloid Neuropathies; Amyloidosis, Hereditary, Transthyretin-Related; Familial Transthyretin Cardiac Amyloidosis</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4528633','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4528633"><span>GS-<span class="hlt">align</span> for glycan structure <span class="hlt">alignment</span> and similarity measurement</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lee, Hui Sun; Jo, Sunhwan; Mukherjee, Srayanta; Park, Sang-Jun; Skolnick, Jeffrey; Lee, Jooyoung; Im, Wonpil</p> <p>2015-01-01</p> <p>Motivation: Glycans play critical roles in many biological processes, and their structural diversity is key for specific protein-glycan recognition. Comparative structural studies of biological molecules provide useful insight into their biological relationships. However, most computational tools are designed for protein structure, and despite their importance, there is no <span class="hlt">currently</span> available tool for comparing glycan structures in a sequence order- and size-independent manner. Results: A novel method, GS-<span class="hlt">align</span>, is developed for glycan structure <span class="hlt">alignment</span> and similarity measurement. GS-<span class="hlt">align</span> generates possible <span class="hlt">alignments</span> between two glycan structures through iterative maximum clique search and fragment superposition. The optimal <span class="hlt">alignment</span> is then determined by the maximum structural similarity score, GS-score, which is size-independent. Benchmark tests against the Protein Data Bank (PDB) N-linked glycan library and PDB homologous/non-homologous N-glycoprotein sets indicate that GS-<span class="hlt">align</span> is a robust computational tool to <span class="hlt">align</span> glycan structures and quantify their structural similarity. GS-<span class="hlt">align</span> is also applied to template-based glycan structure prediction and monosaccharide substitution matrix generation to illustrate its utility. Availability and implementation: http://www.glycanstructure.org/gsalign. Contact: wonpil@ku.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:25857669</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3467747','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3467747"><span><span class="hlt">Fac</span>Pad: Bayesian sparse factor modeling for the inference of pathways responsive to drug treatment</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ma, Haisu; Zhao, Hongyu</p> <p>2012-01-01</p> <p>Motivation: It is well recognized that the effects of drugs are far beyond targeting individual proteins, but rather influencing the complex interactions among many relevant biological pathways. Genome-wide expression profiling before and after drug treatment has become a powerful approach for capturing a global snapshot of cellular response to drugs, as well as to understand drugs’ mechanism of action. Therefore, it is of great interest to analyze this type of transcriptomic profiling data for the identification of pathways responsive to different drugs. However, few computational tools exist for this task. Results: We have developed <span class="hlt">Fac</span>Pad, a Bayesian sparse factor model, for the inference of pathways responsive to drug treatments. This model represents biological pathways as latent factors and aims to describe the variation among drug-induced gene expression alternations in terms of a much smaller number of latent factors. We applied this model to the Connectivity Map data set (build 02) and demonstrated that <span class="hlt">Fac</span>Pad is able to identify many drug–pathway associations, some of which have been validated in the literature. Although this method was originally designed for the analysis of drug-induced transcriptional alternation data, it can be naturally applied to many other settings beyond polypharmacology. Availability and implementation: The R package ‘<span class="hlt">Fac</span>Pad’ is publically available at: http://cran.open-source-solution.org/web/packages/<span class="hlt">Fac</span>Pad/ Contact: hongyu.zhao@yale.edu Supplementary Information: Supplementary data are available at Bioinformatics online. PMID:22923307</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1988RScI...59.1928M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1988RScI...59.1928M"><span>Critical assessment of fluorescence polarization measurements with a <span class="hlt">FACS</span> IV cell sorter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Muller, Claude P.; Krabichler, Gert</p> <p>1988-09-01</p> <p>The usefulness and limitations of the Becton-Dickinson fluorescence-activated cell sorter <span class="hlt">FACS</span> IV for fluorescence polarization measurements were examined. A set of tests to determine the characteristics of the detection geometry, the optical properties of the beam splitter, and the capability to process fluorescence polarization data is presented. Recommendations are provided for correcting instrumental deficiencies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=FACS&id=EJ776317','ERIC'); return false;" href="https://eric.ed.gov/?q=FACS&id=EJ776317"><span><span class="hlt">Fac</span>-Back-OPAC: An Open Source Interface to Your Library System</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>Beccaria, Mike; Scott, Dan</p> <p>2007-01-01</p> <p>The new <span class="hlt">Fac</span>-Back-OPAC (a faceted backup OPAC) is built on code that was originally developed by Casey Durfee in February 2007. It represents the convergence of two prominent trends in library tools: the decoupling of discovery tools from the traditional integrated library system (ILS) and the use of readily available open source components to…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=FACS&id=EJ776317','ERIC'); return false;" href="http://eric.ed.gov/?q=FACS&id=EJ776317"><span><span class="hlt">Fac</span>-Back-OPAC: An Open Source Interface to Your Library System</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>Beccaria, Mike; Scott, Dan</p> <p>2007-01-01</p> <p>The new <span class="hlt">Fac</span>-Back-OPAC (a faceted backup OPAC) is built on code that was originally developed by Casey Durfee in February 2007. It represents the convergence of two prominent trends in library tools: the decoupling of discovery tools from the traditional integrated library system (ILS) and the use of readily available open source components to…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27494801','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27494801"><span>Substrate Engineering Enabling Fluorescence Droplet Entrapment for IVC-<span class="hlt">FACS</span>-Based Ultrahigh-Throughput Screening.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ma, Fuqiang; Fischer, Michael; Han, Yunbin; Withers, Stephen G; Feng, Yan; Yang, Guang-Yu</p> <p>2016-09-06</p> <p>In vitro compartmentalization-based fluorescence-activated cell sorting (IVC-<span class="hlt">FACS</span>) is a powerful screening tool for directed evolution of enzymes. However, the efficiency of IVC-<span class="hlt">FACS</span> is limited by the tendency of the fluorescent reporter to diffuse out of the droplets, which decouples the genotype and phenotype of the target gene. Herein we present a new strategy called fluorescence droplet entrapment (FDE) to solve this problem. The substrate is designed with a polarity that enables it to pass through the oil phase, react with the enzyme and generate an oil-impermeable and fluorescent product that remains entrapped inside the droplet. Several FDE substrates were designed, using two distinct substrate engineering strategies, for the detection of phosphotriesterases, carboxylesterases, and glycosidases activities. Model screening assays in which rare phosphotriesterase-active cells were enriched from large excesses of inactive cells showed that the enrichment efficiency achievable using an FDE substrate was as high as 900-fold: the highest yet reported in such an IVC-<span class="hlt">FACS</span> system. Thus, FDE provides a means to tightly control the onset of the enzymatic reaction, minimize droplet cross-talk, and lower the background fluorescence. It therefore may serve as a useful strategy for the IVC-<span class="hlt">FACS</span> screening of enzymes, antibodies, and other proteins.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title7-vol13/pdf/CFR-2011-title7-vol13-sec1945-18.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title7-vol13/pdf/CFR-2011-title7-vol13-sec1945-18.pdf"><span>7 CFR 1945.18 - United States Department of Agriculture (USDA) Food and Agriculture Council (<span class="hlt">FAC</span>).</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-01-01</p> <p>... 7 Agriculture 13 2011-01-01 2009-01-01 true United States Department of Agriculture (USDA) Food and Agriculture Council (<span class="hlt">FAC</span>). 1945.18 Section 1945.18 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES...</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('https://www.gpo.gov/fdsys/pkg/CFR-2012-title7-vol13/pdf/CFR-2012-title7-vol13-sec1945-18.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title7-vol13/pdf/CFR-2012-title7-vol13-sec1945-18.pdf"><span>7 CFR 1945.18 - United States Department of Agriculture (USDA) Food and Agriculture Council (<span class="hlt">FAC</span>).</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-01-01</p> <p>... 7 Agriculture 13 2012-01-01 2012-01-01 false United States Department of Agriculture (USDA) Food and Agriculture Council (<span class="hlt">FAC</span>). 1945.18 Section 1945.18 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title7-vol13/pdf/CFR-2010-title7-vol13-sec1945-18.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title7-vol13/pdf/CFR-2010-title7-vol13-sec1945-18.pdf"><span>7 CFR 1945.18 - United States Department of Agriculture (USDA) Food and Agriculture Council (<span class="hlt">FAC</span>).</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-01-01</p> <p>... 7 Agriculture 13 2010-01-01 2009-01-01 true United States Department of Agriculture (USDA) Food and Agriculture Council (<span class="hlt">FAC</span>). 1945.18 Section 1945.18 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1019453','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1019453"><span>Re-casting the <span class="hlt">FAC</span> Net: People, Platforms, and Policy in Forward Air Control</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2015-06-01</p> <p>Storm, technological advances, such as satellite communications and the global positioning system (GPS), provided the architecture to distribute... communication and global positioning satellite (GPS) jamming.9 Jamming slows the targeting process because <span class="hlt">FACs</span> must use secondary methods to glean...reconnaissance platforms. Furthermore, GPS and satellite communications enabled over-the- horizon Remotely Piloted Vehicles to support ground missions. These</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=228187','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=228187"><span>Function and evolutionary diversity of fatty acid amino acid conjugates (<span class="hlt">FACs</span>)in Lepidopteran caterpillars</span></a></p> <p><a target="_blank" href="https://www.ars.usda.gov/research/publications/find-a-publication/">USDA-ARS?s Scientific Manuscript database</a></p> <p></p> <p></p> <p>Fatty acid amino acid conjugates (<span class="hlt">FACs</span>) in regurgitant of larval Spodoptera exigua1 were initially identified as plant volatile elicitors and research has been focused on this apparent ecological disadvantage rather than on possible benefit for the caterpillar itself. Recently, we demonstrated that...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.P53C..05S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.P53C..05S"><span>The Consequences of Saturn’s Rotating Asymmetric Ring <span class="hlt">Current</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Southwood, D. J.; Kivelson, M. G.</p> <p>2009-12-01</p> <p>The plasma and field behavior in the dipolar region of the Saturnian magnetosphere is described, based primarily on interpretation of the magnetic field behavior measured by the Cassini spacecraft. Previous authors, such as Provan and Khurana, have pointed out that the regular pulses in field strength at around 10.8 hrs period detected in this region imply the existence not only of a symmetric ring <span class="hlt">current</span> but also of a partial ring <span class="hlt">current</span>. Once spacecraft motion in local time has been allowed for, one finds a close to sinusoidal variation with azimuth and time of the magnetic signal. Hence the partial ring <span class="hlt">current</span> appears to quasi-rigidly rotate about the planetary axis at the same 10.8 hr period as the pulsing of the Saturn kilometric radiation. We point out that, independent of whether the excess <span class="hlt">current</span> is due to asymmetry in flux tube population or in plasma beta (pressure normalized to field pressure), such a <span class="hlt">current</span> gives rise to a rotating circulation system. The compressional field pattern is consistent with an m = 1 pattern of circulation. The fairly uniform inner magnetosphere cam magnetic signature predicted on the basis of inner magnetosphere transverse field components in our past work is modified in a systematic way by the partial ring <span class="hlt">current</span> effects. The circulation due to the partial ring <span class="hlt">current</span> has its own set of distributed field <span class="hlt">aligned</span> <span class="hlt">currents</span> (<span class="hlt">FACs</span>). The rotating transverse perturbation field components are twisted by the <span class="hlt">FACs</span> so that the radial field is reduced at low L-shells and increased at larger L. Overall the cam field is depressed at low L and enhanced as one approaches the boundary of the cam region at L = 10-12. In practice the system must also respond to some local time effects. Loss of plasma is easier on the night-side and flanks than on the day-side and so a day-night asymmetry is imposed tending to increase the perturbation field amplitudes by night. The <span class="hlt">FACs</span> driven by the asymmetric ring <span class="hlt">current</span> should be broadly</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..APR.Y8003O','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..APR.Y8003O"><span>RF Jitter Modulation <span class="hlt">Alignment</span> Sensing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ortega, L. F.; Fulda, P.; Diaz-Ortiz, M.; Perez Sanchez, G.; Ciani, G.; Voss, D.; Mueller, G.; Tanner, D. B.</p> <p>2017-01-01</p> <p>We will present the numerical and experimental results of a new <span class="hlt">alignment</span> sensing scheme which can reduce the complexity of <span class="hlt">alignment</span> sensing systems <span class="hlt">currently</span> used, while maintaining the same shot noise limited sensitivity. This scheme relies on the ability of electro-optic beam deflectors to create angular modulation sidebands in radio frequency, and needs only a single-element photodiode and IQ demodulation to generate error signals for tilt and translation degrees of freedom in one dimension. It distances itself from <span class="hlt">current</span> techniques by eliminating the need for beam centering servo systems, quadrant photodetectors and Gouy phase telescopes. RF Jitter <span class="hlt">alignment</span> sensing can be used to reduce the complexity in the <span class="hlt">alignment</span> systems of many laser optical experiments, including LIGO and the ALPS experiment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/6095550','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/6095550"><span>On the large-scale distribution of magnetospheric <span class="hlt">currents</span> and thermal plasma: Results from magnetic field models and observations</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Spence, H.E.</p> <p>1989-01-01</p> <p>The author presents the results of studies using magnetic field models and observations to determine, as a function of magnetic activity, the distributions of plasma pressure in the Earth's magnetic tail and to characterize field-<span class="hlt">aligned</span> <span class="hlt">currents</span> globally. He first presents a brief history of magnetic field models of the Earth's magnetosphere. He then discuss related work on magnetotail plasma pressure. In the first study, he develops a technique for obtaining pressure gradients and anisotropies consistent with quasi-static equilibrium from recent empirical magnetic field models. He finds that the near-tail magnetic stresses can be balanced by a nearly isotropic plasma pressure with a realistic equatorial gradient. In the second study, he surveys plasma pressures observed near the midnight meridian. He finds that vertical pressure balance is maintained between lobe magnetic and plasma sheet plasma pressure and that observed and model-derived pressures are consistent. The combined model-derived and observed pressure profile falls off more slowly than it would if established by a two-dimensional, adiabatic, lossless convection model. He reassess the convection model and finds that observed quiet time pressure profiles can be reproduced so long as he accounts for the finite tail width. In the next main section, he presents studies on the distribution of field-<span class="hlt">aligned</span> <span class="hlt">currents</span> (<span class="hlt">FACs</span>). First, empirical magnetic models are used to determine the average <span class="hlt">FACs</span> flowing in the magnetosphere as a function of geomagnetic activity. When mapped to the ionosphere, <span class="hlt">FAC</span> systems with region 1 polarity both on the day side (DR1) and the night side (NR1) can be identified; a low-level, region 2-sense system (NPC) flows poleward of the NR1 system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20100028292&hterms=innovation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dinnovation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100028292&hterms=innovation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dinnovation"><span><span class="hlt">Aligning</span> for Innovation - <span class="hlt">Alignment</span> Strategy to Drive Innovation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Johnson, Hurel; Teltschik, David; Bussey, Horace, Jr.; Moy, James</p> <p>2010-01-01</p> <p>With the sudden need for innovation that will help the country achieve its long-term space exploration objectives, the question of whether NASA is <span class="hlt">aligned</span> effectively to drive the innovation that it so desperately needs to take space exploration to the next level should be entertained. Authors such as Robert Kaplan and David North have noted that companies that use a formal system for implementing strategy consistently outperform their peers. They have outlined a six-stage management systems model for implementing strategy, which includes the <span class="hlt">aligning</span> of the organization towards its objectives. This involves the <span class="hlt">alignment</span> of the organization from the top down. This presentation will explore the impacts of existing U.S. industrial policy on technological innovation; assess the <span class="hlt">current</span> NASA organizational <span class="hlt">alignment</span> and its impacts on driving technological innovation; and finally suggest an alternative approach that may drive the innovation needed to take the world to the next level of space exploration, with NASA truly leading the way.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20100028292&hterms=innovation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dinnovation','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20100028292&hterms=innovation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dinnovation"><span><span class="hlt">Aligning</span> for Innovation - <span class="hlt">Alignment</span> Strategy to Drive Innovation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Johnson, Hurel; Teltschik, David; Bussey, Horace, Jr.; Moy, James</p> <p>2010-01-01</p> <p>With the sudden need for innovation that will help the country achieve its long-term space exploration objectives, the question of whether NASA is <span class="hlt">aligned</span> effectively to drive the innovation that it so desperately needs to take space exploration to the next level should be entertained. Authors such as Robert Kaplan and David North have noted that companies that use a formal system for implementing strategy consistently outperform their peers. They have outlined a six-stage management systems model for implementing strategy, which includes the <span class="hlt">aligning</span> of the organization towards its objectives. This involves the <span class="hlt">alignment</span> of the organization from the top down. This presentation will explore the impacts of existing U.S. industrial policy on technological innovation; assess the <span class="hlt">current</span> NASA organizational <span class="hlt">alignment</span> and its impacts on driving technological innovation; and finally suggest an alternative approach that may drive the innovation needed to take the world to the next level of space exploration, with NASA truly leading the way.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9151E..12L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9151E..12L"><span>MUSE <span class="hlt">alignment</span> onto VLT</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Laurent, Florence; Renault, Edgard; Boudon, Didier; Caillier, Patrick; Daguisé, Eric; Dupuy, Christophe; Jarno, Aurélien; Lizon, Jean-Louis; Migniau, Jean-Emmanuel; Nicklas, Harald; Piqueras, Laure</p> <p>2014-07-01</p> <p>MUSE (Multi Unit Spectroscopic Explorer) is a second generation Very Large Telescope (VLT) integral field spectrograph developed for the European Southern Observatory (ESO). It combines a 1' x 1' field of view sampled at 0.2 arcsec for its Wide Field Mode (WFM) and a 7.5"x7.5" field of view for its Narrow Field Mode (NFM). Both modes will operate with the improved spatial resolution provided by GALACSI (Ground Atmospheric Layer Adaptive Optics for Spectroscopic Imaging), that will use the VLT deformable secondary mirror and 4 Laser Guide Stars (LGS) foreseen in 2015. MUSE operates in the visible wavelength range (0.465-0.93 μm). A consortium of seven institutes is <span class="hlt">currently</span> commissioning MUSE in the Very Large Telescope for the Preliminary Acceptance in Chile, scheduled for September, 2014. MUSE is composed of several subsystems which are under the responsibility of each institute. The Fore Optics derotates and anamorphoses the image at the focal plane. A Splitting and Relay Optics feed the 24 identical Integral Field Units (IFU), that are mounted within a large monolithic structure. Each IFU incorporates an image slicer, a fully refractive spectrograph with VPH-grating and a detector system connected to a global vacuum and cryogenic system. During 2012 and 2013, all MUSE subsystems were integrated, <span class="hlt">aligned</span> and tested to the P.I. institute at Lyon. After successful PAE in September 2013, MUSE instrument was shipped to the Very Large Telescope in Chile where that was <span class="hlt">aligned</span> and tested in ESO integration hall at Paranal. After, MUSE was directly transported, fully <span class="hlt">aligned</span> and without any optomechanical dismounting, onto VLT telescope where the first light was overcame the 7th of February, 2014. This paper describes the <span class="hlt">alignment</span> procedure of the whole MUSE instrument with respect to the Very Large Telescope (VLT). It describes how 6 tons could be move with accuracy better than 0.025mm and less than 0.25 arcmin in order to reach <span class="hlt">alignment</span> requirements. The success</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18801373','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18801373"><span>Ferroplasma acidarmanus RPA2 facilitates efficient unwinding of forked DNA substrates by monomers of <span class="hlt">Fac</span>XPD helicase.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pugh, Robert A; Lin, Yuyen; Eller, Chelcie; Leesley, Haley; Cann, Isaac K O; Spies, Maria</p> <p>2008-11-28</p> <p>The strand-separation activity that is important for many cellular DNA processing machineries is provided by DNA helicases. In order to understand the physiological properties of a helicase acting in the context of its macromolecular machinery, it is imperative to identify the proteins that interact with the enzyme and to analyze how these proteins affect its helicase activities. The archaeal Rad3 helicase XPD (xeroderma pigmentosum group D protein) from Ferroplasma acidarmanus (<span class="hlt">Fac</span>XPD) is a superfamily II 5'-->3' DNA helicase. Similar to its mammalian homolog working as an integral part of the transcription factor IIH complex, <span class="hlt">Fac</span>XPD may play an important role in nucleotide excision repair (NER) and transcription initiation. Interaction between <span class="hlt">Fac</span>XPD and other archaeal NER proteins likely modulates their respective activities. Replication protein A (RPA), a single-stranded DNA (ssDNA)-binding protein, is one of the NER proteins that functionally interact with the human transcription factor IIH complex. There are two RPA proteins in F. acidarmanus: <span class="hlt">Fac</span>RPA1, a homodimer of two monomers consisting of two oligonucleotide/oligosaccharide binding folds, and <span class="hlt">Fac</span>RPA2, a monomer containing a single oligonucleotide/oligosaccharide binding fold. In this study, we analyzed the effect of these ssDNA-binding proteins on <span class="hlt">Fac</span>XPD helicase activity. We found that <span class="hlt">Fac</span>RPA2 stimulates DNA unwinding by <span class="hlt">Fac</span>XPD helicase through a novel mechanism by providing a helix-destabilizing function. In contrast, <span class="hlt">Fac</span>RPA1 fails to stimulate helicase activity to the same extent as <span class="hlt">Fac</span>RPA2 and competes with <span class="hlt">Fac</span>XPD for binding to the ssDNA-double-stranded DNA junction. We conclude that the <span class="hlt">Fac</span>RPA2-coated fork is a preferred and likely physiological substrate that a monomer of <span class="hlt">Fac</span>XPD can unwind with a processivity sufficient for expansion of the NER or transcription bubble. We also suggest that duplex melting by a cognate ssDNA-binding protein coordinated with translocation by a helicase may represent</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2142613','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2142613"><span>Multiple protein structure <span class="hlt">alignment</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>Taylor, W. R.; Flores, T. P.; Orengo, C. A.