Inferred Cosmic-Ray Spectrum from Fermi-LAT Gamma-Ray Observations of the Earths Limb

NASA Technical Reports Server (NTRS)

Ackermann, M.; Ajello, M.; Albert, A.; Allafort, A.; Baldini, L.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Bellazzini, R.; Blandford, R. D.;

Two-dimensional radiative transfer for the retrieval of limb emission measurements in the martian atmosphere

NASA Astrophysics Data System (ADS)

Kleinböhl, Armin; Friedson, A. James; Schofield, John T.

2017-01-01

The remote sounding of infrared emission from planetary atmospheres using limb-viewing geometry is a powerful technique for deriving vertical profiles of structure and composition on a global scale. Compared with nadir viewing, limb geometry provides enhanced vertical resolution and greater sensitivity to atmospheric constituents. However, standard limb profile retrieval techniques assume spherical symmetry and are vulnerable to biases produced by horizontal gradients in atmospheric parameters. We present a scheme for the correction of horizontal gradients in profile retrievals from limb observations of the martian atmosphere. It characterizes horizontal gradients in temperature, pressure, and aerosol extinction along the line-of-sight of a limb view through neighboring measurements, and represents these gradients by means of two-dimensional radiative transfer in the forward model of the retrieval. The scheme is applied to limb emission measurements from the Mars Climate Sounder instrument on Mars Reconnaissance Orbiter. Retrieval simulations using data from numerical models indicate that biases of up to 10 K in the winter polar region, obtained with standard retrievals using spherical symmetry, are reduced to about 2 K in most locations by the retrieval with two-dimensional radiative transfer. Retrievals from Mars atmospheric measurements suggest that the two-dimensional radiative transfer greatly reduces biases in temperature and aerosol opacity caused by observational geometry, predominantly in the polar winter regions.

Simulating the Earth System Response to Negative Emissions

NASA Astrophysics Data System (ADS)

Jackson, R. B.; Milne, J.; Littleton, E. W.; Jones, C.; Canadell, J.; Peters, G. P.; van Vuuren, D.; Davis, S. J.; Jonas, M.; Smith, P.; Ciais, P.; Rogelj, J.; Torvanger, A.; Shrestha, G.

2016-12-01

The natural carbon sinks of the land and oceans absorb approximately half the anthropogenic CO2 emitted every year. The CO2 that is not absorbed accumulates in the Earth's atmosphere and traps the suns rays causing an increase in the global mean temperature. Removing this left over CO2 using negative emissions technologies (NETs) has been proposed as a strategy to lessen the accumulating CO2 and avoid dangerous climate change. Using CMIP5 Earth system model simulations this study assessed the impact on the global carbon cycle, and how the Earth system might respond, to negative emissions strategies applied to low emissions scenarios, over different times horizons from the year 2000 to 2300. The modeling results suggest that using NETs to remove atmospheric CO2 over five 50-year time horizons has varying effects at different points in time. The effects of anthropogenic and natural sources and sinks, can result in positive or negative changes in atmospheric CO2 concentration. Results show that historic emissions and the current state of the Earth System have impacts on the behavior of atmospheric CO2, as do instantaneous anthropogenic emissions. Indeed, varying background scenarios seemed to have a greater effect on atmospheric CO2 than the actual amount and timing of NETs. These results show how NETs interact with the physical climate-carbon cycle system and highlight the need for more research on earth-system dynamics as they relate to carbon sinks and sources and anthropogenic perturbations.

The solar XUV He I and He II emission lines. I - Intensities and gross center-to-limb behavior

NASA Technical Reports Server (NTRS)

Mango, S. A.; Bohlin, J. D.; Glackin, D. L.; Linsky, J. L.

1978-01-01

The center-to-limb variation of the He II 304- and 256-A lines and He I 584- and 537-A lines is derived for different solar features, but averaged over the chromospheric supergranulation structure. The general trend is for limb brightening in quiet-sun regions, limb neutrality in unipolar magnetic regions (UMR), and limb darkening in polar coronal holes. The center-to-limb behavior in these optically thick emission lines indicates collisional excitation and decreasing transition-region temperature gradients with respect to optical depth in the sequence quiet sun to UMR to coronal hole.

Inferred cosmic-ray spectrum from Fermi large area telescope γ-ray observations of Earth's limb.

PubMed

Ackermann, M; Ajello, M; Albert, A; Allafort, A; Baldini, L; Barbiellini, G; Bastieri, D; Bechtol, K; Bellazzini, R; Blandford, R D; Bloom, E D; Bonamente, E; Bottacini, E; Bouvier, A; Brandt, T J; Brigida, M; Bruel, P; Buehler, R; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Cecchi, C; Charles, E; Chaves, R C G; Chekhtman, A; Chiang, J; Chiaro, G; Ciprini, S; Claus, R; Cohen-Tanugi, J; Conrad, J; Cutini, S; Dalton, M; D'Ammando, F; de Angelis, A; de Palma, F; Dermer, C D; Digel, S W; Di Venere, L; do Couto e Silva, E; Drell, P S; Drlica-Wagner, A; Favuzzi, C; Fegan, S J; Ferrara, E C; Focke, W B; Franckowiak, A; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Germani, S; Giglietto, N; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Gomez-Vargas, G A; Grenier, I A; Grove, J E; Guiriec, S; Gustafsson, M; Hadasch, D; Hanabata, Y; Harding, A K; Hayashida, M; Hayashi, K; Hewitt, J W; Horan, D; Hou, X; Hughes, R E; Inoue, Y; Jackson, M S; Jogler, T; Jóhannesson, G; Johnson, A S; Kamae, T; Kawano, T; Knödlseder, J; Kuss, M; Lande, J; Larsson, S; Latronico, L; Longo, F; Loparco, F; Lovellette, M N; Lubrano, P; Mayer, M; Mazziotta, M N; McEnery, J E; Mehault, J; Michelson, P F; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monte, C; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nemmen, R; Nuss, E; Ohsugi, T; Okumura, A; Orienti, M; Orlando, E; Ormes, J F; Paneque, D; Panetta, J H; Perkins, J S; Pesce-Rollins, M; Piron, F; Pivato, G; Porter, T A; Rainò, S; Rando, R; Razzano, M; Razzaque, S; Reimer, A; Reimer, O; Ritz, S; Roth, M; Schaal, M; Schulz, A; Sgrò, C; Siskind, E J; Spandre, G; Spinelli, P; Strong, A W; Takahashi, H; Takeuchi, Y; Thayer, J G; Thayer, J B; Thompson, D J; Tibaldo, L; Tinivella, M; Torres, D F; Tosti, G; Troja, E; Tronconi, V; Usher, T L; Vandenbroucke, J; Vasileiou, V; Vianello, G; Vitale, V; Werner, M; Winer, B L; Wood, K S; Wood, M; Yang, Z

2014-04-18

Recent accurate measurements of cosmic-ray (CR) species by ATIC-2, CREAM, and PAMELA reveal an unexpected hardening in the proton and He spectra above a few hundred GeV, a gradual softening of the spectra just below a few hundred GeV, and a harder spectrum of He compared to that of protons. These newly discovered features may offer a clue to the origin of high-energy CRs. We use the Fermi Large Area Telescope observations of the γ-ray emission from Earth's limb for an indirect measurement of the local spectrum of CR protons in the energy range ∼90  GeV-6  TeV (derived from a photon energy range 15 GeV-1 TeV). Our analysis shows that single power law and broken power law spectra fit the data equally well and yield a proton spectrum with index 2.68±0.04 and 2.61±0.08 above ∼200  GeV, respectively.

An eruptive prominence and associated cm-mm emission outside the solar limb

NASA Technical Reports Server (NTRS)

Zodi, A. M.; Correia, E.; Costa, J. E. R.; Kaufmann, P.; Martin, S. F.

1988-01-01

Radio maps at 22 and 44 GHz are presented which show the emission before and after the eruption of a quiescent prominence located at the west limb. The observed radiation followng the eruption is not consistent with thermal bremsstrahlung mechanism. It can be interpreted as due to gyrosynchrotron emission of nonthermal electrons. The observations appear to be similar to the microwave radiation observed in post-flare loops. This radiation is due to nonthermal electrons trapped in the closed magnetic structures formed after the prominence eruption.

CO2 non-LTE limb emissions in Mars' atmosphere as observed by OMEGA/Mars Express

NASA Astrophysics Data System (ADS)

Piccialli, A.; López-Valverde, M. A.; Määttänen, A.; González-Galindo, F.; Audouard, J.; Altieri, F.; Forget, F.; Drossart, P.; Gondet, B.; Bibring, J. P.

2016-06-01

We report on daytime limb observations of Mars upper atmosphere acquired by the OMEGA instrument on board the European spacecraft Mars Express. The strong emission observed at 4.3 μm is interpreted as due to CO2 fluorescence of solar radiation and is detected at a tangent altitude in between 60 and 110 km. The main value of OMEGA observations is that they provide simultaneously spectral information and good spatial sampling of the CO2 emission. In this study we analyzed 98 dayside limb observations spanning over more than 3 Martian years, with a very good latitudinal and longitudinal coverage. Thanks to the precise altitude sounding capabilities of OMEGA, we extracted vertical profiles of the non-local thermodynamic equilibrium (non-LTE) emission at each wavelength and we studied their dependence on several geophysical parameters, such as the solar illumination and the tangent altitude. The dependence of the non-LTE emission on solar zenith angle and altitude follows a similar behavior to that predicted by the non-LTE model. According to our non-LTE model, the tangent altitude of the peak of the CO2 emission varies with the thermal structure, but the pressure level where the peak of the emission is found remains constant at ˜0.03 ± 0.01 Pa, . This non-LTE model prediction has been corroborated by comparing SPICAM and OMEGA observations. We have shown that the seasonal variations of the altitude of constant pressure levels in SPICAM stellar occultation retrievals correlate well with the variations of the OMEGA peak emission altitudes, although the exact pressure level cannot be defined with the spectroscopy for the investigation of the characteristics of the atmosphere of Venus (SPICAM) nighttime data. Thus, observed changes in the altitude of the peak emission provide us information on the altitude of the 0.03 Pa pressure level. Since the pressure at a given altitude is dictated by the thermal structure below, the tangent altitude of the peak emission represents

Remarkable Low Temperature Emission of the 4 November 2003 Limb Flare

NASA Astrophysics Data System (ADS)

Leibacher, J. W.; Harvey, J. W.; Kopp, G.; Hudson, H.; GONG Team

2004-05-01

Strong (> 1.5 times normal intensity) continuum and photospheric line emission of the 4 November 2003 X28 flare was recorded simultaneously by three widely separated GONG instruments. Emission was seen from on the disk to > 20" above the limb for nearly one hour, likely making this event the longest duration white light flare observed to date. GONG observations are one-minute duration integrations of intensity averaged across a Lyot filter bandpass of about 90 pm FWHM centered on the Ni I line at 676.8 nm with 2.5" instrument pixel size. Spatial resolution is limited by diffraction and seeing to greater than 5". Additional measurements include the Doppler shift and strength of the spectrum line. These latter measurements indicate that continuum and line emission contributed about equally to the observed intensity signal. Light curves and images of the flare show a notable two-kernel disk event starting at about 19:33 UTC followed by a much stronger event that peaked at about 19:44. Rare, white-light prominences were visible above the limb after 19:34. Comparison of total solar irradiance measurements from the TIM instrument on board the SORCE spacecraft with full-disk integrated GONG intensities shows the global five-minute oscillation and the white light flare. The latter is much weaker in the GONG data, suggesting that most of the TIM flare signal arises from other, most likely shorter, wavelengths. This work utilizes data obtained by the Global Oscillation Network Group (GONG) Program, managed by the National Solar Observatory, which is operated by AURA, Inc. under a cooperative agreement with the National Science Foundation. SORCE is supported by NASA NAS5-97045

Earth limb views with greenish bands of airglow during STS-99

NASA Image and Video Library

2000-04-06

STS099-355-024 (11-22 February 2000) -- Two separate atmospheric optical phenomena appear in this 35mm photograph captured from the Space Shuttle Endeavour. The thin greenish band above the horizon is airglow; radiation emitted by the atmosphere from a layer about 30-kilometers thick and about 100-kilometers' altitude. The predominant emission in airglow is the green 5577-Angstrom wavelength emission from atomic oxygen atoms, which is also the predominant emission from the aurora. A yellow-orange color is also seen in airglow, which is the emission of the 5800-Angstrom wavelength from sodium atoms. Airglow is always present in the atmosphere; it results from the recombination of molecules that have been broken apart by solar radiation during the day. But airglow is so faint that it can only be seen at night by looking "edge on" at the emission layer, such as the view that astronauts have in Earth orbit. The other phenomenon in the photo appears to be a faint, diffuse red aurora. Red aurora occur from about 200 kilometers to as high as 500 kilometers altitude only in the auroral zones at polar latitudes. They are caused by the emission of 6300- Angstrom wavelength light from oxygen atoms that have been raised to a higher energy level (excited) by collisions with energetic electrons pouring down from the Earth's magnetosphere. The light is emitted when the atoms return to their original unexcited state. With the red light so faint in this picture, scientists are led to believe that the flux density of incoming electrons was small. Also, since there is no green aurora below the red, that indicates that the energy of the incoming electrons was low - higher energy electrons would penetrate deeper into the atmosphere where the green aurora is energized.

The peculiarities of power terrestrial ELF emission in the Earth's ionosphere

NASA Astrophysics Data System (ADS)

Korepanov, Valery; Dudkin, Fedir; Pronenko, Vira; Chvach, Valery

2016-04-01

The near-Earth space is saturated with electromagnetic (EM) waves of terrestrial origin in a wide frequency range. The most powerful natural sources of EM emission are thunderstorms and triggered by them Schumann resonance (SR) radiation which is the narrowband EM noise that occurs due to the global thunderstorm activity in the Earth-ionosphere cavity in frequency range about 7-100 Hz. The considerable part of the terrestrial EM emission belongs to everyday human activity which increases year by year with unpredictable consequences. At the beginning of space exploration era it was considered that high frequency EM waves freely penetrate through the Earth's ionosphere, but the terrestrial EM emission below very low frequency range is limited by ionospheric F2 layer boundary due to great EM losses in plasma. About 40 years ago the power lines harmonic radiation (multiple of 50/60 Hz) was found at satellite observations in a few kilohertz range, nevertheless the ionosphere was considered fully opaque for extremely low frequency (ELF) EM emission. However recently, in spite of theoretical estimations, the SR harmonics and power line emission (PLE) 50/60 Hz were discovered during flights of low Earth orbiting satellites C/NOFS (Simões et al., 2011) and Chibis-M (Dudkin et al., 2015) at heights 400-800 km, i.e. over F2-layer. Last results are a great challenge to the theory of ELF EM emission propagation in the Earth's ionosphere as well as for study of long-term influence of constantly increasing electric energy consumption by human civilization in the Earth's environment. We present the analysis of the space and time distribution for observed PLE and SR harmonics, their connection with power terrestrial sources of ELF emission and possible relation between measured values and ionosphere conditions. Also some electromagnetic parameters have been estimated. Simões, F. A., R. F. Pfaff, and H. T. Freudenreich (2011), Satellite observations of Schumann resonances in the

Global-scale Observations of the Limb and Disk (GOLD): Science Implementation

NASA Astrophysics Data System (ADS)

Solomon, S. C.; McClintock, W. E.; Eastes, R.; Anderson, D. N.; Andersson, L.; Burns, A. G.; Codrescu, M.; Daniell, R. E.; England, S.; Eparvier, F. G.; Evans, J. S.; Krywonos, A.; Lumpe, J. D.; Richmond, A. D.; Rusch, D. W.; Siegmund, O.; Woods, T. N.

2017-12-01

The Global-scale Observations of the Limb and Disk (GOLD) is a NASA mission of opportunity that will image the Earth's thermosphere and ionosphere from geostationary orbit. GOLD will investigate how the thermosphere-ionosphere (T-I) system responds to geomagnetic storms, solar radiation, and upward propagating tides and how the structure of the equatorial ionosphere influences the formation and evolution of equatorial plasma density irregularities. GOLD consists of a pair of identical imaging spectrographs that will measure airglow emissions at far-ultraviolet wavelengths from 132 to 162 nm. On the disk, temperature and composition will be determined during the day using emissions from molecular nitrogen Lyman-Birge-Hopfield (LBH) band and atomic oxygen 135.6 nm, and electron density will be derived at night from 135.6 nm emission. On the limb, exospheric temperature will be derived from LBH emission profiles, and molecular oxygen density will be measured using stellar occultations. This presentation describes the GOLD mission science implementation including the as-built instrument performance and the planned observing scenario. It also describes the results of simulations performed by the GOLD team to validate that the measured instrument performance and observing plan will return adequate data to address the science objectives of the mission.

Premier's imaging IR limb sounder

NASA Astrophysics Data System (ADS)

Kraft, Stefan; Bézy, Jean-Loup; Meynart, Roland; Langen, Jörg; Carnicero Dominguez, Bernardo; Bensi, Paolo; Silvestrin, Pierluigi

2017-11-01

The Imaging IR Limb Sounder (IRLS) is one of the two instruments planned on board of the candidate Earth Explorer Core Mission PREMIER. PREMIER stands for PRocess Exploration through Measurements of Infrared and Millimetre-wave Emitted Radiation. PREMIER went recently through the process of a feasibility study (Phase A) within the Earth Observation Envelope Program. Emerging from recent advanced instrument technologies IRLS shall, next to a millimetre-wave limb sounder (called STEAMR), explore the benefits of three-dimensional limb sounding with embedded cloud imaging capability. Such 3D imaging technology is expected to open a new era of limb sounding that will allow detailed studies of the link between atmospheric composition and climate, since it will map simultaneously fields of temperature and many trace gases in the mid/upper troposphere and stratosphere across a large vertical and horizontal field of view and with high vertical and horizontal resolution. PREMIER shall fly in a tandem formation looking backwards to METOP's swath and thereby improve meteorological and environmental analyses.

Conceptual design study for Infrared Limb Experiment (IRLE)

NASA Technical Reports Server (NTRS)

Baker, Doran J.; Ulwick, Jim; Esplin, Roy; Batty, J. C.; Ware, Gene; Tew, Craig

1989-01-01

The phase A engineering design study for the Infrared Limb Experiment (IRLE) instrument, the infrared portion of the Mesosphere-Lower Thermosphere Explorer (MELTER) satellite payload is given. The IRLE instrument is a satellite instrument, based on the heritage of the Limb Infrared Monitor of the Stratosphere (LIMS) program, that will make global measurements of O3, CO2, NO, NO2, H2O, and OH from earth limb emissions. These measurements will be used to provide improved understanding of the photochemistry, radiation, dynamics, energetics, and transport phenomena in the lower thermosphere, mesosphere, and stratosphere. The IRLE instrument is the infrared portion of the MELTER satellite payload. MELTER is being proposed to NASA Goddard by a consortium consisting of the University of Michigan, University of Colorado and NASA Langley. It is proposed that the Space Dynamics Laboratory at Utah State University (SDL/USU) build the IRLE instrument for NASA Langley. MELTER is scheduled for launch in November 1994 into a sun-synchronous, 650-km circular orbit with an inclination angle of 97.8 deg and an ascending node at 3:00 p.m. local time.

A Unified and Coherent Land Surface Emissivity Earth System Data Record

NASA Astrophysics Data System (ADS)

Knuteson, R. O.; Borbas, E. E.; Hulley, G. C.; Hook, S. J.; Anderson, M. C.; Pinker, R. T.; Hain, C.; Guillevic, P. C.

2014-12-01

Land Surface Temperature and Emissivity (LST&E) data are essential for a wide variety of studies from calculating the evapo-transpiration of plant canopies to retrieving atmospheric water vapor. LST&E products are generated from data acquired by sensors in low Earth orbit (LEO) and by sensors in geostationary Earth orbit (GEO). Although these products represent the same measure, they are produced at different spatial, spectral and temporal resolutions using different algorithms. The different approaches used to retrieve the temperatures and emissivities result in discrepancies and inconsistencies between the different products. NASA has identified a major need to develop long-term, consistent, and calibrated data and products that are valid across multiple missions and satellite sensors. This poster will introduce the land surface emissivity product of the NASA MEASUREs project called A Unified and Coherent Land Surface Temperature and Emissivity (LST&E) Earth System Data Record (ESDR). To develop a unified high spectral resolution emissivity database, the MODIS baseline-fit emissivity database (MODBF) produced at the University of Wisconsin-Madison and the ASTER Global Emissivity Database (ASTER GED) produced at JPL will be merged. The unified Emissivity ESDR will be produced globally at 5km in mean monthly time-steps and for 12 bands from 3.6-14.3 micron and extended to 417 bands using a PC regression approach. The poster will introduce this data product. LST&E is a critical ESDR for a wide variety of studies in particular ecosystem and climate modeling.

The Effect of Solar Radiation on Molecular Nitrogen Emissions Originating in the Sunlit Thermosphere of Earth.

NASA Astrophysics Data System (ADS)

Hatfield, David Brooke

The vibrational distribution of N_2 triplet states in the sunlit upper thermosphere of Earth is measured and modeled for the first time. A comparison is made between measured and theoretical limb column emission rates for bands originating from each upper vibrational level of C^3Pi_ u(v) and A^3Sigma_sp {u}{+}(v). The measured column emission rates for the Second Positive (2PG) bands are 3.2 (+/-0.2), 3.2 (+/-0.2) and 0.6 (+0.0,-0.4) kRayleighs for bands originating from C^3Pi_ u(0<=qrm v<=q2) and 13.3 ( +/-0.2), 10.0 (+/-0.2), 3 (+0,-2) and 2 (+0,-2) kRayleighs for Vegard-Kaplan (VK) bands originating from A^3Sigma_sp{u}{+ }(0<=qrm v<=q3).. Predicted limb column emission rates for C ^3Pi_ u(v) are in excellent agreement with the measured 2PG intensities, but comparisons of predicted A^3Sigma_sp{u }{+}(v) column emissions to measured VK intensities are poor. Despite this discrepancy, the predicted sum of all A^3Sigma_sp {u}{+}(v) emission rates over all v compared well to the sum of measured VK intensities. This implies that the excitation rate into the N_2 triplet states is well understood, but that the cascade mechanisms are not as yet understood sufficiently to use dayglow N_2 band emissions as remote sensing probes of the sunlit thermosphere. The dayglow N_2 emissions are modeled by extending the existing auroral model to include resonance scattering of sunlight and replacing the precipitating auroral electrons with photoelectrons. The effects of solar resonance scattering on the X ^1Sigma_sp{g}{+}, A^3Sigma_sp{u }{+} and B^3Pi _ g states are presented as a function of A^3Sigma_sp{u}{+ } quenching rate. These theoretical predictions have important implications for the analysis of dayglow and auroral emissions. The effect of resonance scattering on the A^3Sigma_sp{u} {+} state is small, and will not be measurable under auroral conditions. This implies that the measured auroral vibrational population of the A^3 Sigma_sp{u}{+} state is valid for sunlit aurora. The

SPECTRO-POLARIMETRIC SIMULATIONS OF THE SOLAR LIMB: ABSORPTION-EMISSION Fe I 6301.5 Å AND 6302.5 Å LINE PROFILES AND TORSIONAL FLOWS IN THE INTERGRANULAR MAGNETIC FLUX CONCENTRATIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shelyag, S.