</p> <p>1994-01-01</p> <p>A method was developed to compare protein structures and to combine them into a multiple structure consensus. Previous methods of multiple structure comparison have only concatenated pairwise <span class="hlt">alignments</span> or produced a consensus structure by averaging coordinate sets. The <span class="hlt">current</span> method is a fusion of the fast structure comparison program SSAP and the multiple sequence <span class="hlt">alignment</span> program MULTAL. As in MULTAL, structures are progressively combined, producing intermediate consensus structures that are compared directly to each other and all remaining single structures. This leads to a hierarchic "condensation," continually evaluated in the light of the emerging conserved core regions. Following the SSAP approach, all interatomic vectors were retained with well-conserved regions distinguished by coherent vector bundles (the structural equivalent of a conserved sequence position). Each bundle of vectors is summarized by a resultant, whereas vector coherence is captured in an error term, which is the only distinction between conserved and variable positions. Resultant vectors are used directly in the comparison, which is weighted by their error values, giving greater importance to the matching of conserved positions. The resultant vectors and their errors can also be used directly in molecular modeling. Applications of the method were assessed by the quality of the resulting sequence <span class="hlt">alignments</span>, phylogenetic tree construction, and databank scanning with the consensus. Visual assessment of the structural superpositions and consensus structure for various well-characterized families confirmed that the consensus had identified a reasonable core. PMID:7849601</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4670706','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4670706"><span>Array tomography: characterizing <span class="hlt">FAC</span>-sorted populations of zebrafish immune cells by their 3D ultrastructure</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wacker, Irene; Chockley, Peter; Bartels, Carolin; Spomer, Waldemar; Hofmann, Andreas; Gengenbach, Ulrich; Singh, Sachin; Thaler, Marlene; Grabher, Clemens; SCHRÖDER, RASMUS R</p> <p>2015-01-01</p> <p>For 3D reconstructions of whole immune cells from zebrafish, isolated from adult animals by <span class="hlt">FAC</span>-sorting we employed array tomography on hundreds of serial sections deposited on silicon wafers. Image stacks were either recorded manually or automatically with the newly released ZEISS Atlas 5 Array Tomography platform on a Zeiss FEGSEM. To characterize different populations of immune cells, organelle inventories were created by segmenting individual cells. In addition, arrays were used for quantification of cell populations with respect to the various cell types they contained. The detection of immunological synapses in cocultures of cell populations from thymus or WKM with cancer cells helped to identify the cytotoxic nature of these cells. Our results demonstrate the practicality and benefit of AT for high-throughput ultrastructural imaging of substantial volumes. Lay Description To look at immune cells from zebrafish we employed array tomography, a technique where arrays of serial sections deposited on solid substrates are used for imaging. Cell populations were isolated from the different organs of zebrafish involved in haematopoiesis, the production of blood cells. They were chemically fixed and centrifuged to concentrate them in a pellet that was then dehydrated and embedded in resin. Using a custom-built handling device it was possible to place hundreds of serial sections on silicon wafers as well ordered arrays. To image a whole cell at a resolution that would allow identifying all the organelles (i.e. compartments surrounded by membranes) inside the cell, stacks of usually 50–100 images were recorded in a scanning electron microscope (SEM). This recording was either done manually or automatically using the newly released Atlas Array Tomography platform on a ZEISS SEM. For the imaging of the sections a pixel size of about 5 nm was chosen, which defines membrane boundaries very well and allows segmentation of the membrane topology. After <span class="hlt">alignment</span> of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27668269','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27668269"><span><span class="hlt">FACS</span>-based Satellite Cell Isolation From Mouse Hind Limb Muscles.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gromova, Anastasia; Tierney, Matthew T; Sacco, Alessandra</p> <p>2015-08-20</p> <p>Fluorescence Activated Cell Sorting (<span class="hlt">FACS</span>) is a sensitive and accurate method for purifying satellite cells, or muscle stem cells, from adult mouse skeletal muscle (Liu et al., 2013; Sacco et al., 2008; Tierney et al., 2014). Mechanical and enzymatic digestion of hind limb muscles releases mononuclear muscle cells into suspension. This protocol employs fractionation strategies to deplete cells expressing the cell surface markers CD45, CD31, CD11b and Ly-6A/E-Sca1, both by magnetic separation and <span class="hlt">FACS</span>-based exclusion, and positively select for cells expressing a7-integrin and CD34. This enables the researcher to successfully enrich satellite cells that uniformly express the paired-box transcription factor Pax7 and are capable of long-term self-renewal, skeletal muscle repair and muscle stem cell pool repopulation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28247352','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28247352"><span>Engraftment of <span class="hlt">FACS</span> Isolated Muscle Stem Cells into Injured Skeletal Muscle.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tierney, Matthew; Sacco, Alessandra</p> <p>2017-01-01</p> <p>Skeletal muscle stem cell (MuSC) isolation and transplantation are invaluable tools to assess their capacity for self-renewal and tissue repair. Significant technical advances in recent years have led to the optimization of these approaches, improving our ability to assess MuSC regenerative potential. Here, we describe the procedures for Fluorescent Activated Cell Sorting (<span class="hlt">FACS</span>)-based isolation of MuSC, their intramuscular transplantation, and analysis of their engraftment into host tissues.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/AD1015798','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/AD1015798"><span>Re-Casting the <span class="hlt">FAC</span> Net: People, Platforms, and Policy in Forward Air Control</span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2015-06-01</p> <p>farther away from targets, which frustrates attempts to identify and track those targets and restrict attack options for supporting fighters. SAM threats...coordinate with the ground forces, artillery fires, special operation forces (SOF), and supporting aircraft. <span class="hlt">FACs</span> identify and track other friendly...forces in the area to prevent fratricide. Tracking forces is a challenge because large units may not actively track the movement of every soldier or</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19950033354&hterms=Magnetohydrodynamic+drive&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DMagnetohydrodynamic%2Bdrive','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19950033354&hterms=Magnetohydrodynamic+drive&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DMagnetohydrodynamic%2Bdrive"><span>Particle/fluid simulations of an eruptive flare: Identifying the field-<span class="hlt">aligned</span> <span class="hlt">currents</span> responsible for the hard x-rays</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Winglee, R. M.</p> <p>1994-01-01</p> <p>While magnetohydrodynamics (MHD) can provide a reasonable description of the overall magnetic reconnection that is believed to drive flares, additional, and often separate processes have to be envoked to in order to explain the electron acceleration that is responsible for many of the observed flare emissions. A new model that incorporates the dynamic coronal <span class="hlt">current</span> sheets, the reconnection site, and possible electron acceleration processes is developed through the use of two-dimensional particle and modified two-fluid simulations. The specific example of an eruptive flare driven by the coalescence of flux tubes supported by prescribed photospheric <span class="hlt">current</span> elements is evaluated. It is shown that the electrons and ions have differential trajectories through the coronal <span class="hlt">current</span> sheet which leads to the development of additonal plasma <span class="hlt">currents</span> that flow around the surface of the <span class="hlt">current</span> sheet. These surface <span class="hlt">currents</span> are explicitly neglected in MHD but they are vital to the flare dynamics because they divert <span class="hlt">current</span> from the coronal <span class="hlt">current</span> sheet into the chromosphere, producing an effective resistivity that aids the development of fast reconnection. Because the surface <span class="hlt">currents</span> are in the plane of the magnetic field, electrons in them experience strong acceleration and can account for the observed hard X-ray emissions. Model predictions are compared with observed time profiles of hard X-ray emissions and Doppler shifts seen in soft X-ray line emissions and are able to account for such features as (1) the asymmetry in the rise and decay time of the hard X-rays, (2) the apparent delay between the largest Doppler shifts and the hard X-ray peak, and (3) the relatively low intensity of the blue-shifted component. The use of particle and fluid simulations is important because it provides different, but complementary treatments of the electron acceleration, the global magnetic morphology, and the flare <span class="hlt">current</span> system.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27043044','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27043044"><span>Evaluation of EBV transformation of human memory B-cells isolated by <span class="hlt">FACS</span> and MACS techniques.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sadreddini, Sanam; Jadidi-Niaragh, Farhad; Younesi, Vahid; Pourlak, Tala; Afkham, Amir; Shokri, Fazel; Yousefi, Mehdi</p> <p>2016-07-01</p> <p>Several studies have been performed to develop effective neutralizing monoclonal antibodies. The Epstein-Barr virus (EBV) can efficiently immortalize B-cells to establish lymphoblastoid cell lines (LCL) and so it has been used extensively for transformation of B-cells to produce and secrete immunoglobulin. The present study addressed the effect of TLR7/8 agonist (R848), feeder cells layer and fluorescence-activated cell sorting (<span class="hlt">FACS</span>) and magnetic-activated cell sorting (MACS) cell separation methods on the transformation efficiency of antibody-producing memory B-cells. For these studies, the antigen used for analyses of antibody formation was the tetanus neurotoxin (TeNT) derived from Clostridium tetani. The results here showed that employing an HFFF.PI6 feeder cell layer, R848 agonist and <span class="hlt">FACS</span>-mediated purification of memory B-cells led to increased transformation efficiency. Altogether, the effects of the R848 and the feeder cells provided an efficient method for EBV transformation of human B-cells. Moreover, there was an advantage in using <span class="hlt">FACS</span> sorting of B-cells over the MACS method in the context of EBV transformation and immortalization of precursors of antigen-specific B-cells.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23075219','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23075219"><span><span class="hlt">FACS</span>-based purification of Arabidopsis microspores, sperm cells and vegetative nuclei.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Borges, Filipe; Gardner, Rui; Lopes, Telma; Calarco, Joseph P; Boavida, Leonor C; Slotkin, R Keith; Martienssen, Robert A; Becker, Jörg D</p> <p>2012-10-17</p> <p>The male germline in flowering plants differentiates by asymmetric division of haploid uninucleated microspores, giving rise to a vegetative cell enclosing a smaller generative cell, which eventually undergoes a second mitosis to originate two sperm cells. The vegetative cell and the sperm cells activate distinct genetic and epigenetic mechanisms to control pollen tube growth and germ cell specification, respectively. Therefore, a comprehensive characterization of these processes relies on efficient methods to isolate each of the different cell types throughout male gametogenesis. We developed stable transgenic Arabidopsis lines and reliable purification tools based on Fluorescence-Activated Cell Sorting (<span class="hlt">FACS</span>) in order to isolate highly pure and viable fractions of each cell/nuclei type before and after pollen mitosis. In the case of mature pollen, this was accomplished by expressing GFP and RFP in the sperm and vegetative nuclei, respectively, resulting in 99% pure sorted populations. Microspores were also purified by <span class="hlt">FACS</span> taking advantage of their characteristic small size and autofluorescent properties, and were confirmed to be 98% pure. We provide simple and efficient <span class="hlt">FACS</span>-based purification protocols for Arabidopsis microspores, vegetative nuclei and sperm cells. This paves the way for subsequent molecular analysis such as transcriptomics, DNA methylation analysis and chromatin immunoprecipitation, in the developmental context of microgametogenesis in Arabidopsis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22144360','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22144360"><span>Use <span class="hlt">FACS</span> sorting in metabolic engineering of Escherichia coli for increased peptide production.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cheng, Qiong; Ruebling-Jass, Kristin; Zhang, Jianzhong; Chen, Qi; Croker, Kevin M</p> <p>2012-01-01</p> <p>Many proteins and peptides have been used in therapeutic or industrial applications. They are often produced as recombinant forms by microbial fermentation. Targeted metabolic engineering of the production strains has usually been the approach taken to increase protein production, and this approach requires sufficient knowledge about cell metabolism and regulation. Random screening is an alternative approach that could circumvent the knowledge requirement, but is hampered by lack of suitable high-throughput screening methods. We developed a novel fluorescence-activated cell sorting (<span class="hlt">FACS</span>) method to screen for cells with increased peptide production. Using a model peptide rich in certain amino acids, we showed that increased fluorescence clones sorted from a plasmid expression library contained genes encoding rate-limiting enzymes for amino acid synthesis. These expression clones showed increased peptide production. This demonstrated that <span class="hlt">FACS</span> could be used as a very powerful tool for metabolic engineering. It can be generally applied to other products or processes if the desired phenotype could be correlated with a fluorescence or light scattering parameter on the <span class="hlt">FACS</span>.</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('https://www.ncbi.nlm.nih.gov/pubmed/27273193','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27273193"><span>Understanding M-ligand bonding and mer-/<span class="hlt">fac</span>-isomerism in tris(8-hydroxyquinolinate) metallic complexes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lima, Carlos F R A C; Taveira, Ricardo J S; Costa, José C S; Fernandes, Ana M; Melo, André; Silva, Artur M S; Santos, Luís M N B F</p> <p>2016-06-28</p> <p>Tris(8-hydroxyquinolinate) metallic complexes, Mq3, are one of the most important classes of organic semiconductor materials. Herein, the nature of the chemical bond in Mq3 complexes and its implications on their molecular properties were investigated by a combined experimental and computational approach. Various Mq3 complexes, resulting from the alteration of the metal and substitution of the 8-hydroxyquinoline ligand in different positions, were prepared. The mer-/<span class="hlt">fac</span>-isomerism in Mq3 was explored by FTIR and NMR spectroscopy, evidencing that, irrespective of the substituent, mer- and <span class="hlt">fac</span>-are the most stable molecular configurations of Al(iii) and In(iii) complexes, respectively. The relative M-ligand bond dissociation energies were evaluated experimentally by electrospray ionization tandem mass spectrometry (ESI-MS-MS), showing a non-monotonous variation along the group (Al > In > Ga). The results reveal a strong covalent character in M-ligand bonding, which allows for through-ligand electron delocalization, and explain the preferred molecular structures of Mq3 complexes as resulting from the interplay between bonding and steric factors. The mer-isomer reduces intraligand repulsions, being preferred for smaller metals, while the <span class="hlt">fac</span>-isomer is favoured for larger metals where stronger covalent M-ligand bonds can be formed due to more extensive through-ligand conjugation mediated by metal "d" orbitals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23126766','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23126766"><span>Oblique electron-cyclotron-emission radial and phase detector of rotating magnetic islands applied to <span class="hlt">alignment</span> and modulation of electron-cyclotron-<span class="hlt">current</span>-drive for neoclassical tearing mode stabilization.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Volpe, F; Austin, M E; Campbell, G; Deterly, T</p> <p>2012-10-01</p> <p>A two channel oblique electron cyclotron emission (ECE) radiometer was installed on the DIII-D tokamak and interfaced to four gyrotrons. Oblique ECE was used to toroidally and radially localize rotating magnetic islands and so assist their electron cyclotron <span class="hlt">current</span> drive (ECCD) stabilization. In particular, after manipulations operated by the interfacing analogue circuit, the oblique ECE signals directly modulated the <span class="hlt">current</span> drive in synch with the island rotation and in phase with the island O-point, for a more efficient stabilization. Apart from the different toroidal location, the diagnostic view is identical to the ECCD launch direction, which greatly simplified the real-time use of the signals. In fact, a simple toroidal extrapolation was sufficient to lock the modulation to the O-point phase. This was accomplished by a specially designed phase shifter of nearly flat response over the 1-7 kHz range. Moreover, correlation analysis of two channels slightly above and below the ECCD frequency allowed checking the radial <span class="hlt">alignment</span> to the island, based on the fact that for satisfactory <span class="hlt">alignment</span> the two signals are out of phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22093786','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22093786"><span>Oblique electron-cyclotron-emission radial and phase detector of rotating magnetic islands applied to <span class="hlt">alignment</span> and modulation of electron-cyclotron-<span class="hlt">current</span>-drive for neoclassical tearing mode stabilization</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Volpe, F.; Austin, M. E.; Campbell, G.; Deterly, T.</p> <p>2012-10-15</p> <p>A two channel oblique electron cyclotron emission (ECE) radiometer was installed on the DIII-D tokamak and interfaced to four gyrotrons. Oblique ECE was used to toroidally and radially localize rotating magnetic islands and so assist their electron cyclotron <span class="hlt">current</span> drive (ECCD) stabilization. In particular, after manipulations operated by the interfacing analogue circuit, the oblique ECE signals directly modulated the <span class="hlt">current</span> drive in synch with the island rotation and in phase with the island O-point, for a more efficient stabilization. Apart from the different toroidal location, the diagnostic view is identical to the ECCD launch direction, which greatly simplified the real-time use of the signals. In fact, a simple toroidal extrapolation was sufficient to lock the modulation to the O-point phase. This was accomplished by a specially designed phase shifter of nearly flat response over the 1-7 kHz range. Moreover, correlation analysis of two channels slightly above and below the ECCD frequency allowed checking the radial <span class="hlt">alignment</span> to the island, based on the fact that for satisfactory <span class="hlt">alignment</span> the two signals are out of phase.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA597578','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA597578"><span>Automatic Word <span class="hlt">Alignment</span></span></a></p> <p><a target="_blank" href="http://www.dtic.mil/">DTIC Science & Technology</a></p> <p></p> <p>2014-02-18</p> <p>for each of the paired units includes forming a first <span class="hlt">alignment</span> of units of the first language to units of the second language, and forming a second...<span class="hlt">alignment</span> of units of the second language to units of the first language . The <span class="hlt">alignment</span> parameters include a first set of parameters for forming an...<span class="hlt">alignment</span> from the first language to the second language and a second set of parameters for forming an <span class="hlt">align</span>­ ment from the second language to the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JInst..12.1008M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JInst..12.1008M"><span>Free-air ionization chamber, <span class="hlt">FAC</span>-IR-300, designed for medium energy X-ray dosimetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mohammadi, S. M.; Tavakoli-Anbaran, H.; Zeinali, H. Z.</p> <p>2017-01-01</p> <p>The primary standard for X-ray photons is based on parallel-plate free-air ionization chamber (<span class="hlt">FAC</span>). Therefore, the Atomic Energy Organization of Iran (AEOI) is tried to design and build the free-air ionization chamber, <span class="hlt">FAC</span>-IR-300, for low and medium energy X-ray dosimetry. The main aim of the present work is to investigate specification of the <span class="hlt">FAC</span>-IR-300 ionization chamber and design it. <span class="hlt">FAC</span>-IR-300 dosimeter is composed of two parallel plates, a high voltage (HV) plate and a collector plate, along with a guard electrode that surrounds the collector plate. The guard plate and the collector were separated by an air gap. For obtaining uniformity in the electric field distribution, a group of guard strips was used around the ionization chamber. These characterizations involve determining the exact dimensions of the ionization chamber by using Monte Carlo simulation and introducing correction factors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JMEP...25.3194S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JMEP...25.3194S"><span>Effect of HNT on the Microstructure, Thermal and Mechanical Properties of Al/<span class="hlt">FACS</span>-HNT Composites Produced by GPI</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Siewiorek, A.; Malczyk, P.; Sobczak, N.; Sobczak, J. J.; Czulak, A.; Kozera, R.; Gude, M.; Boczkowska, A.; Homa, M.</p> <p>2016-08-01</p> <p>To develop an optimised manufacturing method of fly ash-reinforced metal matrix composites, the preliminary tests were performed on the cenospheres selected from fly ash (<span class="hlt">FACS</span>) with halloysite nanotubes (HNTs) addition. The preform made out of <span class="hlt">FACS</span> with and without the addition of HNT (with 5 and 10 wt.%) has been infiltrated by the pure aluminium (Al) via adapted gas pressure infiltration process. This paper reveals the influence of HNT addition on the microstructure (analysis was done by computed tomography and scanning electron microscopy combined with energy-dispersive x-ray spectroscopy), thermal properties (thermal expansion coefficient, thermal conductivity and specific heat) and the mechanical properties (hardness and compression test) of manufactured composites. The analysis of structure-property relationships for Al/<span class="hlt">FACS</span>-HNT composites produced shows that the addition of 5 wt.% of HNT to <span class="hlt">FACS</span> preform contributes to receiving of the best mechanical and structural properties of investigated composites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4082353','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4082353"><span>Simultaneous <span class="hlt">Alignment</span> and Folding of Protein Sequences</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Waldispühl, Jérôme; O'Donnell, Charles W.; Will, Sebastian; Devadas, Srinivas; Backofen, Rolf</p> <p>2014-01-01</p> <p>Abstract Accurate comparative analysis tools for low-homology proteins remains a difficult challenge in computational biology, especially sequence <span class="hlt">alignment</span> and consensus folding problems. We present partiFold-<span class="hlt">Align</span>, the first algorithm for simultaneous <span class="hlt">alignment</span> and consensus folding of unaligned protein sequences; the algorithm's complexity is polynomial in time and space. Algorithmically, partiFold-<span class="hlt">Align</span> exploits sparsity in the set of super-secondary structure pairings and <span class="hlt">alignment</span> candidates to achieve an effectively cubic running time for simultaneous pairwise <span class="hlt">alignment</span> and folding. We demonstrate the efficacy of these techniques on transmembrane β-barrel proteins, an important yet difficult class of proteins with few known three-dimensional structures. Testing against structurally derived sequence <span class="hlt">alignments</span>, partiFold-<span class="hlt">Align</span> significantly outperforms state-of-the-art pairwise and multiple sequence <span class="hlt">alignment</span> tools in the most difficult low-sequence homology case. It also improves secondary structure prediction where <span class="hlt">current</span> approaches fail. Importantly, partiFold-<span class="hlt">Align</span> requires no prior training. These general techniques are widely applicable to many more protein families (partiFold-<span class="hlt">Align</span> is available at http://partifold.csail.mit.edu/). PMID:24766258</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/16012107','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/16012107"><span>Joint Bayesian estimation of <span class="hlt">alignment</span> and phylogeny.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Redelings, Benjamin D; Suchard, Marc A</p> <p>2005-06-01</p> <p>We describe a novel model and algorithm for simultaneously estimating multiple molecular sequence <span class="hlt">alignments</span> and the phylogenetic trees that relate the sequences. Unlike <span class="hlt">current</span> techniques that base phylogeny estimates on a single estimate of the <span class="hlt">alignment</span>, we take <span class="hlt">alignment</span> uncertainty into account by considering all possible <span class="hlt">alignments</span>. Furthermore, because the <span class="hlt">alignment</span> and phylogeny are constructed simultaneously, a guide tree is not needed. This sidesteps the problem in which <span class="hlt">alignments</span> created by progressive <span class="hlt">alignment</span> are biased toward the guide tree used to generate them. Joint estimation also allows us to model rate variation between sites when estimating the <span class="hlt">alignment</span> and to use the evidence in shared insertion/deletions (indels) to group sister taxa in the phylogeny. Our indel model makes use of affine gap penalties and considers indels of multiple letters. We make the simplifying assumption that the indel process is identical on all branches. As a result, the probability of a gap is independent of branch length. We use a Markov chain Monte Carlo (MCMC) method to sample from the posterior of the joint model, estimating the most probable <span class="hlt">alignment</span> and tree and their support simultaneously. We describe a new MCMC transition kernel that improves our algorithm's mixing efficiency, allowing the MCMC chains to converge even when started from arbitrary <span class="hlt">alignments</span>. Our software implementation can estimate <span class="hlt">alignment</span> uncertainty and we describe a method for summarizing this uncertainty in a single plot.