2015-03-01

Using radiative magnetohydrodynamic simulations of the magnetized solar photosphere and detailed spectro-polarimetric diagnostics with the Fe I 6301.5 Å and 6302.5 Å photospheric lines in the local thermodynamic equilibrium approximation, we model active solar granulation as if it was observed at the solar limb. We analyze general properties of the radiation across the solar limb, such as the continuum and the line core limb darkening and the granulation contrast. We demonstrate the presence of profiles with both emission and absorption features at the simulated solar limb, and pure emission profiles above the limb. These profiles are associated with the regionsmore » of strong linear polarization of the emergent radiation, indicating the influence of the intergranular magnetic fields on the line formation. We analyze physical origins of the emission wings in the Stokes profiles at the limb, and demonstrate that these features are produced by localized heating and torsional motions in the intergranular magnetic flux concentrations.« less

47 CFR 25.216 - Limits on emissions from mobile earth stations for protection of aeronautical radionavigation...

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 2 2013-10-01 2013-10-01 false Limits on emissions from mobile earth stations... Technical Standards § 25.216 Limits on emissions from mobile earth stations for protection of aeronautical radionavigation-satellite service. (a) The e.i.r.p. density of emissions from mobile earth stations placed in...

47 CFR 25.216 - Limits on emissions from mobile earth stations for protection of aeronautical radionavigation...

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 2 2011-10-01 2011-10-01 false Limits on emissions from mobile earth stations... Technical Standards § 25.216 Limits on emissions from mobile earth stations for protection of aeronautical radionavigation-satellite service. (a) The e.i.r.p. density of emissions from mobile earth stations placed in...

47 CFR 25.216 - Limits on emissions from mobile earth stations for protection of aeronautical radionavigation...

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 2 2014-10-01 2014-10-01 false Limits on emissions from mobile earth stations... Technical Standards § 25.216 Limits on emissions from mobile earth stations for protection of aeronautical radionavigation-satellite service. (a) The e.i.r.p. density of emissions from mobile earth stations placed in...

47 CFR 25.216 - Limits on emissions from mobile earth stations for protection of aeronautical radionavigation...

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 2 2012-10-01 2012-10-01 false Limits on emissions from mobile earth stations... Technical Standards § 25.216 Limits on emissions from mobile earth stations for protection of aeronautical radionavigation-satellite service. (a) The e.i.r.p. density of emissions from mobile earth stations placed in...

18 F-sodium fluoride positron emission tomography of the equine distal limb: Exploratory study in three horses.

PubMed

Spriet, M; Espinosa, P; Kyme, A Z; Phillips, K L; Katzman, S A; Galuppo, L D; Stepanov, P; Beylin, D

2018-01-01

Positron emission tomography (PET) is a cross-sectional, functional imaging modality that has recently become available to the horse. The use of 18 F-sodium fluoride ( 18 F-NaF), a PET bone tracer, has not previously been reported in this species. To assess the feasibility of 18 F-NaF PET in the equine distal limb and explore possible applications in the horse in comparison with other imaging modalities. Exploratory descriptive study involving three research horses. Horses were placed under general anaesthesia prior to intravenous (i.v.) administration of 1.5 MBq/kg of 18 F-NaF. Positron emission tomography imaging of both front feet and fetlocks was performed using a portable scanner. Computed tomography (CT) of the distal limb was performed under a separate anaesthetic episode. Bone scintigraphy and magnetic resonance imaging (MRI) were subsequently performed under standing sedation. Images obtained from PET and other imaging modalities were independently assessed and the results correlated. Positron emission tomography images were obtained without complication. The radiation exposure rate was similar to equine bone scintigraphy. Positron emission tomography detected focal 18 F-NaF uptake in areas where other imaging modalities did not identify any abnormalities. This included sites of ligamentous attachment, subchondral compact bone plate and the flexor cortex of the navicular bone. 18 F-NaF uptake was identified in some, but not all, osseous fragments and areas of osseous formation, suggesting a distinction between active and inactive lesions. A small number of horses were included and histopathology was not available. 18 F-NaF PET imaging of the equine distal limb provides useful additional information when compared with CT, MRI and scintigraphy and has the potential for both research and clinical applications in the horse. The Summary is available in Chinese - see Supporting information. © 2017 EVJ Ltd.

Preamputation evaluation of lower-limb skeletal muscle perfusion with H(2) (15)O positron emission tomography.

PubMed

Scremin, Oscar U; Figoni, Stephen F; Norman, Keith; Scremin, A M Erika; Kunkel, Charles F; Opava-Rutter, Dorene; Schmitter, Eric D; Bert, Alberto; Mandelkern, Mark

2010-06-01

To establish whether muscle blood flow (MBF) measurements with O-water positron emission tomography could reliably identify patients with critical limb ischemia and detect and quantify a distal deficit in skeletal MBF in these cases. O-water positron emission tomography scans were performed at rest or during unloaded ankle plantar and dorsiflexion exercise of the diseased leg in 17 subjects with leg ischemia or on a randomly selected leg of 18 age-matched healthy control subjects. TcPO2 was evaluated with Novametrix monitors and perfusion of skin topically heated to 44 degrees C and adjacent nonheated areas with a Moor Instruments laser Doppler imaging scanner. The enhancement of MBF induced by exercise was significantly lower in ischemic than in normal legs, and the sensitivity and specificity of this phenomenon were similar to those of laser Doppler imaging or TcPO2 in identifying ischemia subjects. In addition, the exercise MBF deficit was predominant at the distal-leg levels, indicating the ability of the technique to help determine the correct level of amputation. Skeletal MBF of legs with severe ischemia can be detected accurately with O-water positron emission tomography and could add valuable information about viability of skeletal muscle in the residual limb when deciding the level of an amputation.

Kinetic Temperature and Carbon Dioxide from Broadband Infrared Limb Emission Measurements Taken from the TIMED/SABER Instrument

NASA Technical Reports Server (NTRS)

Mertens, Christopher J.; Russell III, James M.; Mlynczak, Martin G.; She, Chiao-Yao; Schmidlin, Francis J.; Goldberg, Richard A.; Lopez-Puertas, Manuel; Wintersteiner, Peter P.; Picard, Richard H.; Winick, Jeremy R.;

Exploring the fine structure at the limb in coronal holes

NASA Technical Reports Server (NTRS)

Karovska, Magarita; Blundell, Solon F.; Habbal, Shadia Rifai

1994-01-01

The fine structure of the solar limb in coronal holes is explored at temperatures ranging from 10(exp 4) to 10(exp 6) K. An image enhancement algorithm orignally developed for solar eclipse observations is applied to a number of simultaneous multiwavelength observations made with the Harvard Extreme Ultraviolet Spectrometer experiment on Skylab. The enhanced images reveal the presence of filamentary structures above the limb with a characteristic separation of approximately 10 to 15 sec . Some of the structures extend from the solar limb into the corona to at least 4 min above the solar limb. The brightness of these structures changes as a function of height above the limb. The brightest emission is associated with spiculelike structures in the proximity of the limb. The emission characteristic of high-temperature plasma is not cospatial with the emission at lower temperatures, indicating the presence of different temperature plasmas in the field of view.

Limb-Nadir Matching for Tropospheric NO2: A New Algorithm in the SCIAMACHY Operational Level 2 Processor

NASA Astrophysics Data System (ADS)

Meringer, Markus; Gretschany, Sergei; Lichtenberg, Gunter; Hilboll, Andreas; Richter, Andreas; Burrows, John P.

2015-11-01

SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric ChartographY) aboard ESA's environmental satellite ENVISAT observed the Earth's atmosphere in limb, nadir, and solar/lunar occultation geometries covering the UV-Visible to NIR spectral range. Limb and nadir geometries were the main operation modes for the retrieval of scientific data. The new version 6 of ESA's level 2 processor now provides for the first time an operational algorithm to combine measurements of these two geometries in order to generate new products. As a first instance the retrieval of tropospheric NO2 has been implemented based on IUP-Bremen's reference algorithm. We will detail the single processing steps performed by the operational limb-nadir matching algorithm and report the results of comparisons with the scientific tropospheric NO2 products of IUP and the Tropospheric Emission Monitoring Internet Service (TEMIS).

An Algorithm for Converting Static Earth Sensor Measurements into Earth Observation Vectors

NASA Technical Reports Server (NTRS)

Harman, R.; Hashmall, Joseph A.; Sedlak, Joseph

2004-01-01

An algorithm has been developed that converts penetration angles reported by Static Earth Sensors (SESs) into Earth observation vectors. This algorithm allows compensation for variation in the horizon height including that caused by Earth oblateness. It also allows pitch and roll to be computed using any number (greater than 1) of simultaneous sensor penetration angles simplifying processing during periods of Sun and Moon interference. The algorithm computes body frame unit vectors through each SES cluster. It also computes GCI vectors from the spacecraft to the position on the Earth's limb where each cluster detects the Earth's limb. These body frame vectors are used as sensor observation vectors and the GCI vectors are used as reference vectors in an attitude solution. The attitude, with the unobservable yaw discarded, is iteratively refined to provide the Earth observation vector solution.

Global-scale Observations of the Limb and Disk (GOLD) Mission -Ultraviolet Remote Sensing of Earth's Space Environment from Geostationary Orbit

NASA Astrophysics Data System (ADS)

Burns, A. G.; Eastes, R.

2017-12-01

The GOLD mission of opportunity will fly a far ultraviolet imaging spectrograph in geostationary (GEO) orbit as a hosted payload. The mission is scheduled for launch in late January 2018 on SES-14, a commercial communications satellite that will be stationed over eastern South America at 47.5 degrees west longitude. GOLD is on schedule to be the first NASA science mission to fly as a hosted payload on a commercial communications satellite. The GOLD imager has two identical channels. Each channel can scan the full disk at a 30 minute cadence, making spectral images of Earth's UV emission from 132 to 162 nm, as well as make a measurement on the Earth's limb. Remote sensing techniques that have been proven on previous Low Earth Orbit (LEO) missions will be used to derive fundamental parameters for the neutral and ionized space environment. Parameters that will be derived include composition (O/N2 ratio) and temperature of the neutral atmosphere on the dayside disk. On the nightside, peak electron densities will be obtained in the low latitude ionosphere. Many of the algorithms developed for the mission are extensions of ones used on previous earth and planetary missions, with modifications for observations from geostationary orbit. All the algorithms have been tested using simulated observations based on the actual instrument performance. From geostationary orbit, GOLD can repeatedly image the same geographic locations over most of the hemisphere at a cadence comparable to that of the T-I system (order of an hour). Such time resolution and spatial coverage will allow the mission to track the changes due to geomagnetic storms, variations in solar extreme ultraviolet radiation, and forcing from the lower atmosphere. In addition to providing a new perspective by being able to repeatedly remotely sense the same hemisphere at a high cadence, GOLD's simultaneous measurements of not only composition but also temperatures across the disk will provide a valuable, new parameter

Harvesting renewable energy from Earth's mid-infrared emissions.

PubMed

Byrnes, Steven J; Blanchard, Romain; Capasso, Federico

2014-03-18

It is possible to harvest energy from Earth's thermal infrared emission into outer space. We calculate the thermodynamic limit for the amount of power available, and as a case study, we plot how this limit varies daily and seasonally in a location in Oklahoma. We discuss two possible ways to make such an emissive energy harvester (EEH): A thermal EEH (analogous to solar thermal power generation) and an optoelectronic EEH (analogous to photovoltaic power generation). For the latter, we propose using an infrared-frequency rectifying antenna, and we discuss its operating principles, efficiency limits, system design considerations, and possible technological implementations.

Near Earth space sporadic radio emission busts occurring during sunrise

NASA Technical Reports Server (NTRS)

Dudnik, A. V.; Zaljubovsky, I. I.; Kartashev, V. M.; Lasarev, A. V.; Shmatko, E. S.

1985-01-01

During the period of low solar activity at sunrise the effect of sporadic high frequency near Earth space radio emission was experimentally discovered at middle latitudes. The possible mechanism of its origin is discussed.

Earth views and an illuminated earth limb

NASA Image and Video Library

1998-11-20

STS047-54-016 (12 - 20 Sept 1992) --- The colors in this photograph provide insight into the relative density of the atmosphere. The crew members had many opportunities to witness sunrises and sunsets, considering they orbit the Earth every 90 minutes, but few, they said, compared to this scene. It captures the silhouette of several mature thunderstorms with their cirrus anvil tops spreading out against the tropopause (the top of the lowest layer of Earth's atmosphere) at sunset. The lowest layer (troposphere) is the densest and refracts light at the red end of the visible spectrum (7,400 Angstroms), while the blues (4,000 Angstroms) are separated in the least dense portion of the atmosphere (middle and upper atmosphere, or stratosphere and mesosphere). Several layers of blue can be seen. NASA scientists studying the photos believe this stratification to be caused by the scattering of light by particulate trapped in the stratosphere and mesosphere particulate that generally originate from volcanic eruptions, such as those of Mt. Pinatubo in the Philippines and, most recently, Mt. Spurr in Alaska.

Global-scale Observations of the Limb and Disk (GOLD) Mission - A New Approach to Ultraviolet Remote Sensing of Earth's Space Environment

NASA Astrophysics Data System (ADS)

Eastes, R.; McClintock, W. E.; Anderson, D. N.; Andersson, L.; Burns, A. G.; Codrescu, M.; Daniell, R. E.; England, S.; Krywonos, A.; Lumpe, J. D.; Richmond, A. D.; Rusch, D. W.; Siegmund, O.; Solomon, S. C.; Strickland, D. J.; Woods, T. N.; Budzien, S. A.; Dymond, K.; Eparvier, F. G.; Jones, S.; Martinis, C. R.; Oberheide, J.; Talaat, E. R.; Barrett, R.; Harvey, J.

2016-12-01

The GOLD mission of opportunity will fly a far ultraviolet imaging spectrograph in geostationary (GEO) orbit as a hosted payload. The mission is scheduled for launch in late 2017 on SES-14, a commercial communications satellite that will be stationed over eastern South America at 47.5 degrees west longitude. GOLD is on schedule to be the first NASA science mission to fly as a hosted payload on a commercial communications satellite. The GOLD imager has two identical channels. Each channel can scan the full disk at a 30 minute cadence, making spectral images of Earth's UV emission from 132 to 162 nm, as well as make a measurement on the Earth's limb. Remote sensing techniques that have been proven on previous Low Earth Orbit (LEO) missions will be used to derive fundamental parameters for the neutral and ionized space environment. Parameters that will be derived include composition (O/N2 ratio) and temperature of the neutral atmosphere on the dayside disk. On the nightside, peak electron densities will be obtained in the low latitude ionosphere. Similar imaging of atmospheric composition from LEO, at only a daily cadence for revisiting locations, has already provided many new insights into the behavior of Earth's Thermosphere-Ionosphere (T-I) system. From geostationary orbit, GOLD can repeatedly image the same geographic locations over most of the hemisphere at a cadence comparable to that of the T-I system (order of an hour). Such time resolution and spatial coverage will allow the mission to track the changes due to geomagnetic storms, variations in solar extreme ultraviolet radiation, and forcing from the lower atmosphere. In addition to providing a new perspective by being able to repeatedly remotely sense the same hemisphere at a high cadence, GOLD's simultaneous measurements of not only composition but also temperatures across the disk will provide a valuable, new parameter for understanding of how the T-I system responds to forcing from the sun and the lower

Techniques to minimize adjacent band emissions from Earth Exploration Satellites to protect the Space Research (Category B) Earth Stations in the 8400-8450 MHz band

NASA Technical Reports Server (NTRS)

Wang, Charles C.; Sue, Miles K.; Manshadi, Farzin

2004-01-01

The Earth Exploration Satellites operating in the 8025-8400 MHz band can have strong adjacent band emissions on the8400-8450 MHz band which is allocated for Space Research (Category-B). The unwanted emission may exceed the protection criterion establish by the ITU-R for the protection of the Space Research (Category B) earth stations, i.e., deep-space earth stations. An SFCG Action Item (SF 23/14) was created during the 23rd SFCG meeting to explore technical and operational techniques to reduce the adjacent band emissions. In response to this action item, a study was conducted and results are presented in this document.

Tropospheric Emission Spectrometer for the Earth Observing System

NASA Technical Reports Server (NTRS)

Glavich, Thomas A.; Beer, Reinhard

1991-01-01

A Tropospheric Emission Spectrometer (TES) for the Earth Observing System (EOS) series of polar-orbiting platforms is described. TES is aimed at studying tropospheric chemistry, in particular, the exchange of gases between the surface and the atmosphere, urban and regional pollution, acid rain precursors, sources and sinks of greenhouse gases, and the interchange of gases between the troposphere and the stratosphere. TES is a high-resolution (0.025/cm) infrared Fourier transform spectrometer operating in the passive thermal-emission mode in a very wide spectral range (600 to 4350/cm; 2.3 to 16.7 microns). TES has 32 spatial pixels in each of four optically conjugated linear detector arrays, each optimized for a different spectral region.

Steady X-Ray Synchrotron Emission in the Northeastern Limb of SN 1006

NASA Technical Reports Server (NTRS)

Katsuda, Satoru; Petre, Robert; Mori, Koji; Reynolds, Stephen; Long, Knox; Winkler, P.; Tsunemi, Hiroshi

2010-01-01

We investigate time variations and detailed spatial structures of X-ray synchrotron emission in the northeastern limb of SN 1006, using two Chandra observations taken in 2000 and 2008. We extract spectra from a number of small ([approx]10'') regions. After taking account of proper motion and isolating the synchrotron from the thermal emission, we study time variations in the synchrotron emission in the small regions. We find that there are no regions showing strong flux variations. Our analysis shows an apparent flux decline in the overall synchrotron flux of [approx]4% at high energies, but we suspect that this is mostly a calibration effect, and that flux is actually constant to [approx]1%. This is much less than the variation found in other remnants where it was used to infer magnetic-field strengths up to 1 mG. We attribute the lack of variability to the smoothness of the synchrotron morphology, in contrast to the small-scale knots found to be variable in other remnants. The smoothness is to be expected for a Type Ia remnant encountering uniform material. Finally, we find a spatial correlation between the flux and the cutoff frequency in synchrotron emission. The simplest interpretation is that the cutoff frequency depends on the magnetic-field strength. This would require that the maximum energy of accelerated electrons is not limited by synchrotron losses, but by some other effect. Alternatively, the rate of particle injection and acceleration may vary due to some effect not yet accounted for, such as a dependence on shock obliquity.

The OMPS Limb Profiler instrument

NASA Astrophysics Data System (ADS)

Rault, D. F.; Xu, P.

2011-12-01

The Ozone Mapping and Profiler Suite (OMPS) will continue the monitoring of the global distribution of the Earth's middle atmosphere ozone and aerosol. OMPS is composed of three instruments, namely the Total Column Mapper (heritage: TOMS, OMI), the Nadir Profiler (heritage: SBUV) and the Limb Profiler (heritage: SOLSE/LORE, OSIRIS, SCIAMACHY, SAGE III). The ultimate goal of the mission is to better understand and quantify the rate of stratospheric ozone recovery. OMPS is scheduled to be launched on the NPOESS Preparatory Project (NPP) platform in October 2011. The focus of the paper will be on the Limb Profiler (LP) instrument. The LP instrument will measure the Earth's limb radiance, from which ozone profile will be retrieved from the upper tropopause uo to 60km. End-to-end studies of the sensor and retrieval algorithm indicate the following expected performance for ozone: accuracy of 5% or better from the tropopause up to 50 km, precision of about 3-5% from 18 to 50 km, and vertical resolution of 1.5-2 km with vertical sampling of 1 km and along-track horizontal sampling of 1 deg latitude. The paper will describe the mission, discuss the retrieval algorithm, and summarize the expected performance. If available, the paper will also present early on-orbit data.

Angular radiation models for earth-atmosphere system. Volume 2: Longwave radiation

NASA Technical Reports Server (NTRS)

Suttles, J. T.; Green, R. N.; Smith, G. L.; Wielicki, B. A.; Walker, I. J.; Taylor, V. R.; Stowe, L. L.

1989-01-01

The longwave angular radiation models that are required for analysis of satellite measurements of Earth radiation, such as those from the Earth Radiation Budget Experiment (ERBE) are presented. The models contain limb-darkening characteristics and mean fluxes. Limb-darkening characteristics are the longwave anisotropic factor and the standard deviation of the longwave radiance. Derivation of these models from the Nimbus 7 ERB (Earth Radiation Budget) data set is described. Tabulated values and computer-generated plots are included for the limb-darkening and mean-flux models.

Tropospheric Emission Spectrometer (TES) for the Earth Observing System (EOS) CHEM Satellite

NASA Technical Reports Server (NTRS)

Beer, R.; Glavich, T.; Rider, D.

2000-01-01

The Tropospheric Emission Spectrometer (TES) is an imaging infrared Fourier transform spectrometer scheduled to be launched into polar sun-synchronous orbit on the Earth Observing System (EOS) CHEM satellite in December 2002.

Limb flares measurement from Langkawi National Observatory on 5th January 2016

NASA Astrophysics Data System (ADS)

Kamarudin, F.; Tahar, M. R.; Saibaka, N. R.

2017-05-01

Sun is the source of energy and has a lot of activity that will be influence the Earth. One of the solar activities is the limb flare or prominence. It release energy and expel outward the Sun surface. Langkawi National Observatory (LNO) had started photographic solar activity in Hα since 2008. LNO used the dedicated solar telescope to monitor and observed the solar activity daily. In 5th January 2016, LNO captured one limb flare at the south-west position of the Sun. The maximum height of the limb flare is 267,347 km and it increase gradually build up the velocity. Luckily, this eruption does not facing and directed towards Earth so there was no significant impact.

Mars atmosphere studies with the OMEGA/Mars Express experiment: I. Overview and detection of lfuorescent emission by CO2

NASA Astrophysics Data System (ADS)

Drossart, P.; Combes, M.; Encrenaz, T.; Melchiorri, R.; Fouchet, T.; Forget, F.; Moroz, V.; Ignatiev, N.; Bibring, J.-P.; Langevin, Y.; OMEGA Team

Observations of Mars by the OMEGA/Mars Express experiment provide extended maps of the martian disk at all latitudes, and with various conditions of illumination, between 0.4 to 5 micron. The atmospheric investigations so far conducted by our team are focussed on the infrared part of the spectrum (1-5 micron), and include: the development of a correction algorithm for atmospheric gaseous absorption, to give access to fine mineralogic studies, largely decorrelated from atmospheric effects the study of dust opacity effects in the near infrared, with the aim to correct also the rough spectra from dust opacity perturbation the study of minor constituents like CO, to search for regional or global variations the study of CO2 emission at 4.3 micron related to fluorescent emission This last effect is prominently detected in limb observations obtained in 3-axis stabilized mode of Mars Express, with high altitude emission in the CO2 fundamental at 4.3 micron, usually seen in absorption in nadir observations. These emissions are related to non-LTE atmospheric layers, well above the solid surface in the mesosphere. Such emissions are also present in Earth and Venus limb observations. They are present also in nadir observations, but are reinforced in limb viewing geometry due to the tangential view. A numerical model of these emission will be presented.

Environmental monitoring for the DOE coolside and LIMB demonstration extension projects

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, T.; Contos, L.; Adams, L.

1992-02-01

The purpose of this document is to present environmental monitoring data collected during the US DOE Limestone Injection Multistage Burner (LIMB) Demonstration Project Extension. The objective of the LIMB program is to demonstrate the sulfur dioxide (SO{sub 2}) and nitrogen oxide (NO{sub x}) emission reduction capabilities of the LIMB system. The LIMB system is a retrofit technology to be used for existing coal-fired boilers equipped with electrostatic precipitators. (VC)

The magnetic connectivity of coronal shocks from behind-the-limb flares to the visible solar surface during γ-ray events

NASA Astrophysics Data System (ADS)

Plotnikov, I.; Rouillard, A. P.; Share, G. H.

2017-12-01

Context. The observation of >100 MeV γ-rays in the minutes to hours following solar flares suggests that high-energy particles interacting in the solar atmosphere can be stored and/or accelerated for long time periods. The occasions when γ-rays are detected even when the solar eruptions occurred beyond the solar limb as viewed from Earth provide favorable viewing conditions for studying the role of coronal shocks driven by coronal mass ejections (CMEs) in the acceleration of these particles. Aims: In this paper, we investigate the spatial and temporal evolution of the coronal shocks inferred from stereoscopic observations of behind-the-limb flares to determine if they could be the source of the particles producing the γ-rays. Methods: We analyzed the CMEs and early formation of coronal shocks associated with γ-ray events measured by the Fermi-Large Area Telescope (LAT) from three eruptions behind the solar limb as viewed from Earth on 2013 Oct. 11, 2014 Jan. 06 and Sep. 01. We used a 3D triangulation technique, based on remote-sensing observations to model the expansion of the CME shocks from above the solar surface to the upper corona. Coupling the expansion model to various models of the coronal magnetic field allowed us to derive the time-dependent distribution of shock Mach numbers and the magnetic connection of particles produced by the shock to the solar surface visible from Earth. Results: The reconstructed shock fronts for the three events became magnetically connected to the visible solar surface after the start of the flare and just before the onset of the >100 MeV γ-ray emission. The shock surface at these connections also exhibited supercritical Mach numbers required for significant particle energization. The strongest γ-ray emissions occurred when the flanks of the shocks were connected in a quasi-perpendicular geometry to the field lines reaching the visible surface. Multipoint, in situ, measurements of solar energetic particles (SEPs) were

Rare earth activated NaY (MoO4)2 phosphors for NIR emission

NASA Astrophysics Data System (ADS)

Tawalare, P. K.; Bhatkar, V. B.; Talewar, R. A.; Joshi, C. P.; Moharil, S. V.

2018-05-01

Efficient NIR emission is reported for NaY(MoO4)2 activated with Nd3+ or Yb3+. Characteristic emission of rare earth ions is sensitized by MoO4-2 group. The excitation is in the near UV region of 350-400 nm. These phosphors could be useful for modifying the solar spectrum so as to match with the spectral response of c-Si solar cells.

Effect of Surface Reflectivity Variations On Uv-visible Limb Scattering Measurements of The Atmosphere

NASA Astrophysics Data System (ADS)

Oikarinen, L.

Solar UV and visible radiation scattered at the limb of the Earth's atmosphere is used for measuring density profiles of atmosperic trace gases. For example, the OSIRIS instrument on Odin and SCIAMACHY on Envisat use this technique. A limb-viewing instrument does not see Earth's surface or tropospheric clouds directly. However, in- direct light reflected from the surface or low altitude clouds can make up tens of per cents of the signal. Furthermore, the surface area that contributes to limb intensity ex- tends over 1000 km along the instrument line-of-sight and 200 km across it. Over this area surface reflectivity can vary from almost 0% to 100%. Inaccurate modelling of reflected intensity is a potential source of error in the trace gas retrieval. Generally, radiative transfer models used for analysing limb measure- ments have to assume that the surface has a constant albedo. We have used a three- dimensional Monte Carlo radiative transfer model to study the effects of surface vari- ation to limb radiance. Based on the simulations, we have developed an approximate method for averaging surface albedo for limb scattering measurements with the help of a simple single scattering radiative transfer model.

From LIMS to OMPS-LP: Limb Ozone Observations for Future Reanalyses

NASA Technical Reports Server (NTRS)

Wargan, K.; Kramarova, N.; Remsberg, E.; Coy, L.; Harvey, L.; Livesey, N.; Pawson, S.

2017-01-01

High vertical resolution and accuracy of ozone data from satellite-borne limb sounders has made them an invaluable tool in scientific studies of the middle and upper atmosphere. However, it was not until recently that these measurements were successfully incorporated in atmospheric reanalyses: of the major multidecadal reanalyses only ECMWF's (European Centre for Medium-Range Weather Forecasts') ERA (ECMWF Re-Analysis)-Interim/ERA5 and NASA's MERRA-2 (Modern-Era Retrospective Analysis for Research and Applications-2) use limb ozone data. Validation and comparison studies have demonstrated that the addition of observations from the Microwave Limb Sounder (MLS) on EOS (Earth Observing System) Aura greatly improved the quality of ozone fields in MERRA-2 making these assimilated data sets useful for scientific research. In this presentation, we will show the results of test experiments assimilating retrieved ozone from the Limb Infrared Monitor of the Stratosphere (LIMS, 1978/1979) and Ozone Mapping Profiler Suite Limb Profiler (OMPS-LP, 2012 to present). Our approach builds on the established assimilation methodology used for MLS in MERRA-2 and, in the case of OMPS-LP, extends the excellent record of MLS ozone assimilation into the post-EOS era in Earth observations. We will show case studies, discuss comparisons of the new experiments with MERRA-2, strategies for bias correction and the potential for combined assimilation of multiple limb ozone data types in future reanalyses for studies of multidecadal stratospheric ozone changes including trends.

STS-43 Earth observation of a colorful sunrise

NASA Image and Video Library

1991-08-11

STS-43 Earth observation taken aboard Atlantis, Orbiter Vehicle (OV) 104, captures the Earth's limb at sunrise with unusual cloud patterns silhouetted by the sunlight and rising into the terminator lines.

THEORETICAL EMISSION SPECTRA OF ATMOSPHERES OF HOT ROCKY SUPER-EARTHS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ito, Yuichi; Ikoma, Masahiro; Kawahara, Hajime

Motivated by recent detection of transiting high-density super-Earths, we explore the detectability of hot rocky super-Earths orbiting very close to their host stars. In an environment hot enough for their rocky surfaces to be molten, they would have an atmosphere composed of gas species from the magma oceans. In this study, we investigate the radiative properties of the atmosphere that is in gas/melt equilibrium with the underlying magma ocean. Our equilibrium calculations yield Na, K, Fe, Si, SiO, O, and O{sub 2} as the major atmospheric species. We compile the radiative absorption line data of those species available in the literature andmore » calculate their absorption opacities in the wavelength region of 0.1–100 μm. Using them, we integrate the thermal structure of the atmosphere. Then, we find that thermal inversion occurs in the atmosphere because of the UV absorption by SiO. In addition, we calculate the ratio of the planetary to stellar emission fluxes during secondary eclipse, and we find prominent emission features induced by SiO at 4 μm detectable by Spitzer, and those at 10 and 100 μm detectable by near-future space telescopes.« less

The role of the space station in earth science research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaye, Jack A.

1999-01-22

The International Space Station (ISS) has the potential to be a valuable platform for earth science research. By virtue of its being in a mid-inclination orbit (51.5 deg.), ISS provides the opportunity for nadir viewing of nearly 3/4 of the Earth's surface, and allows viewing to high latitudes if limb-emission or occultation viewing techniques are used. ISS also provides the opportunity for viewing the Earth under a range of lighting conditions, unlike the polar sun-synchronous satellites that are used for many earth observing programs. The ISS is expected to have ample power and data handling capability to support Earth-viewing instruments,more » provide opportunities for external mounting and retrieval of instruments, and be in place for a sufficiently long period that long-term data records can be obtained. On the other hand, there are several questions related to contamination, orbital variations, pointing knowledge and stability, and viewing that are of concern in consideration of ISS for earth science applications. The existence of an optical quality window (the Window Observational Research Facility, or WORF), also provides the opportunity for Earth observations from inside the pressurized part of ISS. Current plans by NASA for earth science research from ISS are built around the Stratospheric Aerosol and Gas Experiment (SAGE III) instrument, planned for launch in 2002.« less

Optical Profiling of the Atmospheric Limb CubeSat Experiment

NASA Astrophysics Data System (ADS)

Jeppesen, M.; Taylor, M. J.; Swenson, C.; Marchant, A.

2014-12-01

The Earth's lower thermosphere is an important interface region between the neutral atmosphere and the "space weather" environment. While the high-latitude region of the thermosphere responds promptly to energy inputs, relatively little is known about the global/regional response to these energy inputs. Global temperatures are predicted to respond within 3-6 hours, but the details of the thermal response of the atmosphere as energy transports away from high-latitude source regions is not well understood. The Optical Profiling of the Atmospheric Limb (OPAL) mission aims to characterize this thermal response through observation of the temperature structure of the lower thermosphere at mid- and low-latitudes. The OPAL instrument is designed to map global thermospheric temperature variability over the critical "thermospheric gap" region (~100-140 km altitude) by spectroscopic analysis of molecular oxygen A-band emission (758 - 768 nm). The OPAL instrument is a grating-based imaging spectrometer with refractive optics and a high-efficiency volume holographic grating (VHG). The scene is sampled by 7 parallel slits that form non-overlapping spectral profiles at the focal plane with resolution of 0.5 nm (spectral), 1.5 km (limb profiling), and 60 km (horizontal sampling). A CCD camera at the instrument focal plane delivers low noise and high sensitivity. The instrument is designed to strongly reject stray light from daylight regions of the earth. The OPAL mission is funded by the National Science Foundation (NSF) CubeSat-based Science Missions for Geospace and Atmospheric Research program. The OPAL instrument and mission will be designed, built and executed by a team comprised of students and professors from Utah State University, Dixie State University and the University of Maryland Eastern Shore, with support from professional scientists and engineers from the Space Dynamics Laboratory and Hawk Institute for Space Science.

The versatility of limb scattered sunlight measurements

NASA Astrophysics Data System (ADS)

Bourassa, A. E.; Degenstein, D. A.; Sioris, C.; Rieger, L. A.; Zawada, D.

2017-12-01

Vertically resolved measurements of limb scattered sunlight spectra in the UV-Vis-NIR spectral range have been made from several satellite instruments in low earth orbit for many years, and there has been much success in using these measurements for retrievals of trace gas and aerosol from the upper troposphere to the mesosphere. Due in a large part to improvements in radiative transfer modelling, the versatility of the limb scatter measurement has continued to grow over the last several years. Using OSIRIS and OMPS instruments as primary examples, this talk will review the current capability of limb scatter measurements, and highlight recent results on ozone variability and trends in the UTLS, the continuation of the aerosol extinction record, NO2 distributions in the upper troposphere, and a new tomographic retrieval of ozone from the OMPS measurements. The future of limb scatter observations will also be discussed, including the development of two new Canadian suborbital instrument concepts that are targeted at high spatial resolution UTLS water vapor and cloud/aerosol measurements.

Earth observations taken from Space Shuttle Columbia during STS-80 mission

NASA Image and Video Library

1996-11-24

STS080-759-038 (19 Nov.-7 Dec. 1996) --- As photographed by the crewmembers aboard the space shuttle Columbia, a full moon is about to set beyond the limb of Earth. A full moon should be round but when it is near the limb, or edge of Earth, the atmosphere tends to distort the shape. The atmosphere, stratosphere, ionosphere is in reality acting as a lens, thus the distorted shape of the Moon. As the Moon reaches the Earth's horizon it will become "eggshaped".

Sunrise, Earth Limb, SW Pacific Ocean

NASA Image and Video Library

1992-09-20

STS047-54-018 (12-20 Sept. 1992) --- The colors in this photograph provide insight into the relative density of the atmosphere. The crew members had many opportunities to witness sunrises and sunsets, considering they orbit the Earth every 90 minutes, but few, they said, compared to this scene. It captures the silhouette of several mature thunderstorms with their cirrus anvil tops spreading out against the tropopause (the top of the lowest layer of Earth's atmosphere) at sunset. The lowest layer (troposphere) is the densest and refracts light at the red end of the visible spectrum (7,400 Angstroms), while the blues (4,000 Angstroms) are separated in the least dense portion of the atmosphere (middle and upper atmosphere, or stratosphere and mesosphere). Several layers of blue can be seen. NASA scientists studying the photos believe this stratification to be caused by the scattering of light by particulate trapped in the stratosphere and mesosphere particulate that generally originate from volcanic eruptions, such as those of Mt. Pinatubo in the Philippines and, most recently, Mt. Spurr in Alaska.

Nitrogen airglow sources - Comparison of Triton, Titan, and earth

NASA Technical Reports Server (NTRS)

Strobel, Darrell F.; Meier, R. R.; Summers, Michael E.; Strickland, Douglas J.

1991-01-01

The individual contributions of direct solar excitation, photoelectron excitation, and magnetospheric electron excitation of Triton and Titan airglow observed by the Voyager Ultraviolet Spectrometer (UVS) are quantified. The principal spectral features of Triton's airglow are shown to be consistent with precipitation of magnetospheric electrons with power dissipation about 500 million W. Solar excitation rates of the dominant N2 and N(+) emission features are factors of 2-7 weaker than magnetospheric electron excitation. On Titan, the calculated disk center and bright limb N(+) 1085 A intensities due to solar excitation agree with observed values, while the 970 A feature is mostly N21 c5 band emission. The calculated LBH intensity by photoelectrons suggests that magnetospheric electrons play a minor role in Titan's UV airglow. On earth, solar/photoelectron excitation explains the observed N(+) 1085 A and LBH intensites and accounts for only 40 percent of the N(+) 916 A intensity.

Lightcurve Analysis for Two Near-Earth Asteroids Eclipsed by the Earth's Shadow

NASA Astrophysics Data System (ADS)

Birtwhistle, Peter

2018-07-01

Photometry was obtained from Great Shefford Observatory of near-Earth asteroids 2012 XE54 in 2012 and 2016 VA in 2016 during close approaches. A superfast rotation period has been determined for 2012 XE54 and H-G magnitude system coefficients have been estimated for 2016 VA. While under observation, 2012 XE54 underwent a deep penumbral eclipse by the Earth's shadow and 2016 VA also experienced a total eclipse by the Earth's shadow. The dimming due to the eclipses is modeled taking into account solar limb darkening.

Satellite Emission Range Inferred Earth Survey (SERIES) project

NASA Technical Reports Server (NTRS)

Buennagel, L. A.; Macdoran, P. F.; Neilan, R. E.; Spitzmesser, D. J.; Young, L. E.

1984-01-01

The Global Positioning System (GPS) was developed by the Department of Defense primarily for navigation use by the United States Armed Forces. The system will consist of a constellation of 18 operational Navigation Satellite Timing and Ranging (NAVSTAR) satellites by the late 1980's. During the last four years, the Satellite Emission Range Inferred Earth Surveying (SERIES) team at the Jet Propulsion Laboratory (JPL) has developed a novel receiver which is the heart of the SERIES geodetic system designed to use signals broadcast from the GPS. This receiver does not require knowledge of the exact code sequence being transmitted. In addition, when two SERIES receivers are used differentially to determine a baseline, few cm accuracies can be obtained. The initial engineering test phase has been completed for the SERIES Project. Baseline lengths, ranging from 150 meters to 171 kilometers, have been measured with 0.3 cm to 7 cm accuracies. This technology, which is sponsored by the NASA Geodynamics Program, has been developed at JPL to meet the challenge for high precision, cost-effective geodesy, and to complement the mobile Very Long Baseline Interferometry (VLBI) system for Earth surveying.

The emission in the region E>0.1MeV during disk and limb faint solar flares

NASA Astrophysics Data System (ADS)

Irene, Arkhangelskaja; Andrew, Arkhangelskiy; Yury, Kotov; Alexandr, Glyanenko; Maria, Kolchina; Alexey, Kirichenko

2013-06-01

Hard X-ray and gamma-ray emission in energy band E>50 keV was first observed by AVS-F apparatus onboard CORONAS-F satellite (detector SONG-D) during some solar flares with classes B and C by GOES classification. Such component registered in flares with duration less than 30 min. However γ-emission up to several tens of MeV was observed during some classes B and C events, which temporal profiles were not corresponded to Neupert effect. For example, during class B2.3 limb solar flare January 7, 2005 maximum observed energy was Emax˜36 MeV and during class B4.6 disk solar event January 12, 2005 maximum observed energy was Emax˜7 MeV. Properties of temporal profiles and energy spectra of faint solar flares, during which emission in the energy band of E>0.1 MeV were registered are discussed in the presented work. There is not any strong correlation between presence or absence of hard X-ray and γ-ray emission and the intensity of soft X-ray emission during solar flares. The one of illustration of this fact is the absence of any observed statistically significant count rate exceed above background level during some class M flares in the energy band E>0.1 MeV. The typical example of such flares is event November 8, 2001 (class M4.2, lasts from 14:59 UT up to 16:00 UT, maximum of soft X-ray emission was at 15:35 UT on GOES data).

Limb Sensing, on the Path to Better Weather Forecasting.

NASA Astrophysics Data System (ADS)

Gordley, L. L.; Marshall, B. T.; Lachance, R. L.; Fritts, D. C.; Fisher, J.

2017-12-01

Earth limb observations from orbiting sensors have a rich history. The cold space background, long optical paths, and limb geometry provide formidable advantages for calibration, sensitivity and retrieval of vertically well-resolved geophysical parameters. The measurement of limb ray refraction now provides temperature and pressure profiles unburdened by requirements of spectral calibration or gas concentration knowledge, leading to reliable long-term trends. This talk discusses those advantages and our relevant achievements with data from the SOFIE instrument on the AIM satellite. We then describe a path to advances in calibration, sensitivity, profile fidelity, and synergy between limb sensors and nadir sounders. These advances also include small-sat compatible size, elimination of on-board calibration systems and simple static designs, dramatically reducing risk, complexity and cost. Finally, we show how these advances, made possible by modern ADCS, FPA and GPS capabilities, will lead to improvements in weather forecasting and climate observation.

Retrieval of O+ Density From Combined OII 83.4 nm and OII 61.7 nm Limb Emissions

NASA Astrophysics Data System (ADS)

Geddes, G.; Finn, S. C.; Stephan, A. W.; Cook, T.; Chakrabarti, S.

2016-12-01

OII 83.4 nm and OII 61.7 nm emissions are produced by photoionization of neutral oxygen in the thermosphere. While OII 83.4 nm photons are resonantly scattered by O+ ions, OII 61.7 nm photons do not interact with the ionosphere. Combined observations of these two features, which share a production mechanism but have different paths through the ionosphere, can be used to infer the O+ density causing the scattering of OII 83.4 nm. We retrieve O+ density from synthetic measurements of the OII 83.4 nm and OII 61.7 nm emission features using a Markov chain Monte Carlo technique. This method allows us to quantify constraints on retrieved ionospheric parameters, giving an estimate of O+ density retrieval capability in preparation for the Limb-Imaging Ionospheric and Thermospheric Extreme-ultraviolet Spectrograph (LITES), scheduled to fly on the International Space Station in November 2016. This work is also applicable to observations from the Ionospheric Connection Explorer (ICON), scheduled for launch in June 2017.

Connecting Surface Emissions, Convective Uplifting, and Long-Range Transport of Carbon Monoxide in the Upper Troposphere: New Observations from the Aura Microwave Limb Sounder

NASA Technical Reports Server (NTRS)

Jiang, Jonathan H.; Livesey, Nathaniel J.; Su, Hui; Neary, Lori; McConnell, John C.; Richards, Nigel A. D.