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28328697','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28328697"><span>The Fear-avoidance Components Scale (<span class="hlt">FACS</span>): Responsiveness to Functional Restoration Treatment in a Chronic Musculoskeletal Pain Disorder (CMPD) Population.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Neblett, Randy; Mayer, Tom G; Williams, Mark J; Asih, Sali; Cuesta-Vargas, Antonio I; Hartzell, Meredith M; Gatchel, Robert J</p> <p>2017-03-21</p> <p>To assess the clinical validity and factor structure of the Fear-Avoidance Components Scale (<span class="hlt">FACS</span>), a new fear-avoidance (FA) measure. In this study, 426 chronic musculoskeletal pain disorder (CMPD) patients were admitted to a functional restoration program (FRP). They were categorized into five <span class="hlt">FACS</span> severity levels, from Subclinical to Extreme, at admission, and again at discharge. Associations with objective lifting performance and other patient-reported psychosocial measures were determined at admission and discharge, and objective work outcomes for this predominantly disabled cohort, were assessed one-year later. Those patients in the Severe and Extreme <span class="hlt">FACS</span> severity groups at admission were more likely to "drop out" of treatment than those in the lower severity groups (P=0.05). At both admission and discharge, the <span class="hlt">FACS</span> severity groups were highly and inversely correlated with objective lifting performance and patient-reported FA-related psychosocial variables, including kinesiophobia, pain intensity, depressive symptoms, perceived disability, perceived injustice, and insomnia (Ps<0.001). All variables showed improvement at FRP discharge. Patients in the Extreme <span class="hlt">FACS</span> severity group at discharge were less likely to return to, or retain, work one-year later (P≤0.02). The factor analysis identified a two-factor solution. Strong associations were found among <span class="hlt">FACS</span> scores and other patient-reported psychosocial and objective lifting performance variables at both admission and discharge. High discharge <span class="hlt">FACS</span> scores were associated with worse work outcomes one-year after discharge. The <span class="hlt">FACS</span> appears to be a valid and clinically useful measure for predicting attendance, physical performance, distress and relevant work outcomes in FRP treatment of CMPD patients.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Sport+AND+dance&pg=4&id=EJ1076239','ERIC'); return false;" href="http://eric.ed.gov/?q=Sport+AND+dance&pg=4&id=EJ1076239"><span><span class="hlt">Aligning</span> Assessments for COSMA Accreditation</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>Laird, Curt; Johnson, Dennis A.; Alderman, Heather</p> <p>2015-01-01</p> <p>Many higher education sport management programs are <span class="hlt">currently</span> in the process of seeking accreditation from the Commission on Sport Management Accreditation (COSMA). This article provides a best-practice method for <span class="hlt">aligning</span> student learning outcomes with a sport management program's mission and goals. Formative and summative assessment procedures…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=strategic+AND+management+AND+articles&id=EJ1076239','ERIC'); return false;" href="https://eric.ed.gov/?q=strategic+AND+management+AND+articles&id=EJ1076239"><span><span class="hlt">Aligning</span> Assessments for COSMA Accreditation</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>Laird, Curt; Johnson, Dennis A.; Alderman, Heather</p> <p>2015-01-01</p> <p>Many higher education sport management programs are <span class="hlt">currently</span> in the process of seeking accreditation from the Commission on Sport Management Accreditation (COSMA). This article provides a best-practice method for <span class="hlt">aligning</span> student learning outcomes with a sport management program's mission and goals. Formative and summative assessment procedures…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28780067','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28780067"><span>Novel large-particle <span class="hlt">FACS</span> purification of adult ventricular myocytes reveals accumulation of myosin and actin disproportionate to cell size and proteome in normal post-weaning development.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>López, Javier E; Sharma, Janhavi; Avila, Jorge; Wood, Taylor S; VanDyke, Jonathan E; McLaughlin, Bridget; Abbey, Craig K; Wong, Andrew; Myagmar, Bat-Erdene; Swigart, Philip M; Simpson, Paul C; Chiamvimonvat, Nipavan</p> <p>2017-10-01</p> <p>Quantifying cellular proteins in ventricular myocytes (MCs) is challenging due to tissue heterogeneity and the variety of cell sizes in the heart. In post-weaning cardiac ontogeny, rod-shaped MCs make up the majority of the cardiac mass while remaining a minority of cardiac cells in number. <span class="hlt">Current</span> biochemical analyses of cardiac proteins do not correlate well the content of MC-specific proteins to cell type or size in normally developing tissue. To develop a new large-particle fluorescent-activated cell sorting (LP-<span class="hlt">FACS</span>) strategy for the purification of adult rod-shaped MCs. This approach is developed to enable growth-scaled measurements per-cell of the MC proteome and sarcomeric proteins (i.e. myosin heavy chain (MyHC) and alpha-actin (α-actin)) content. Individual cardiac cells were isolated from 21 to 94days old mice. An LP-<span class="hlt">FACS</span> jet-in-air system with a 200-μm nozzle was defined for the first time to purify adult MCs. Cell-type specific immunophenotyping and sorting yielded ≥95% purity of adult MCs independently of cell morphology and size. This approach excluded other cell types and tissue contaminants from further analysis. MC proteome, MyHC and α-actin proteins were measured in linear biochemical assays normalized to cell numbers. Using the allometric coefficient α, we scaled the MC-specific rate of protein accumulation to growth post-weaning. MC-specific volumes (α=1.02) and global protein accumulation (α=0.94) were proportional (i.e. isometric) to body mass. In contrast, MyHC and α-actin accumulated at a much greater rate (i.e. hyperallometric) than body mass (α=1.79 and 2.19 respectively) and MC volumes (α=1.76 and 1.45 respectively). Changes in MC proteome and cell volumes measured in LP-<span class="hlt">FACS</span> purified MCs are proportional to body mass post-weaning. Oppositely, MyHC and α-actin are concentrated more rapidly than what would be expected from MC proteome accumulation, cell enlargement, or animal growth alone. LP-<span class="hlt">FACS</span> provides a new standard for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMSM51A1343Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMSM51A1343Y"><span>The α- and β-<span class="hlt">current</span> separation of MI-coupled system using Whalen-relation and Hall conjugate <span class="hlt">current</span> analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yoshikawa, A.</p> <p>2009-12-01</p> <p>We propose an inclusive techunique for analyzing MI-coupled <span class="hlt">current</span> system using Whalen-relation for non-linear and quasi-steady Alfvenic disturbance and Hall conjugate <span class="hlt">current</span> (HCC) analysis. By applying Whalen-relation to the Alfvenic disturbance near the ionosphere, arbitrary incompressible MHD fields of (b,v) can be separated into the incident part to the ionosphere and reflected part from the ionosphere. Separated incident field from (b,v) gives electromotive force (emf) for generation of ionospheric <span class="hlt">current</span> system. This “emf” is propagating from the magnetosphere with the incident field-<span class="hlt">aligned</span> <span class="hlt">current</span> accompanied by the incident Alfvenic disturbances. Reflected fields are generated to cancel out the divergent part of ionospheric <span class="hlt">current</span> produced by this “emf” from the magnetosphere. Thus, this formulation is very useful for describing and analyzing of MI-coupling process from viewpoint of “cause and effect”. This formulation clarify that induced charge in the ionosphere and their associated reflected electric field is composed by the direct reflection part for incident field and polarization part generated to cancel out the divergence part of ionospheric <span class="hlt">current</span> caused by coupling of incident field to the gradient of ionospheric conductivities. Cleary, both divergent part of primary Pedersen and primary Hall <span class="hlt">current</span> possibly become source of polarization field and their associated secondary ionospheric <span class="hlt">current</span> system including reflected <span class="hlt">FAC</span>. Therefore, we can expect to separate the MI-coupled <span class="hlt">current</span> system into two orthogonal <span class="hlt">current</span> system, the first is originating divergence of primary Pedersen <span class="hlt">current</span> and the second is originating divergence of primary Hall <span class="hlt">current</span>. We call the former <span class="hlt">current</span> system as α-<span class="hlt">current</span> channel and the latter <span class="hlt">current</span> system as β-<span class="hlt">current</span> channel. The α-<span class="hlt">current</span> channel is directly coupled to the magnetospheric source region, which supplies “emf” of ionospheric <span class="hlt">current</span> system. A feed back Hall effect from the β-<span class="hlt">current</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910000118&hterms=Engine+alignment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DEngine%2Balignment','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910000118&hterms=Engine+alignment&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DEngine%2Balignment"><span><span class="hlt">Alignment</span> Tool For Inertia Welding</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Snyder, Gary L.</p> <p>1991-01-01</p> <p>Compact, easy-to-use tool <span class="hlt">aligns</span> drive bar of inertia welder over hole in stub. Ensures drive bar concentric to hole within 0.002 in. (0.051 mm.). Holds two batteries and light bulb. Electrical circuit completed, providing <span class="hlt">current</span> to bulb when pin in contact with post. When pin centered in post hole, it does not touch post, and lamp turns off. Built for use in making repair welds on liquid-oxygen-injector posts in Space Shuttle main engine. Version having suitably modified dimensions used to facilitate <span class="hlt">alignment</span> in other forests of post.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910000118&hterms=inertia&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dinertia','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910000118&hterms=inertia&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3Dinertia"><span><span class="hlt">Alignment</span> Tool For Inertia Welding</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Snyder, Gary L.</p> <p>1991-01-01</p> <p>Compact, easy-to-use tool <span class="hlt">aligns</span> drive bar of inertia welder over hole in stub. Ensures drive bar concentric to hole within 0.002 in. (0.051 mm.). Holds two batteries and light bulb. Electrical circuit completed, providing <span class="hlt">current</span> to bulb when pin in contact with post. When pin centered in post hole, it does not touch post, and lamp turns off. Built for use in making repair welds on liquid-oxygen-injector posts in Space Shuttle main engine. Version having suitably modified dimensions used to facilitate <span class="hlt">alignment</span> in other forests of post.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=universidades&pg=3&id=EJ733391','ERIC'); return false;" href="http://eric.ed.gov/?q=universidades&pg=3&id=EJ733391"><span><span class="hlt">Alignment</span> of Developments in Higher Education</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>Cowan, John; George, Judith W.; Pinheiro-Torres, Andreia</p> <p>2004-01-01</p> <p>This study builds upon the concept of <span class="hlt">alignment</span> within the curriculum (due to Biggs) and suggests, in the context of two <span class="hlt">current</span> examples, an integrated methodology for effectively <span class="hlt">aligned</span> development activities within universities. Higher Education institutions face important challenges. Firstly, quality enhancement of the curriculum is now an…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22054130','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22054130"><span>Water-stable <span class="hlt">fac</span>-{TcO₃}⁺ complexes - a new field of technetium chemistry.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Braband, Henrik</p> <p>2011-01-01</p> <p>The development of technetium chemistry has been lagging behind that of its heavier congener rhenium, primarily because the inherent radioactivity of all Tc isotopes has limited the number of laboratories that can study the chemistry of this fascinating element. Although technetium is an artificial element, it is not rare. Significant amounts of the isotope (99)Tc are produced every day as a fission byproduct in nuclear power plants. Therefore, a fundamental understanding of the chemistry of (99)Tc is essential to avoid its release into the environment. In this article the chemistry of technetium at its highest oxidation state (+VII) is reviewed with a special focus on recent developments which make water-stable complexes of the general type [TcO(3)(tacn-R)](+) (tacn-R = 1,4,7-triazacyclononane or derivatives) accessible. Complexes containing the <span class="hlt">fac</span>-{TcO(3)}(+) core display a unique reactivity. In analogy to [OsO(4)] and [RuO(4)], complexes containing the <span class="hlt">fac</span>-{TcO(3)}(+) core undergo with alkenes metal-mediated, vicinal cis-dihydroxylation reactions (alkene-glycol interconversion) in water via a (3+2)-cycloaddition reaction. Therefore, water-stable <span class="hlt">fac</span>-{(99m)TcO(3)}(+) complexes pave the way for a new labeling strategy for radiopharmaceutical applications, based on (3+2)-cycloaddition reactions. This new concept for the labeling of biomolecules with small [(99m)TcO(3)(tacn-R)](+)-type complexes by way of a (3+2)-cycloaddition with alkenes is discussed in detail. The herein reported developments in high-valent technetium chemistry create a new field of research with this artificial element. This demonstrates the potential of fundamental research to provide new impetus of innovation for the development of new methods for radiopharmaceutical applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28851289','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28851289"><span>Coral cell separation and isolation by fluorescence-activated cell sorting (<span class="hlt">FACS</span>).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rosental, Benyamin; Kozhekbaeva, Zhanna; Fernhoff, Nathaniel; Tsai, Jonathan M; Traylor-Knowles, Nikki</p> <p>2017-08-29</p> <p>Generalized methods for understanding the cell biology of non-model species are quite rare, yet very much needed. In order to address this issue, we have modified a technique traditionally used in the biomedical field for ecological and evolutionary research. Fluorescent activated cell sorting (<span class="hlt">FACS</span>) is often used for sorting and identifying cell populations. In this study, we developed a method to identify and isolate different cell populations in corals and other cnidarians. Using fluorescence-activated cell sorting (<span class="hlt">FACS</span>), coral cell suspension were sorted into different cellular populations using fluorescent cell markers that are non-species specific. Over 30 different cell markers were tested. Additionally, cell suspension from Aiptasia pallida was also tested, and a phagocytosis test was done as a downstream functional assay. We found that 24 of the screened markers positively labeled coral cells and 16 differentiated cell sub-populations. We identified 12 different cellular sub-populations using three markers, and found that each sub-population is primarily homogeneous. Lastly, we verified this technique in a sea anemone, Aiptasia pallida, and found that with minor modifications, a similar gating strategy can be successfully applied. Additionally, within A. pallida, we show elevated phagocytosis of sorted cells based on an immune associated marker. In this study, we successfully adapted <span class="hlt">FACS</span> for isolating coral cell populations and conclude that this technique is translatable for future use in other species. This technique has the potential to be used for different types of studies on the cellular stress response and other immunological studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4128386','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4128386"><span><span class="hlt">FACS</span> and MACS sorting strategies to isolate and enrich human spermatogonial stem cells</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Valli, Hanna; Sukhwani, Meena; Dovey, Serena L.; Peters, Karen A.; Donohue, Julia; Castro, Carlos A.; Chu, Tianjiao; Marshall, Gary R.; Orwig, Kyle E.</p> <p>2014-01-01</p> <p>Objective Determine the molecular characteristics of human spermatogonia and optimize methods to enrich spermatogonial stem cells (SSCs). Design Laboratory study using human tissues Setting Research institute Patient(s)/Animal(s) Normal adult human testicular tissue. Interventions Human testicular tissue was fixed or digested with enzymes to produce a cell suspension. Human testis cells were fractionated by <span class="hlt">FACS</span> and MACS. Main Outcome Measure(s) Immunostaining for selected markers, human-to-nude mouse xenotransplantation assay. Results Immunohistochemistry co-staining revealed the relative expression patterns of SALL4, UTF1, ZBTB16, UCHL1 and ENO2 in human undifferentiated spermatogonia as well as the extent of overlap with the differentiation marker, KIT. Whole mount analyses revealed that human undifferentiated spermatogonia (UCHL1+) were typically arranged in clones of 1–4 cells while differentiated spermatogonia (KIT+) were typically arranged in clones of 8 or more cells. The ratio of undifferentiated to differentiated spermatogonia is greater in humans than in rodents. SSC colonizing activity was enriched in the THY1dim and ITGA6+ fractions of human testes sorted by <span class="hlt">FACS</span>. ITGA6 was effective for sorting human SSCs by MACS; THY1 and EPCAM were not. Conclusions Human spermatogonial differentiation correlates with increased clone size and onset of KIT expression, similar to rodents. The undifferentiated to differentiated developmental dynamics in human spermatogonia is different than rodents. THY1, ITGA6 and EPCAM can be used to enrich human SSC colonizing activity by <span class="hlt">FACS</span>, but only ITGA6 is amenable to high throughput sorting by MACS. PMID:24890267</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940019219','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940019219"><span>A comparison of locally adaptive multigrid methods: LDC, <span class="hlt">FAC</span> and FIC</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Khadra, Khodor; Angot, Philippe; Caltagirone, Jean-Paul</p> <p>1993-01-01</p> <p>This study is devoted to a comparative analysis of three 'Adaptive ZOOM' (ZOom Overlapping Multi-level) methods based on similar concepts of hierarchical multigrid local refinement: LDC (Local Defect Correction), <span class="hlt">FAC</span> (Fast Adaptive Composite), and FIC (Flux Interface Correction)--which we proposed recently. These methods are tested on two examples of a bidimensional elliptic problem. We compare, for V-cycle procedures, the asymptotic evolution of the global error evaluated by discrete norms, the corresponding local errors, and the convergence rates of these algorithms.</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('https://www.ncbi.nlm.nih.gov/pubmed/25863783','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25863783"><span>Expanding the Utility of FUCCI Reporters Using <span class="hlt">FACS</span>-Based Omics Analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chappell, James; Boward, Ben; Dalton, Stephen</p> <p>2016-01-01</p> <p>The FUCCI indicator system is a powerful tool for spatio-temporal analysis of the cell cycle, but its utility has been restricted so far to a limited range of applications. Here, we describe how to establish and validate the FUCCI system in murine pluripotent stem cells (PSCs) and describe the utility of transgenic FUCCI mice. We then describe how the FUCCI system can be used to generate material for a wide-range of omics-based applications in conjunction with <span class="hlt">FACS</span> isolation of cells. This significantly broadens the potential applications of FUCCI reporters for studying the molecular basis of development and disease.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22914940','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22914940"><span><span class="hlt">FACS</span> analysis of the planarian stem cell compartment as a tool to understand regenerative mechanisms.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Romero, Belen Tejada; Evans, Deborah J; Aboobaker, A Aziz</p> <p>2012-01-01</p> <p>Planarians provide a relatively simple model system in which to study stem cell dynamics and regenerative phenomena. As with other systems understanding the dynamics of stem cell and stem cell progeny is crucial in order to get at the molecular mechanisms orchestrating stem cell biology. Planarians have an abundant adult stem cell population that can be observed using Fluorescence-Activated Cell Sorting (<span class="hlt">FACS</span>). This approach allows different subpopulations of stem cells and their progeny to be monitored and sorted for downstream studies in response to different regenerative scenarios, drug treatments, or RNAi knockdown of genes required for regenerative events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25091197','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25091197"><span>Multifunctionalization of cetuximab with bioorthogonal chemistries and parallel EGFR profiling of cell-lines using imaging, <span class="hlt">FACS</span> and immunoprecipitation approaches.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Reschke, Melanie L; Uprety, Rajendra; Bodhinayake, Imithri; Banu, Matei; Boockvar, John A; Sauve, Anthony A</p> <p>2014-12-01</p> <p>The ability to derivatize antibodies is <span class="hlt">currently</span> limited by the chemical structure of antibodies as polypeptides. Modern methods of bioorthogonal and biocompatible chemical modifications could make antibody functionalization more predictable and easier, without compromising the functions of the antibody. To explore this concept, we modified the well-known anti-epidermal growth factor receptor (EGFR) drug, cetuximab (Erbitux®), with 5-azido-2-nitro-benzoyl (ANB) modifications by optimization of an acylation protocol. We then show that the resulting ANB-cetuximab can be reliably modified with dyes (TAMRA and carboxyrhodamine) or a novel synthesized cyclooctyne modified biotin. The resulting dye- and biotin-modified cetuximabs were then tested across several assay platforms with several cell lines including U87, LN229, F98EGFR, F98WT and HEK293 cells. The assay platforms included fluorescence microscopy, <span class="hlt">FACS</span> and biotin-avidin based immunoprecipitation methods. The modified antibody performs consistently in all of these assay platforms, reliably determining relative abundances of EGFR expression on EGFR expressing cells (LN229 and F98EGFR) and failing to cross react with weak to negative EGFR expressing cells (U87, F98WT and HEK293). The ease of achieving diverse and assay relevant functionalizations as well as the consequent rapid construction of highly correlated antigen expression data sets highlights the power of bioorthogonal and biocompatible methods to conjugate macromolecules. These data provide a proof of concept for a multifunctionalization strategy that leverages the biochemical versatility and antigen specificity of antibodies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017APS..APR.Y8002S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017APS..APR.Y8002S"><span>Cavity <span class="hlt">alignment</span> using fringe scanning</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sinkunaite, Laura Paulina; Kawabe, Keita; Landry, Michael</p> <p>2017-01-01</p> <p>LIGO employs two 4-km long Fabry-Pérot arm cavities, which need to be <span class="hlt">aligned</span> in order for an interferometer to be locked on a TEM00 mode. Once the cavity is locked, <span class="hlt">alignment</span> signals can be derived from wave-front sensors which measure the TEM01 mode content. However, the <span class="hlt">alignment</span> state is not always good enough for locking on TEM00. Even when this is the case, the <span class="hlt">alignment</span> can be evaluated using a free swinging cavity, that shows flashes when higher-order modes become resonant. By moving test masses, small changes are made to the mirror orientation, and hence the TEM00 mode can be optimized iteratively. <span class="hlt">Currently</span>, this is a manual procedure, and thus it is very time-consuming. Therefore, this project is aimed to study another possible way to lock the cavity on the TEM00 mode. Misalignment information can also be extracted from the power of the higher-order modes transmitted through the cavity. This talk will present an algorithm for this alternative and faster way to derive the <span class="hlt">alignment</span> state of the arm cavities. Supported by APS FIP, NSF, and Caltech SFP.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24744735','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24744735"><span>Plant volatile eliciting <span class="hlt">FACs</span> in lepidopteran caterpillars, fruit flies, and crickets: a convergent evolution or phylogenetic inheritance?</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yoshinaga, Naoko; Abe, Hiroaki; Morita, Sayo; Yoshida, Tetsuya; Aboshi, Takako; Fukui, Masao; Tumlinson, James H; Mori, Naoki</p> <p>2014-01-01</p> <p>Fatty acid amino acid conjugates (<span class="hlt">FACs</span>), first identified in lepidopteran caterpillar spit as elicitors of plant volatile emission, also have been reported as major components in gut tracts of Drosophila melanogaster and cricket Teleogryllus taiwanemma. The profile of <span class="hlt">FAC</span> analogs in these two insects was similar to that of tobacco hornworm Manduca sexta, showing glutamic acid conjugates predominantly over glutamine conjugates. The physiological function of <span class="hlt">FACs</span> is presumably to enhance nitrogen assimilation in Spodoptera litura larvae, but in other insects it is totally unknown. Whether these insects share a common synthetic mechanism of <span class="hlt">FACs</span> is also unclear. In this study, the biosynthesis of <span class="hlt">FACs</span> was examined in vitro in five lepidopteran species (M. sexta, Cephonodes hylas, silkworm, S. litura, and Mythimna separata), fruit fly larvae and T. taiwanemma. The fresh midgut tissues of all of the tested insects showed the ability to synthesize glutamine conjugates in vitro when incubated with glutamine and sodium linolenate. Such direct conjugation was also observed for glutamic acid conjugates in all the insects but the product amount was very small and did not reflect the in vivo <span class="hlt">FAC</span> patterns in each species. In fruit fly larvae, the predominance of glutamic acid conjugates could be explained by a shortage of substrate glutamine in midgut tissues, and in M. sexta, a rapid hydrolysis of glutamine conjugates has been reported. In crickets, we found an additional unique biosynthetic pathway for glutamic acid conjugates. T. taiwanemma converted glutamine conjugates to glutamic acid conjugates by deaminating the side chain of the glutamine moiety. Considering these findings together with previous results, a possibility that <span class="hlt">FACs</span> in these insects are results of convergent evolution cannot be ruled out, but it is more likely that the ancestral insects had the glutamine conjugates and crickets and other insects developed glutamic acid conjugates in a different way.