2007-01-01

Two years of observations of upper tropospheric (UT) carbon monoxide (CO) from the Aura Microwave Limb Sounder are analyzed; in combination with the CO surface emission climatology and data from the NCEP analyses. It is shown that spatial distribution, temporal variation and long-range transport of UT CO are closely related to the surface emissions, deep-convection and horizontal winds. Over the Asian monsoon region, surface emission of CO peaks in boreal spring due to high biomass burning in addition to anthropogenic emission. However, the UT CO peaks in summer when convection is strongest and surface emission of CO is dominated by anthropogenic source. The long-range transport of CO from Southeast Asia across the Pacific to North America, which occurs most frequently during boreal summer, is thus a clear imprint of Asian anthropogenic pollution influencing global air quality.

Mars, Venus, Earth and Titan UV Laboratory Aeronomy by Electron Impact

NASA Astrophysics Data System (ADS)

Malone, C. P.; Ajello, J. M.; McClintock, W. E.; Eastes, R.; Evans, J. S.; Holsclaw, G.; Schneider, N. M.; Jain, S.; Gerard, J. C. M. C.; Hoskins, A.

2017-12-01

The UV response of the Mars, Earth, Titan and Venus upper atmospheres to the solar radiation fields [solar wind and solar EUV] is the focus of the present generation of Mars, Earth, Titan and Venus missions. These missions are Mars Express (MEX), the Mars Atmosphere and Volatile Evolution Mission (MAVEN), Cassini at Titan, Global-scale Observations of the Limb and Disk (GOLD) mission for Earth and Venus Express (VEX). Each spacecraft is equipped with a UV spectrometer that senses far ultraviolet (FUV) emissions from 110-190 nm, whose dayglow intensities are proportional to three quantities:1) particle (electron, ion) fluxes, 2) the altitude distribution of species in the ionosphere: CO, CO2, O, N2 at Venus and Mars and N2, O and O2 at Titan and Earth and 3) the emission cross section for the interaction process. UV spectroscopy provides a benchmark to the present space environment and indicates pathways for removing upper atmosphere gas (e.g., water escape from Mars and Earth) or N2 escape at Titan over eons. We present a UV laboratory program that utilizes an instrument, unique in the world, at the University of Colorado that can measure excitation mechanisms by particle (electron, ion) impact and the resulting emission cross sections that include processes occurring in a planetary atmosphere, particularly the optically forbidden emissions presented by the Cameron bands, the Lyman Birge Hopfield bands and the OI 135.6 nm multiplet. There are presently uncertainties by a factor of two in the existing measurements of the emission cross section, affecting modeling of electron transport. We have utilized the MAVEN Imaging Ultraviolet Spectrograph (IUVS) engineering model which operates at moderate spectral resolution ( 0.5-1.0nm FWHM) to obtain the full vibrational spectra of the Cameron band system CO(a 3Π → X 1Σ+) from both CO direct excitation and CO2 dissociative excitation, and for the dipole-allowed Fourth Positive band system of CO, while for N2 we have

The Retrieval of Ozone Profiles from Limb Scatter Measurements: Results from the Shuttle Ozone Limb Sounding Experiment

NASA Technical Reports Server (NTRS)

McPeters, Richard D.; Janz, Scott J.; Hilsenrath, Ernest; Brown, Tammy L.; Flittner, David E.; Heath, Donald F.

1999-01-01

Two instruments were flown on shuttle flight STS-87 to test a new technique for inferring the ozone vertical profile using measurements of scattered sunlight from the Earth's limb. The instruments were an ultraviolet imaging spectrometer designed to measure ozone between 30 and 50 km, and a multi-filter imaging photometer that uses 600 nm radiances to measure ozone between 15 km and 35 km. Two orbits of limb data were obtained on December 2, 1997. For the scans analyzed the ozone profile was measured from 15 km to 50 km with approximately 3 km vertical resolution. Comparisons with a profile from an ozonesonde launched from Ascension Island showed agreement mostly within +/- 5%. The tropopause at 15 km was clearly detected.

Earth - Antarctica Mosaic

NASA Image and Video Library

1996-02-01

This color picture of the limb of the Earth, looking north past Antarctica, is a mosaic of 11 images taken during a ten-minute period near 5:45 p.m. PST Dec. 8, 1990, by NASA’s Galileo imaging system. http://photojournal.jpl.nasa.gov/catalog/PIA00116

Telescope-optical system performance analysis for the Cryogenic Limb Array Etalon Spectrometer (CLAES) on the Upper Atmospheric Research Satellite

NASA Technical Reports Server (NTRS)

Roche, A. E.; Forney, P. B.; Morrow, H. E.; Anapol, M.

1983-01-01

A first-order performance analysis of the CLAES telescope-optical system is presented. The experiment involves the passive measurement of earth-limb radiance over a 10-60 km tangent altitude range, and is based on a solid Fabry-Perot spectrometer which provides spectral resolution of 0.25/cm for atmospheric emission spectroscopy over the 3.5-12 micron IR range. The optical system is required to provide a high degree of off-axis rejection and stray-light control, primarily to suppress intense emission from the earth surface. The astigmatism and other geometric aberrations are corrected by a secondary mirror which produces an excellent image of the primary one, allowing for location of a diffraction control or Lyot stop. The off-axis scattering performance of the telescope is examined in terms of the mirror scatter coefficient and point source rejection ratio. A mirror bidirectional reflectance distribution function of 0.0001 at 1 deg with a 1/theta-squared roll-off between 1 and 0.2 deg is realizable based on recent measurements. This results in an off-axis radiance term that is generally small in comparison with the system-limiting NER.

SAGE 3: A visible wavelength limb sounder

NASA Technical Reports Server (NTRS)

Chu, W. P.; Mccormick, M. P.; Zawodny, J.; Mcmaster, L. R.

1990-01-01

A brief description is presented for the SAGE 3 (Stratospheric Aerosol and Gas Experiment 3) instrument that has been selected to fly onboard the National Polar Platform 1 (NPOP 1) for the Earth Observational System (Eos) in 1996. The SAGE 3 instrument will perform earth limb sounding with the solar occultation technique measuring the ultraviolet (UV), the visible, and the near infrared (IR) wavelength solar radiation. The instrument will produce atmospheric data for the vertical distribution of aerosol, ozone, nitrogen dioxide, water vapor, and oxygen. The details of the instrument design, data flow, and processing requirements are discussed.

The Global-Scale Observations of the Limb and Disk (GOLD) Mission

NASA Astrophysics Data System (ADS)

Eastes, R. W.; McClintock, W. E.; Burns, A. G.; Anderson, D. N.; Andersson, L.; Codrescu, M.; Correira, J. T.; Daniell, R. E.; England, S. L.; Evans, J. S.; Harvey, J.; Krywonos, A.; Lumpe, J. D.; Richmond, A. D.; Rusch, D. W.; Siegmund, O.; Solomon, S. C.; Strickland, D. J.; Woods, T. N.; Aksnes, A.; Budzien, S. A.; Dymond, K. F.; Eparvier, F. G.; Martinis, C. R.; Oberheide, J.

2017-10-01

The Earth's thermosphere and ionosphere constitute a dynamic system that varies daily in response to energy inputs from above and from below. This system can exhibit a significant response within an hour to changes in those inputs, as plasma and fluid processes compete to control its temperature, composition, and structure. Within this system, short wavelength solar radiation and charged particles from the magnetosphere deposit energy, and waves propagating from the lower atmosphere dissipate. Understanding the global-scale response of the thermosphere-ionosphere ( T-I) system to these drivers is essential to advancing our physical understanding of coupling between the space environment and the Earth's atmosphere. Previous missions have successfully determined how the "climate" of the T-I system responds. The Global-scale Observations of the Limb and Disk (GOLD) mission will determine how the "weather" of the T-I responds, taking the next step in understanding the coupling between the space environment and the Earth's atmosphere. Operating in geostationary orbit, the GOLD imaging spectrograph will measure the Earth's emissions from 132 to 162 nm. These measurements will be used image two critical variables—thermospheric temperature and composition, near 160 km—on the dayside disk at half-hour time scales. At night they will be used to image the evolution of the low latitude ionosphere in the same regions that were observed earlier during the day. Due to the geostationary orbit being used the mission observes the same hemisphere repeatedly, allowing the unambiguous separation of spatial and temporal variability over the Americas.

Earth observation

NASA Image and Video Library

2014-09-04

ISS040-E-129950 (4 Sept. 2014) --- In this photograph. taken by one of the Expedition 40 crew members aboard the Earth-orbiting International Space Station, the orange spot located in the very center is the sun, which appears to be sitting on Earth's limb. At far right, a small bright spot is believed to be a reflection from somewhere in the camera system or something on the orbital outpost. When the photographed was exposed, the orbital outpost was flying at an altutude of 226 nautical miles above a point near French Polynesia in the Pacific Ocean.

Limb-darkening functions as derived from along-track operation of the ERBE scanning radiometer for January 1985

NASA Technical Reports Server (NTRS)

Smith, G. Louis; Manalo, Natividad; Suttles, John T.; Walker, Ira

1989-01-01

During January 1985, the scanning radiometer aboard the Earth Radiation Budget Satellite was operated to scan along-track. These data have been analyzed to produce limb-darkening functions for Earth emitted radiation, which relate the radiance in any given direction to the radiant exitance. Limb-darkening functions are presented in tabular form and shown as figures for 10 day cases and 12 night cases, corresponding to various scene types and latitude zones. The scene types were computed using measurements within 10 deg of zenith. The limb-darkening functions have values of 1.03 to 1.09 at zenith, with 1.06 being typical. It is found that latitude causes a variation on the order of 1 percent, except for zenith angles greater than 70 deg. These limb-darkening models are about 2 percent higher at zenith than the models derived from Nimbus 7 data.

Sunrise, Earth Limb, SW Pacific Ocean

NASA Technical Reports Server (NTRS)

1992-01-01

The colors of this sunrise/sunset scene provide insights into the relative density of the Earth's atmosphere (15.5S, 158.5E). This scene captures the silhouette of several thunderstorms with their cirrus anvil tops spreading out against the tropopause - the top of the lowest layer of atmosphere, the troposphere which is also the most dense and refracts light at the red end of the spectrum while the blues refract in the stratosphere, the highest layer.

The Optical Profiling of the Atmospheric Limb (OPAL) CubeSat Experiment

NASA Astrophysics Data System (ADS)

Jeppesen, M.; Miller, J.; Cox, W.; Taylor, M. J.; Swenson, C.; Neilsen, T. L.; Fish, C. S.; Scherliess, L.; Christensen, A. B.; Cleave, M.

2015-12-01

The Earth's lower thermosphere is an important interface region between the neutral atmosphere and the "space weather" environment. While the high-latitude region of the thermosphere responds promptly to energy inputs, relatively little is known about the global/regional response to these energy inputs. Global temperatures are predicted to respond within 3-6 hours, but the details of the thermal response of the atmosphere as energy transports away from high-latitude source regions is not well understood. The Optical Profiling of the Atmospheric Limb (OPAL) mission aims to characterize this thermal response through observation of the temperature structure of the lower thermosphere at mid- and low-latitudes. The OPAL instrument is designed to map global thermospheric temperature variability over the critical "thermospheric gap" region (~100-140 km altitude) by spectroscopic analysis of molecular oxygen A-band emission (758 - 768 nm). The OPAL instrument is a grating-based imaging spectrometer with refractive optics and a high-efficiency volume holographic grating (VHG). The scene is sampled by 7 parallel slits that form non-overlapping spectral profiles at the focal plane with resolution of 0.5 nm (spectral), 1.5 km (limb profiling), and 60 km (horizontal sampling). A CCD camera at the instrument focal plane delivers low noise and high sensitivity. The instrument is designed to strongly reject stray light from daylight regions of the earth. The OPAL mission is funded by the National Science Foundation (NSF) CubeSat-based Science Missions for Geospace and Atmospheric Research program. The OPAL instrument, CubeSat bus and mission are being designed, built and executed by a team comprised of students and professors from Utah State University, Dixie State University and the University of Maryland Eastern Shore, with support from professional scientists and engineers from the Space Dynamics Laboratory and Hawk Institute for Space Science.

THE CHROMOSPHERIC SOLAR LIMB BRIGHTENING AT RADIO, MILLIMETER, SUB-MILLIMETER, AND INFRARED WAVELENGTHS

DOE Office of Scientific and Technical Information (OSTI.GOV)

De la Luz, V.

2016-07-10

Observations of the emission at radio, millimeter, sub-millimeter, and infrared wavelengths in the center of the solar disk validate the autoconsistence of semi-empirical models of the chromosphere. Theoretically, these models must reproduce the emission at the solar limb. In this work, we tested both the VALC and C7 semi-empirical models by computing their emission spectrum in the frequency range from 2 GHz to 10 THz at solar limb altitudes. We calculate the Sun's theoretical radii as well as their limb brightening. Non-local thermodynamic equilibrium was computed for hydrogen, electron density, and H{sup −}. In order to solve the radiative transfermore » equation, a three-dimensional (3D) geometry was employed to determine the ray paths, and Bremsstrahlung, H{sup −}, and inverse Bremsstrahlung opacity sources were integrated in the optical depth. We compared the computed solar radii with high-resolution observations at the limb obtained by Clark. We found that there are differences between the observed and computed solar radii of 12,000 km at 20 GHz, 5000 km at 100 GHz, and 1000 km at 3 THz for both semi-empirical models. A difference of 8000 km in the solar radii was found when comparing our results against the heights obtained from H α observations of spicules-off at the solar limb. We conclude that the solar radii cannot be reproduced by VALC and C7 semi-empirical models at radio—infrared wavelengths. Therefore, the structures in the high chromosphere provide a better measurement of the solar radii and their limb brightening as shown in previous investigations.« less

Environmental monitoring for the DOE coolside and LIMB demonstration extension projects

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, T.; Contos, L.; Adams, L.

1992-03-01

The purpose of this document is to present environmental monitoring data collected during the US Department of Energy Limestone Injection Multistage Burner (DOE LIMB) Demonstration Project Extension at the Ohio Edison Edgewater Generating Station in Lorain, Ohio. The DOE project is an extension of the US Environmental Protection Agency's (EPA's) original LIMB Demonstration. The program is operated nuclear DOE's Clean Coal Technology Program of emerging clean coal technologies'' under the categories of in boiler control of oxides of sulfur and nitrogen'' as well as post-combustion clean-up.'' The objective of the LIMB program is to demonstrate the sulfur dioxide (SO{sub 2})more » and nitrogen oxide (NO{sub x}) emission reduction capabilities of the LIMB system. The LIMB system is a retrofit technology to be used for existing coal-fired boilers equipped with electrostatic precipitators (ESPs).« less

Observation of Solar Wind Charge Exchange Emission from Exospheric Material in and Outside Earth's Magnetosheath

NASA Technical Reports Server (NTRS)

Snowden, S. L.; Collier, M. R.; Cravens, T.; Kuntz, K. D.; Lepri, S. T.; Robertson, I.; Tomas, L.

2008-01-01

A long XMM-Newton exposure is used to observe solar wind charge exchange (SWCX) emission from exospheric material in and outside Earth s magnetosheath. The light curve of the O VII (0.5-0.62 keV) band is compared with a model for the expected emission, and while the emission is faint and the light curve has considerable scatter, the correlation is significant to better than 99.9%. This result demonstrates the validity of the geocoronal SWCX emission model for predicting a contribution to astrophysical observations to a scale factor of order unity (1.36). The results also demonstrate the potential utility of using X-ray observations to study global phenomena of the magnetosheath which currently are only investigated using in situ measurements.

On the Solar Chromosphere Observed at the LIMB with Hinode

NASA Astrophysics Data System (ADS)

Judge, Philip G.; Carlsson, Mats

2010-08-01

Broadband images in the Ca II H line, from the Broadband Filter Imager (BFI) instrument on the Hinode spacecraft, show emission from spicules emerging from and visible right down to the observed limb. Surprisingly, little absorption of spicule light is seen along their lengths. We present formal solutions to the transfer equation for given (ad hoc) source functions, including a stratified chromosphere from which spicules emanate. The model parameters are broadly compatible with earlier studies of spicules. The visibility of Ca II spicules down to the limb in Hinode data seems to require that spicule emission be Doppler shifted relative to the stratified atmosphere, either by supersonic turbulent or organized spicular motion. The non-spicule component of the chromosphere is almost invisible in the broadband BFI data, but we predict that it will be clearly visible in high spectral resolution data. Broadband Ca II H limb images give the false impression that the chromosphere is dominated by spicules. Our analysis serves as a reminder that the absence of a signature can be as significant as its presence.

The Upper Atmosphere Research Satellite microwave limb sounder instrument

NASA Astrophysics Data System (ADS)

Barath, F. T.; Chavez, M. C.; Cofield, R. E.; Flower, D. A.; Frerking, M. A.; Gram, M. B.; Harris, W. M.; Holden, J. R.; Jarnot, R. F.; Kloezeman, W. G.

1993-06-01

The microwave limb sounder (MLS) on the Upper Atmosphere Research Satellite (UARS) is the first satellite experiment using limb sounding techniques at microwave frequencies. Primary measurement objectives are stratospheric ClO, O3, H2O, temperature, and pressure. Measurements are of thermal emission: all are performed simultaneously and continuously and are not degraded by ice clouds or volcanic aerosols. The instrument has a 1.6-m mechanically scanning antenna system and contains heterodyne radiometers in spectral bands centred near 63, 183, and 205 GHz. The radiometers operate at ambient temperature and use Schottky-diode mixers with local oscillators derived from phase-locked Gunn oscillators. Frequency tripling by varactor multipliers generates the 183- and 205-GHz local oscillators, and quasi-optical techniques inject these into the mixers. Six 15-channel filter banks spectrally resolve stratospheric thermal emission lines and produce an output spectrum every 2 s. Thermal stability is sufficient for 'total power' measurements which do not require fast chopping. Radiometric calibration, consisting of measurements of cold space and an internal target, is performed every 65-s limb scan. Instrument in-orbit performance has been excellent, and all objectives are being met.

The Upper Atmosphere Research Satellite microwave limb sounder instrument

NASA Technical Reports Server (NTRS)

Barath, F. T.; Chavez, M. C.; Cofield, R. E.; Flower, D. A.; Frerking, M. A.; Gram, M. B.; Harris, W. M.; Holden, J. R.; Jarnot, R. F.; Kloezeman, W. G.

1993-01-01

The microwave limb sounder (MLS) on the Upper Atmosphere Research Satellite (UARS) is the first satellite experiment using limb sounding techniques at microwave frequencies. Primary measurement objectives are stratospheric ClO, O3, H2O, temperature, and pressure. Measurements are of thermal emission: all are performed simultaneously and continuously and are not degraded by ice clouds or volcanic aerosols. The instrument has a 1.6-m mechanically scanning antenna system and contains heterodyne radiometers in spectral bands centred near 63, 183, and 205 GHz. The radiometers operate at ambient temperature and use Schottky-diode mixers with local oscillators derived from phase-locked Gunn oscillators. Frequency tripling by varactor multipliers generates the 183- and 205-GHz local oscillators, and quasi-optical techniques inject these into the mixers. Six 15-channel filter banks spectrally resolve stratospheric thermal emission lines and produce an output spectrum every 2 s. Thermal stability is sufficient for 'total power' measurements which do not require fast chopping. Radiometric calibration, consisting of measurements of cold space and an internal target, is performed every 65-s limb scan. Instrument in-orbit performance has been excellent, and all objectives are being met.

Autonomous celestial navigation based on Earth ultraviolet radiance and fast gradient statistic feature extraction

NASA Astrophysics Data System (ADS)

Lu, Shan; Zhang, Hanmo

2016-01-01

To meet the requirement of autonomous orbit determination, this paper proposes a fast curve fitting method based on earth ultraviolet features to obtain accurate earth vector direction, in order to achieve the high precision autonomous navigation. Firstly, combining the stable characters of earth ultraviolet radiance and the use of transmission model software of atmospheric radiation, the paper simulates earth ultraviolet radiation model on different time and chooses the proper observation band. Then the fast improved edge extracting method combined Sobel operator and local binary pattern (LBP) is utilized, which can both eliminate noises efficiently and extract earth ultraviolet limb features accurately. And earth's centroid locations on simulated images are estimated via the least square fitting method using part of the limb edges. Taken advantage of the estimated earth vector direction and earth distance, Extended Kalman Filter (EKF) is applied to realize the autonomous navigation finally. Experiment results indicate the proposed method can achieve a sub-pixel earth centroid location estimation and extremely enhance autonomous celestial navigation precision.

Pulsations in the Earth's Lower Ionosphere Synchronized With Solar Flare Emission

NASA Astrophysics Data System (ADS)

Hayes, Laura A.; Gallagher, Peter T.; McCauley, Joseph; Dennis, Brian R.; Ireland, Jack; Inglis, Andrew

2017-10-01

Solar flare emission at X-ray and extreme ultraviolet (EUV) energies can cause substantial enhancements in the electron density in the Earth's lower ionosphere. It has now become clear that flares exhibit quasi-periodic pulsations with timescales of minutes at X-ray energies, but to date, it has not been known if the ionosphere is sensitive to this variability. Here using a combination of very low frequency (24 kHz) measurement together with space-based X-ray and EUV observations, we report pulsations of the ionospheric D region, which are synchronized with a set of pulsating flare loops. Modeling of the ionosphere show that the D region electron density varies by up to an order of magnitude over the timescale of the pulsations (˜ 20 min). Our results reveal that the Earth's ionosphere is more sensitive to small-scale changes in solar soft X-ray flux than previously thought and implies that planetary ionospheres are closely coupled to small-scale changes in solar/stellar activity.

Microwave Limb Sounder/El Niño Watch - Water Vapor Measurement, October, 1997

NASA Image and Video Library

1997-10-30

This image shows atmospheric water vapor in Earth upper troposphere, about 10 kilometers 6 miles above the surface, as measured by NASA Microwave Limb Sounder MLS instrument flying aboard the Upper Atmosphere Research Satellite.

Multispectral studies of western limb and farside maria from Galileo Earth-Moon Encounter 1

NASA Astrophysics Data System (ADS)

Williams, David A.; Greeley, Ronald; Neukum, Gerhard; Wagner, Roland; Kadel, Steven D.