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3978339','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3978339"><span>Plant volatile eliciting <span class="hlt">FACs</span> in lepidopteran caterpillars, fruit flies, and crickets: a convergent evolution or phylogenetic inheritance?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yoshinaga, Naoko; Abe, Hiroaki; Morita, Sayo; Yoshida, Tetsuya; Aboshi, Takako; Fukui, Masao; Tumlinson, James H.; Mori, Naoki</p> <p>2013-01-01</p> <p>Fatty acid amino acid conjugates (<span class="hlt">FACs</span>), first identified in lepidopteran caterpillar spit as elicitors of plant volatile emission, also have been reported as major components in gut tracts of Drosophila melanogaster and cricket Teleogryllus taiwanemma. The profile of <span class="hlt">FAC</span> analogs in these two insects was similar to that of tobacco hornworm Manduca sexta, showing glutamic acid conjugates predominantly over glutamine conjugates. The physiological function of <span class="hlt">FACs</span> is presumably to enhance nitrogen assimilation in Spodoptera litura larvae, but in other insects it is totally unknown. Whether these insects share a common synthetic mechanism of <span class="hlt">FACs</span> is also unclear. In this study, the biosynthesis of <span class="hlt">FACs</span> was examined in vitro in five lepidopteran species (M. sexta, Cephonodes hylas, silkworm, S. litura, and Mythimna separata), fruit fly larvae and T. taiwanemma. The fresh midgut tissues of all of the tested insects showed the ability to synthesize glutamine conjugates in vitro when incubated with glutamine and sodium linolenate. Such direct conjugation was also observed for glutamic acid conjugates in all the insects but the product amount was very small and did not reflect the in vivo <span class="hlt">FAC</span> patterns in each species. In fruit fly larvae, the predominance of glutamic acid conjugates could be explained by a shortage of substrate glutamine in midgut tissues, and in M. sexta, a rapid hydrolysis of glutamine conjugates has been reported. In crickets, we found an additional unique biosynthetic pathway for glutamic acid conjugates. T. taiwanemma converted glutamine conjugates to glutamic acid conjugates by deaminating the side chain of the glutamine moiety. Considering these findings together with previous results, a possibility that <span class="hlt">FACs</span> in these insects are results of convergent evolution cannot be ruled out, but it is more likely that the ancestral insects had the glutamine conjugates and crickets and other insects developed glutamic acid conjugates in a different way. PMID</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EP%26S...68..148A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EP%26S...68..148A"><span>Localized field-<span class="hlt">aligned</span> <span class="hlt">currents</span> and 4-min TEC and ground magnetic oscillations during the 2015 eruption of Chile's Calbuco volcano</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Aoyama, Tadashi; Iyemori, Toshihiko; Nakanishi, Kunihito; Nishioka, Michi; Rosales, Domingo; Veliz, Oscar; Safor, Erick Vidal</p> <p>2016-08-01</p> <p>The Calbuco volcano in southern Chile erupted on April 22, 2015. About 2 h after the first eruption, a Swarm satellite passed above the volcano and observed enhancement of small-amplitude (~0.5 nT) magnetic fluctuations with wave-packet structure which extends 15° in latitude. Similar wave packet is seen at the geomagnetic conjugate point of the volcano. Just after the eruption, geomagnetic fluctuations with the spectral peaks around the vertical acoustic resonance periods, 215 and 260 s, were also observed at Huancayo Geomagnetic Observatory located on the magnetic equator. Besides these observations, around 4-min, i.e., 175, 205 and 260 s, oscillations of total electron content (TEC) were observed at global positioning system stations near the volcano. The horizontal propagation velocity and the spatial scale of the TEC oscillation are estimated to be 720 m/s and 1600 km, respectively. These observations strongly suggest that the atmospheric waves induced by explosive volcanic eruption generate TEC variation and electric <span class="hlt">currents</span>. The Swarm observation may be explained as a manifestation of their magnetic effects observed in the topside ionosphere.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24273448','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24273448"><span>Synthesis and characterization of <span class="hlt">fac</span>-Re(CO)3-aspartic-N-monoacetic acid, a structural analogue of a potential new renal tracer, <span class="hlt">fac</span>-(99m)Tc(CO)3(ASMA).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Klenc, Jeffrey; Lipowska, Malgorzata; Taylor, Andrew T; Marzilli, Luigi G</p> <p>2012-09-01</p> <p>The reaction of an aminopolycarboxylate ligand, aspartic-N-monoacetic acid (ASMA), with [Re(CO)3(H2O)3](+) was examined. The tridentate coordination of ASMA to this Re(I) tricarbonyl precursor yielded <span class="hlt">fac</span>-Re(CO)3(ASMA) as a mixture of diastereomers. The chemistry is analogous to that of the Tc(I) tricarbonyl complex, which yields <span class="hlt">fac</span>-(99m)Tc(CO)3(ASMA) under similar conditions. The formation, structure, and isomerization of <span class="hlt">fac</span>-Re(CO)3(ASMA) products were characterized by HPLC, (1)H NMR spectroscopy, and X-ray crystallography. The two major <span class="hlt">fac</span>-Re(CO)3(ASMA) diastereomeric products each have a linear ONO coordination mode with two adjacent five-membered chelate rings, but they differ in the endo or exo orientation of the uncoordinated acetate group, in agreement with expectations based on previous studies. Conditions have been identified for the expedient isomerization of <span class="hlt">fac</span>-Re(CO)3(ASMA) to a mixture consisting primarily of one major product. Because different isomeric species typically have different pharmacokinetic characteristics, these conditions may provide for the practical isolation of a single (99m)Tc(CO)3(ASMA) species, thus allowing the isolation of the isomer that has optimal imaging and pharmacokinetic characteristics. This information will aid in the design of future (99m)Tc radiopharmaceuticals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3835576','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3835576"><span>Synthesis and characterization of <span class="hlt">fac</span>-Re(CO)3-aspartic-N-monoacetic acid, a structural analogue of a potential new renal tracer, <span class="hlt">fac</span>-99mTc(CO)3(ASMA)</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Klenc, Jeffrey; Lipowska, Malgorzata; Taylor, Andrew T.; Marzilli, Luigi G.</p> <p>2013-01-01</p> <p>The reaction of an aminopolycarboxylate ligand, aspartic-N-monoacetic acid (ASMA), with [Re(CO)3(H2O)3]+ was examined. The tridentate coordination of ASMA to this ReI tricarbonyl precursor yielded <span class="hlt">fac</span>-Re(CO)3(ASMA) as a mixture of diastereomers. The chemistry is analogous to that of the TcI tricarbonyl complex, which yields <span class="hlt">fac</span>-99mTc(CO)3(ASMA) under similar conditions. The formation, structure, and isomerization of <span class="hlt">fac</span>-Re(CO)3(ASMA) products were characterized by HPLC, 1H NMR spectroscopy, and X-ray crystallography. The two major <span class="hlt">fac</span>-Re(CO)3(ASMA) diastereomeric products each have a linear ONO coordination mode with two adjacent five-membered chelate rings, but they differ in the endo or exo orientation of the uncoordinated acetate group, in agreement with expectations based on previous studies. Conditions have been identified for the expedient isomerization of <span class="hlt">fac</span>-Re(CO)3(ASMA) to a mixture consisting primarily of one major product. Because different isomeric species typically have different pharmacokinetic characteristics, these conditions may provide for the practical isolation of a single 99mTc(CO)3(ASMA) species, thus allowing the isolation of the isomer that has optimal imaging and pharmacokinetic characteristics. This information will aid in the design of future 99mTc radiopharmaceuticals. PMID:24273448</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM11B2091C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM11B2091C"><span>Flow Pattern relative to the Substorm <span class="hlt">Current</span> Wedge</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chu, X.; McPherron, R. L.; Hsu, T.</p> <p>2013-12-01</p> <p>Magnetospheric substorms play a key role in the coupling of the solar wind and the magnetosphere. The Substorm <span class="hlt">Current</span> Wedge (SCW) is a key element in the present physical model of substorms. It is widely accepted that the SCW is created by earthward busty flows, but the generation mechanism is still unknown. Previous studies suggest pressure gradients and magnetic vortices are possible candidates. Due to the sparse coverage of satellites in space, these studies were strongly dependent on the assumption that the satellites were in the generation region of the field-<span class="hlt">aligned</span> <span class="hlt">currents</span> (<span class="hlt">FAC</span>) forming the SCW. In this work, we take advantage of an inversion technique that determines the parameters describing the SCW and perform a statistical study on the plasma and magnetic field parameters of the flow pattern relative to the SCW. The inversion technique finds the location and the intensity of the SCW from midlatitude magnetic data. The technique has been validated using auroral observations, Equivalent Ionospheric <span class="hlt">Currents</span> (EIC), SYM-H index from SuperMAG, and magnetic perturbations at geosynchronous orbit by the GOES satellite. A database of substorm events has been created using midlatitude positive bays, which are the ground signature of the SCW at lower latitudes. The inversion technique is applied to each event in the database to determine the location of the origin of the SCW. The inversion results are also used to find conjunction events with space observations from VAP (RBSP), THEMIS and GOES. The plasma and magnetic field parameters such as the pressure gradient and magnetic vorticity are then categorized as a function of their location relative to the origin of the SCW. How the distribution/pattern of the pressure gradient and vorticity are related to the properties of the SCW (locations and intensity of the <span class="hlt">FAC</span>), and flows (entropy, velocity and density) will be determined.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4045882','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4045882"><span>MP-<span class="hlt">Align</span>: <span class="hlt">alignment</span> of metabolic pathways</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 Comparing the metabolic pathways of different species is useful for understanding metabolic functions and can help in studying diseases and engineering drugs. Several comparison techniques for metabolic pathways have been introduced in the literature as a first attempt in this direction. The approaches are based on some simplified representation of metabolic pathways and on a related definition of a similarity score (or distance measure) between two pathways. More recent comparative research focuses on <span class="hlt">alignment</span> techniques that can identify similar parts between pathways. Results We propose a methodology for the pairwise comparison and <span class="hlt">alignment</span> of metabolic pathways that aims at providing the largest conserved substructure of the pathways under consideration. The proposed methodology has been implemented in a tool called MP-<span class="hlt">Align</span>, which has been used to perform several validation tests. The results showed that our similarity score makes it possible to discriminate between different domains and to reconstruct a meaningful phylogeny from metabolic data. The results further demonstrate that our <span class="hlt">alignment</span> algorithm correctly identifies subpathways sharing a common biological function. Conclusion The results of the validation tests performed with MP-<span class="hlt">Align</span> are encouraging. A comparison with another proposal in the literature showed that our <span class="hlt">alignment</span> algorithm is particularly well-suited to finding the largest conserved subpathway of the pathways under examination. PMID:24886436</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/992866','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/992866"><span>Girder <span class="hlt">Alignment</span> Plan</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wolf, Zackary; Ruland, Robert; LeCocq, Catherine; Lundahl, Eric; Levashov, Yurii; Reese, Ed; Rago, Carl; Poling, Ben; Schafer, Donald; Nuhn, Heinz-Dieter; Wienands, Uli; /SLAC</p> <p>2010-11-18</p> <p>The girders for the LCLS undulator system contain components which must be <span class="hlt">aligned</span> with high accuracy relative to each other. The <span class="hlt">alignment</span> is one of the last steps before the girders go into the tunnel, so the <span class="hlt">alignment</span> must be done efficiently, on a tight schedule. This note documents the <span class="hlt">alignment</span> plan which includes efficiency and high accuracy. The motivation for girder <span class="hlt">alignment</span> involves the following considerations. Using beam based <span class="hlt">alignment</span>, the girder position will be adjusted until the beam goes through the center of the quadrupole and beam finder wire. For the machine to work properly, the undulator axis must be on this line and the center of the undulator beam pipe must be on this line. The physics reasons for the undulator axis and undulator beam pipe axis to be centered on the beam are different, but the <span class="hlt">alignment</span> tolerance for both are similar. In addition, the beam position monitor must be centered on the beam to preserve its calibration. Thus, the undulator, undulator beam pipe, quadrupole, beam finder wire, and beam position monitor axes must all be <span class="hlt">aligned</span> to a common line. All relative <span class="hlt">alignments</span> are equally important, not just, for example, between quadrupole and undulator. We begin by making the common axis the nominal beam axis in the girder coordinate system. All components will be initially <span class="hlt">aligned</span> to this axis. A more accurate <span class="hlt">alignment</span> will then position the components relative to each other, without incorporating the girder itself.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3073079','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3073079"><span><span class="hlt">FACS</span> identifies unique cocaine-induced gene regulation in selectively activated adult striatal neurons</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Guez-Barber, Danielle; Fanous, Sanya; Golden, Sam A.; Schrama, Regina; Koya, Eisuke; Stern, Anna L.; Bossert, Jennifer M.; Harvey, Brandon K.; Picciotto, Marina R.; Hope, Bruce T.</p> <p>2011-01-01</p> <p>Numerous studies with the neural activity marker Fos indicate that cocaine activates only a small proportion of sparsely distributed striatal neurons. Until now, efficient methods were not available to assess neuroadaptations induced specifically within these activated neurons. We used fluorescence-activated cell sorting (<span class="hlt">FACS</span>) to purify striatal neurons activated during cocaine-induced locomotion in naïve and cocaine-sensitized cfos-lacZ transgenic rats. Activated neurons were labeled with an antibody against β-galactosidase, the protein product of the lacZ gene. Cocaine induced a unique gene expression profile selectively in the small proportion of activated neurons that was not observed in the non-activated majority of neurons. These genes included altered levels of the immediate early genes arc, fosB, and nr4a3, as well as genes involved in p38 MAPK signaling and cell-type specificity. We propose that this <span class="hlt">FACS</span> method can be used to study molecular neuroadaptations in specific neurons encoding the behavioral effects of abused drugs and other learned behaviors. PMID:21411666</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25170020','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25170020"><span>Quantitative analysis of mammalian translation initiation sites by <span class="hlt">FACS</span>-seq.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Noderer, William L; Flockhart, Ross J; Bhaduri, Aparna; Diaz de Arce, Alexander J; Zhang, Jiajing; Khavari, Paul A; Wang, Clifford L</p> <p>2014-08-28</p> <p>An approach combining fluorescence-activated cell sorting and high-throughput DNA sequencing (<span class="hlt">FACS</span>-seq) was employed to determine the efficiency of start codon recognition for all possible translation initiation sites (TIS) utilizing AUG start codons. Using <span class="hlt">FACS</span>-seq, we measured translation from a genetic reporter library representing all 65,536 possible TIS sequences spanning the -6 to +5 positions. We found that the motif RYMRMVAUGGC enhanced start codon recognition and translation efficiency. However, dinucleotide interactions, which cannot be conveyed by a single motif, were also important for modeling TIS efficiency. Our dataset combined with modeling allowed us to predict genome-wide translation initiation efficiency for all mRNA transcripts. Additionally, we screened somatic TIS mutations associated with tumorigenesis to identify candidate driver mutations consistent with known tumor expression patterns. Finally, we implemented a quantitative leaky scanning model to predict alternative initiation sites that produce truncated protein isoforms and compared predictions with ribosome footprint profiling data. The comprehensive analysis of the TIS sequence space enables quantitative predictions of translation initiation based on genome sequence. © 2014 The Authors. Published under the terms of the CC BY 4.0 license.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28375558','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28375558"><span>Analysis of the advantages of cis reporters in optimized <span class="hlt">FACS</span>-Gal.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sánchez-Luengo, Miguel Ángel; Rovira, Miguel; Serrano, Manuel; Fernandez-Marcos, Pablo Jose; Martinez, Lola</p> <p>2017-07-01</p> <p>Flow cytometry is a powerful multiparametric technology, widely used for the identification, quantification, and isolation of defined populations of cells based on the expression of target proteins. It also allows for the use of surrogate reporters, either enzymatic or fluorescent, to indirectly monitor the expression of these target proteins. In this work, we optimised the dissociation protocol for the detection of the enzymatic reporter LacZ using the <span class="hlt">FACS</span>-Gal detection system with the fluorogenic substrate FDG to compare cis- versus trans-positioned reporters efficiency. Particularly, for the <span class="hlt">FACS</span>-Gal optimization, we studied lung and haematopoietic tissues, focusing on cell recovery, viability, FDG loading conditions and distribution of cellular populations. Reporter genes such as LacZ can be placed together with the gene of interest in the same polycistronic mRNA (in cis), or in independent alleles (in trans), which can strongly affect the correlation with the reporter readout. To address this issue, we generated a mouse model containing both types of reporters for the same gene, and compared them. Our results clearly indicate that trans-positioned reporters can be misleading, and that using a reporter gene in cis rather than trans is a much more specific method to sort for cells undergoing Cre-mediated recombination. © 2017 International Society for Advancement of Cytometry. © 2017 International Society for Advancement of Cytometry.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2842249','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2842249"><span>Gene-specific <span class="hlt">FACS</span> sorting method for target selection in high-throughput amplicon sequencing</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>2010-01-01</p> <p>Background In addition to shotgun sequencing, next generation sequencing has been shown to be suitable for deep sequencing of many specific PCR-amplified target genes in parallel. However, unspecific product formation is a common problem in amplicon sequencing since these fragments are difficult to fully remove by gel purification, and their presence inevitably reduces the number of mappable sequence reads that can be obtained in each sequencing run. Results We have used a novel flow cytometric sorting approach to specifically enrich Roche/454 DNA Capture beads carrying target DNA sequences on their surface, and reject beads carrying unspecific sequences. This procedure gives a nearly three-fold increase in the fraction of informative sequences obtained. Presented results also show that there are no significant differences in the distribution or presence of different genotypes between a <span class="hlt">FACS</span>-enriched sample and a standard-enriched control sample. Conclusions Target-specific <span class="hlt">FACS</span> enrichment prior to Roche/454 sequencing provides a quick, inexpensive way of increasing the amount of high quality data obtained in a single sequencing run, without introducing any sequence bias. PMID:20184782</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4299517','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4299517"><span>Quantitative analysis of mammalian translation initiation sites by <span class="hlt">FACS</span>-seq</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Noderer, William L; Flockhart, Ross J; Bhaduri, Aparna; Diaz de Arce, Alexander J; Zhang, Jiajing; Khavari, Paul A; Wang, Clifford L</p> <p>2014-01-01</p> <p>An approach combining fluorescence-activated cell sorting and high-throughput DNA sequencing (<span class="hlt">FACS</span>-seq) was employed to determine the efficiency of start codon recognition for all possible translation initiation sites (TIS) utilizing AUG start codons. Using <span class="hlt">FACS</span>-seq, we measured translation from a genetic reporter library representing all 65,536 possible TIS sequences spanning the −6 to +5 positions. We found that the motif RYMRMVAUGGC enhanced start codon recognition and translation efficiency. However, dinucleotide interactions, which cannot be conveyed by a single motif, were also important for modeling TIS efficiency. Our dataset combined with modeling allowed us to predict genome-wide translation initiation efficiency for all mRNA transcripts. Additionally, we screened somatic TIS mutations associated with tumorigenesis to identify candidate driver mutations consistent with known tumor expression patterns. Finally, we implemented a quantitative leaky scanning model to predict alternative initiation sites that produce truncated protein isoforms and compared predictions with ribosome footprint profiling data. The comprehensive analysis of the TIS sequence space enables quantitative predictions of translation initiation based on genome sequence. PMID:25170020</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22251045','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22251045"><span>FACSGen 2.0 animation software: generating three-dimensional <span class="hlt">FACS</span>-valid facial expressions for emotion research.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Krumhuber, Eva G; Tamarit, Lucas; Roesch, Etienne B; Scherer, Klaus R</p> <p>2012-04-01</p> <p>In this article, we present FACSGen 2.0, new animation software for creating static and dynamic three-dimensional facial expressions on the basis of the Facial Action Coding System (<span class="hlt">FACS</span>). FACSGen permits total control over the action units (AUs), which can be animated at all levels of intensity and applied alone or in combination to an infinite number of faces. In two studies, we tested the validity of the software for the AU appearance defined in the <span class="hlt">FACS</span> manual and the conveyed emotionality of FACSGen expressions. In Experiment 1, four <span class="hlt">FACS</span>-certified coders evaluated the complete set of 35 single AUs and 54 AU combinations for AU presence or absence, appearance quality, intensity, and asymmetry. In Experiment 2, lay participants performed a recognition task on emotional expressions created with FACSGen software and rated the similarity of expressions displayed by human and FACSGen faces. Results showed good to excellent classification levels for all AUs by the four <span class="hlt">FACS</span> coders, suggesting that the AUs are valid exemplars of <span class="hlt">FACS</span> specifications. Lay participants' recognition rates for nine emotions were high, and comparisons of human and FACSGen expressions were very similar. The findings demonstrate the effectiveness of the software in producing reliable and emotionally valid expressions, and suggest its application in numerous scientific areas, including perception, emotion, and clinical and neuroscience research. (PsycINFO Database Record (c) 2012 APA, all rights reserved).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25878826','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25878826"><span>Crystal structures of <span class="hlt">fac</span>-tri-chlorido-tris-(tri-methyl-phosphane-κP)rhodium(III) monohydrate and <span class="hlt">fac</span>-tri-chlorido-tris-(tri-methyl-phosphane-κP)rhodium(III) methanol hemisolvate: rhodium structures that are isotypic with their iridium analogs.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Merola, Joseph S; Franks, Marion A</p> <p>2015-02-01</p> <p>The crystal structures of two solvates of <span class="hlt">fac</span>-tri-chlorido-tris-(tri-methyl-phosphane-κP)rhodium(III) are reported, i.e. one with water in the crystal lattice, <span class="hlt">fac</span>-[RhCl3(Me3P)3]·H2O, and one with methanol in the crystal lattice, <span class="hlt">fac</span>-[RhCl3(Me3P)3]·0.5CH3OH. These rhodium compounds exhibit distorted octahedral coordination spheres at the metal and are isotypic with the analogous iridium compounds previously reported by us [Merola et al. (2013 ▶). Polyhedron, 54, 67-73]. Comparison is made between the rhodium and iridium compounds, highlighting their isostructural relationships.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19036514','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19036514"><span>The application of silicalite-1/fly ash cenosphere (S/<span class="hlt">FAC</span>) zeolite composite for the adsorption of methyl tert-butyl ether (MTBE).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lu, Jia; Xu, Fang; Wang, Deju; Huang, Jue; Cai, Weimin</p> <p>2009-06-15</p> <p>Silicalite-1/fly ash cenosphere (S/<span class="hlt">FAC</span>) zeolite composite has been applied for batch adsorption of methyl tert-butyl ether (MTBE) from water systems. Here the key experimental conditions, including the ratio of initial MTBE concentration to the amount weight of S/<span class="hlt">FAC</span>, adsorption time and temperature, have been discussed in detail. The results show that approximately 93-95% MTBE could be adsorbed with initial concentration of MTBE solution 1000 microg l(-1). The column flow-through experiments also prove the high capacity of S/<span class="hlt">FAC</span> composite for MTBE removal. The distinct advantages of S/<span class="hlt">FAC</span> zeolite composite as adsorbent lie in (1) enhanced adsorption rate and capacity based on hierarchical micro and meso/macroporosity of S/<span class="hlt">FAC</span>; (2) more easily operation and recycling process by assembly of nano-sized silicalite-1 zeolite on <span class="hlt">FAC</span> support.</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://hdl.handle.net/2060/20150021409','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150021409"><span>Technology <span class="hlt">Alignment</span> and Portfolio Prioritization (TAPP)</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Funaro, Gregory V.; Alexander, Reginald A.</p> <p>2015-01-01</p> <p>Technology <span class="hlt">Alignment</span> and Portfolio Prioritization (TAPP) is a method being developed by the Advanced Concepts Office, at NASA Marshall Space Flight Center. The TAPP method expands on <span class="hlt">current</span> technology assessment methods by incorporating the technological structure underlying technology development, e.g., organizational structures and resources, institutional policy and strategy, and the factors that motivate technological change. This paper discusses the methods ACO is <span class="hlt">currently</span> developing to better perform technology assessments while taking into consideration Strategic <span class="hlt">Alignment</span>, Technology Forecasting, and Long Term Planning.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/11740085','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/11740085"><span>The optical sensor <span class="hlt">fac</span>-tricarbonylchloro(di-2-pyridylmethanone p-nitrophenylhydrazone)rhenium(I) dimethyl sulfoxide solvate.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bakir, M</p> <p>2001-12-01</p> <p>The first metal complex of di-2-pyridylmethanone p-nitrophenylhydrazone (dpknph), i.e. the title compound, <span class="hlt">fac</span>-[ReCl(C17H13N5O2)(CO)3]*C2H6OS, crystallizes as well separated pseudo-tetrahedral DMSO (DMSO is dimethyl sulfoxide) and pseudo-octahedral <span class="hlt">fac</span>-[ReCl(dpknph)(CO)3] moieties. Two N atoms from dpknph, three C atoms from the carbonyl groups and one chloride ion occupy the coordination sphere around rhenium. The coordinated dpknph ligand forms a six-membered ring in a boat conformation, with the pyridine rings in a butterfly formation. The p-nitrophenylhydrazone moiety is planar, with all C and N atoms in sp2-hybridized forms. The molecules pack as stacks of interlocked <span class="hlt">fac</span>-[ReCl(dpknph)(CO)3]*DMSO units via a network of non-covalent bonds that include solute-solute, solvent-solute and pi-pi interactions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMSM51C2193C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMSM51C2193C"><span>Multipoint Observations of Oval-<span class="hlt">aligned</span> Transpolar Arc Formation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cumnock, J. A.; Le, G.; Zhang, Y.; Slavin, J. A.</p> <p>2013-12-01</p> <p>We analyze changes in field-<span class="hlt">aligned</span> <span class="hlt">currents</span> associated with auroral oval-<span class="hlt">aligned</span> transpolar arc formation during quiet times on time scales of a few minutes. This is accomplished using observations from the highly accurate multipoint magnetic field measurements provided by the Space Technology 5 mission which consists of three micro-satellites in low Earth orbit. Simultaneous measurements of precipitating particles are provided by three DMSP satellites. We analyze field-<span class="hlt">aligned</span> <span class="hlt">currents</span> associated with the dusk oval. For the first time we observe the field-<span class="hlt">aligned</span> <span class="hlt">currents</span> associated with the formation of an oval-<span class="hlt">aligned</span> transpolar arc poleward of the auroral oval which in one case are large compared with the field-<span class="hlt">aligned</span> <span class="hlt">currents</span> associated with the auroral oval measured 10 minutes earlier. These events clearly illustrate the dynamic nature of oval-<span class="hlt">aligned</span> arc formation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22107899','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22107899"><span>Flow Accelerated Erosion-Corrosion (<span class="hlt">FAC</span>) considerations for secondary side piping in the AP1000{sup R} nuclear power plant design</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Vanderhoff, J. F.; Rao, G. V.; Stein, A.</p> <p>2012-07-01</p> <p>The issue of Flow Accelerated Erosion-Corrosion (<span class="hlt">FAC</span>) in power plant piping is a known phenomenon that has resulted in material replacements and plant accidents in operating power plants. Therefore, it is important for <span class="hlt">FAC</span> resistance to be considered in the design of new nuclear power plants. This paper describes the design considerations related to <span class="hlt">FAC</span> that were used to develop a safe and robust AP1000{sup R} plant secondary side piping design. The primary <span class="hlt">FAC</span> influencing factors include: - Fluid Temperature - Pipe Geometry/layout - Fluid Chemistry - Fluid Velocity - Pipe Material Composition - Moisture Content (in steam lines) Due to the unknowns related to the relative impact of the influencing factors and the complexities of the interactions between these factors, it is difficult to accurately predict the expected wear rate in a given piping segment in a new plant. This paper provides: - a description of <span class="hlt">FAC</span> and the factors that influence the <span class="hlt">FAC</span> degradation rate, - an assessment of the level of <span class="hlt">FAC</span> resistance of AP1000{sup R} secondary side system piping, - an explanation of options to increase <span class="hlt">FAC</span> resistance and associated benefits/cost, - discussion of development of a tool for predicting <span class="hlt">FAC</span> degradation rate in new nuclear power plants. (authors)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4565956','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4565956"><span>Long-term outcomes of phakic patients with diabetic macular oedema treated with intravitreal fluocinolone acetonide (<span class="hlt">FAc</span>) implants</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yang, Y; Bailey, C; Holz, F G; Eter, N; Weber, M; Baker, C; Kiss, S; Menchini, U; Ruiz Moreno, J M; Dugel, P; Lotery, A</p> <p>2015-01-01</p> <p>Purpose Diabetic macular oedema (DMO) is a leading cause of blindness in working-age adults. Slow-release, nonbioerodible fluocinolone acetonide (<span class="hlt">FAc</span>) implants have shown efficacy in the treatment of DMO; however, the National Institute for Health and Care Excellence recommends that <span class="hlt">FAc</span> should be used in patients with chronic DMO considered insufficiently responsive to other available therapies only if the eye to be treated is pseudophakic. The goal of this analysis was to examine treatment outcomes in phakic patients who received 0.2 μg/day <span class="hlt">FAc</span> implant. Methods This analysis of the phase 3 FAME (Fluocinolone Acetonide in Diabetic Macular Edema) data examines the safety and efficacy of <span class="hlt">FAc</span> implants in patients who underwent cataract extraction before (cataract before implant (CBI) group) or after (cataract after implant (CAI) group) receiving the implant. The data were further examined by DMO duration. Results Best corrected visual acuity (BCVA) after 36 months was comparable in the CAI and CBI groups. Both the percentage of patients gaining ≥3 lines of vision and mean change in BCVA letter score were numerically greater in the CAI group. In addition, most patients who underwent cataract surgery experienced a net gain in BCVA from presurgery baseline as well as from original study baseline. Conclusions These data support the use of 0.2 μg/day <span class="hlt">FAc</span> implants in phakic as well as in pseudophakic patients. These findings will serve as a pilot for design of future studies to evaluate the potential protective effect of <span class="hlt">FAc</span> implants before cataract surgery in patients with DMO and cataract. PMID:26113503</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/22525617','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/22525617"><span>Tidal <span class="hlt">alignment</span> of galaxies</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Blazek, Jonathan; Vlah, Zvonimir; Seljak, Uroš E-mail: zvlah@stanford.edu</p> <p>2015-08-01</p> <p>We develop an analytic model for galaxy intrinsic <span class="hlt">alignments</span> (IA) based on the theory of tidal <span class="hlt">alignment</span>. We calculate all relevant nonlinear corrections at one-loop order, including effects from nonlinear density evolution, galaxy biasing, and source density weighting. Contributions from density weighting are found to be particularly important and lead to bias dependence of the IA amplitude, even on large scales. This effect may be responsible for much of the luminosity dependence in IA observations. The increase in IA amplitude for more highly biased galaxies reflects their locations in regions with large tidal fields. We also consider the impact of smoothing the tidal field on halo scales. We compare the performance of this consistent nonlinear model in describing the observed <span class="hlt">alignment</span> of luminous red galaxies with the linear model as well as the frequently used 'nonlinear <span class="hlt">alignment</span> model,' finding a significant improvement on small and intermediate scales. We also show that the cross-correlation between density and IA (the 'GI' term) can be effectively separated into source <span class="hlt">alignment</span> and source clustering, and we accurately model the observed <span class="hlt">alignment</span> down to the one-halo regime using the tidal field from the fully nonlinear halo-matter cross correlation. Inside the one-halo regime, the average <span class="hlt">alignment</span> of galaxies with density tracers no longer follows the tidal <span class="hlt">alignment</span> prediction, likely reflecting nonlinear processes that must be considered when modeling IA on these scales. Finally, we discuss tidal <span class="hlt">alignment</span> in the context of cosmic shear measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1328989','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1328989"><span>Tidal <span class="hlt">alignment</span> of galaxies</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Blazek, Jonathan; Vlah, Zvonimir; Seljak, Uroš</p> <p>2015-08-01</p> <p>We develop an analytic model for galaxy intrinsic <span class="hlt">alignments</span> (IA) based on the theory of tidal <span class="hlt">alignment</span>. We calculate all relevant nonlinear corrections at one-loop order, including effects from nonlinear density evolution, galaxy biasing, and source density weighting. Contributions from density weighting are found to be particularly important and lead to bias dependence of the IA amplitude, even on large scales. This effect may be responsible for much of the luminosity dependence in IA observations. The increase in IA amplitude for more highly biased galaxies reflects their locations in regions with large tidal fields. We also consider the impact of smoothing the tidal field on halo scales. We compare the performance of this consistent nonlinear model in describing the observed <span class="hlt">alignment</span> of luminous red galaxies with the linear model as well as the frequently used "nonlinear <span class="hlt">alignment</span> model," finding a significant improvement on small and intermediate scales. We also show that the cross-correlation between density and IA (the "GI" term) can be effectively separated into source <span class="hlt">alignment</span> and source clustering, and we accurately model the observed <span class="hlt">alignment</span> down to the one-halo regime using the tidal field from the fully nonlinear halo-matter cross correlation. Inside the one-halo regime, the average <span class="hlt">alignment</span> of galaxies with density tracers no longer follows the tidal <span class="hlt">alignment</span> prediction, likely reflecting nonlinear processes that must be considered when modeling IA on these scales. Finally, we discuss tidal <span class="hlt">alignment</span> in the context of cosmic shear measurements.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1993PhDT.......160B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1993PhDT.......160B"><span><span class="hlt">Alignability</span> of Optical Interconnects</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beech, Russell Scott</p> <p></p> <p>With the continuing drive towards higher speed, density, and functionality in electronics, electrical interconnects become inadequate. Due to optics' high speed and bandwidth, freedom from capacitive loading effects, and freedom from crosstalk, optical interconnects can meet more stringent interconnect requirements. But, an optical interconnect requires additional components, such as an optical source and detector, lenses, holographic elements, etc. Fabrication and assembly of an optical interconnect requires precise <span class="hlt">alignment</span> of these components. The successful development and deployment of optical interconnects depend on how easily the interconnect components can be <span class="hlt">aligned</span> and/or how tolerant the interconnect is to misalignments. In this thesis, a method of quantitatively specifying the relative difficulty of properly <span class="hlt">aligning</span> an optical interconnect is described. Ways of using this theory of <span class="hlt">alignment</span> to obtain design and packaging guidelines for optical interconnects are examined. The measure of the ease with which an optical interconnect can be <span class="hlt">aligned</span>, called the <span class="hlt">alignability</span>, uses the efficiency of power transfer as a measure of <span class="hlt">alignment</span> quality. The <span class="hlt">alignability</span> is related to interconnect package design through the overall cost measure, which depends upon various physical parameters of the interconnect, such as the cost of the components and the time required for fabrication and <span class="hlt">alignment</span>. Through a mutual dependence on detector size, the relationship between an interconnect's <span class="hlt">alignability</span> and its bandwidth, signal-to-noise ratio, and bit-error -rate is examined. The results indicate that a range of device sizes exists for which given performance threshold values are satisfied. Next, the <span class="hlt">alignability</span> of integrated planar-optic backplanes is analyzed in detail. The resulting data show that the <span class="hlt">alignability</span> can be optimized by varying the substrate thickness or the angle of reflection. By including the effects of crosstalk, in a multi-channel backplane, the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/21124210','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/21124210"><span>Daily Bone <span class="hlt">Alignment</span> With Limited Repeat CT Correction Rivals Daily Ultrasound <span class="hlt">Alignment</span> for Prostate Radiotherapy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>O'Daniel, Jennifer C.; Dong Lei Zhang Lifei; Wang He; Tucker, Susan L.; Kudchadker, Rajat J.; Lee, Andrew K.; Cheung, Rex; Cox, James D.; Kuban, Deborah A.; Mohan, Radhe</p> <p>2008-05-01</p> <p>Purpose: To compare the effectiveness of daily ultrasound (US)- and computed tomography (CT)-guided <span class="hlt">alignments</span> with an off-line correction protocol using daily bone <span class="hlt">alignment</span> plus a correction factor for systematic internal prostate displacement (CF{sub ID}). Methods and Materials: Ten prostate cancer patients underwent CT scans three times weekly using an integrated CT-linear accelerator system, followed by <span class="hlt">alignment</span> using US for daily radiotherapy. Intensity-modulated radiotherapy plans were designed with our <span class="hlt">current</span> clinical margins. The treatment plan was copied onto the repeat CT images and <span class="hlt">aligned</span> using several methods: (1) bone <span class="hlt">alignment</span> plus CF{sub ID} after three off-line CT scans (bone+3CT), (2) bone <span class="hlt">alignment</span> plus CF{sub ID} after six off-line CT scans (bone+6CT), (3) US <span class="hlt">alignment</span>, and (4) CT <span class="hlt">alignment</span>. The accuracy of the repeated US and CT measurements to determine the CF{sub ID} was compared. The target dosimetric effect was quantified. Results: The CF{sub ID} for internal systematic prostate displacements was more accurately measured with limited repeat CT scans than with US (residual error, 0.0 {+-} 0.7 mm vs. 2.0 {+-} 3.2 mm). Bone+3CT, bone+6CT, and US provided equivalent prostate and seminal vesicle dose coverage, but bone+3CT and bone+6CT produced more precise daily <span class="hlt">alignments</span>. Daily CT <span class="hlt">alignment</span> provided the greatest target dose coverage. Conclusion: Daily bone <span class="hlt">alignment</span> plus CF{sub ID} for internal systematic prostate displacement provided better daily <span class="hlt">alignment</span> precision and equivalent dose coverage compared with daily US <span class="hlt">alignment</span>. The CF{sub ID} should be based on at least three repeat CT scans, which could be collected before the start of treatment or during the first 3 treatment days. Daily bone <span class="hlt">alignment</span> plus CF{sub ID} provides another option for accurate prostate cancer patient positioning.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24510286','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24510286"><span>RNA expression profiling from <span class="hlt">FACS</span>-isolated cells of the Drosophila intestine.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dutta, Devanjali; Xiang, Jinyi; Edgar, Bruce A</p> <p>2013-11-13</p> <p>This unit describes a protocol for the isolation of Drosophila intestinal cell populations for the purpose of cell type-specific transcriptome profiling. A method to select a cell type of interest labeled with green or yellow fluorescent protein (GFP, YFP) by making use of the GAL4-UAS bipartite system and fluorescent-activated cell sorting (<span class="hlt">FACS</span>) is presented. Total RNA is isolated from the sorted cells and linear RNA amplification is used to obtain sufficient amounts of high-quality RNA for analysis by microarray, RT-PCR, or RNA sequencing. This method will be useful for quantitative transcriptome comparison across intestinal cell types under normal and various experimental conditions. Copyright © 2013 John Wiley & Sons, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27375894','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27375894"><span>Crystal structure of <span class="hlt">fac</span>-aquatricarbonyl[(S)-valin-ato-κ(2) N,O]-rhenium(I).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Piletska, Kseniia O; Domasevitch, Kostiantyn V; Shtemenko, Alexander V</p> <p>2016-04-01</p> <p>In the mol-ecule of the title compound, [Re(C5H10NO2)(CO)3(H2O)], the Re(I) atom adopts a distorted octa-hedral coordination sphere defined by one aqua and three carbonyl ligands as well as one amino N and one carboxyl-ate O atom of the chelating valinate anion. The carbonyl ligands are arranged in a <span class="hlt">fac</span>-configuration around the Re(I) ion. In the crystal, an intricate hydrogen-bonding system under participation of two O-H, two N-H and one C-H donor groups and the carboxyl-ate and carbonyl O atoms as acceptor groups contribute to the formation of a three-dimensional supra-molecular network.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1994SPIE.2220....6H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1994SPIE.2220....6H"><span>Self-<span class="hlt">aligning</span> spatial filter</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Haniff, Tariq M.; Hu, Albert K.; Green, Evan D.</p> <p>1994-07-01</p> <p>In this paper we describe a prototype self-<span class="hlt">aligning</span> spatial filter (SASF). We present studies of the design and the results of fabrication prior to the final processing step. The SASF consists of an electrostatically actuated platform on which an optical spatial filter (pinhole) has been fabricated. The pinhole is in the center of a four quadrant split-cell photodetector, which serves as the <span class="hlt">alignment</span> gauge for the system. When a focused beam at the pinhole is <span class="hlt">aligned</span>, all four detectors sense the same optical <span class="hlt">current</span>. In future devices, this information from the photodetectors will be fed back to the electrostatic actuation system to push the platform and <span class="hlt">align</span> the beam. The electrostatic actuators are formed from the parallel walls of vertical side- wall capacitors built between the silicon bulk and the movable platform. Electrical signal paths in the integrated system used diffused interconnects, while the photodetectors are simply reverse-biased p+n diodes. Fabrication techniques are similar to surface micromachining, except that a wafer bonding step is used to create single crystal structures.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JGRA..119.8543Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JGRA..119.8543Z"><span>On the generation/decay of the storm-enhanced density plumes: Role of the convection flow and field-<span class="hlt">aligned</span> ion flow</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zou, Shasha; Moldwin, Mark B.; Ridley, Aaron J.; Nicolls, Michael J.; Coster, Anthea J.; Thomas, Evan G.; Ruohoniemi, J. Michael</p> <p>2014-10-01</p> <p>Storm-enhanced density (SED) plumes are prominent ionospheric electron density increases at the dayside middle and high latitudes. The generation and decay mechanisms of the plumes are still not clear. We present observations of SED plumes during six storms between 2010 and 2013 and comprehensively analyze the associated ionospheric parameters within the plumes, including vertical ion flow, field-<span class="hlt">aligned</span> ion flow and flux, plasma temperature, and field-<span class="hlt">aligned</span> <span class="hlt">currents</span>, obtained from multiple instruments, including GPS total electron content (TEC), Poker Flat Incoherent Scatter Radar (PFISR), Super Dual Auroral Radar Network, and Active Magnetosphere and Planetary Electrodynamics Response Experiment. The TEC increase within the SED plumes at the PFISR site can be 1.4-5.5 times their quiet time value. The plumes are usually associated with northwestward E × B flows ranging from a couple of hundred m s-1 to > 1 km s-1. Upward vertical flows due to the projection of these E × B drifts are mainly responsible for lifting the plasma in sunlit regions to higher altitude and thus leading to plume density enhancement. The upward vertical flows near the poleward part of the plumes are more persistent, while those near the equatorward part are more patchy. In addition, the plumes can be collocated with either upward or downward field-<span class="hlt">aligned</span> <span class="hlt">currents</span> (<span class="hlt">FACs</span>) but are usually observed equatorward of the peak of the Region 1 upward <span class="hlt">FAC</span>, suggesting that the northwestward flows collocated with plumes can be either subauroral or auroral flows. Furthermore, during the decay phase of the plume, large downward ion flows, as large as ~200 m s-1, and downward fluxes, as large as 1014 m-2 s-1, are often observed within the plumes. In our study of six storms, enhanced ambipolar diffusion due to an elevated pressure gradient is able to explain two of the four large downward flow/flux cases, but this mechanism is not sufficient for the other two cases where the flows are of larger</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20739310','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20739310"><span>GASSST: global <span class="hlt">alignment</span> short sequence search tool.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rizk, Guillaume; Lavenier, Dominique</p> <p>2010-10-15</p> <p>The rapid development of next-generation sequencing technologies able to produce huge amounts of sequence data is leading to a wide range of new applications. This triggers the need for fast and accurate <span class="hlt">alignment</span> software. Common techniques often restrict indels in the <span class="hlt">alignment</span> to improve speed, whereas more flexible <span class="hlt">aligners</span> are too slow for large-scale applications. Moreover, many <span class="hlt">current</span> <span class="hlt">aligners</span> are becoming inefficient as generated reads grow ever larger. Our goal with our new <span class="hlt">aligner</span> GASSST (Global <span class="hlt">Alignment</span> Short Sequence Search Tool) is thus 2-fold-achieving high performance with no restrictions on the number of indels with a design that is still effective on long reads. We propose a new efficient filtering step that discards most <span class="hlt">alignments</span> coming from the seed phase before they are checked by the costly dynamic programming algorithm. We use a carefully designed series of filters of increasing complexity and efficiency to quickly eliminate most candidate <span class="hlt">alignments</span> in a wide range of configurations. The main filter uses a precomputed table containing the <span class="hlt">alignment</span> score of short four base words <span class="hlt">aligned</span> against each other. This table is reused several times by a new algorithm designed to approximate the score of the full dynamic programming algorithm. We compare the performance of GASSST against BWA, BFAST, SSAHA2 and PASS. We found that GASSST achieves high sensitivity in a wide range of configurations and faster overall execution time than other state-of-the-art <span class="hlt">aligners</span>. GASSST is distributed under the CeCILL software license at http://www.irisa.fr/symbiose/projects/gassst/ guillaume.rizk@irisa.fr; dominique.lavenier@irisa.fr Supplementary data are available at Bioinformatics online.