1995-11-01

New visible and near-infrared multispectral images of the Moon obtained by the Galileo solid-state imaging system, along with lunar orbiter images (for crater counts), and spectral mixing analyses were used to characterize western limb and eastern farside maria and determine compositional and age relationships in selected regions. Results indicate that (1) western limb mare deposits have less variability in titanium content (<2-7 wt% TiO2) and age (2.79-3.86 Ga) than areally extensive maria on the nearside; (2) areally extensive basin-filling maria generally have higher titanium contents than smaller, crater-filling mare patches and ponds; (3) ancient maria covered by highland material (cryptomaria) may be present in the Mendel-Rydberg and South Pole-Aitken basins; and (4) maria with compositional and age variations occur in the Grimaldi, Crüger, Mendel-Rydberg, and Apollo regions. No extensive high-titanium (>6 wt% TiO2) mare basalts were observed on the western limb and farside, which may reflect the inability of such denser magmas to penetrate the thicker farside crust.

The Earth and Moon As Seen by 2001 Mars Odyssey's Thermal Emission Imaging System

NASA Technical Reports Server (NTRS)

2001-01-01

2001 Mars Odyssey's Thermal Emission Imaging System (THEMIS) took this portrait of the Earth and its companion Moon, using the infrared camera, one of two cameras in the instrument. It was taken at a distance of 3,563,735 kilometers (more than 2 million miles) on April 19, 2001 as the 2001 Mars Odyssey spacecraft left the Earth. From this distance and perspective the camera was able to acquire an image that directly shows the true distance from the Earth to the Moon. The Earth's diameter is about 12,750 km, and the distance from the Earth to the Moon is about 385,000 km, corresponding to 30 Earth diameters. The dark region seen on Earth in the infrared temperature image is the cold south pole, with a temperature of minus 50 degrees Celsius (minus 58 degrees Fahrenheit). The small bright region above it is warm Australia. This image was acquired using the 9.1 um infrared filter, one of nine filters that the instrument will use to map the mineral composition and temperature of the martian surface. From this great distance, each picture element (pixel) in the image corresponds to a region 900 by 900 kilometers or greater in size or about size of the state of Texas. Once Odyssey reaches Mars orbit each infrared pixel will cover a region only 100 by 100 meters on the surface, about the size of a major league baseball field.

Limb Correction of Polar-Orbiting Imagery for the Improved Interpretation of RGB Composites

NASA Technical Reports Server (NTRS)

Jedlovec, Gary J.; Elmer, Nicholas

2016-01-01

Red-Green-Blue (RGB) composite imagery combines information from several spectral channels into one image to aid in the operational analysis of atmospheric processes. However, infrared channels are adversely affected by the limb effect, the result of an increase in optical path length of the absorbing atmosphere between the satellite and the earth as viewing zenith angle increases. This paper reviews a newly developed technique to quickly correct for limb effects in both clear and cloudy regions using latitudinally and seasonally varying limb correction coefficients for real-time applications. These limb correction coefficients account for the increase in optical path length in order to produce limb-corrected RGB composites. The improved utility of a limb-corrected Air Mass RGB composite from the application of this approach is demonstrated using Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) imagery. However, the limb correction can be applied to any polar-orbiting sensor infrared channels, provided the proper limb correction coefficients are calculated. Corrected RGB composites provide multiple advantages over uncorrected RGB composites, including increased confidence in the interpretation of RGB features, improved situational awareness for operational forecasters, and the ability to use RGB composites from multiple sensors jointly to increase the temporal frequency of observations.

Fermi large area telescope observations of the cosmic-ray induced γ -ray emission of the Earth’s atmosphere

DOE PAGES

Abdo, A. A.; Ackermann, M.; Ajello, M.; ...

2009-12-29

In this paper, we report on measurements of the cosmic-ray induced γ-ray emission of Earth’s atmosphere by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. The Large Area Telescope has observed the Earth during its commissioning phase and with a dedicated Earth limb following observation in September 2008. These measurements yielded ~6.4 × 10 6 photons with energies > 100 MeV and ~ 250 hours total live time for the highest quality data selection. This allows the study of the spatial and spectral distributions of these photons with unprecedented detail. In additon, the spectrum of the emission—oftenmore » referred to as Earth albedo gamma-ray emission—has a power-law shape up to 500 GeV with spectral index Γ = 2.79 ± 0.06 .« less

MaGa, a web-based collaborative database for gas emissions: a tool to improve the knowledge on Earth degassing

NASA Astrophysics Data System (ADS)

Frigeri, A.; Cardellini, C.; Chiodini, G.; Frondini, F.; Bagnato, E.; Aiuppa, A.; Fischer, T. P.; Lehnert, K. A.

2014-12-01

The study of the main pathways of carbon flux from the deep Earth requires the analysis of a large quantity and variety of data on volcanic and non-volcanic gas emissions. Hence, there is need for common frameworks to aggregate available data and insert new observations. Since 2010 we have been developing the Mapping Gas emissions (MaGa) web-based database to collect data on carbon degassing form volcanic and non-volcanic environments. MaGa uses an Object-relational model, translating the experience of field surveyors into the database schema. The current web interface of MaGa allows users to browse the data in tabular format or by browsing an interactive web-map. Enabled users can insert information as measurement methods, instrument details as well as the actual values collected in the field. Measurements found in the literature can be inserted as well as direct field observations made by human-operated instruments. Currently the database includes fluxes and gas compositions from active craters degassing, diffuse soil degassing and fumaroles both from dormant volcanoes and open-vent volcanoes from literature survey and data about non-volcanic emission of the Italian territory. Currently, MaGa holds more than 1000 volcanic plume degassing fluxes, data from 30 sites of diffuse soil degassing from italian volcanoes, and about 60 measurements from fumarolic and non volcanic emission sites. For each gas emission site, the MaGa holds data, pictures, descriptions on gas sampling, analysis and measurement methods, together with bibliographic references and contacts to researchers having experience on each site. From 2012, MaGa developments started to be focused towards the framework of the Deep Earth Carbon Degassing research initiative of the Deep Carbon Observatory. Whithin the DECADE initiative, there are others data systems, as EarthChem and the Smithsonian Institution's Global Volcanism Program. An interoperable interaction between the DECADE data systems is being

Sporadic radio emission connected with a definite manifestation of solar activity in the near Earth space

NASA Technical Reports Server (NTRS)

Dudnic, A. V.; Zaljubovski, I. I.; Kartashev, V. M.; Shmatko, E. S.

1985-01-01

Sporadic radio emission of near Earth space at the frequency of 38 MHz is shown to appear in the event of a rapid development of instabilities in the ionospheric plasma. The instabilities are generated due to primary ionospheric disturbances occurring under the influence of solar chromospheric flares.

STS-45 Earth observation of the Aurora Australis or Southern Lights

NASA Image and Video Library

1992-04-02

STS-45 Earth observation taken onboard Atlantis, Orbiter Vehicle (OV) 104, is of the Aurora Australis or Southern Lights. The green appearing auroral activity engulfs the thin blue line on the Earth's limb. Aurorae were observed and photographed throughout the STS-45 nine-day mission.

STS-45 Earth observation of the Aurora Australis or Southern Lights

NASA Technical Reports Server (NTRS)

1992-01-01

STS-45 Earth observation taken onboard Atlantis, Orbiter Vehicle (OV) 104, is of the Aurora Australis or Southern Lights. The green appearing auroral activity engulfs the thin blue line on the Earth's limb. Aurorae were observed and photographed throughout the STS-45 nine-day mission.

The UARS and EOS Microwave Limb Sounder (MLS) Experiments.

NASA Astrophysics Data System (ADS)

Waters, J. W.; Read, W. G.; Froidevaux, L.; Jarnot, R. F.; Cofield, R. E.; Flower, D. A.; Lau, G. K.; Pickett, H. M.; Santee, M. L.; Wu, D. L.; Boyles, M. A.; Burke, J. R.; Lay, R. R.; Loo, M. S.; Livesey, N. J.; Lungu, T. A.; Manney, G. L.; Nakamura, L. L.;  Perun, V. S.;  Ridenoure, B. P.;  Shippony, Z.;  Siegel, P. H.;  Thurstans, R. P.;  Harwood, R. S.;  Pumphrey, H. C.;  Filipiak, M. J.

1999-01-01

The Microwave Limb Sounder (MLS) experiments obtain measurements of atmospheric composition, temperature, and pressure by observations of millimeter- and submillimeter-wavelength thermal emission as the instrument field of view is scanned through the atmospheric limb. Features of the measurement technique include the ability to measure many atmospheric gases as well as temperature and pressure, to obtain measurements even in the presence of dense aerosol and cirrus, and to provide near-global coverage on a daily basis at all times of day and night from an orbiting platform. The composition measurements are relatively insensitive to uncertainties in atmospheric temperature. An accurate spectroscopic database is available, and the instrument calibration is also very accurate and stable. The first MLS experiment in space, launched on the (NASA) Upper Atmosphere Research Satellite (UARS) in September 1991, was designed primarily to measure stratospheric profiles of ClO, O3, H2O, and atmospheric pressure as a vertical reference. Global measurement of ClO, the predominant radical in chlorine destruction of ozone, was an especially important objective of UARS MLS. All objectives of UARS MLS have been accomplished and additional geophysical products beyond those for which the experiment was designed have been obtained, including measurement of upper-tropospheric water vapor, which is important for climate change studies. A follow-on MLS experiment is being developed for NASA's Earth Observing System (EOS) and is scheduled to be launched on the EOS CHEMISTRY platform in late 2002. EOS MLS is designed for many stratospheric measurements, including HOx radicals, which could not be measured by UARS because adequate technology was not available, and better and more extensive upper-tropospheric and lower-stratospheric measurements.

Retrieval of O2(1Σ) and O2(1Δ) volume emission rates in the mesosphere and lower thermosphere using SCIAMACHY MLT limb scans

NASA Astrophysics Data System (ADS)

Zarboo, Amirmahdi; Bender, Stefan; Burrows, John P.; Orphal, Johannes; Sinnhuber, Miriam

2018-01-01

We present the retrieved volume emission rates (VERs) from the airglow of both the daytime and twilight O2(1Σ) band and O2(1Δ) band emissions in the mesosphere and lower thermosphere (MLT). The SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) onboard the European Space Agency Envisat satellite observes upwelling radiances in limb-viewing geometry during its special MLT mode over the range 50-150 km. In this study we use the limb observations in the visible (595-811 nm) and near-infrared (1200-1360 nm) bands. We have investigated the daily mean latitudinal distributions and the time series of the retrieved VER in the altitude range from 53 to 149 km. The maximal observed VERs of O2(1Δ) during daytime are typically 1 to 2 orders of magnitude larger than those of O2(1Σ). The latter peaks at around 90 km, whereas the O2(1Δ) emissivity decreases with altitude, with the largest values at the lower edge of the observations (about 53 km). The VER values in the upper mesosphere (above 80 km) are found to depend on the position of the sun, with pronounced high values occurring during summer for O2(1Δ). O2(1Σ) emissions show additional high values at polar latitudes during winter and spring. These additional high values are presumably related to the downwelling of atomic oxygen after large sudden stratospheric warmings (SSWs). Accurate measurements of the O2(1Σ) and O2(1Δ) airglow, provided that the mechanism of their production is understood, yield valuable information about both the chemistry and dynamics in the MLT. For example, they can be used to infer the amounts and distribution of ozone, solar heating rates, and temperature in the MLT.

Expedition Seven Takes Breathtaking Photo of Earth's Atmosphere

NASA Technical Reports Server (NTRS)

2003-01-01

This Expedition Seven image, taken while aboard the International Space Station (ISS), shows the limb of the Earth at the bottom transitioning into the orange-colored stratosphere, the lowest and most dense portion of the Earth's atmosphere. The troposphere ends abruptly at the tropopause, which appears in the image as the sharp boundary between the orange- and blue-colored atmosphere. The silvery blue noctilucent clouds extend far above the Earth's troposphere. The silver of the setting moon is visible at upper right.

From LIMS to OMPS-LP: limb ozone observations for future reanalyses

NASA Astrophysics Data System (ADS)

Wargan, K.; Kramarova, N. A.; Remsberg, E. E.; Coy, L.; Harvey, L.; Livesey, N. J.; Pawson, S.

2017-12-01

High vertical resolution and accuracy of ozone data from satellite-borne limb sounders have made them an invaluable tool in scientific studies of the middle and upper atmosphere. However, it was not until recently that these measurements were successfully incorporated in atmospheric reanalyses: of the major multidecadal reanalyses only ECMWF's ERA-Interim/ERA5 and NASA's MERRA-2 use limb ozone data. Validation and comparison studies have demonstrated that the addition of observations from the Microwave Limb Sounder (MLS) on EOS Aura greatly improved the quality of ozone fields in MERRA-2 making these assimilated data sets useful for scientific research. In this presentation, we will show the results of test experiments assimilating retrieved ozone from the Limb Infrared Monitor of the Stratosphere (LIMS, 1978/1979) and Ozone Mapping Profiler Suite Limb Profiler (OMPS-LP, 2012 to present). Our approach builds on the established assimilation methodology used for MLS in MERRA-2 and, in the case of OMPS-LP, extends the excellent record of MLS ozone assimilation into the post-EOS era in Earth observations. We will show case studies, discuss comparisons of the new experiments with MERRA-2, strategies for bias correction and the potential for combined assimilation of multiple limb ozone data types in future reanalyses for studies of multidecadal stratospheric ozone changes including trends.

Cluster observations of EMIC triggered emissions in association with Pc1 waves near Earth's plasmapause

NASA Astrophysics Data System (ADS)

Pickett, J. S.; Grison, B.; Omura, Y.; Engebretson, M. J.; Dandouras, I.; Masson, A.; Adrian, M. L.; Santolík, O.; Décréau, P. M. E.; Cornilleau-Wehrlin, N.; Constantinescu, D.

2010-05-01

The Cluster spacecraft were favorably positioned on the nightside near the equatorial plasmapause of Earth at L ˜ 4.3 on 30 March 2002 to observe electromagnetic ion cyclotron (EMIC) rising tone emissions in association with Pc1 waves at 1.5 Hz. The EMIC rising tone emissions were found to be left-hand, circularly polarized, dispersive, and propagating away from the equator. Their burstiness and dispersion of ˜30s/Hz rising out of the 1.5 Hz Pc1 waves are consistent with their identification as EMIC triggered chorus emissions, the first to be reported through in situ observations near the plasmapause. Along with the expected H+ ring current ions seen at higher energies (>300 eV), lower energy ions (300 eV and less) were observed during the most intense EMIC triggered emission events. Nonlinear wave-particle interactions via cyclotron resonance between the ˜2-10 keV H+ ions with temperature anisotropy and the linearly-amplified Pc1 waves are suggested as a possible generation mechanism for the EMIC triggered emissions.

Earth Limb taken by the Expedition 17 Crew

NASA Image and Video Library

2008-07-22

ISS017-E-011603 (22 July 2008) --- Layers of Earth's atmosphere, brightly colored as the sun rises over central Asia, and Polar Mesospheric Clouds (also known as noctilucent clouds) are featured in this image photographed by an Expedition 17 crewmember on the International Space Station. The image was acquired in support of International Polar Year research.

Results of the IRIS UV Burst Survey, Part I: Active Regions Tracked Limb to Limb

NASA Astrophysics Data System (ADS)

Madsen, C. A.; DeLuca, E.

2017-12-01

We present results from the first phase of an effort to thoroughly characterize UV bursts within the Interface Region Imaging Spectrograph (IRIS) data catalogue. The observational signatures of these phenomena include dramatically intensified and broadened NUV/FUV emission line profiles with absorption features from cool metallic ions. These properties suggest that UV bursts originate from plasma at transition region temperatures (≥ 80,000 K) which is deeply embedded in the cool lower chromosphere ( 5,000 K). Rigorously characterizing the energetic and dynamical properties of UV bursts is crucial since they have considerable potential to heat active region chromospheres and could provide critical constraints for models of magnetic reconnection in these regions. The survey first focuses on IRIS observations of active regions tracked from limb to limb. All observations consist of large field-of-view raster scans of 320 or 400 steps each, which allow for widespread detection of many burst profiles at the expense of having limited short-term time evolution information. We detect bursts efficiently by applying a semi-automated single-Gaussian fitting technique to Si IV 1393.8 Å emission profiles that isolates the distinct burst population in a 4-D parameter space. The robust sample of NUV/FUV burst spectra allows for precise constraints of properties critical for modeling reconnection in the chromosphere, including outflow kinetic energy, density estimates from intensity ratios of Si IV 1402.8 Å and O IV 1401.2 Å emission lines, and coincident measures of emission in other wavelengths. We also track burst properties throughout the lifetimes of their host active regions, noting changes in detection rate and preferential location as the active regions evolve. Finally, the tracked active region observations provide a unique opportunity to investigate line-of-sight effects on observed UV burst spectral properties, particularly the strength of Ni II 1393.3 Å absorption

Aura Atmospheric Data Products and Their Availability from NASA Goddard Earth Sciences DAAC

NASA Technical Reports Server (NTRS)

Ahmad, S.; Johnson, J.; Gopalan, A.; Smith, P.; Leptoukh, G.; Kempler, S.

2004-01-01

NASA's EOS-Aura spacecraft was launched successfully on July 15, 2004. The four instruments onboard the spacecraft are the Microwave Limb Sounder (MLS), the Ozone Monitoring Instrument (OMI), the Tropospheric Emission Spectrometer (TES), and the High Resolution Dynamics Limb Sounder (HBDLS). The Aura instruments are designed to gather earth sciences measurements across the ultraviolet, visible, infra-red, thermal and microwave regions of the electromagnetic spectrum. Aura will provide over 70 distinct standard atmospheric data products for use in ozone layer and surface UV-B monitoring, air quality forecast, and atmospheric chemistry and climate change studies (http://eosaura.gsfc.nasa.gov/). These products include earth-atmosphere radiances and solar spectral irradiances; total column, tropospheric, and profiles of ozone and other trace gases, surface W-B flux; clouds and aerosol characteristics; and temperature, geopotential height, and water vapor profiles. The MLS, OMI, and HIRDLS data products will be archived at the NASA Goddard Earth Sciences (GES) Distributed Active Archive Center (DAAC), while data from TES will be archived at NASA Langley Research Center DAAC. Some of the standard products which have gone through quick preliminary checks are already archived at the GES DAAC (http://daac.nsfc.nasa.gov/) and are available to the Aura science team and data validation team members for data validation; and to the application and visualization software developers, for testing their application modules. Once data are corrected for obvious calibration problems and partially validated using in-situ observations, they would be made available to the broader user community. This presentation will provide details of the whole suite of Aura atmospheric data products, and the time line of the availability of the rest of the preliminary products and of the partially validated provisional products. Software and took available for data access, visualization, and data

Time-Dependent Cryospheric Longwave Surface Emissivity Feedback in the Community Earth System Model

NASA Astrophysics Data System (ADS)

Kuo, Chaincy; Feldman, Daniel R.; Huang, Xianglei; Flanner, Mark; Yang, Ping; Chen, Xiuhong

2018-01-01

Frozen and unfrozen surfaces exhibit different longwave surface emissivities with different spectral characteristics, and outgoing longwave radiation and cooling rates are reduced for unfrozen scenes relative to frozen ones. Here physically realistic modeling of spectrally resolved surface emissivity throughout the coupled model components of the Community Earth System Model (CESM) is advanced, and implications for model high-latitude biases and feedbacks are evaluated. It is shown that despite a surface emissivity feedback amplitude that is, at most, a few percent of the surface albedo feedback amplitude, the inclusion of realistic, harmonized longwave, spectrally resolved emissivity information in CESM1.2.2 reduces wintertime Arctic surface temperature biases from -7.2 ± 0.9 K to -1.1 ± 1.2 K, relative to observations. The bias reduction is most pronounced in the Arctic Ocean, a region for which Coupled Model Intercomparison Project version 5 (CMIP5) models exhibit the largest mean wintertime cold bias, suggesting that persistent polar temperature biases can be lessened by including this physically based process across model components. The ice emissivity feedback of CESM1.2.2 is evaluated under a warming scenario with a kernel-based approach, and it is found that emissivity radiative kernels exhibit water vapor and cloud cover dependence, thereby varying spatially and decreasing in magnitude over the course of the scenario from secular changes in atmospheric thermodynamics and cloud patterns. Accounting for the temporally varying radiative responses can yield diagnosed feedbacks that differ in sign from those obtained from conventional climatological feedback analysis methods.

Calibration of the Microwave Limb Sounder on the Upper Atmosphere Research Satellite

NASA Technical Reports Server (NTRS)

Jarnot, R. F.; Cofield, R. E.; Waters, J. W.; Flower, D. A.; Peckham, G. E.

1996-01-01

The Microwave Limb Sounder (MLS) is a three-radiometer, passive, limb emission instrument onboard the Upper Atmosphere Research Satellite (UARS). Radiometric, spectral and field-of-view calibrations of the MLS instrument are described in this paper. In-orbit noise performance, gain stability, spectral baseline and dynamic range are described, as well as use of in-flight data for validation and refinement of prelaunch calibrations. Estimated systematic scaling uncertainties (3 sigma) on calibrated limb radiances from prelaunch calibrations are 2.6% in bands 1 through 3, 3.4% in band 4, and 6% in band 5. The observed systematic errors in band 6 are about 15%, consistent with prelaunch calibration uncertainties. Random uncertainties on individual limb radiance measurements are very close to the levels predicted from measured radiometer noise temperature, with negligible contribution from noise and drifts on the regular in-flight gain calibration measurements.

STS-39 Earth observation of Earth's limb at sunset shows atmospheric layers

NASA Image and Video Library

1991-05-06

STS039-610-037 (28 April-6 May 1991) --- Numerous atmospheric scattering layers over Earth are apparent in this frame. The layers consist of fine particles suspended in very stable layers of the atmosphere. This photo was taken with a 70mm Rolliflex camera during the Space Shuttle Discovery's eight day mission. Crew members onboard were astronauts Michael L. Coats, L. Blaine Hammond, Guion S. Bluford, Richard J. Hieb, Gregory J. Harbaugh, Donald R. McMonagle and Charles L. (Lacy) Veach.

Kinesthetic perceptions of earth- and body-fixed axes.