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2951093','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2951093"><span>GASSST: global <span class="hlt">alignment</span> short sequence search tool</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rizk, Guillaume; Lavenier, Dominique</p> <p>2010-01-01</p> <p>Motivation: The rapid development of next-generation sequencing technologies able to produce huge amounts of sequence data is leading to a wide range of new applications. This triggers the need for fast and accurate <span class="hlt">alignment</span> software. Common techniques often restrict indels in the <span class="hlt">alignment</span> to improve speed, whereas more flexible <span class="hlt">aligners</span> are too slow for large-scale applications. Moreover, many <span class="hlt">current</span> <span class="hlt">aligners</span> are becoming inefficient as generated reads grow ever larger. Our goal with our new <span class="hlt">aligner</span> GASSST (Global <span class="hlt">Alignment</span> Short Sequence Search Tool) is thus 2-fold—achieving high performance with no restrictions on the number of indels with a design that is still effective on long reads. Results: We propose a new efficient filtering step that discards most <span class="hlt">alignments</span> coming from the seed phase before they are checked by the costly dynamic programming algorithm. We use a carefully designed series of filters of increasing complexity and efficiency to quickly eliminate most candidate <span class="hlt">alignments</span> in a wide range of configurations. The main filter uses a precomputed table containing the <span class="hlt">alignment</span> score of short four base words <span class="hlt">aligned</span> against each other. This table is reused several times by a new algorithm designed to approximate the score of the full dynamic programming algorithm. We compare the performance of GASSST against BWA, BFAST, SSAHA2 and PASS. We found that GASSST achieves high sensitivity in a wide range of configurations and faster overall execution time than other state-of-the-art <span class="hlt">aligners</span>. Availability: GASSST is distributed under the CeCILL software license at http://www.irisa.fr/symbiose/projects/gassst/ Contact: guillaume.rizk@irisa.fr; dominique.lavenier@irisa.fr Supplementary information: Supplementary data are available at Bioinformatics online. PMID:20739310</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27454115','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27454115"><span>Heuristics for multiobjective multiple sequence <span class="hlt">alignment</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Abbasi, Maryam; Paquete, Luís; Pereira, Francisco B</p> <p>2016-07-15</p> <p><span class="hlt">Aligning</span> multiple sequences arises in many tasks in Bioinformatics. However, the <span class="hlt">alignments</span> produced by the <span class="hlt">current</span> software packages are highly dependent on the parameters setting, such as the relative importance of opening gaps with respect to the increase of similarity. Choosing only one parameter setting may provide an undesirable bias in further steps of the analysis and give too simplistic interpretations. In this work, we reformulate multiple sequence <span class="hlt">alignment</span> from a multiobjective point of view. The goal is to generate several sequence <span class="hlt">alignments</span> that represent a trade-off between maximizing the substitution score and minimizing the number of indels/gaps in the sum-of-pairs score function. This trade-off gives to the practitioner further information about the similarity of the sequences, from which she could analyse and choose the most plausible <span class="hlt">alignment</span>. We introduce several heuristic approaches, based on local search procedures, that compute a set of sequence <span class="hlt">alignments</span>, which are representative of the trade-off between the two objectives (substitution score and indels). Several algorithm design options are discussed and analysed, with particular emphasis on the influence of the starting <span class="hlt">alignment</span> and neighborhood search definitions on the overall performance. A perturbation technique is proposed to improve the local search, which provides a wide range of high-quality <span class="hlt">alignments</span>. The proposed approach is tested experimentally on a wide range of instances. We performed several experiments with sequences obtained from the benchmark database BAliBASE 3.0. To evaluate the quality of the results, we calculate the hypervolume indicator of the set of score vectors returned by the algorithms. The results obtained allow us to identify reasonably good choices of parameters for our approach. Further, we compared our method in terms of correctly <span class="hlt">aligned</span> pairs ratio and columns correctly <span class="hlt">aligned</span> ratio with respect to reference <span class="hlt">alignments</span>. Experimental results show</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013JMoSt1032..118B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013JMoSt1032..118B"><span>Synthesis, and molecular sensing behavior of <span class="hlt">fac</span>-[Re(CO)3(κ2-N,N-dpksc)Cl], dpksc = di-2-pyridyl ketone semicarbazone</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bakir, Mohammed; Brown, Ordel</p> <p>2013-01-01</p> <p>When [Re(CO)5Cl] was allowed to react with di-2-pyridyl ketone semicarbazone hydrochloride (dpksc.HCl) in refluxing toluene, <span class="hlt">fac</span>-[Re(CO)3(κ2-N,N-dpksc)Cl] was isolated. The identity of <span class="hlt">fac</span>-[Re(CO)3(κ2-N,N-dpksc)Cl] was elucidated from the results of its elemental analysis and confirmed using a number of spectroscopic measurements. Spectroscopic measurements done on non-aqueous solvents divulged sensitivity of <span class="hlt">fac</span>-[Re(CO)3(κ2-N,N-dpksc)Cl] to changes in its surroundings. 1H NMR studies revealed significant solvent dependence as manifested by the chemical shift variations; the exchange of the amine protons with solvent deuterium in CDCl3 and d6-acetone; the temperature dependence of the chemical shifts of the amine and amide protons and insignificant temperature dependence of the aromatic proton. The electronic absorption spectra of <span class="hlt">fac</span>-[Re(CO)3(κ2-N,N-dpksc)Cl] measured on non-aqueous solvents disclosed two high energy intra-ligand charge transfer (ILCT) transitions. Optical measurements performed on protophilic solutions of <span class="hlt">fac</span>-[Re(CO)3(κ2-N,N-dpksc)Cl] in the presence of bases and acids showed the appearance and disappearance of a low energy ILCT electronic transitions and established reversible inter-conversion between <span class="hlt">fac</span>-[Re(CO)3(κ2-N,N-dpksc)Cl] and its conjugate base, <span class="hlt">fac</span>-[Re(CO)3(κ2-N,N-dpksc-H)Cl]-. Thermo-optical measurements done on protophilic solutions of <span class="hlt">fac</span>-[Re(CO)3(κ2-N,N-dpksc)Cl] disclosed the absence of thermal acid-base inter-conversion between <span class="hlt">fac</span>-[Re(CO)3(κ2-N,N-dpksc)Cl] and <span class="hlt">fac</span>-[Re(CO)3(κ2-N,N-dpksc-H)Cl]- and established reversible electronic transfer between the high energy electronic transitions of <span class="hlt">fac</span>-[Re(CO)3(κ2-N,N-dpksc)Cl]. Optosensing measurements done on protophilic solutions of <span class="hlt">fac</span>-[Re(CO)3(κ2-N,N-dpksc)Cl] showed acids and bases in concentrations as low as 1.00 × 10-10 M can be detected and determined using protophilic solutions of of <span class="hlt">fac</span>-[Re(CO)3(κ2-N,N-dpksc)Cl]. Electrochemical measurements on dmf solutions of <span class="hlt">fac</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27486160','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27486160"><span>Assessment of Fever Advisory Cards (<span class="hlt">FACs</span>) as an Initiative to Improve Febrile Neutropenia Management in a Regional Cancer Center Emergency Department.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kapil, Priyanka; MacMillan, Meghan; Carvalho, Maritza; Lymburner, Patricia; Fung, Ron; Almeida, Bernadette; Van Dorn, Laurie; Enright, Katherine</p> <p>2016-09-01</p> <p>We aimed to improve the time to antibiotics (TTA) for patients treated with chemotherapy who present to the emergency department (ED) with febrile neutropenia (FN) by using standardized fever advisory cards (<span class="hlt">FACs</span>). Patients treated with chemotherapy who visited the ED at the Peel Regional Cancer Center in Ontario, Canada, with suspected FN were identified, before (April 2012 to March 2013) and after (October 2013 to March 2014) <span class="hlt">FAC</span> implementation. The primary outcome of interest was TTA. Additional process measures included Canadian Triage and Acuity Scale score, time to physician assessment, and <span class="hlt">FAC</span> compliance. Outcomes were analyzed with descriptive statistics and control charts to determine whether the change in primary measures were within statistical control over time. Between the pre-<span class="hlt">FAC</span> cohort (n = 239) and post-<span class="hlt">FAC</span> cohort (n = 69), TTA did not change significantly post-<span class="hlt">FACs</span> (195 v 244 min, P = .09), with monthly averages demonstrating normal variation by statistical process control methodology. The introduction of <span class="hlt">FACs</span> increased the percentage of patients with correctly assigned Canadian Triage and Acuity Scale scores (87% v 100%) but did not affect time to physician assessment. Compliance with <span class="hlt">FACs</span> among patients was not ideal, with only 62.5% using them as intended. The distribution of <span class="hlt">FACs</span> was associated with an improved incidence of correct FN triaging but did not demonstrate a meaningful improvement in the quality of FN management. This may be explained by <span class="hlt">FAC</span> use among patients not being ideal. Next steps in the continued effort toward high-quality FN care include redesign of <span class="hlt">FACs</span>, reinforcement of provider and patient education, and ED outreach. Copyright © 2016 by American Society of Clinical Oncology.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1991SPIE.1494..377G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1991SPIE.1494..377G"><span>ORFEUS <span class="hlt">alignment</span> concept</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Graue, R.; Kampf, D.; Rippel, H.; Witte, G.</p> <p>1991-09-01</p> <p>The <span class="hlt">alignment</span> concept of ORFEUS, a short-term scientific space payload scheduled for launching by the STS in January 1993, is discussed. ORFEUS comprises two alternatively operating spectrometers (Echelle and Rowland) implemented in a CFC telescope with a 4-m tube length and an aperture of 1000 mm. The lightweight primary mirror has a focal length of 2426 mm. In order to achieve the required spectrometric high telescope resolution in the UV range (40-125 nm), a sophisticated <span class="hlt">alignment</span> concept was developed. The centering of the <span class="hlt">alignment</span> diaphragm (diameter: 15 microns) in the focus of the primary mirror has to be provided in the vertical tube position by means of an autocollimation telescope. The spectrometers have to be integrated into the horizontal telescope <span class="hlt">aligned</span> within a special antigravity device to reduce optical surface deformations and to ensure the optical performance of the primary. The <span class="hlt">alignment</span> of all optical components is to be performed in the visible spectral range.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3393670','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3393670"><span>Unequivocal Identification of Subpopulations in Putative Multiclonal Trypanosoma cruzi Strains by <span class="hlt">FACs</span> Single Cell Sorting and Genotyping</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Valadares, Helder Magno Silva; Pimenta, Juliana Ramos; Segatto, Marcela; Veloso, Vanja Maria; Gomes, Mônica Lúcia; Chiari, Egler; Gollob, Kenneth John; Bahia, Maria Terezinha; de Lana, Marta; Franco, Glória Regina; Machado, Carlos Renato; Pena, Sérgio Danilo Junho; Macedo, Andréa Mara</p> <p>2012-01-01</p> <p>Trypanosoma cruzi, the etiological agent of Chagas disease, is a polymorphic species. Evidence suggests that the majority of the T. cruzi populations isolated from afflicted humans, reservoir animals, or vectors are multiclonal. However, the extent and the complexity of multiclonality remain to be established, since aneuploidy cannot be excluded and <span class="hlt">current</span> conventional cloning methods cannot identify all the representative clones in an infection. To answer this question, we adapted a methodology originally described for analyzing single spermatozoids, to isolate and study single T. cruzi parasites. Accordingly, the cloning apparatus of a Fluorescence-Activated Cell Sorter (<span class="hlt">FACS</span>) was used to sort single T. cruzi cells directly into 96-wells microplates. Cells were then genotyped using two polymorphic genomic markers and four microsatellite loci. We validated this methodology by testing four T. cruzi populations: one control artificial mixture composed of two monoclonal populations – Silvio X10 cl1 (TcI) and Esmeraldo cl3 (TcII) – and three naturally occurring strains, one isolated from a vector (A316A R7) and two others derived from the first reported human case of Chagas disease. Using this innovative approach, we were able to successfully describe the whole complexity of these natural strains, revealing their multiclonal status. In addition, our results demonstrate that these T. cruzi populations are formed of more clones than originally expected. The method also permitted estimating of the proportion of each subpopulation of the tested strains. The single-cell genotyping approach allowed analysis of intrapopulation diversity at a level of detail not achieved previously, and may thus improve our comprehension of population structure and dynamics of T. cruzi. Finally, this methodology is capable to settle once and for all controversies on the issue of multiclonality. PMID:22802979</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('https://www.ncbi.nlm.nih.gov/pubmed/22802979','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22802979"><span>Unequivocal identification of subpopulations in putative multiclonal Trypanosoma cruzi strains by <span class="hlt">FACs</span> single cell sorting and genotyping.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Valadares, Helder Magno Silva; Pimenta, Juliana Ramos; Segatto, Marcela; Veloso, Vanja Maria; Gomes, Mônica Lúcia; Chiari, Egler; Gollob, Kenneth John; Bahia, Maria Terezinha; de Lana, Marta; Franco, Glória Regina; Machado, Carlos Renato; Pena, Sérgio Danilo Junho; Macedo, Andréa Mara</p> <p>2012-01-01</p> <p>Trypanosoma cruzi, the etiological agent of Chagas disease, is a polymorphic species. Evidence suggests that the majority of the T. cruzi populations isolated from afflicted humans, reservoir animals, or vectors are multiclonal. However, the extent and the complexity of multiclonality remain to be established, since aneuploidy cannot be excluded and <span class="hlt">current</span> conventional cloning methods cannot identify all the representative clones in an infection. To answer this question, we adapted a methodology originally described for analyzing single spermatozoids, to isolate and study single T. cruzi parasites. Accordingly, the cloning apparatus of a Fluorescence-Activated Cell Sorter (<span class="hlt">FACS</span>) was used to sort single T. cruzi cells directly into 96-wells microplates. Cells were then genotyped using two polymorphic genomic markers and four microsatellite loci. We validated this methodology by testing four T. cruzi populations: one control artificial mixture composed of two monoclonal populations--Silvio X10 cl1 (TcI) and Esmeraldo cl3 (TcII)--and three naturally occurring strains, one isolated from a vector (A316A R7) and two others derived from the first reported human case of Chagas disease. Using this innovative approach, we were able to successfully describe the whole complexity of these natural strains, revealing their multiclonal status. In addition, our results demonstrate that these T. cruzi populations are formed of more clones than originally expected. The method also permitted estimating of the proportion of each subpopulation of the tested strains. The single-cell genotyping approach allowed analysis of intrapopulation diversity at a level of detail not achieved previously, and may thus improve our comprehension of population structure and dynamics of T. cruzi. Finally, this methodology is capable to settle once and for all controversies on the issue of multiclonality.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23985742','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23985742"><span>Community shifts of actively growing lake bacteria after N-acetyl-glucosamine addition: improving the BrdU-<span class="hlt">FACS</span> method.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tada, Yuya; Grossart, Hans-Peter</p> <p>2014-02-01</p> <p>In aquatic environments, community dynamics of bacteria, especially actively growing bacteria (AGB), are tightly linked with dissolved organic matter (DOM) quantity and quality. We analyzed the community dynamics of DNA-synthesizing and accordingly AGB by linking an improved bromodeoxyuridine immunocytochemistry approach with fluorescence-activated cell sorting (BrdU-<span class="hlt">FACS</span>). <span class="hlt">FACS</span>-sorted cells of even oligotrophic ecosystems in winter were characterized by 16S rRNA gene analysis. In incubation experiments, we examined community shifts of AGB in response to the addition of N-acetyl-glucosamine (NAG), one of the most abundant aminosugars in aquatic systems. Our improved BrdU-<span class="hlt">FACS</span> analysis revealed that AGB winter communities of oligotrophic Lake Stechlin (northeastern Germany) substantially differ from those of total bacteria and consist of Alpha-, Beta-, Gamma-, Deltaproteobacteria, Actinobacteria, Candidatus OP10 and Chloroflexi. AGB populations with different BrdU-fluorescence intensities and cell sizes represented different phylotypes suggesting that single-cell growth potential varies at the taxon level. NAG incubation experiments demonstrated that a variety of widespread taxa related to Alpha-, Beta-, Gammaproteobacteria, Bacteroidetes, Actinobacteria, Firmicutes, Planctomycetes, Spirochaetes, Verrucomicrobia and Chloroflexi actively grow in the presence of NAG. The BrdU-<span class="hlt">FACS</span> approach enables detailed phylogenetic studies of AGB and, thus, to identify those phylotypes which are potential key players in aquatic DOM cycling.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20379604','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20379604"><span>Human mammalian cell sorting using a highly integrated micro-fabricated fluorescence-activated cell sorter (micro<span class="hlt">FACS</span>).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cho, Sung Hwan; Chen, Chun H; Tsai, Frank S; Godin, Jessica M; Lo, Yu-Hwa</p> <p>2010-06-21</p> <p>We demonstrate a high performance microfabricated <span class="hlt">FACS</span> system with highly integrated microfluidics, optics, acoustics, and electronics. Single cell manipulation at a high speed is made possible by the fast response time (approximately 0.1 ms) of the integrated PZT actuator and the nozzle structure at the sorting junction. A Teflon AF-coated optofluidic waveguide along the microfluidic channel guides the illumination light, enabling multi-spot detection, while a novel space-time coding technology enhances the detection sensitivity of the micro<span class="hlt">FACS</span> system. The real-time control loop system is implemented using a field-programmable-gate-array (FPGA) for automated and accurate sorting. The micro<span class="hlt">FACS</span> achieves a high purification enrichment factor: up to approximately 230 fold for both polystyrene microbeads and suspended human mammalian cells (K562) at a high throughput (>1000 cells s(-1)). The sorting mechanism is independent of cell properties such as size, density, and shape, thus the presented system can be applied to sort out any pure sub-populations. This new lab-on-a-chip <span class="hlt">FACS</span> system, therefore, holds promise to revolutionize microfluidic cytometers to meet cost, size, and performance goals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25193845','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25193845"><span>Synthesis of novel CeO2-BiVO4/<span class="hlt">FAC</span> composites with enhanced visible-light photocatalytic properties.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Jin; Wang, Bing; Li, Chuang; Cui, Hao; Zhai, Jianping; Li, Qin</p> <p>2014-09-01</p> <p>To utilize visible light more effectively in photocatalytic reactions, a fly ash cenosphere (<span class="hlt">FAC</span>)-supported CeO2-BiVO4 (CeO2-BiVO4/<span class="hlt">FAC</span>) composite photocatalyst was prepared by modified metalorganic decomposition and impregnation methods. The physical and photophysical properties of the composite have been characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and UV-Visible diffuse reflectance spectra. The XRD patterns exhibited characteristic diffraction peaks of both BiVO4 and CeO2 crystalline phases. The XPS results showed that Ce was present as both Ce(4+) and Ce(3+) oxidation states in CeO2 and dispersed on the surface of BiVO4 to constitute a p-n heterojunction composite. The absorption threshold of the CeO2-BiVO4/<span class="hlt">FAC</span> composite shifted to a longer wavelength in the UV-Vis absorption spectrum compared to the pure CeO2 and pure BiVO4. The composites exhibited enhanced photocatalytic activity for Methylene Blue (MB) degradation under visible light irradiation. It was found that the 7.5wt.% CeO2-BiVO4/<span class="hlt">FAC</span> composite showed the highest photocatalytic activity for MB dye wastewater treatment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18975933','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18975933"><span>Photochemical reactions of <span class="hlt">fac</span>-[Mn(CO)3(phen)imidazole]+: evidence for long-lived radical species intermediates.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>de Aguiar, Inara; Inglez, Simone D; Lima, Francisco C A; Daniel, Juliana F S; McGarvey, Bruce R; Tedesco, Antônio C; Carlos, Rose M</p> <p>2008-12-15</p> <p>The electronic absorption spectrum of <span class="hlt">fac</span>-[Mn(CO)(3)(phen)imH](+), <span class="hlt">fac</span>-1 in CH(2)Cl(2) is characterized by a strong absorption band at 378 nm (epsilon(max) = 3200 mol(-1) L cm(-1)). On the basis of quantum mechanical calculations, the visible absorption band has been assigned to ligand-to-ligand charge-transfer (LLCT, im-->phen) and metal-to-ligand charge-transfer (MLCT, Mn-->phen) charge transfer transition. When <span class="hlt">fac</span>-1 in CH(2)Cl(2) is irradiated with 350 nm continuous light, the absorption features are gradually shifted to represent those of the meridional complex mer-[Mn(CO)(3)(phen)imH](+), mer-1 (lambda(max) = 556 nm). The net photoreaction under these conditions is a photoisomerization, although, the presence of the long-lived radical species was also detected by (1)H NMR and FTIR spectroscopy. 355 nm continuous photolysis of <span class="hlt">fac</span>-1 in CH(3)CN solution also gives the long-lived intermediate which is readily trapped by metylviologen (MV(2+)) giving rise to the formation of the one-electron reduced methyl viologen (MV(*+)). The UV-vis spectra monitored during the slow (45 min) thermal back reaction exhibited isosbestic conversion at 426 nm. On the basis of spectroscopic techniques and quantum mechanical calculations, the role of the radicals produced is analyzed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4579026','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4579026"><span>Maq<span class="hlt">FACS</span> (Macaque Facial Action Coding System) can be used to document facial movements in Barbary macaques (Macaca sylvanus)</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Julle-Danière, Églantine; Whitehouse, Jamie; Joly, Marine; Gass, Carolin; Burrows, Anne M.; Waller, Bridget M.</p> <p>2015-01-01</p> <p>Human and non-human primates exhibit facial movements or displays to communicate with one another. The evolution of form and function of those displays could be better understood through multispecies comparisons. Anatomically based coding systems (Facial Action Coding Systems: <span class="hlt">FACS</span>) are developed to enable such comparisons because they are standardized and systematic and aid identification of homologous expressions underpinned by similar muscle contractions. To date, <span class="hlt">FACS</span> has been developed for humans, and subsequently modified for chimpanzees, rhesus macaques, orangutans, hylobatids, dogs, and cats. Here, we wanted to test whether the Maq<span class="hlt">FACS</span> system developed in rhesus macaques (Macaca mulatta) could be used to code facial movements in Barbary macaques (M. sylvanus), a species phylogenetically close to the rhesus macaques. The findings show that the facial movement capacity of Barbary macaques can be reliably coded using the Maq<span class="hlt">FACS</span>. We found differences in use and form of some movements, most likely due to specializations in the communicative repertoire of each species, rather than morphological differences. PMID:26401458</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110011832','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110011832"><span>Rotational <span class="hlt">Alignment</span> Altered by Source Position Correlations</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jacobs, Chris S.; Heflin, M. B.; Lanyi, G. E.; Sovers, O. J.; Steppe, J. A.</p> <p>2010-01-01</p> <p>In the construction of modern Celestial Reference Frames (CRFs) the overall rotational <span class="hlt">alignment</span> is only weakly constrained by the data. Therefore, common practice has been to apply a 3-dimensional No-Net-Rotation (NNR) constraint in order to <span class="hlt">align</span> an under-construction frame to the ICRF. We present evidence that correlations amongst source position parameters must be accounted for in order to properly <span class="hlt">align</span> a CRF at the 5-10 (mu)as level of uncertainty found in <span class="hlt">current</span> work. Failure to do so creates errors at the 10-40 (mu)as level.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AAS...21942421M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AAS...21942421M"><span>HETDEX: Optical <span class="hlt">Alignment</span> Of The Virus Spectrographs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martin, Emily; Marshall, J.; Rheault, J.; DePoy, D.; Prochaska, T.; Allen, R.; Hill, G.; HETDEX Collaboration</p> <p>2012-01-01</p> <p>We present an optical <span class="hlt">alignment</span> procedure for the Visible Integral-Field Replicable Unit Spectrograph (VIRUS) collimator. Texas A&M is helping to build the VIRUS spectrographs, designed in collaboration with The University of Texas at Austin. The Hobby Eberly Telescope Dark Energy Experiment (HETDEX) will use as many as 192 units of this instrument to search for answers regarding Dark Energy. Texas A&M is <span class="hlt">currently</span> assembling the collimators for VIRUS and designing <span class="hlt">alignment</span> fixtures to aid in the assembly. We used ZEMAX models of VIRUS optics made by UT engineers to analyze various <span class="hlt">alignment</span> methods we have considered. Our <span class="hlt">current</span> plan uses two steps to properly <span class="hlt">align</span> the collimator within the tolerance of 0.1-degrees. This will permit interchangeability among the various VIRUS parts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19760022260','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19760022260"><span>Shuttle onboard IMU <span class="hlt">alignment</span> methods</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Henderson, D. M.</p> <p>1976-01-01</p> <p>The <span class="hlt">current</span> approach to the shuttle IMU <span class="hlt">alignment</span> is based solely on the Apollo Deterministic Method. This method is simple, fast, reliable and provides an accurate estimate for the present cluster to mean of 1,950 transformation matrix. If four or more star sightings are available, the application of least squares analysis can be utilized. The least squares method offers the next level of sophistication to the IMU <span class="hlt">alignment</span> solution. The least squares method studied shows that a more accurate estimate for the misalignment angles is computed, and the IMU drift rates are a free by-product of the analysis. Core storage requirements are considerably more; estimated 20 to 30 times the core required for the Apollo Deterministic Method. The least squares method offers an intermediate solution utilizing as much data that is available without a complete statistical analysis as in Kalman filtering.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23140486','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23140486"><span>The tree <span class="hlt">alignment</span> problem.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Varón, Andrés; Wheeler, Ward C</p> <p>2012-11-09</p> <p>The inference of homologies among DNA sequences, that is, positions in multiple genomes that share a common evolutionary origin, is a crucial, yet difficult task facing biologists. Its computational counterpart is known as the multiple sequence <span class="hlt">alignment</span> problem. There are various criteria and methods available to perform multiple sequence <span class="hlt">alignments</span>, and among these, the minimization of the overall cost of the <span class="hlt">alignment</span> on a phylogenetic tree is known in combinatorial optimization as the Tree <span class="hlt">Alignment</span> Problem. This problem typically occurs as a subproblem of the Generalized Tree <span class="hlt">Alignment</span> Problem, which looks for the tree with the lowest <span class="hlt">alignment</span> cost among all possible trees. This is equivalent to the Maximum Parsimony problem when the input sequences are not <span class="hlt">aligned</span>, that is, when phylogeny and <span class="hlt">alignments</span> are simultaneously inferred. For large data sets, a popular heuristic is Direct Optimization (DO). DO provides a good tradeoff between speed, scalability, and competitive scores, and is implemented in the computer program POY. All other (competitive) algorithms have greater time complexities compared to DO. Here, we introduce and present experiments a new algorithm Affine-DO to accommodate the indel (<span class="hlt">alignment</span> gap) models commonly used in phylogenetic analysis of molecular sequence data. Affine-DO has the same time complexity as DO, but is correctly suited for the affine gap edit distance. We demonstrate its performance with more than 330,000 experimental tests. These experiments show that the solutions of Affine-DO are close to the lower bound inferred from a linear programming solution. Moreover, iterating over a solution produced using Affine-DO shows little improvement. Our results show that Affine-DO is likely producing near-optimal solutions, with approximations within 10% for sequences with small divergence, and within 30% for random sequences, for which Affine-DO produced the worst solutions. The Affine-DO algorithm has the necessary scalability and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3605350','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3605350"><span>The tree <span class="hlt">alignment</span> problem</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>2012-01-01</p> <p>Background The inference of homologies among DNA sequences, that is, positions in multiple genomes that share a common evolutionary origin, is a crucial, yet difficult task facing biologists. Its computational counterpart is known as the multiple sequence <span class="hlt">alignment</span> problem. There are various criteria and methods available to perform multiple sequence <span class="hlt">alignments</span>, and among these, the minimization of the overall cost of the <span class="hlt">alignment</span> on a phylogenetic tree is known in combinatorial optimization as the Tree <span class="hlt">Alignment</span> Problem. This problem typically occurs as a subproblem of the Generalized Tree <span class="hlt">Alignment</span> Problem, which looks for the tree with the lowest <span class="hlt">alignment</span> cost among all possible trees. This is equivalent to the Maximum Parsimony problem when the input sequences are not <span class="hlt">aligned</span>, that is, when phylogeny and <span class="hlt">alignments</span> are simultaneously inferred. Results For large data sets, a popular heuristic is Direct Optimization (DO). DO provides a good tradeoff between speed, scalability, and competitive scores, and is implemented in the computer program POY. All other (competitive) algorithms have greater time complexities compared to DO. Here, we introduce and present experiments a new algorithm Affine-DO to accommodate the indel (<span class="hlt">alignment</span> gap) models commonly used in phylogenetic analysis of molecular sequence data. Affine-DO has the same time complexity as DO, but is correctly suited for the affine gap edit distance. We demonstrate its performance with more than 330,000 experimental tests. These experiments show that the solutions of Affine-DO are close to the lower bound inferred from a linear programming solution. Moreover, iterating over a solution produced using Affine-DO shows little improvement. Conclusions Our results show that Affine-DO is likely producing near-optimal solutions, with approximations within 10% for sequences with small divergence, and within 30% for random sequences, for which Affine-DO produced the worst solutions. The Affine-DO algorithm has</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3875414','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3875414"><span><span class="hlt">FACS</span>-Based Isolation, Propagation and Characterization of Mouse Embryonic Cardiomyocytes Based on VCAM-1 Surface Marker Expression</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Pontén, Annica; Walsh, Stuart; Malan, Daniela; Xian, Xiaojie; Schéele, Susanne; Tarnawski, Laura; Fleischmann, Bernd K.; Jovinge, Stefan</p> <p>2013-01-01</p> <p>Purification of cardiomyocytes from the embryonic mouse heart, embryonic stem (ES) or induced pluripotent stem cells (iPS) is a challenging task and will require specific isolation procedures. Lately the significance of surface markers for the isolation of cardiac cell populations with fluorescence activated cell sorting (<span class="hlt">FACS</span>) has been acknowledged, and the hunt for cardiac specific markers has intensified. As cardiomyocytes have traditionally been characterized by their expression of specific transcription factors and structural proteins, and not by specific surface markers, this constitutes a significant bottleneck. Lately, Flk-1, c-kit and the cellular prion protein have been reported to specify cardiac progenitors, however, no surface markers have so far been reported to specify a committed cardiomyocyte. Herein show for the first time, that embryonic cardiomyocytes can be isolated with 98% purity, based on their expression of vascular cell adhesion molecule-1 (VCAM-1). The <span class="hlt">FACS</span>-isolated cells express phenotypic markers for embryonic committed cardiomyocytes but not cardiac progenitors. An important aspect of <span class="hlt">FACS</span> is to provide viable cells with retention of functionality. We show that VCAM-1 positive cardiomyocytes can be isolated with 95% viability suitable for in vitro culture, functional assays or expression analysis. In patch-clamp experiments we provide evidence of functionally intact cardiomyocytes of both atrial and ventricular subtypes. This work establishes that cardiomyocytes can be isolated with a high degree of purity and viability through <span class="hlt">FACS</span>, based on specific surface marker expression as has been done in the hematopoietic field for decades. Our <span class="hlt">FACS</span> protocol represents a significant advance in which purified populations of cardiomyocytes may be isolated and utilized for downstream applications, such as purification of ES-cell derived cardiomyocytes. PMID:24386094</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24386094','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24386094"><span><span class="hlt">FACS</span>-based isolation, propagation and characterization of mouse embryonic cardiomyocytes based on VCAM-1 surface marker expression.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pontén, Annica; Walsh, Stuart; Malan, Daniela; Xian, Xiaojie; Schéele, Susanne; Tarnawski, Laura; Fleischmann, Bernd K; Jovinge, Stefan</p> <p>2013-01-01</p> <p>Purification of cardiomyocytes from the embryonic mouse heart, embryonic stem (ES) or induced pluripotent stem cells (iPS) is a challenging task and will require specific isolation procedures. Lately the significance of surface markers for the isolation of cardiac cell populations with fluorescence activated cell sorting (<span class="hlt">FACS</span>) has been acknowledged, and the hunt for cardiac specific markers has intensified. As cardiomyocytes have traditionally been characterized by their expression of specific transcription factors and structural proteins, and not by specific surface markers, this constitutes a significant bottleneck. Lately, Flk-1, c-kit and the cellular prion protein have been reported to specify cardiac progenitors, however, no surface markers have so far been reported to specify a committed cardiomyocyte. Herein show for the first time, that embryonic cardiomyocytes can be isolated with 98% purity, based on their expression of vascular cell adhesion molecule-1 (VCAM-1). The <span class="hlt">FACS</span>-isolated cells express phenotypic markers for embryonic committed cardiomyocytes but not cardiac progenitors. An important aspect of <span class="hlt">FACS</span> is to provide viable cells with retention of functionality. We show that VCAM-1 positive cardiomyocytes can be isolated with 95% viability suitable for in vitro culture, functional assays or expression analysis. In patch-clamp experiments we provide evidence of functionally intact cardiomyocytes of both atrial and ventricular subtypes. This work establishes that cardiomyocytes can be isolated with a high degree of purity and viability through <span class="hlt">FACS</span>, based on specific surface marker expression as has been done in the hematopoietic field for decades. Our <span class="hlt">FACS</span> protocol represents a significant advance in which purified populations of cardiomyocytes may be isolated and utilized for downstream applications, such as purification of ES-cell derived cardiomyocytes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27306043','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27306043"><span>Theoretical study on mechanism of the photochemical ligand substitution of <span class="hlt">fac</span>-[Re(I)(bpy)(CO)3(PR3)](+) complex.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Saita, Kenichiro; Harabuchi, Yu; Taketsugu, Tetsuya; Ishitani, Osamu; Maeda, Satoshi</p> <p>2016-07-14</p> <p>The mechanism of the CO ligand dissociation of <span class="hlt">fac</span>-[Re(I)(bpy)(CO)3P(OMe)3](+) has theoretically been investigated, as the dominant process of the photochemical ligand substitution (PLS) reactions of <span class="hlt">fac</span>-[Re(I)(bpy)(CO)3PR3](+), by using the (TD-)DFT method. The PLS reactivity can be determined by the topology of the T1 potential energy surface because the photoexcited complex is able to decay into the T1 state by internal conversions (through conical intersections) and intersystem crossings (via crossing seams) with sufficiently low energy barriers. The T1 state has a character of the metal-to-ligand charge-transfer ((3)MLCT) around the Franck-Condon region, and it changes to the metal-centered ((3)MC) state as the Re-CO bond is elongated and bent. The equatorial CO ligand has a much higher energy barrier to leave than that of the axial CO, so that the axial CO ligand selectively dissociates in the PLS reaction. The single-component artificial force induced reaction (SC-AFIR) search reveals the CO dissociation pathway in photostable <span class="hlt">fac</span>-[Re(I)(bpy)(CO)3Cl]; however, the dissociation barrier on the T1 state is substantially higher than that in <span class="hlt">fac</span>-[Re(I)(bpy)(CO)3PR3](+) and the minimum-energy seams of crossings (MESXs) are located before and below the barrier. The MESXs have also been searched in <span class="hlt">fac</span>-[Re(I)(bpy)(CO)3PR3](+) and no MESXs were found before and below the barrier.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/biblio/6178080','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/biblio/6178080"><span>Precision <span class="hlt">alignment</span> device</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Jones, N.E.</p> <p>1988-03-10</p> <p>Apparatus for providing automatic <span class="hlt">alignment</span> of beam devices having an associated structure for directing, collimating, focusing, reflecting, or otherwise modifying the main beam. A reference laser is attached to the structure enclosing the main beam producing apparatus and produces a reference beam substantially parallel to the main beam. Detector modules containing optical switching devices and optical detectors are positioned in the path of the reference beam and are effective to produce an electrical output indicative of the <span class="hlt">alignment</span> of the main beam. This electrical output drives servomotor operated adjustment screws to adjust the position of elements of the structure associated with the main beam to maintain <span class="hlt">alignment</span> of the main beam. 5 figs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/867295','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/867295"><span>Precision <span class="hlt">alignment</span> device</span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Jones, Nelson E.</p> <p>1990-01-01</p> <p>Apparatus for providing automatic <span class="hlt">alignment</span> of beam devices having an associated structure for directing, collimating, focusing, reflecting, or otherwise modifying the main beam. A reference laser is attached to the structure enclosing the main beam producing apparatus and produces a reference beam substantially parallel to the main beam. Detector modules containing optical switching devices and optical detectors are positioned in the path of the reference beam and are effective to produce an electrical output indicative of the <span class="hlt">alignment</span> of the main beam. This electrical output drives servomotor operated adjustment screws to adjust the position of elements of the structure associated with the main beam to maintain <span class="hlt">alignment</span> of the main beam.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/873815','DOE-PATENT-XML'); return false;" href="http://www.osti.gov/scitech/servlets/purl/873815"><span>Hybrid vehicle motor <span class="hlt">alignment</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/doepatents">DOEpatents</a></p> <p>Levin, Michael Benjamin</p> <p>2001-07-03</p> <p>A rotor of an electric motor for a motor vehicle is <span class="hlt">aligned</span> to an axis of rotation for a crankshaft of an internal combustion engine having an internal combustion engine and an electric motor. A locator is provided on the crankshaft, a piloting tool is located radially by the first locator to the crankshaft. A stator of the electric motor is <span class="hlt">aligned</span> to a second locator provided on the piloting tool. The stator is secured to the engine block. The rotor is <span class="hlt">aligned</span> to the crankshaft and secured thereto.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3647543','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3647543"><span>Implementation of a Parallel Protein Structure <span class="hlt">Alignment</span> Service on Cloud</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hung, Che-Lun; Lin, Yaw-Ling</p> <p>2013-01-01</p> <p>Protein structure <span class="hlt">alignment</span> has become an important strategy by which to identify evolutionary relationships between protein sequences. Several <span class="hlt">alignment</span> tools are <span class="hlt">currently</span> available for online comparison of protein structures. In this paper, we propose a parallel protein structure <span class="hlt">alignment</span> service based on the Hadoop distribution framework. This service includes a protein structure <span class="hlt">alignment</span> algorithm, a refinement algorithm, and a MapReduce programming model. The refinement algorithm refines the result of <span class="hlt">alignment</span>. To process vast numbers of protein structures in parallel, the <span class="hlt">alignment</span> and refinement algorithms are implemented using MapReduce. We analyzed and compared the structure <span class="hlt">alignments</span> produced by different methods using a dataset randomly selected from the PDB database. The experimental results verify that the proposed algorithm refines the resulting <span class="hlt">alignments</span> more accurately than existing algorithms. Meanwhile, the computational performance of the proposed service is proportional to the number of processors used in our cloud platform. PMID:23671842</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23671842','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23671842"><span>Implementation of a parallel protein structure <span class="hlt">alignment</span> service on cloud.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hung, Che-Lun; Lin, Yaw-Ling</p> <p>2013-01-01</p> <p>Protein structure <span class="hlt">alignment</span> has become an important strategy by which to identify evolutionary relationships between protein sequences. Several <span class="hlt">alignment</span> tools are <span class="hlt">currently</span> available for online comparison of protein structures. In this paper, we propose a parallel protein structure <span class="hlt">alignment</span> service based on the Hadoop distribution framework. This service includes a protein structure <span class="hlt">alignment</span> algorithm, a refinement algorithm, and a MapReduce programming model. The refinement algorithm refines the result of <span class="hlt">alignment</span>. To process vast numbers of protein structures in parallel, the <span class="hlt">alignment</span> and refinement algorithms are implemented using MapReduce. We analyzed and compared the structure <span class="hlt">alignments</span> produced by different methods using a dataset randomly selected from the PDB database. The experimental results verify that the proposed algorithm refines the resulting <span class="hlt">alignments</span> more accurately than existing algorithms. Meanwhile, the computational performance of the proposed service is proportional to the number of processors used in our cloud platform.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25099134','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25099134"><span>Reform<span class="hlt">Align</span>: improved multiple sequence <span class="hlt">alignments</span> using a profile-based meta-<span class="hlt">alignment</span> approach.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lyras, Dimitrios P; Metzler, Dirk</p> <p>2014-08-07</p> <p>Obtaining an accurate sequence <span class="hlt">alignment</span> is fundamental for consistently analyzing biological data. Although this problem may be efficiently solved when only two sequences are considered, the exact inference of the optimal <span class="hlt">alignment</span> easily gets computationally intractable for the multiple sequence <span class="hlt">alignment</span> case. To cope with the high computational expenses, approximate heuristic methods have been proposed that address the problem indirectly by progressively <span class="hlt">aligning</span> the sequences in pairs according to their relatedness. These methods however are not flexible to change the <span class="hlt">alignment</span> of an already <span class="hlt">aligned</span> group of sequences in the view of new data, resulting thus in compromises on the quality of the deriving <span class="hlt">alignment</span>. In this paper we present Reform<span class="hlt">Align</span>, a novel meta-<span class="hlt">alignment</span> approach that may significantly improve on the quality of the deriving <span class="hlt">alignments</span> from popular <span class="hlt">aligners</span>. We call Reform<span class="hlt">Align</span> a meta-<span class="hlt">aligner</span> as it requires an initial <span class="hlt">alignment</span>, for which a variety of <span class="hlt">alignment</span> programs can be used. The main idea behind Reform<span class="hlt">Align</span> is quite straightforward: at first, an existing <span class="hlt">alignment</span> is used to construct a standard profile which summarizes the initial <span class="hlt">alignment</span> and then all sequences are individually re-<span class="hlt">aligned</span> against the formed profile. From each sequence-profile comparison, the <span class="hlt">alignment</span> of each sequence against the profile is recorded and the final <span class="hlt">alignment</span> is indirectly inferred by merging all the individual sub-<span class="hlt">alignments</span> into a unified set. The employment of Reform<span class="hlt">Align</span> may often result in <span class="hlt">alignments</span> which are significantly more accurate than the starting <span class="hlt">alignments</span>. We evaluated the effect of Reform<span class="hlt">Align</span> on the generated <span class="hlt">alignments</span> from ten leading <span class="hlt">alignment</span> methods using real data of variable size and sequence identity. The experimental results suggest that the proposed meta-<span class="hlt">aligner</span> approach may often lead to statistically significant more accurate <span class="hlt">alignments</span>. Furthermore, we show that Reform<span class="hlt">Align</span> results in more substantial improvement in</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('https://www.ncbi.nlm.nih.gov/pubmed/27420611','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27420611"><span>Shod wear and foot <span class="hlt">alignment</span> in clinical gait analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Louey, Melissa Gar Yee; Sangeux, Morgan</p> <p>2016-09-01</p> <p>Sagittal plane <span class="hlt">alignment</span> of the foot presents challenges when the subject wears shoes during gait analysis. Typically, visual <span class="hlt">alignment</span> is performed by positioning two markers, the heel and toe markers, <span class="hlt">aligned</span> with the foot within the shoe. Alternatively, software <span class="hlt">alignment</span> is possible when the sole of the shoe lies parallel to the ground, and the change in the shoe's sole thickness is measured and entered as a parameter. The aim of this technical note was to evaluate the accuracy of visual and software foot <span class="hlt">alignment</span> during shod gait analysis. We calculated the static standing ankle angles of 8 participants (mean age: 8.7 years, SD: 2.9 years) wearing bilateral solid ankle foot orthoses (BSAFOs) with and without shoes using the visual and software <span class="hlt">alignment</span> methods. All participants were able to stand with flat feet in both static trials and the ankle angles obtained in BSAFOs without shoes was considered the reference. We showed that the <span class="hlt">current</span> implementation of software <span class="hlt">alignment</span> introduces a bias towards more ankle dorsiflexion, mean=3°, SD=3.4°, p=0.006, and proposed an adjusted software <span class="hlt">alignment</span> method. We found no statistical differences using visual <span class="hlt">alignment</span> and adjusted software <span class="hlt">alignment</span> between the shoe and shoeless conditions, p=0.19 for both. Visual <span class="hlt">alignment</span> or adjusted software <span class="hlt">alignment</span> are advised to represent foot <span class="hlt">alignment</span> accurately.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986radc.rept.....B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986radc.rept.....B"><span><span class="hlt">Alignment</span> of tactical tropo antennas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bradley, Philip A.</p> <p>1986-07-01</p> <p><span class="hlt">Alignment</span> problems of parabolic reflector antennas for troposcatter radio communications are analyzed. Defects of previous <span class="hlt">alignment</span> techniques are delineated and a new technique for automatic antenna <span class="hlt">alignment</span> is presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3114744','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3114744"><span>Meta-<span class="hlt">Alignment</span> with Crumble and Prune: Partitioning very large <span class="hlt">alignment</span> problems for performance and parallelization</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>2011-01-01</p> <p>Background Continuing research into the global multiple sequence <span class="hlt">alignment</span> problem has resulted in more sophisticated and principled <span class="hlt">alignment</span> methods. Unfortunately these new algorithms often require large amounts of time and memory to run, making it nearly impossible to run these algorithms on large datasets. As a solution, we present two general methods, Crumble and Prune, for breaking a phylogenetic <span class="hlt">alignment</span> problem into smaller, more tractable sub-problems. We call Crumble and Prune meta-<span class="hlt">alignment</span> methods because they use existing <span class="hlt">alignment</span> algorithms and can be used with many <span class="hlt">current</span> <span class="hlt">alignment</span> programs. Crumble breaks long <span class="hlt">alignment</span> problems into shorter sub-problems. Prune divides the phylogenetic tree into a collection of smaller trees to reduce the number of sequences in each <span class="hlt">alignment</span> problem. These methods are orthogonal: they can be applied together to provide better scaling in terms of sequence length and in sequence depth. Both methods partition the problem such that many of the sub-problems can be solved independently. The results are then combined to form a solution to the full <span class="hlt">alignment</span> problem. Results Crumble and Prune each provide a significant performance improvement with little loss of accuracy. In some cases, a gain in accuracy was observed. Crumble and Prune were tested on real and simulated data. Furthermore, we have implemented a system called Job-tree that allows hierarchical sub-problems to be solved in parallel on a compute cluster, significantly shortening the run-time. Conclusions These methods enabled us to solve gigabase <span class="hlt">alignment</span> problems. These methods could enable a new generation of biologically realistic <span class="hlt">alignment</span> algorithms to be applied to real world, large scale <span class="hlt">alignment</span> problems. PMID:21569267</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1232140','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1232140"><span>Pairwise Sequence <span class="hlt">Alignment</span> Library</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jeff Daily, PNNL</p> <p>2015-05-20</p> <p>Vector extensions, such as SSE, have been part of the x86 CPU since the 1990s, with applications in graphics, signal processing, and scientific applications. Although many algorithms and applications can naturally benefit from automatic vectorization techniques, there are still many that are difficult to vectorize due to their dependence on irregular data structures, dense branch operations, or data dependencies. Sequence <span class="hlt">alignment</span>, one of the most widely used operations in bioinformatics workflows, has a computational footprint that features complex data dependencies. The trend of widening vector registers adversely affects the state-of-the-art sequence <span class="hlt">alignment</span> algorithm based on striped data layouts. Therefore, a novel SIMD implementation of a parallel scan-based sequence <span class="hlt">alignment</span> algorithm that can better exploit wider SIMD units was implemented as part of the Parallel Sequence <span class="hlt">Alignment</span> Library (parasail). Parasail features: Reference implementations of all known vectorized sequence <span class="hlt">alignment</span> approaches. Implementations of Smith Waterman (SW), semi-global (SG), and Needleman Wunsch (NW) sequence <span class="hlt">alignment</span> algorithms. Implementations across all modern CPU instruction sets including AVX2 and KNC. Language interfaces for C/C++ and Python.