PubMed

Darling, W G; Hondzinski, J M

1999-06-01

The major purpose of this research was to determine whether kinesthetic/proprioceptive perceptions of the earth-fixed vertical axis are more accurate than perceptions of intrinsic axes. In one experiment, accuracy of alignment of the forearm to earth-fixed vertical and head- and trunk-longitudinal axes by seven blindfolded subjects was compared in four tasks: (1) Earth-Arm--arm (humerus) orientation was manipulated by the experimenter; subjects aligned the forearm parallel to the vertical axis, which was also aligned with the head and trunk longitudinal axis; (2) Head--head, trunk, and upper-limb orientations were manipulated by the experimenter, subjects aligned the forearm parallel to the longitudinal axis of the head using only elbow flexion/extension and shoulder internal/external rotation; (3) Trunk--same as (2), except that subjects aligned the forearm parallel to the trunk-longitudinal axis; (4) Earth--same as (2), except that subjects aligned the forearm parallel to the earth-fixed vertical. Head, trunk, and gravitational axes were never parallel in tasks 2, 3, and 4 so that subjects could not simultaneously match their forearm to all three axes. The results showed that the errors for alignment of the forearm with the earth-fixed vertical were lower than for the trunk- and head-longitudinal axes. Furthermore, errors in the Earth condition were less dependent on alterations of the head and trunk orientation than in the Head and Trunk conditions. These data strongly suggest that the earth-fixed vertical is used as one axis for the kinesthetic sensory coordinate system that specifies upper-limb orientation at the perceptual level. We also examined the effects of varying gravitational torques at the elbow and shoulder on the accuracy of forearm alignment to earth-fixed axes. Adding a 450 g load to the forearm to increase gravitational torques when the forearm is not vertical did not improve the accuracy of forearm alignment with the vertical. Furthermore

Limb Retrievals of TES solarband/IR data (and MCS solarband data)

NASA Astrophysics Data System (ADS)

Wolff, M. J.; Pankine, A.

2016-12-01

Vertical variations in aerosol distributions (and their microphysicalproperties) can have a dramatic impact on the state and evolution of theMartian atmosphere. This has been clearly delineated recent work usingretrieval products produced by the Mars Climate Sounder (MCS) teamfrom limb observations by the MCS IR bolometers. However, similarproducts for Thermal EmissionSpectrometer (TES) limb observationshave not been as widely disseminated. In addition, the solar bandchannels of both datasets have been essentially unanalyzed. Ouroverarching goal has been to fill these gaps in order to addressparticle size studies, as well as to generate products that can beused by the wider community. In our presentation we will include: 1) A summary of our limb radiative transfer algorithms and retrievalscheme; 2) The limitations imposed by "Smoothing Error" and by systematicradiometric error on retrievals in lower and upper atmosphere, respectively;3) vertical profiles of opacity and particle size associated with theevolution of the 2001 TES dust storm; and 4) the use of limbretrievals to estimate integrated-column optical depths (validatedagainst Mars Exploration Rover and TES emission phase functionmeasurements); and 5) the plans for an ongoing archive to be used forthe distribution of the derived profiles and associated retrievalmetadata. This work has been supported by NASA with a Mars Data AnalysisProgram award (grant NNX10AO23G).

High-Resolution Spectroscopic Database for the NASA Earth Observing System Program

NASA Technical Reports Server (NTRS)

Rothman, Laurence S.; Starr, David (Technical Monitor)

2002-01-01

The purpose of this project is to develop and enhance the HITRAN molecular spectroscopic database and associated software to support the observational programs of the Earth Observing System (EOS). In particular, the focus is on the EOS projects: the Atmospheric Infrared Sounder (AIRS), the High-Resolution Dynamics Limb Sounder (HIRDLS), Measurements of Pollution in the Troposphere (MOPITT), the Tropospheric Emission Spectrometer (TES), and the Stratospheric Aerosol and Gas Experiment (SAGE III). The data requirements of these programs in terms of spectroscopy are varied, but usually call for additional spectral parameters or improvements to existing molecular bands. In addition, cross-section data for heavier molecular species must be expanded and made amenable to modeling in remote sensing. The effort in the project also includes developing software and distribution to make access, manipulation, and use of HITRAN functional to the EOS program.

Gamma emission of the atmosphere in the vicinity of the Earth. [28 keV to 4. 1 MeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Golenetskii, S.V.; Gur'yan, Yu.A.; Il'inskii, V.N.

1975-01-01

The X-ray and ..gamma..-emissions of the earth's atmosphere were measured on Kosmos 461 in the range of 28 keV to 4.1 MeV. The energy spectrum of the emission was measured and the geomagnetic dependence of intensity in the continuous spectrum and in the 0.511-MeV line was determined. Measurements on Kosmos 135 yielded data on the height dependence of the atmospheric ..gamma..-quantum flux. 10 references.

Environmental monitoring for the DOE coolside and LIMB demonstration extension projects. Quarterly report for the period of February, March and April 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, T.; Contos, L.; Adams, L.

1992-02-01

The purpose of this document is to present environmental monitoring data collected during the US DOE Limestone Injection Multistage Burner (LIMB) Demonstration Project Extension. The objective of the LIMB program is to demonstrate the sulfur dioxide (SO{sub 2}) and nitrogen oxide (NO{sub x}) emission reduction capabilities of the LIMB system. The LIMB system is a retrofit technology to be used for existing coal-fired boilers equipped with electrostatic precipitators. (VC)

Rare Earth Garnet Selective Emitter

NASA Technical Reports Server (NTRS)

Lowe, Roland A.; Chubb, Donald L.; Farmer, Serene C.; Good, Brian S.

1994-01-01

Thin film Ho-YAG and Er-YAG emitters with a platinum substrate exhibit high spectral emittance in the emission band (epsilon(sub lambda) approx. = 0.75, sup 4)|(sub 15/2) - (sup 4)|(sub 13/2),for Er-YAG and epsilon(sub lambda) approx. = 0.65, (sup 5)|(sub 7) - (sup 5)|(sub 8) for Ho-YAG) at 1500 K. In addition, low out-of-band spectral emittance, epsilon(sub lambda) less than 0.2, suggest these materials would be excellent candidates for high efficiency selective emitters in thermophotovoltaic (TPV) systems operating at moderate temperatures (1200-1500 K). Spectral emittance measurements of the thin films were made (1.2 less than lambda less than 3.0 microns) and compared to the theoretical emittances calculated using measured values of the spectral extinction coefficient. In this paper we present the results for a new class of rare earth ion selective emitters. These emitters are thin sections (less than 1 mm) of yttrium aluminum garnet (YAG) single crystal with a rare earth substitutional impurity. Selective emitters in the near IR are of special interest for thermophotovoltaic (TPV) energy conversion. The most promising solid selective emitters for use in a TPV system are rare earth oxides. Early spectral emittance work on rare earth oxides showed strong emission bands in the infrared (0.9 - 3 microns). However, the emittance outside the emission band was also significant and the efficiency of these emitters was low. Recent improvements in efficiency have been made with emitters fabricated from fine (5 - 10 microns) rare earth oxide fibers similar to the Welsbach mantle used in gas lanterns. However, the rare earth garnet emitters are more rugged than the mantle type emitters. A thin film selective emitter on a low emissivity substrate such as gold, platinum etc., is rugged and easily adapted to a wide variety of thermal sources. The garnet structure and its many subgroups have been successfully used as hosts for rare earth ions, introduced as substitutional

Prevalence and Characteristics of Phantom Limb Pain and Residual Limb Pain in the Long Term after Upper Limb Amputation

ERIC Educational Resources Information Center

Desmond, Deirdre M.; MacLachlan, Malcolm

2010-01-01

This study aims to describe the prevalence and characteristics of phantom limb pain and residual limb pain after upper limb amputation. One-hundred and forty-one participants (139 males; mean age 74.8 years; mean time since amputation 50.1 years) completed a self-report questionnaire assessing residual and phantom limb pain experience. Prevalence…

Observation of Solar Wind Charge Exchange Emission From Exospheric Material in and Outside Earth's Magnetosheath 2008 September 25

NASA Technical Reports Server (NTRS)

Snowden, S. L.; Collier, M. R.; Cravens, T.; Kuntz, K. D.; Lepri, S. T.; Robertson, I.; Tomas, L.

2009-01-01

A long XMM-Newton exposure is used to observe solar wind charge exchange (SWCX) emission from exospheric material in and outside Earth's magnetosheath. The light curve of the O vii (0.5-0.62 keV) band is compared with a model for the expected emission, and while the emission is faint and the light curve has considerable scatter, the correlation is significant to better than 99.9%. This result demonstrates the validity of the geocoronal SWCX emission model for predicting a contribution to astrophysical observations to a scale factor of order unity (1.5). In addition, an average value of the SWCX O vii emission from the magnetosheath over the observation of 2.6 +/- 0.5 LU is derived. The results also demonstrate the potential utility of using X-ray observations to study global phenomena of the magnetosheath which currently are only investigated using in situ measurements.

The influence of rotation on optical emission profiles of O stars

NASA Astrophysics Data System (ADS)

Hillier, D. John; Bouret, Jean-Claude; Lanz, Thierry; Busche, Joseph R.

2012-10-01

We study the formation of photospheric emission lines in O stars and show that the rectangular profiles, sometimes double peaked, that are observed for some stars are a direct consequence of rotation, and it is unnecessary to invoke an enhanced density structure in the equatorial regions. Emission lines, such as N IV λ4058 and the N III λλ4634-4640-4642 multiplet, exhibit non-standard 'limb-darkening' laws. The lines can be in absorption for rays striking the centre of the star and in emission for rays near the limb. Weak features in the flux spectrum do not necessarily indicate an intrinsically weak feature - instead the feature can be weak because of cancellation between absorption in 'core' rays and emission from rays near the limb. Rotation also modifies line profiles of wind diagnostics such as He II λ4686 and Hα and should not be neglected when inferring the actual stratification, level and nature of wind structures.

Limb deficiency and prosthetic management. 2. Aging with limb loss.

PubMed

Flood, Katherine M; Huang, Mark E; Roberts, Toni L; Pasquina, Paul F; Nelson, Virginia S; Bryant, Phillip R

2006-03-01

This self-directed learning module highlights the issues faced by people aging with limb loss. It is part of the study guide on limb deficiency and vascular rehabilitation in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. This article specifically focuses on the impact that limb loss has on health and physical function throughout the life span. Case examples are used to illustrate what effect limb loss in childhood or young adulthood has on the incidence and management of new impairments or disease processes commonly associated with aging. To discuss the impact of early-life limb loss on the incidence and management of physiologic and functional changes associated with aging.

A review of supernumerary and absent limbs and digits of the upper limb.

PubMed

Klaassen, Zachary; Choi, Monica; Musselman, Ruth; Eapen, Deborah; Tubbs, R Shane; Loukas, Marios

2012-03-01

For years people have been enamored by anomalies of the human limbs, particularly supernumerary and absent limbs and digits. Historically, there are a number of examples of such anomalies, including royal families of ancient Chaldea, tribes from Arabia, and examples from across nineteenth century Europe. The development of the upper limbs in a growing embryo is still being elucidated with the recent advent of homeobox genes, but researchers agree that upper limbs develop between stages 12-23 through a complex embryological process. Maternal thalidomide intake during limb development is known to cause limb reduction and subsequent amelia or phocomelia. Additionally, a number of clinical reports have illustrated different limb anomaly cases, with each situation unique in phenotype and developmental abnormality. Supernumerary and absent limbs and digits are not unique to humans, and a number of animal cases have also been reported. This review of the literature illustrates the historical, anatomical, and clinical aspects of supernumerary and absent limbs and digits for the upper limb.

The Day the Earth Smiled: Sneak Preview

NASA Image and Video Library

2013-07-22

In this rare image taken on July 19, 2013, the wide-angle camera on NASA's Cassini spacecraft has captured Saturn's rings and our planet Earth and its moon in the same frame. It is only one footprint in a mosaic of 33 footprints covering the entire Saturn ring system (including Saturn itself). At each footprint, images were taken in different spectral filters for a total of 323 images: some were taken for scientific purposes and some to produce a natural color mosaic. This is the only wide-angle footprint that has the Earth-moon system in it. The dark side of Saturn, its bright limb, the main rings, the F ring, and the G and E rings are clearly seen; the limb of Saturn and the F ring are overexposed. The "breaks" in the brightness of Saturn's limb are due to the shadows of the rings on the globe of Saturn, preventing sunlight from shining through the atmosphere in those regions. The E and G rings have been brightened for better visibility. Earth, which is 898 million miles (1.44 billion kilometers) away in this image, appears as a blue dot at center right; the moon can be seen as a fainter protrusion off its right side. An arrow indicates their location in the annotated version. (The two are clearly seen as separate objects in the accompanying composite image PIA14949.) The other bright dots nearby are stars. This is only the third time ever that Earth has been imaged from the outer solar system. The acquisition of this image, along with the accompanying composite narrow- and wide-angle image of Earth and the moon and the full mosaic from which both are taken, marked the first time that inhabitants of Earth knew in advance that their planet was being imaged. That opportunity allowed people around the world to join together in social events to celebrate the occasion. This view looks toward the unilluminated side of the rings from about 20 degrees below the ring plane. Images taken using red, green and blue spectral filters were combined to create this natural color

On the Nature of Off-limb Flare Continuum Sources Detected by SDO /HMI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heinzel, P.; Kašparová, J.; Kleint, L.

The Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory has provided unique observations of off-limb flare emission. White-light continuum enhancements were detected in the “continuum” channel of the Fe 6173 Å line during the impulsive phase of the observed flares. In this paper we aim to determine which radiation mechanism is responsible for such enhancement being seen above the limb, at chromospheric heights around or below 1000 km. Using a simple analytical approach, we compare two candidate mechanisms, the hydrogen recombination continuum (Paschen) and the Thomson continuum due to scattering of disk radiation on flare electrons. Both mechanismsmore » depend on the electron density, which is typically enhanced during the impulsive phase of a flare as the result of collisional ionization (both thermal and also non-thermal due to electron beams). We conclude that for electron densities higher than 10{sup 12} cm{sup −3}, the Paschen recombination continuum significantly dominates the Thomson scattering continuum and there is some contribution from the hydrogen free–free emission. This is further supported by detailed radiation-hydrodynamical (RHD) simulations of the flare chromosphere heated by the electron beams. We use the RHD code FLARIX to compute the temporal evolution of the flare-heating in a semi-circular loop. The synthesized continuum structure above the limb resembles the off-limb flare structures detected by HMI, namely their height above the limb, as well as the radiation intensity. These results are consistent with recent findings related to hydrogen Balmer continuum enhancements, which were clearly detected in disk flares by the IRIS near-ultraviolet spectrometer.« less

Evidence of Convective Redistribution of Carbon Monoxide in Aura Tropospheric Emission Sounder (TES) and Microwave Limb Sounder (MLS) Observations

NASA Technical Reports Server (NTRS)

Manyin, Michael; Douglass, Anne; Schoeberl, Mark

2010-01-01

Vertical convective transport is a key element of the tropospheric circulation. Convection lofts air from the boundary layer into the free troposphere, allowing surface emissions to travel much further, and altering the rate of chemical processes such as ozone production. This study uses satellite observations to focus on the convective transport of CO from the boundary layer to the mid and upper troposphere. Our hypothesis is that strong convection associated with high rain rate regions leads to a correlation between mid level and upper level CO amounts. We first test this hypothesis using the Global Modeling Initiative (GMI) chemistry and transport model. We find the correlation is robust and increases as the precipitation rate (the strength of convection) increases. We next examine three years of CO profiles from the Tropospheric Emission Sounder (TES) and Microwave Limb Sounder (MLS) instruments aboard EOS Aura. Rain rates are taken from the Tropical Rainfall Measuring Mission (TRMM) 3B-42 multi-satellite product. Again we find a correlation between mid-level and upper tropospheric CO, which increases with rain rate. Our result shows the critical importance of tropical convection in coupling vertical levels of the troposphere in the transport of trace gases. The effect is seen most clearly in strong convective regions such as the Inter-tropical Convergence Zone.

Determination of rare earth elements in geological materials by inductively coupled argon plasma/atomic emission spectrometry

USGS Publications Warehouse

Crock, J.G.; Lichte, F.E.

1982-01-01

Inductively coupled argon plasma/optical emission spectrometery (ICAP/OES) is useful as a simultaneous, multielement analytical technique for the determination of trace elements in geological materials. A method for the determination of trace-level rare earth elements (REE) in geological materials using an ICAP 63-channel emission spectrometer is described. Separation and preconcentration of the REE and yttrium from a sample digest are achieved by a nitric acid gradient cation exchange and hydrochloric acid anion exchange. Precision of 1-4% relative standard deviation and comparable accuracy are demonstrated by the triplicate analysis of three splits of BCR-1 and BHVO-1. Analyses of other geological materials including coals, soils, and rocks show comparable precision and accuracy.

Assessing the Impact of Earth Radiation Pressure Acceleration on Low-Earth Orbit Satellites

NASA Astrophysics Data System (ADS)

Vielberg, Kristin; Forootan, Ehsan; Lück, Christina; Kusche, Jürgen; Börger, Klaus

2017-04-01

The orbits of satellites are influenced by several external forces. The main non-gravitational forces besides thermospheric drag, acting on the surface of satellites, are accelerations due to the Earth and Solar Radiation Pres- sure (SRP and ERP, respectively). The sun radiates visible and infrared light reaching the satellite directly, which causes the SRP. Earth also emits and reflects the sunlight back into space, where it acts on satellites. This is known as ERP acceleration. The influence of ERP increases with decreasing distance to the Earth, and for low-earth orbit (LEO) satellites ERP must be taken into account in orbit and gravity computations. Estimating acceler- ations requires knowledge about energy emitted from the Earth, which can be derived from satellite remote sensing data, and also by considering the shape and surface material of a satellite. In this sensitivity study, we assess ERP accelerations based on different input albedo and emission fields and their modelling for the satellite missions Challenging Mini-Satellite Payload (CHAMP) and Gravity Recovery and Climate Experiment (GRACE). As input fields, monthly 1°x1° products of Clouds and the Earth's Radiant En- ergy System (CERES), L3 are considered. Albedo and emission models are generated as latitude-dependent, as well as in terms of spherical harmonics. The impact of different albedo and emission models as well as the macro model and the altitude of satellites on ERP accelerations will be discussed.

Environmental monitoring for the DOE coolside and LIMB demonstration extension projects. Final report, May--August 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, T.; Contos, L.; Adams, L.

1992-03-01

The purpose of this document is to present environmental monitoring data collected during the US Department of Energy Limestone Injection Multistage Burner (DOE LIMB) Demonstration Project Extension at the Ohio Edison Edgewater Generating Station in Lorain, Ohio. The DOE project is an extension of the US Environmental Protection Agency`s (EPA`s) original LIMB Demonstration. The program is operated nuclear DOE`s Clean Coal Technology Program of ``emerging clean coal technologies`` under the categories of ``in boiler control of oxides of sulfur and nitrogen`` as well as ``post-combustion clean-up.`` The objective of the LIMB program is to demonstrate the sulfur dioxide (SO{sub 2})more » and nitrogen oxide (NO{sub x}) emission reduction capabilities of the LIMB system. The LIMB system is a retrofit technology to be used for existing coal-fired boilers equipped with electrostatic precipitators (ESPs).« less

Analysis of consistency of global net land-use change carbon emission scenario using offline vegetation model and earth system model

NASA Astrophysics Data System (ADS)

Kato, E.; Kawamiya, M.

2010-12-01

For CMIP5 experiments, emissions scenarios data sets for climate models are prepared as Representative Concentration Pathways (RCPs) by the Integrated Assessment Models (IAMs). IAMs also have depicted regional land-use scenarios based on the socioeconomic assumption of the future scenarios of RCPs. In the land-use harmonization project, gridded land-use transition data has been constructed from the regional IAMs future land-use scenarios which smoothly connects historical reconstructions of land-use based on HYDE 3 data and FAO wood harvest data. In this study, using the gridded transition land-use scenario data, global net CO2 emission from land-use change for each RCPs scenarios is evaluated with a offline version of terrestrial biogeochemical model, VISIT (Vegetation Integrative SImulation Tool), utilizing a protocol to estimate carbon emission from deforested biomass considering delayed decomposition of product pools, and regrowth absorption from the secondary lands with abandoned agricultural lands. From the model output, effect of CO2 fertilization and land-use scenario itself on the emission is assessed to see the consistency of the scenarios. In addition, to see the effect of climate change and the climate-carbon feedback on terrestrial ecosystems, net land-use change CO2 emission is also evaluated with an earth system model, MIROC-ESM incorporating a DGVM with land-use change component. In the simulations with earth system model, RCP 6.0 scenario has been evaluated by model runs with and without land-use change forcing.

The orbiter PLB and Earth limb during STS-121

NASA Image and Video Library

2006-07-15

S121-E-07909 (15 July 2006) --- Backdropped by the blackness of space and Earth's horizon, Space Shuttle Discovery's aft cargo bay, its vertical stabilizer and orbital maneuvering system (OMS) pods are seen in this image photographed by an STS-121 crewmember onboard the shuttle. The Italian-built Leonardo Multi-Purpose Logistics Module (MPLM) is visible in the cargo bay.

The orbiter PLB and Earth limb during STS-121

NASA Image and Video Library

2006-07-15

S121-E-07904 (15 July 2006) --- Backdropped by the blackness of space and Earth's horizon, Space Shuttle Discovery's aft cargo bay, its vertical stabilizer and orbital maneuvering system (OMS) pods are seen in this image photographed by an STS-121 crewmember onboard the shuttle. The Italian-built Leonardo Multi-Purpose Logistics Module (MPLM) is visible in the cargo bay.

Cassini UVIS Observations of Titan Ultraviolet Airglow Spectra with Laboratory Modeling from Electron- and Proton-Excited N2 Emission Studies

NASA Astrophysics Data System (ADS)

Ajello, J. M.; West, R. A.; Malone, C. P.; Gustin, J.; Esposito, L. W.; McClintock, W. E.; Holsclaw, G. M.; Stevens, M. H.