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007LNCS.4825..494T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007LNCS.4825..494T"><span>A Method for Recommending Ontology <span class="hlt">Alignment</span> Strategies</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tan, He; Lambrix, Patrick</p> <p></p> <p>In different areas ontologies have been developed and many of these ontologies contain overlapping information. Often we would therefore want to be able to use multiple ontologies. To obtain good results, we need to find the relationships between terms in the different ontologies, i.e. we need to <span class="hlt">align</span> them. <span class="hlt">Currently</span>, there already exist a number of different <span class="hlt">alignment</span> strategies. However, it is usually difficult for a user that needs to <span class="hlt">align</span> two ontologies to decide which of the different available strategies are the most suitable. In this paper we propose a method that provides recommendations on <span class="hlt">alignment</span> strategies for a given <span class="hlt">alignment</span> problem. The method is based on the evaluation of the different available <span class="hlt">alignment</span> strategies on several small selected pieces from the ontologies, and uses the evaluation results to provide recommendations. In the paper we give the basic steps of the method, and then illustrate and discuss the method in the setting of an <span class="hlt">alignment</span> problem with two well-known biomedical ontologies. We also experiment with different implementations of the steps in the method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28287544','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28287544"><span>Single-cell Gene Expression Profiling Using <span class="hlt">FACS</span> and qPCR with Internal Standards.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Porter, Joshua R; Telford, William G; Batchelor, Eric</p> <p>2017-02-25</p> <p>Gene expression measurements from bulk populations of cells can obscure the considerable transcriptomic variation of individual cells within those populations. Single-cell gene expression measurements can help assess the role of noise in gene expression, identify correlations in the expression of pairs of genes, and reveal subpopulations of cells that respond differently to a stimulus. Here, we describe a procedure to measure the expression of up to 96 genes in single mammalian cells isolated from a population growing in tissue culture. Cells are sorted into lysis buffer by fluorescence-activated cell sorting (<span class="hlt">FACS</span>), and the mRNA species of interest are reverse-transcribed and amplified. Gene expression is then measured using a microfluidic real-time PCR machine, which performs up to 96 qPCR assays on up to 96 samples at a time. We also describe the generation and use of PCR amplicon standards to enable the estimation of the absolute number of each transcript. Compared with other methods of measuring gene expression in single cells, this approach allows for the quantification of more distinct transcripts than RNA FISH at a lower cost than RNA-Seq.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26237570','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26237570"><span>Regional Cell Specific RNA Expression Profiling of <span class="hlt">FACS</span> Isolated Drosophila Intestinal Cell Populations.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dutta, Devanjali; Buchon, Nicolas; Xiang, Jinyi; Edgar, Bruce A</p> <p>2015-08-03</p> <p>The adult Drosophila midgut is built of five distinct cell types, including stem cells, enteroblasts, enterocytes, enteroendocrine cells, and visceral muscles, and is divided into five major regions (R1 to R5), which are morphologically and functionally distinct from each other. This unit describes a protocol for the isolation of Drosophila intestinal cell populations for the purpose of cell type-specific transcriptome profiling from the five different regions. A method to select a cell type of interest labeled with green or yellow fluorescent protein (GFP, YFP) by making use of the GAL4-UAS bipartite system and fluorescent-activated cell sorting (<span class="hlt">FACS</span>) is presented. Total RNA is isolated from the sorted cells of each region, and linear RNA amplification is used to obtain sufficient amounts of high-quality RNA for analysis by microarray, RT-PCR, or RNA sequencing. This method will be useful for quantitative transcriptome comparison across intestinal cell types in the different regions under normal and various experimental conditions. Copyright © 2015 John Wiley & Sons, Inc.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28207001','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28207001"><span>Genome editing using <span class="hlt">FACS</span> enrichment of nuclease-expressing cells and indel detection by amplicon analysis.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lonowski, Lindsey A; Narimatsu, Yoshiki; Riaz, Anjum; Delay, Catherine E; Yang, Zhang; Niola, Francesco; Duda, Katarzyna; Ober, Elke A; Clausen, Henrik; Wandall, Hans H; Hansen, Steen H; Bennett, Eric P; Frödin, Morten</p> <p>2017-03-01</p> <p>This protocol describes methods for increasing and evaluating the efficiency of genome editing based on the CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats-CRISPR-associated 9) system, transcription activator-like effector nucleases (TALENs) or zinc-finger nucleases (ZFNs). First, Indel Detection by Amplicon Analysis (IDAA) determines the size and frequency of insertions and deletions elicited by nucleases in cells, tissues or embryos through analysis of fluorophore-labeled PCR amplicons covering the nuclease target site by capillary electrophoresis in a sequenator. Second, <span class="hlt">FACS</span> enrichment of cells expressing nucleases linked to fluorescent proteins can be used to maximize knockout or knock-in editing efficiencies or to balance editing efficiency and toxic/off-target effects. The two methods can be combined to form a pipeline for cell-line editing that facilitates the testing of new nuclease reagents and the generation of edited cell pools or clonal cell lines, reducing the number of clones that need to be generated and increasing the ease with which they are screened. The pipeline shortens the time line, but it most prominently reduces the workload of cell-line editing, which may be completed within 4 weeks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=204107','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=204107"><span>Isolation and Characterization of Frankia sp. Strain <span class="hlt">FaC</span>1 Genes Involved in Nitrogen Fixation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ligon, James M.; Nakas, James P.</p> <p>1987-01-01</p> <p>Genomic DNA was isolated from Frankia sp. strain <span class="hlt">FaC</span>1, an Alnus root nodule endophyte, and used to construct a genomic library in the cosmid vector pHC79. The genomic library was screened by in situ colony hybridization to identify clones of Frankia nitrogenase (nif) genes based on DNA sequence homology to structural nitrogenase genes from Klebsiella pneumoniae. Several Frankia nif clones were isolated, and hybridization with individual structural nitrogenase gene fragments (nifH, nifD, and nifK) from K. pneumoniae revealed that they all contain the nifD and nifK genes, but lack the nifH gene. Restriction endonuclease mapping of the nifD and nifK hybridizing region from one clone revealed that the nifD and nifK genes in Frankia sp. are contiguous, while the nifH gene is absent from a large region of DNA on either side of the nifDK gene cluster. Additional hybridizations with gene fragments derived from K. pneumoniae as probes and containing other genes involved in nitrogen fixation demonstrated that the Frankia nifE and nifN genes, which play a role in the biosynthesis of the iron-molybdenum cofactor, are located adjacent to the nifDK gene cluster. Images PMID:16347453</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/20857956','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/20857956"><span>Fluorescent protein pair emit intracellular FRET signal suitable for <span class="hlt">FACS</span> screening</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Johansson, Daniel X.; Brismar, Hjalmar . E-mail: mats.persson@ki.se</p> <p>2007-01-12</p> <p>The fluorescent proteins ECFP and HcRed were shown to give an easily resolved FRET-signal when expressed as a fusion inside mammalian cells. HeLa-tat cells expressing ECFP, pHcRed, or the fusion protein pHcRed-ECFP were analyzed by flow cytometry after excitation of ECFP. Cells expressing HcRed-ECFP, or ECFP and HcRed, were mixed and <span class="hlt">FACS</span>-sorted for FRET positive cells: HcRed-ECFP cells were greatly enriched (72 times). Next, cloned human antibodies were fused with ECFP and expressed anchored to the ER membrane. Their cognate antigens (HIV-1 gp120 or gp41) were fused to HcRed and co-expressed in the ER. An increase of 13.5 {+-} 1.5% (mean {+-} SEM) and 8.0 {+-} 0.7% in ECFP fluorescence for the specific antibodies reacting with gp120 or gp41, respectively, was noted after photobleaching. A positive control (HcRed-ECFP) gave a 14.8 {+-} 2.6% increase. Surprisingly, the unspecific antibody (anti-TT) showed 12.1 {+-} 1.1% increase, possibly because overexpression in the limited ER compartment gave false FRET signals.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/923119','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/923119"><span>PDV Probe <span class="hlt">Alignment</span> Technique</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Whitworth, T L; May, C M; Strand, O T</p> <p>2007-10-26</p> <p>This <span class="hlt">alignment</span> technique was developed while performing heterodyne velocimetry measurements at LLNL. There are a few minor items needed, such as a white card with aperture in center, visible <span class="hlt">alignment</span> laser, IR back reflection meter, and a microscope to view the bridge surface. The work was performed on KCP flyers that were 6 and 8 mils wide. The probes used were Oz Optics manufactured with focal distances of 42mm and 26mm. Both probes provide a spot size of approximately 80?m at 1550nm. The 42mm probes were specified to provide an internal back reflection of -35 to -40dB, and the probe back reflections were measured to be -37dB and -33dB. The 26mm probes were specified as -30dB and both measured -30.5dB. The probe is initially <span class="hlt">aligned</span> normal to the flyer/bridge surface. This provides a very high return signal, up to -2dB, due to the bridge reflectivity. A white card with a hole in the center as an aperture can be used to check the reflected beam position relative to the probe and launch beam, and the <span class="hlt">alignment</span> laser spot centered on the bridge, see Figure 1 and Figure 2. The IR back reflection meter is used to measure the dB return from the probe and surface, and a white card or similar object is inserted between the probe and surface to block surface reflection. It may take several iterations between the visible <span class="hlt">alignment</span> laser and the IR back reflection meter to complete this <span class="hlt">alignment</span> procedure. Once <span class="hlt">aligned</span> normal to the surface, the probe should be tilted to position the visible <span class="hlt">alignment</span> beam as shown in Figure 3, and the flyer should be translated in the X and Y axis to reposition the <span class="hlt">alignment</span> beam onto the flyer as shown in Figure 4. This tilting of the probe minimizes the amount of light from the bridge reflection into the fiber within the probe while maintaining the <span class="hlt">alignment</span> as near normal to the flyer surface as possible. When the back reflection is measured after the tilt adjustment, the level should be about -3dB to -6dB higher than the probes</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=curriculum&pg=3&id=EJ965707','ERIC'); return false;" href="http://eric.ed.gov/?q=curriculum&pg=3&id=EJ965707"><span>Curriculum <span class="hlt">Alignment</span> Research Suggests that <span class="hlt">Alignment</span> Can Improve Student Achievement</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>Squires, David</p> <p>2012-01-01</p> <p>Curriculum <span class="hlt">alignment</span> research has developed showing the relationship among three <span class="hlt">alignment</span> categories: the taught curriculum, the tested curriculum and the written curriculum. Each pair (for example, the taught and the written curriculum) shows a positive impact for <span class="hlt">aligning</span> those results. Following this, <span class="hlt">alignment</span> results from the Third…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://eric.ed.gov/?q=curriculum&pg=3&id=EJ965707','ERIC'); return false;" href="https://eric.ed.gov/?q=curriculum&pg=3&id=EJ965707"><span>Curriculum <span class="hlt">Alignment</span> Research Suggests that <span class="hlt">Alignment</span> Can Improve Student Achievement</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>Squires, David</p> <p>2012-01-01</p> <p>Curriculum <span class="hlt">alignment</span> research has developed showing the relationship among three <span class="hlt">alignment</span> categories: the taught curriculum, the tested curriculum and the written curriculum. Each pair (for example, the taught and the written curriculum) shows a positive impact for <span class="hlt">aligning</span> those results. Following this, <span class="hlt">alignment</span> results from the Third…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23896286','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23896286"><span>Isolation of circulating tumor cells by immunomagnetic enrichment and fluorescence-activated cell sorting (IE/<span class="hlt">FACS</span>) for molecular profiling.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Magbanua, Mark Jesus M; Park, John W</p> <p>2013-12-01</p> <p>Circulating tumor cells (CTCs) are cells shed by the primary tumor into the blood stream capable of initiating distant metastasis. In the past decade, numerous assays have been developed to reliably detect these extremely rare cells. However, methods for purification of CTCs with little or no contamination of normal blood cells for molecular profiling are limited. We have developed a novel protocol to isolate CTCs by combining immunomagnetic enrichment and fluorescence-activated cell sorting (IE/<span class="hlt">FACS</span>). The two-part assay includes (1) immunomagnetic capture using magnetic beads conjugated to monoclonal antibody against an epithelial cell adhesion marker (EpCAM) to enrich for tumor cells; and (2) <span class="hlt">FACS</span> analysis using EpCAM to purify tumor cells away from mononuclear cells of hematopoietic lineage. Downstream molecular analyses of single and pooled cells confirmed the isolation of highly pure CTCs with characteristics typical that of malignant cells. Copyright © 2013 Elsevier Inc. All rights reserved.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/5617705','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/5617705"><span>Stromal cells in long-term murine bone marrow culture: <span class="hlt">FACS</span> studies and origin of stromal cells in radiation chimeras</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Lennon, J.E.; Micklem, H.S.</p> <p>1986-05-01</p> <p>Adherent layers from hematopoietically active long-term bone marrow cultures (LTBMC), incubated with fluorescent beads, were analyzed for autofluorescence and phagocytic ability, using a fluorescence-activated cell sorter (<span class="hlt">FACS</span>). Four groups of cells were separated from the adherent layers, including a group of large polygonal fibroblastoid stromal cells. Long-term chimeras were made by lethal irradiation of CBA/Ca (CBA) and C57Bl6/J (B6) mice and repopulation with phosphoglycerate kinase (PGK-1) alloenzyme-congenic bone marrow cells. Hematopoietically active LTBMC were established from such chimeras, and donor and host contributions of <span class="hlt">FACS</span>-sorted adherent-layer cells were measured. While macrophages and other hematopoietic cells were of donor origin, the fibroblastoid stromal cells were mainly or entirely host derived.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017JInst..12P2002M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017JInst..12P2002M"><span>Investigation of electron-loss and photon scattering correction factors for <span class="hlt">FAC</span>-IR-300 ionization chamber</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mohammadi, S. M.; Tavakoli-Anbaran, H.; Zeinali, H. Z.</p> <p>2017-02-01</p> <p>The parallel-plate free-air ionization chamber termed <span class="hlt">FAC</span>-IR-300 was designed at the Atomic Energy Organization of Iran, AEOI. This chamber is used for low and medium X-ray dosimetry on the primary standard level. In order to evaluate the air-kerma, some correction factors such as electron-loss correction factor (ke) and photon scattering correction factor (ksc) are needed. ke factor corrects the charge loss from the collecting volume and ksc factor corrects the scattering of photons into collecting volume. In this work ke and ksc were estimated by Monte Carlo simulation. These correction factors are calculated for mono-energy photon. As a result of the simulation data, the ke and ksc values for <span class="hlt">FAC</span>-IR-300 ionization chamber are 1.0704 and 0.9982, respectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5345794','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5345794"><span>The diagnostic accuracy of a single CEA blood test in detecting colorectal cancer recurrence: Results from the <span class="hlt">FACS</span> trial</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Nicholson, Brian D.; Primrose, John; Perera, Rafael; James, Timothy; Pugh, Sian; Mant, David</p> <p>2017-01-01</p> <p>Objective To evaluate the diagnostic accuracy of a single CEA (carcinoembryonic antigen) blood test in detecting colorectal cancer recurrence. Background Patients who have undergone curative resection for primary colorectal cancer are typically followed up with scheduled CEA testing for 5 years. Decisions to investigate further (usually by CT imaging) are based on single test results, reflecting international guidelines. Methods A secondary analysis was undertaken of data from the <span class="hlt">FACS</span> trial (two arms included CEA testing). The composite reference standard applied included CT-CAP imaging, clinical assessment and colonoscopy. Accuracy in detecting recurrence was evaluated in terms of sensitivity, specificity, likelihood ratios, predictive values, time-dependent area under the ROC curves, and operational performance when used prospectively in clinical practice are reported. Results Of 582 patients, 104 (17.9%) developed recurrence during the 5 year follow-up period. Applying the recommended threshold of 5μg/L achieves at best 50.0% sensitivity (95% CI: 40.1–59.9%); in prospective use in clinical practice it would lead to 56 missed recurrences (53.8%; 95% CI: 44.2–64.4%) and 89 false alarms (56.7% of 157 patients referred for investigation). Applying a lower threshold of 2.5μg/L would reduce the number of missed recurrences to 36.5% (95% CI: 26.5–46.5%) but would increase the false alarms to 84.2% (924/1097 referred). Some patients are more prone to false alarms than others—at the 5μg/L threshold, the 89 episodes of unnecessary investigation were clustered in 29 individuals. Conclusion Our results demonstrated very low sensitivity for CEA, bringing to question whether it could ever be used as an independent triage test. It is not feasible to improve the diagnostic performance of a single test result by reducing the recommended action threshold because of the workload and false alarms generated. <span class="hlt">Current</span> national and international guidelines merit re</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28282381','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28282381"><span>The diagnostic accuracy of a single CEA blood test in detecting colorectal cancer recurrence: Results from the <span class="hlt">FACS</span> trial.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Shinkins, Bethany; Nicholson, Brian D; Primrose, John; Perera, Rafael; James, Timothy; Pugh, Sian; Mant, David</p> <p>2017-01-01</p> <p>To evaluate the diagnostic accuracy of a single CEA (carcinoembryonic antigen) blood test in detecting colorectal cancer recurrence. Patients who have undergone curative resection for primary colorectal cancer are typically followed up with scheduled CEA testing for 5 years. Decisions to investigate further (usually by CT imaging) are based on single test results, reflecting international guidelines. A secondary analysis was undertaken of data from the <span class="hlt">FACS</span> trial (two arms included CEA testing). The composite reference standard applied included CT-CAP imaging, clinical assessment and colonoscopy. Accuracy in detecting recurrence was evaluated in terms of sensitivity, specificity, likelihood ratios, predictive values, time-dependent area under the ROC curves, and operational performance when used prospectively in clinical practice are reported. Of 582 patients, 104 (17.9%) developed recurrence during the 5 year follow-up period. Applying the recommended threshold of 5μg/L achieves at best 50.0% sensitivity (95% CI: 40.1-59.9%); in prospective use in clinical practice it would lead to 56 missed recurrences (53.8%; 95% CI: 44.2-64.4%) and 89 false alarms (56.7% of 157 patients referred for investigation). Applying a lower threshold of 2.5μg/L would reduce the number of missed recurrences to 36.5% (95% CI: 26.5-46.5%) but would increase the false alarms to 84.2% (924/1097 referred). Some patients are more prone to false alarms than others-at the 5μg/L threshold, the 89 episodes of unnecessary investigation were clustered in 29 individuals. Our results demonstrated very low sensitivity for CEA, bringing to question whether it could ever be used as an independent triage test. It is not feasible to improve the diagnostic performance of a single test result by reducing the recommended action threshold because of the workload and false alarms generated. <span class="hlt">Current</span> national and international guidelines merit re-evaluation and options to improve performance, such as making</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19920015553','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19920015553"><span>Optics <span class="hlt">Alignment</span> Panel</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Schroeder, Daniel J.</p> <p>1992-01-01</p> <p>The Optics <span class="hlt">Alignment</span> Panel (OAP) was commissioned by the HST Science Working Group to determine the optimum <span class="hlt">alignment</span> of the OTA optics. The goal was to find the position of the secondary mirror (SM) for which there is no coma or astigmatism in the camera images due to misaligned optics, either tilt or decenter. The despace position was reviewed of the SM and the optimum focus was sought. The results of these efforts are as follows: (1) the best estimate of the <span class="hlt">aligned</span> position of the SM in the notation of HDOS is (DZ,DY,TZ,TY) = (+248 microns, +8 microns, +53 arcsec, -79 arcsec), and (2) the best focus, defined to be that despace which maximizes the fractional energy at 486 nm in a 0.1 arcsec radius of a stellar image, is 12.2 mm beyond paraxial focus. The data leading to these conclusions, and the estimated uncertainties in the final results, are presented.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19890003471','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19890003471"><span>Improved docking <span class="hlt">alignment</span> system</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Monford, Leo G. (Inventor)</p> <p>1988-01-01</p> <p>Improved techniques are provided for the <span class="hlt">alignment</span> of two objects. The present invention is particularly suited for 3-D translation and 3-D rotational <span class="hlt">alignment</span> of objects in outer space. A camera is affixed to one object, such as a remote manipulator arm of the spacecraft, while the planar reflective surface is affixed to the other object, such as a grapple fixture. A monitor displays in real-time images from the camera such that the monitor displays both the reflected image of the camera and visible marking on the planar reflective surface when the objects are in proper <span class="hlt">alignment</span>. The monitor may thus be viewed by the operator and the arm manipulated so that the reflective surface is perpendicular to the optical axis of the camera, the roll of the reflective surface is at a selected angle with respect to the camera, and the camera is spaced a pre-selected distance from the reflective surface.</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><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><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" 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><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></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="481"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22407711','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22407711"><span>Whole-genome <span class="hlt">alignment</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dewey, Colin N</p> <p>2012-01-01</p> <p>Whole-genome <span class="hlt">alignment</span> (WGA) is the prediction of evolutionary relationships at the nucleotide level between two or more genomes. It combines aspects of both colinear sequence <span class="hlt">alignment</span> and gene orthology prediction, and is typically more challenging to address than either of these tasks due to the size and complexity of whole genomes. Despite the difficulty of this problem, numerous methods have been developed for its solution because WGAs are valuable for genome-wide analyses, such as phylogenetic inference, genome annotation, and function prediction. In this chapter, we discuss the meaning and significance of WGA and present an overview of the methods that address it. We also examine the problem of evaluating whole-genome <span class="hlt">aligners</span> and offer a set of methodological challenges that need to be tackled in order to make the most effective use of our rapidly growing databases of whole genomes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?