2011-12-01

laboratory spectra, we have analyzed the intensity and identified each spectral feature from the limb or disk emission spectrum. The strongest dipole-allowed transitions of N2 occur in the EUV. The electronic transitions proceed from the X 1Σg+ ground-state to about seven closely spaced (~12-15 eV) Rydberg-valence (RV) states, which are the source of the molecular emissions in the EUV observed by spacecraft and have recently been studied in our laboratory at medium-to-high spectral resolution (delta-λ = 0.1 Å FWHM). Three of these RV states (b 1Πu, b' 1Σu+, and c4' 1Σu+) are highly-perturbed, weakly-to-strongly predissociated, and have significant emission cross sections, which will be summarized in this paper. We will also discuss our recently published proton and electron impact emission cross sections for the LBH (a 1Πg - X 1Σg+) band system of N2, and their significance to the modeling of the day and night FUV spectra of the atmospheres of Earth and Titan.

Two-year solid hydrogen cooler for the Cryogenic Limb Array Etalon Spectrometer (CLAES) instrument

NASA Technical Reports Server (NTRS)

Naes, L. G.; Nast, T. C.; Roche, A. E.; Forney, P. B.

1983-01-01

The Cryogenic Limb Array Etalon Spectrometer (CLAES) will be one of thirteen instruments on board the Upper Atmospheric Research Satellite (UARS) in late 1988. CLAES is to be employed for the measurement of stratospheric trace species concentrations affecting the ozone layer balance. It is an earth-limb viewing instrument which requires cryogenic cooling in order to obtain the necessary performance sensitivity. The present investigation is concerned with the solid hydrogen cryogen subsystem which provides the instrument temperature needed. Attention is given to the studies which led to the selection of solid hydrogen as cooling agent, the baseline cooler system, aspects of baseline performance sensitivity, and nominal cooler operations.

The Simulated Impact of Dimethyl Sulfide Emissions on the Earth System

NASA Astrophysics Data System (ADS)

Cameron-Smith, P. J.; Elliott, S.; Shrivastava, M. B.; Burrows, S. M.; Maltrud, M. E.; Lucas, D. D.; Ghan, S.

2015-12-01

Dimethyl sulfide (DMS) is one of many biologically derived gases and particles emitted from the ocean that has the potential to affect climate. In the case of DMS it is oxidized to sulfate, which increases the aerosol loading in the atmosphere either through nucleation or condensation on other aerosols, which in turn changes the energy balance of the Earth by reflection of sunlight either through direct reflection by the aerosols or by modifying clouds. We have previously shown that the geographical distribution of DMS emission from the ocean may be quite sensitive to climate changes, especially in the Southern Ocean. Our state-of-the-art sulfur-cycle Earth system model (ESM), based on the Community Earth System Model (CESM) climate model, includes an ocean sulfur ecosystem model, the oxidation of DMS to sulfate by atmospheric chemistry, and the indirect effect of sulfate on radiation via clouds using the Modal Aerosol Model (MAM). Our multi-decadal simulations calculate the impact of DMS on the energy balance and climate of the Earth system, and its sensitivity/feedback to climate change. The estimate from our simulations is that DMS is responsible for ~6 W/m2 of reflected sunlight in the pre-industrial era (globally averaged), and ~4 W/m2 in the present era. The reduction is caused by increased competition with cloud condensation nuclei from anthropogenic aerosols in the present era, and therefore partially offsets the cooling from the anthropogenic aerosols. The distribution of these effects are not uniform, and doesn't necessarily follow the simulated DMS distribution, because some clouds are more sensitive to DMS derived sulfate than others, and there are surface feedbacks such as the ice-albedo feedback. Although our calculated impact of DMS is higher than some previous studies, it is not much higher than recent observational estimates (McCoy, et al., 2015). We are now porting these capabilities to the US Department of Energy's Accelerated Climate Modeling

SHOCK-CLOUD INTERACTION AND PARTICLE ACCELERATION IN THE SOUTHWESTERN LIMB OF SN 1006

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miceli, M.; Orlando, S.; Bocchino, F.

2014-02-20

The supernova remnant SN 1006 is a powerful source of high-energy particles and evolves in a relatively tenuous and uniform environment despite interacting with an atomic cloud in its northwestern limb. The X-ray image of SN 1006 reveals an indentation in the southwestern part of the shock front and the H I maps show an isolated (southwestern) cloud, having the same velocity as the northwestern cloud, whose morphology fits perfectly in the indentation. We performed spatially resolved spectral analysis of a set of small regions in the southwestern nonthermal limb and studied the deep X-ray spectra obtained within the XMM-Newton SN 1006 Largemore » Program. We also analyzed archive H I data, obtained by combining single-dish and interferometric observations. We found that the best-fit value of N {sub H} derived from the X-ray spectra significantly increases in regions corresponding to the southwestern cloud, while the cutoff energy of the synchrotron emission decreases. The N {sub H} variation corresponds perfectly with the H I column density of the southwestern cloud, as measured from the radio data. The decrease in the cutoff energy at the indentation clearly reveals that the back side of the cloud is actually interacting with the remnant. The southwestern limb therefore presents a unique combination of efficient particle acceleration and high ambient density, thus being the most promising region for γ-ray hadronic emission in SN 1006. We estimate that such emission will be detectable with the Fermi telescope within a few years.« less

Validation of Special Sensor Ultraviolet Limb Imager (SSULI) Ionospheric Tomography using ALTAIR Incoherent Scatter Radar Measurements

NASA Astrophysics Data System (ADS)

Dymond, K.; Nicholas, A. C.; Budzien, S. A.; Stephan, A. W.; Coker, C.; Hei, M. A.; Groves, K. M.

2015-12-01

The Special Sensor Ultraviolet Limb Imager (SSULI) instruments are ultraviolet limb scanning sensors flying on the Defense Meteorological Satellite Program (DMSP) satellites. The SSULIs observe the 80-170 nanometer wavelength range covering emissions at 91 and 136 nm, which are produced by radiative recombination of the ionosphere. We invert these emissions tomographically using newly developed algorithms that include optical depth effects due to pure absorption and resonant scattering. We present the details of our approach including how the optimal altitude and along-track sampling were determined and the newly developed approach we are using for regularizing the SSULI tomographic inversions. Finally, we conclude with validations of the SSULI inversions against ALTAIR incoherent scatter radar measurements and demonstrate excellent agreement between the measurements.

Variability of fire emissions on interannual to multi-decadal timescales in two Earth System models

NASA Astrophysics Data System (ADS)

Ward, D. S.; Shevliakova, E.; Malyshev, S.; Lamarque, J.-F.; Wittenberg, A. T.

2016-12-01

Connections between wildfires and modes of variability in climate are sought as a means for predicting fire activity on interannual to multi-decadal timescales. Several fire drivers, such as temperature and local drought index, have been shown to vary on these timescales, and analysis of tree-ring data suggests covariance between fires and climate oscillation indices in some regions. However, the shortness of the satellite record of global fire events limits investigations on larger spatial scales. Here we explore the interplay between climate variability and wildfire emissions with the preindustrial long control numerical experiments and historical ensembles of CESM1 and the NOAA/GFDL ESM2Mb. We find that interannual variability in fires is underpredicted in both Earth System models (ESMs) compared to present day fire emission inventories. Modeled fire emissions respond to the El Niño/southern oscillation (ENSO) and Pacific decadal oscillation (PDO) with increases in southeast Asia and boreal North America emissions, and decreases in southern North America and Sahel emissions, during the ENSO warm phase in both ESMs, and the PDO warm phase in CESM1. Additionally, CESM1 produces decreases in boreal northern hemisphere fire emissions for the warm phase of the Atlantic Meridional Oscillation. Through analysis of the long control simulations, we show that the 20th century trends in both ESMs are statistically significant, meaning that the signal of anthropogenic activity on fire emissions over this time period is detectable above the annual to decadal timescale noise. However, the trends simulated by the two ESMs are of opposite sign (CESM1 decreasing, ESM2Mb increasing), highlighting the need for improved understanding, proxy observations, and modeling to resolve this discrepancy.

Dynamic inter-limb resistance exercise device for long-duration space flight

NASA Technical Reports Server (NTRS)

Schwandt, Douglas F.; Watenpaugh, Donald E.; Parazynski, Scott E.; Hargens, Alan R.

1991-01-01

Essential for fitness on Earth, resistive exercise is even more important for astronauts, who must maintain muscle and bone strength in the absence of gravity. To meet this need, designers and scientists at NASA Ames Research Center, Life Science Division, have worked to develop more effective exercise devices for long-duration exposure to microgravity. One of these concepts is the Inter-Limb Resistance Device which allows the subject to exercise one limb directly against another, strengthening muscle groups in the arms, legs, and back. It features a modular harness with an inelastic cable and instrumented pulley. Forces similar to other high resistance exercise equipment are generated. Sensors in the pulley measure force and velocity for performance feedback display and data acquisition. This free-floating apparatus avoids vibration of sensitive experiments on board spacecraft. Compact with low mass, this hardware is also well suited for a 'safe haven' from radiation on board Space Station Freedom, and may prove useful in confined environments on Earth, such as Antarctic stations, submarines, and other underwater habitats. Potential spin-offs of this technology include products for personal strengthening and cardiovascular conditioning, rehabilitation of hospital patients, fitness exercise for the disabled, and retraining after sports injuries.

Dayglow emissions of the O2 Herzberg bands and the Rayleigh backscattered spectrum of the earth

NASA Technical Reports Server (NTRS)

Frederick, J. E.; Abrams, R. B.

1982-01-01

It is pointed out that numerous fluorescent emissions from the Herzberg bands of molecular oxygen lie in the spectral region 242-300 nm. This coincides with the wavelength range used by orbiting spectrometers that observe the Rayleigh backscattered spectrum of the earth for the purpose of monitoring the vertical distribution of stratospheric ozone. Model calculations suggest that Herzberg band emissions in the dayglow could provide significant contamination of the ozone measurements if the quenching rate of O2(A3Sigma) is sufficiently small. It is noted that this is especially true near 255 nm, where the most intense fluorescent emissions relative to the Rayleigh scattered signal are located and where past satellite measurements have shown a persistent excess radiance above that expected for a pure ozone absorbing and molecular scattering atmosphere. Very small quenching rates, however, are adequate to reduce the dayglow emission to negligible levels. Noting that available laboratory data have not definitely established the quenching on the rate of O2(A3Sigma) as a function of vibration level, it is emphasized that such information is required before the Herzberg band contributions can be evaluated with confidence.

Sideband-Separating, Millimeter-Wave Heterodyne Receiver

NASA Technical Reports Server (NTRS)

Ward, John S.; Bumble, Bruce; Lee, Karen A.; Kawamura, Jonathan H.; Chattopadhyay, Goutam; Stek, paul; Stek, Paul

2010-01-01

Researchers have demonstrated a submillimeter-wave spectrometer that combines extremely broad bandwidth with extremely high sensitivity and spectral resolution to enable future spacecraft to measure the composition of the Earth s troposphere in three dimensions many times per day at spatial resolutions as high as a few kilometers. Microwave limb sounding is a proven remote-sensing technique that measures thermal emission spectra from molecular gases along limb views of the Earth s atmosphere against a cold space background.

Standardized Approach to Quantitatively Measure Residual Limb Skin Health in Individuals with Lower Limb Amputation.

PubMed

Rink, Cameron L; Wernke, Matthew M; Powell, Heather M; Tornero, Mark; Gnyawali, Surya C; Schroeder, Ryan M; Kim, Jayne Y; Denune, Jeffrey A; Albury, Alexander W; Gordillo, Gayle M; Colvin, James M; Sen, Chandan K

2017-07-01

Objective: (1) Develop a standardized approach to quantitatively measure residual limb skin health. (2) Report reference residual limb skin health values in people with transtibial and transfemoral amputation. Approach: Residual limb health outcomes in individuals with transtibial ( n  = 5) and transfemoral ( n  = 5) amputation were compared to able-limb controls ( n  = 4) using noninvasive imaging (hyperspectral imaging and laser speckle flowmetry) and probe-based approaches (laser doppler flowmetry, transcutaneous oxygen, transepidermal water loss, surface electrical capacitance). Results: A standardized methodology that employs noninvasive imaging and probe-based approaches to measure residual limb skin health are described. Compared to able-limb controls, individuals with transtibial and transfemoral amputation have significantly lower transcutaneous oxygen tension, higher transepidermal water loss, and higher surface electrical capacitance in the residual limb. Innovation: Residual limb health as a critical component of prosthesis rehabilitation for individuals with lower limb amputation is understudied in part due to a lack of clinical measures. Here, we present a standardized approach to measure residual limb health in people with transtibial and transfemoral amputation. Conclusion: Technology advances in noninvasive imaging and probe-based measures are leveraged to develop a standardized approach to quantitatively measure residual limb health in individuals with lower limb loss. Compared to able-limb controls, resting residual limb physiology in people that have had transfemoral or transtibial amputation is characterized by lower transcutaneous oxygen tension and poorer skin barrier function.

The application of spaceborne GPS to atmospheric limb sounding and global change monitoring

NASA Technical Reports Server (NTRS)

Melbourne, W. G.; Davis, E. S.; Duncan, C. B.; Hajj, G. A.; Hardy, K. R.; Kursinski, E. R.; Meehan, T. K.; Young, L. E.; Yunck, T. P.

1994-01-01

This monograph is intended for readers with minimal background in radio science who seek a relatively comprehensive treatment of the mission and technical aspects of an Earth-orbiting radio occultation satellite. Part 1 (chapters 1-6) describes mission concepts and programmatic information; Part 2 (chapters 7-12) deals with the theoretical aspects of analyzing and interpreting radio occultation measurements. In this mission concept the navigation signals from a Global Positioning System (GPS) satellite that is being occulted by the Earth's limb are observed by a GPS flight receiver on board a low Earth orbiter (LEO) satellite. This technique can be used to recover profiles of the Earth's atmospheric refractivity, pressure, and temperature using small, dedicated, and relatively low-cost space systems. Chapter 2 summarizes the basic space system concepts of the limb-sounding technique and describes a low-cost strawman demonstration mission. Chapter 3 discusses some of the scientific benefits of using radio occultation on a suite of small satellites. Chapter 4 provides a more detailed discussion of several system elements in a radio occultation mission, including the launch system for small payloads, the LEO microsat, the GPS constellation, the GPS flight receiver payload, the mission operations ground control and data receiving system, the ground-based GPS global tracking network for precision orbit determination, and the central data processing and archive system. Chapter 5 addresses the various technology readiness questions that invariably arise. Chapter 6 discusses the overall costs of a demonstration mission such as GPS/MET (meteorological) proposed by the University Navstar Consortium (UNAVCO). Chapter 7 describes a geometrical optics approach to coplanar atmospheric occultation. Chapter 8 addresses major questions regarding accuracy of the occultation techniques. Chapter 9 describes some simulations that have been performed to evaluate the sensitivity of the

3D model of auroral emissions for Europa

NASA Astrophysics Data System (ADS)

Cessateur, G.; Barthelemy, M.; Rubin, M.; Lilensten, J.; Maggiolo, R.; De Keyser, J.; Gunell, H.; Loreau, J.

2017-12-01

As archetype of icy satellites, Europa will be one of the primary targets of the ESA JUICE and NASA Europa Clipper missions. Through surface sputtering, Europa does possess a thin neutral gas atmosphere, mainly composed of O2 and H2O. Valuable information can therefore be retrieved from auroral and airglow measurements. We present here a 3D electron-excitation-transport-emission coupled model of oxygen line emissions produced through precipitating electrons. The density and temperature of the electrons are first derived from the multifluid MHD model from Rubin et al. (2015). Oxygen emission lines in the UV have first been modelled, such as those at 130.5 and 135.6 nm, and there is a nonhomogenous distribution of the emission. For 135.6 nm, the line emission can be significant and reach 700 Rayleigh close to the surface for a polar limb viewing angle. Visible emissions with the red-doublet (630-636.4 nm) and green (577.7 nm) oxygen lines are also considered with emission intensities reaching 7150 R and 200 R, respectively, for limb polar viewing. Using different cross section data, a sensitivity study has also been performed to assess the impact of the uncertainties on the auroral emissions.

Effects of varying inter-limb spacing to limb length ratio in metachronal swimming

NASA Astrophysics Data System (ADS)

Lai, Hong Kuan; Merkel, Rachael; Santhanakrishnan, Arvind

2016-11-01

Crustaceans such as shrimp, krill and crayfish swim by rhythmic paddling of four to five pairs of closely spaced limbs. Each pair is phase-shifted in time relative to the neighboring pair, resulting in a metachronal wave that travels in the direction of animal motion. The broad goal of this study is to investigate how the mechanical design of the swimming limbs affect scalability of metachronal swimming in terms of limb-based Reynolds number (Re). A scaled robotic model of metachronal paddling was developed, consisting of four pairs of hinged acrylic plates actuated using stepper motors that were immersed in a rectangular tank containing water-glycerin fluid medium. 2D PIV measurements show that the propulsive jets transition from being primarily horizontal (thrust-producing direction) at Re of order 10 to angled vertically at Re of order 100. The ratio of inter-limb spacing to limb length among metachronal swimming organisms ranges between 0.2 to 0.65. 2D PIV will be used to examine the jets generated between adjacent limbs for varying inter-limb spacing to limb length ratios. The effect of increasing this ratio to beyond the biologically observed range will be discussed.

Polarisation of auroral emission lines in the Earth's upper atmosphere : first results and perspectives

NASA Astrophysics Data System (ADS)

Lamy, H.; Barthelemy, M.; Simon Wedlund, C.; Lilensten, J.; Bommier, V.

2011-12-01

Polarisation of light is a key observable to provide information about asymmetry or anisotropy within a radiative source. Following the pioneering and controversial work of Duncan in 1959, the polarisation of auroral emission lines in the Earth's upper atmosphere has been overlooked for a long time, even though the red intense auroral line (6300Å) produced by collisional impacts with electrons precipitating along magnetic field lines is a good candidate to search for polarisation. This problem was investigated again by Lilensten et al (2006) and observations were obtained by Lilensten et al (2008) confirming that the red auroral emission line is polarised. More recent measurements obtained by Barthélemy et al (2011) are presented and discussed. The results are compared to predictions of the theoretical work of Bommier et al (2011) and are in good agreement. Following these encouraging results, a new dedicated spectropolarimeter is currently under construction between BIRA-IASB and IPAG to provide simultaneously the polarisation of the red line and of other interesting auroral emission lines such as N2+ 1NG (4278Å), other N2 bands, etc... Perspectives regarding the theoretical polarisation of some of these lines will be presented. The importance of these polarisation measurements in the framework of atmospheric modeling and geomagnetic activity will be discussed.

Variability of fire emissions on interannual to multi-decadal timescales in two Earth System models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, D. S.; Shevliakova, E.; Malyshev, S.

Connections between wildfires and modes of variability in climate are sought as a means for predicting fire activity on interannual to multi-decadal timescales. Several fire drivers, such as temperature and local drought index, have been shown to vary on these timescales, and analysis of tree-ring data suggests covariance between fires and climate oscillation indices in some regions. HBut, the shortness of the satellite record of global fire events limits investigations on larger spatial scales. Here we explore the interplay between climate variability and wildfire emissions with the preindustrial long control numerical experiments and historical ensembles of CESM1 and the NOAA/GFDLmore » ESM2Mb. We find that interannual variability in fires is underpredicted in both Earth System models (ESMs) compared to present day fire emission inventories. Modeled fire emissions respond to the El Niño/southern oscillation (ENSO) and Pacific decadal oscillation (PDO) with increases in southeast Asia and boreal North America emissions, and decreases in southern North America and Sahel emissions, during the ENSO warm phase in both ESMs, and the PDO warm phase in CESM1. In addition, CESM1 produces decreases in boreal northern hemisphere fire emissions for the warm phase of the Atlantic Meridional Oscillation. Through analysis of the long control simulations, we show that the 20th century trends in both ESMs are statistically significant, meaning that the signal of anthropogenic activity on fire emissions over this time period is detectable above the annual to decadal timescale noise. However, the trends simulated by the two ESMs are of opposite sign (CESM1 decreasing, ESM2Mb increasing), highlighting the need for improved understanding, proxy observations, and modeling to resolve this discrepancy.« less

Variability of fire emissions on interannual to multi-decadal timescales in two Earth System models

DOE PAGES

Ward, D. S.; Shevliakova, E.; Malyshev, S.; ...

2016-12-02

Connections between wildfires and modes of variability in climate are sought as a means for predicting fire activity on interannual to multi-decadal timescales. Several fire drivers, such as temperature and local drought index, have been shown to vary on these timescales, and analysis of tree-ring data suggests covariance between fires and climate oscillation indices in some regions. HBut, the shortness of the satellite record of global fire events limits investigations on larger spatial scales. Here we explore the interplay between climate variability and wildfire emissions with the preindustrial long control numerical experiments and historical ensembles of CESM1 and the NOAA/GFDLmore » ESM2Mb. We find that interannual variability in fires is underpredicted in both Earth System models (ESMs) compared to present day fire emission inventories. Modeled fire emissions respond to the El Niño/southern oscillation (ENSO) and Pacific decadal oscillation (PDO) with increases in southeast Asia and boreal North America emissions, and decreases in southern North America and Sahel emissions, during the ENSO warm phase in both ESMs, and the PDO warm phase in CESM1. In addition, CESM1 produces decreases in boreal northern hemisphere fire emissions for the warm phase of the Atlantic Meridional Oscillation. Through analysis of the long control simulations, we show that the 20th century trends in both ESMs are statistically significant, meaning that the signal of anthropogenic activity on fire emissions over this time period is detectable above the annual to decadal timescale noise. However, the trends simulated by the two ESMs are of opposite sign (CESM1 decreasing, ESM2Mb increasing), highlighting the need for improved understanding, proxy observations, and modeling to resolve this discrepancy.« less

Night OH In The Mesosphere Of Venus and Earth: A Comparative Planetology Perspective

NASA Astrophysics Data System (ADS)

Parkinson, Chris; Brecht, A.; Bougher, S.; Mills, F.; Yung, Y.

2009-09-01

Satellite measurements of the terrestrial nightside mesosphere from the MLS/Aura MLS instrument show a layer of OH near 82 km. This layer confirms earlier measurements by ground-based UVFTS. The MLS and UVFTS observations measure OH in the lowest vibrational state and are distinct, but related chemically, from vibrationally-excited emission from the OH Meinel bands in the near infrared. The Caltech 1-D KINETICS model has been extended to include vibrational dependence of OH reactions and shows good agreement with MLS OH data and with observations of the Meinel bands. The model shows a chemical lifetime of HOx that increases from less than a day at 80 km to over a month at 87 km. Above this altitude transport processes become an important part of HOx chemistry. The model predicts that ground state OH represents 99% of the total OH up to 84 km. Similarly, Venus airglow emissions detected at wave-lengths of 1.40-1.49 and 2.6-3.14 μm in limb obser-vations by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on the Venus Express space-craft are attributed to the OH (2-0) and (1-0) Meinel band transitions as well. The integrated emission rates for the OH (2-0) and (1-0) bands were measured to be 100±40 and 880±90 kR respectively, both peaking at an altitude of 96±2 km near midnight local time for the considered orbit. We use the same Caltech 1-D KINETICS model to model these observations for Venus as was used for the Earth and discuss the conclusions from a comparative planetology perspective, highlighting the similarities and differences between Venus and Earth.

Radiographic features of the limbs of juvenile and subadult loggerhead sea turtles (Caretta caretta)

PubMed Central

Valente, Ana Luisa; Marco, Ignasi; Zamora, Maria Angeles; Parga, Maria Luz; Lavín, Santiago; Alegre, Ferran; Cuenca, Rafaela

2007-01-01

This study aimed to provide the normal radiographic anatomic appearance of the limbs of the loggerhead sea turtle, Caretta caretta. Dorsopalmar and dorsoplantar radiographs were taken of the forelimbs and hindlimbs of 15 juvenile and 15 subadult loggerhead sea turtles, 17 alive and 13 dead. For comparison, computed tomographic, gross anatomic, osteologic, and histologic studies were performed on the limbs of 5 of the sea turtles. Bones from the distal part of the fore and hind flippers were seen in detail with a mammographic film–screen combination. The pectoral and pelvic girdles, superimposed by the carapace, were better seen on standard radiographs with the use of rare-earth intensifying screens. Mammographic radiographs of the manus of 5 small juvenile turtles showed active growth zones. Visualization of bone contours in the distal part of the limbs was clearer than in mammals owing to the very few superimpositions. The presence of a substantial amount of cartilage in the epiphyses produced better visibility of limb ends. We conclude that use of a mammography film–screen combination is the best way to evaluate the bony and joint structures of the limbs of sea turtles. Radiography provides reliable images for clinical purposes. Considering the low cost and logistics of this technique, it is a practical ancillary test for marine animal rehabilitation centers to use. PMID:17955906

Mechanisms controlling the dependence of surface warming on cumulative carbon emissions over the next century in a suite of Earth system models

NASA Astrophysics Data System (ADS)

Williams, Richard; Roussenov, Vassil; Goodwin, Philip; Resplandy, Laure; Bopp, Laurent

2017-04-01

Insight into how to avoid dangerous climate may be obtained from Earth system model projections, which reveal a near-linear dependence of global-mean surface warming on cumulative carbon emissions. This dependence of surface warming on carbon emissions is interpreted in terms of a product of three terms: the dependence of surface warming on radiative forcing, the fractional radiative forcing contribution from atmospheric CO2 and the dependence of radiative forcing from atmospheric CO2 on cumulative carbon emissions. Mechanistically each of these dependences varies, respectively, with ocean heat uptake, the CO2 and non-CO2 radiative forcing, and the ocean and terrestrial uptake of carbon. An ensemble of 9 Earth System models forced by up to 4 Representative Concentration Pathways are diagnosed. In all cases, the dependence of surface warming on carbon emissions evolves primarily due to competing effects of heat and carbon uptake over the upper ocean: there is a reduced effect of radiative forcing from CO2 due to ocean carbon uptake, which is partly compensated by enhanced surface warming due to a reduced effect of ocean heat uptake. There is a wide spread in the dependence of surface warming on carbon emissions, undermining the ability to identify the maximum permitted carbon emission to avoid dangerous climate. Our framework reveals how uncertainty in the future warming trend is high over the next few decades due to relatively high uncertainties in ocean heat uptake, non-CO2 radiative forcing and the undersaturation of carbon in the ocean.

CO concentration in the upper stratosphere and mesosphere of Titan from VIMS dayside limb observations at 4.7 μm

NASA Astrophysics Data System (ADS)

Fabiano, F.; López Puertas, M.; Adriani, A.; Moriconi, M. L.; D'Aversa, E.; Funke, B.; López-Valverde, M. A.; Ridolfi, M.; Dinelli, B. M.

2017-09-01

During the last 30 years, many works have focused on the determination of the CO abundance in Titan's atmosphere, but no measurement above 300 km has been done yet due to the faint signal of CO. Nevertheless, such measurements are particularly awaited as a confirmation of photochemical models predictions that CO is uniformly mixed in the whole atmosphere. Moreover, since CO is the main atmospheric reservoir of oxygen, its actual abundance has implications on the origins of Titan's atmosphere. In this work, we analyse a set of Cassini VIMS daytime limb observations of Titan at 4.7 μm, which is dominated by solar-pumped non-LTE (non-local thermodynamic equilibrium) emission of CO ro-vibrational bands. In order to retrieve the CO abundance from these observations, we developed a non-LTE model for the CO vibrational levels. The retrieval of the CO concentration is performed following a bayesian approach and using the calculated non-LTE populations. The data set analysed consists of 47 limb scanning sequences -about 1500 spectra- acquired by VIMS in 2006 and 2007. CO relative abundance profiles from 200 to 500 km are obtained, for each set analysed. The mean result shows no significant variations with altitude and is consistent with the prediction of a well-mixed vertical profile. However, if compared with Earth-based mm measurements, a small vertical gradient is plausible.

On Orbit Commissioning of the Earth Observing System Microwave Limb Sounder (EOS MLS) On the Aura Spacecraft

NASA Technical Reports Server (NTRS)

Lay, Richard R.; Lee, Karen A.; Holden, James R.; Oswald, John E.; Jarnot, Robert F.; Pickett, Herbert M.; Stek, Paul C.; Cofield, Richard E., III; Flower, Dennis A.; Schwartz, Michael J.;

Earth limb views with greenish bands of airglow during STS-99

NASA Image and Video Library

2000-04-06

STS099-356-026 (11-22 February 2000) ---Because of its time exposure, this STS-99 35mm frame provides a view of several stars. The thin greenish band above the horizon is airglow; radiation emitted by the atmosphere from a layer about 30 kilometers thick and about 100 kilometers altitude. The predominant emission in airglow is the green 5577-Angstrom wavelength emission from atomic oxygen atoms. Airglow is always and everywhere present in the atmosphere; it results from the recombination of molecules that have been broken apart by solar radiation during the day. But airglow is so faint that it can only be seen at night by looking "edge on" at the emission layer, such as the view astronauts have in orbit.

Paré and prosthetics: the early history of artificial limbs.

PubMed

Thurston, Alan J

2007-12-01

There is evidence for the use of prostheses from the times of the ancient Egyptians. Prostheses were developed for function, cosmetic appearance and a psycho-spiritual sense of wholeness. Amputation was often feared more than death in some cultures. It was believed that it not only affected the amputee on earth, but also in the afterlife. The ablated limbs were buried and then disinterred and reburied at the time of the amputee's death so the amputee could be whole for eternal life. One of the earliest examples comes from the 18th dynasty of ancient Egypt in the reign of Amenhotep II in the fifteenth century bc. A mummy in the Cairo Museum has clearly had the great toe of the right foot amputated and replaced with a prosthesis manufactured from leather and wood. The first true rehabilitation aids that could be recognized as prostheses were made during the civilizations of Greece and Rome. During the Dark Ages prostheses for battle and hiding deformity were heavy, crude devices made of available materials - wood, metal and leather. Such were the materials available to Ambroise Paré who invented both upper-limb and lower-limb prostheses. His 'Le Petit Lorrain', a mechanical hand operated by catches and springs, was worn by a French Army captain in battle. Subsequent refinements in medicine, surgery and prosthetic science greatly improved amputation surgery and the function of prostheses. What began as a modified crutch with a wooden or leather cup and progressed through many metamorphoses has now developed into a highly sophisticated prosthetic limb made of space-age materials.

Atmospheric limb sounding with imaging FTS

NASA Astrophysics Data System (ADS)

Friedl-Vallon, Felix; Riese, Martin; Preusse, Peter; Oelhaf, Hermann; Fischer, Herbert

Imaging Fourier transform spectrometers in the thermal infrared are a promising new class of sensors for atmospheric science. The availability of fast and sensitive large focal plane arrays with appropriate spectral coverage in the infrared region allows the conception and construction of innovative sensors for Nadir and Limb geometry. Instruments in Nadir geometry have already reached prototype status (e.g. Geostationary Imaging Fourier Transform Spectrometer / U. Wisconsin and NASA) or are in Phase A study (infrared sounding mission on Meteosat third generation / ESA and EUMETSAT). The first application of the new technical possibilities to atmospheric limb sounding from space, the Imaging Michelson Interferometer for Passive Atmospheric Sounding (IMIPAS), is currently studied by industry in the context of preparatory work for the next set of ESA earth explorers. The scientific focus of the instrument is on the processes controlling the composition of the mid/upper troposphere and lower stratosphere. The instrument concept of IMIPAS has been conceived at the research centres Karlsruhe and J¨lich. The development of a precursor instrument (GLORIA-AB) at these research institutions u started already in 2005. The instrument will be able to fly on board of various airborne platforms. First scientific missions are planned for the second half of the year 2009 on board the new German research aircraft HALO. This airborne sensor serves its own scientific purpose, but it also provides a test bed to learn about this new instrument class and its peculiarities and to learn to exploit and interpret the wealth of information provided by a limb imaging IR Fourier transform spectrometer. The presentation will discuss design considerations and challenges for GLORIA-AB and put them in the context of the planned satellite application. It will describe the solutions found, present first laboratory figures of merit for the prototype instrument and outline the new scientific

Thermal Stability of a 4 Meter Primary Reflector for the Scanning Microwave Limb Sounder

NASA Technical Reports Server (NTRS)

Cofield, Richard; Kasl, Eldon P.

2010-01-01

We describe the fabrication and thermal-stability analysis and test of a composite demonstration model of the Scanning Microwave Limb Sounder (SMLS) primary reflector, having full 4m height and 1/3 the width planned for flight. SMLS is a space-borne heterodyne radiometer which will measure pressure, temperature and atmospheric constituents from thermal emission between 180 and 660 GHz. Current MLS instruments in low Earth orbit scan pencil-beam antennas (sized to resolve about one scale height) vertically over the atmospheric limb. SMLS, planned for the Global Atmospheric Composition Mission of the NRC Decadal Survey, adds azimuthal scanning for better horizontal and temporal resolution and coverage than typical orbit spacing provides. SMLS combines the wide scan range of the parabolic torus with unblocked offset Cassegrain optics. The resulting system is diffraction-limited in the vertical plane but highly astigmatic in the horizontal, having a beam aspect ratio [tilde operator]1:20. Symmetry about the nadir axis ensures that beam shape is nearly invariant over +/-65(white bullet) azimuth. The a feeds a low-noise SIS receiver whose FOV is swept over the reflector system by a small scanning mirror. Using finiteelement models of antenna reflectors and structure, we evaluate thermal deformations and the resulting optical performance for 4 orbital environments and isothermal soak. We compare deformations with photogrammetric measurements made during wide-range (ambient+[-97,+75](white bullet) C) thermal soak tests of the primary in a chamber. This range exceeds predicted orbital soak ranges by large factors, implying in-orbit thermal stability of 0.21(mu)m rms/(white bullet)C, which meets SMLS requirements.

Multiscale Auroral Emission Statistics as Evidence of Turbulent Reconnection in Earth's Midtail Plasma Sheet

NASA Technical Reports Server (NTRS)

Klimas, Alex; Uritsky, Vadim; Donovan, Eric

2010-01-01

We provide indirect evidence for turbulent reconnection in Earth's midtail plasma sheet by reexamining the statistical properties of bright, nightside auroral emission events as observed by the UVI experiment on the Polar spacecraft and discussed previously by Uritsky et al. The events are divided into two groups: (1) those that map to absolute value of (X(sub GSM)) < 12 R(sub E) in the magnetotail and do not show scale-free statistics and (2) those that map to absolute value of (X(sub GSM)) > 12 R(sub E) and do show scale-free statistics. The absolute value of (X(sub GSM)) dependence is shown to most effectively organize the events into these two groups. Power law exponents obtained for group 2 are shown to validate the conclusions of Uritsky et al. concerning the existence of critical dynamics in the auroral emissions. It is suggested that the auroral dynamics is a reflection of a critical state in the magnetotail that is based on the dynamics of turbulent reconnection in the midtail plasma sheet.

Differentiation of cartilaginous anlagen in entire embryonic mouse limbs cultured in a rotating bioreactor

NASA Astrophysics Data System (ADS)

Montufar-Solis, D.; Oakley, C. R.; Jefferson, Y.; Duke, P. J.

2003-10-01

Mechanisms involved in development of the embryonic limb have remained the same throughout eons of genetic and environmental evolution under Earth gravity (lg). During the spaceflight era it has been of interest to explore the ancient theory that form of the skeleton develops in response to gravity, and that changes in gravitational forces can change the developmental pattern of the limb. This has been shown in vivo and in vitro, allowing the hypergravity of centrifugation and microgravity of space to be used as tools to increase our knowledge of limb development. In recapitulations of spaceflight experiments, premetatarsals were cultured in suspension in a bioreactor, and found to be shorter and less differentiated than those cultured in standard culture dishes. This study only measured length of the metatarsals, and did not account for possible changes due to the skeletal elements having a more in vivo 3D shape while in suspension vs. flattened tissues compressed by their own weight. A culture system with an outcome closer to in vivo and that supports growth of younger limb buds than traditional systems will allow studies of early Hox gene expression, and contribute to the understanding of very early stages of development. The purpose of the current experiment was to determine if entire limb buds could be cultured in the bioreactor, and to compare the growth and differentiation with that of culturing in a culture dish system. Fore and hind limbs from E11-E13 ICR mouse embryos were cultured for six days, either in the bioreactor or in center-well organ culture dishes, fixed, and embedded for histology. E13 specimens grown in culture dishes were flat, while bioreactor culture specimens had a more in vivo-like 3D limb shape. Sections showed excellent cartilage differentiation in both culture systems, with more cell maturation, and hypertrophy in the specimens cultured in the bioreactor. Younger limb buds fused together during culture, so an additional set of El 1

Fermi -LAT Observations of High-energy Behind-the-limb Solar Flares

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ackermann, M.; Buehler, R.; Allafort, A.

2017-02-01

We report on the Fermi -LAT detection of high-energy emission from the behind-the-limb (BTL) solar flares that occurred on 2013 October 11, and 2014 January 6 and September 1. The Fermi -LAT observations are associated with flares from active regions originating behind both the eastern and western limbs, as determined by STEREO . All three flares are associated with very fast coronal mass ejections (CMEs) and strong solar energetic particle events. We present updated localizations of the >100 MeV photon emission, hard X-ray (HXR) and EUV images, and broadband spectra from 10 keV to 10 GeV, as well as microwavemore » spectra. We also provide a comparison of the BTL flares detected by Fermi -LAT with three on-disk flares and present a study of some of the significant quantities of these flares as an attempt to better understand the acceleration mechanisms at work during these occulted flares. We interpret the HXR emission to be due to electron bremsstrahlung from a coronal thin-target loop top with the accelerated electron spectra steepening at semirelativistic energies. The >100 MeV gamma-rays are best described by a pion-decay model resulting from the interaction of protons (and other ions) in a thick-target photospheric source. The protons are believed to have been accelerated (to energies >10 GeV) in the CME environment and precipitate down to the photosphere from the downstream side of the CME shock and landed on the front side of the Sun, away from the original flare site and the HXR emission.« less

Fermi-LAT Observations of High-energy Behind-the-limb Solar Flares

DOE PAGES

Ackermann, M.; Allafort, A.; Baldini, L.; ...

2017-01-31

In this paper, we report on the Fermi-LAT detection of high-energy emission from the behind-the-limb (BTL) solar flares that occurred on 2013 October 11, and 2014 January 6 and September 1. The Fermi-LAT observations are associated with flares from active regions originating behind both the eastern and western limbs, as determined by STEREO. All three flares are associated with very fast coronal mass ejections (CMEs) and strong solar energetic particle events. We present updated localizations of the >100 MeV photon emission, hard X-ray (HXR) and EUV images, and broadband spectra from 10 keV to 10 GeV, as well as microwavemore » spectra. We also provide a comparison of the BTL flares detected by Fermi-LAT with three on-disk flares and present a study of some of the significant quantities of these flares as an attempt to better understand the acceleration mechanisms at work during these occulted flares. We interpret the HXR emission to be due to electron bremsstrahlung from a coronal thin-target loop top with the accelerated electron spectra steepening at semirelativistic energies. The >100 MeV gamma-rays are best described by a pion-decay model resulting from the interaction of protons (and other ions) in a thick-target photospheric source. In conclusion, the protons are believed to have been accelerated (to energies >10 GeV) in the CME environment and precipitate down to the photosphere from the downstream side of the CME shock and landed on the front side of the Sun, away from the original flare site and the HXR emission.« less

Production and recycling of oceanic crust in the early Earth

NASA Astrophysics Data System (ADS)

van Thienen, P.; van den Berg, A. P.; Vlaar, N. J.

2004-08-01

Because of the strongly different conditions in the mantle of the early Earth regarding temperature and viscosity, present-day geodynamics cannot simply be extrapolated back to the early history of the Earth. We use numerical thermochemical convection models including partial melting and a simple mechanism for melt segregation and oceanic crust production to investigate an alternative suite of dynamics which may have been in operation in the early Earth. Our modelling results show three processes that may have played an important role in the production and recycling of oceanic crust: (1) Small-scale ( x×100 km) convection involving the lower crust and shallow upper mantle. Partial melting and thus crustal production takes place in the upwelling limb and delamination of the eclogitic lower crust in the downwelling limb. (2) Large-scale resurfacing events in which (nearly) the complete crust sinks into the (eventually lower) mantle, thereby forming a stable reservoir enriched in incompatible elements in the deep mantle. New crust is simultaneously formed at the surface from segregating melt. (3) Intrusion of lower mantle diapirs with a high excess temperature (about 250 K) into the upper mantle, causing massive melting and crustal growth. This allows for plumes in the Archean upper mantle with a much higher excess temperature than previously expected from theoretical considerations.

Study of a Vuilleumier cycle cryogenic refrigerator for detector cooling on the limb scanning infrared radiometer

NASA Technical Reports Server (NTRS)

Russo, S. C.

1976-01-01

A program to detect and monitor the presence of trace constituents in the earth's atmosphere by using the Limb Scanning Infrared Radiometer (LSIR) is reported. The LSIR, which makes radiometric measurements of the earth's limb radiance profile from a space platform, contains a detector assembly that must be cooled to a temperature of 65 + or - 2 K. The feasibility of cooling the NASA-type detector package with Vuilleumier (VM) cryogenic refrigerator was investigated to develop a preliminary conceptual design of a VM refrigerator that is compatible with a flight-type LSIR instrument. The scope of the LSIR program consists of analytical and design work to establish the size, weight, power consumption, interface requirements, and other important characteristics of a cryogenic cooler that would meet the requirements of the LSIR. The cryogenic cooling requirements under the conditions that NASA specified were defined. Following this, a parametric performance analysis was performed to define the interrelationships between refrigeration characteristics and mission requirements. This effort led to the selection of an optimum refrigerator design for the LSIR mission.

Tropospheric Emission Spectrometer and Airborne Emission Spectrometer

NASA Technical Reports Server (NTRS)

Glavich, T.; Beer, R.

1996-01-01

The Tropospheric Emission Spectrometer (TES) is an instrument being developed for the NASA Earth Observing System Chemistry Platform. TES will measure the distribution of ozone and its precursors in the lower atmosphere. The Airborne Emission Spectrometer (AES) is an aircraft precursor to TES. Applicable descriptions are given of instrument design, technology challenges, implementation and operations for both.

A sunset Earth observation image taken during STS-100

NASA Image and Video Library

2001-04-26

S100-E-5498 (26 April 2001) --- Earth's limb--the edge of the planet seen at twilight--was captured with a digital still camera by one of the STS-100 crew members aboard the Space Shuttle Endeavour. Near center frame the silhouette of cloud layers can be seen in the atmosphere, above which lies an airglow layer (left).

Hyperinnervation improves Xenopus laevis limb regeneration.

PubMed

Mitogawa, Kazumasa; Makanae, Aki; Satoh, Akira

2018-01-15

Xenopus laevis (an anuran amphibian) shows limb regeneration ability between that of urodele amphibians and that of amniotes. Xenopus frogs can initiate limb regeneration but fail to form patterned limbs. Regenerated limbs mainly consist of cone-shaped cartilage without any joints or branches. These pattern defects are thought to be caused by loss of proper expressions of patterning-related genes. This study shows that hyperinnervation surgery resulted in the induction of a branching regenerate. The hyperinnervated blastema allows the identification and functional analysis of the molecules controlling this patterning of limb regeneration. This paper focuses on the nerve affects to improve Xenopus limb patterning ability during regeneration. The nerve molecules, which regulate limb patterning, were also investigated. Blastemas grown in a hyperinnervated forelimb upregulate limb patterning-related genes (shh, lmx1b, and hoxa13). Nerves projecting their axons to limbs express some growth factors (bmp7, fgf2, fgf8, and shh). Inputs of these factors to a blastema upregulated some limb patterning-related genes and resulted in changes in the cartilage patterns in the regenerates. These results indicate that additional nerve factors enhance Xenopus limb patterning-related gene expressions and limb regeneration ability, and that bmp, fgf, and shh are candidate nerve substitute factors. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

The benefit of limb cloud imaging for tropospheric infrared limb sounding

NASA Astrophysics Data System (ADS)

Adams, S.; Spang, R.; Preusse, P.; Heinemann, G.

2009-03-01

Advances in detector technology enable a new generation of infrared limb sounders to measure 2-D images of the atmosphere. A proposed limb cloud imager (LCI) mode will measure clouds with very high spatial resolution. For the inference of temperature and trace gas distributions, detector pixels of the LCI have to be combined into super-pixels which provide the required signal-to-noise ratio and information content for the retrievals. This study examines the extent to which tropospheric coverage can be improved in comparison to limb sounding using a fixed field of view with the size of the super-pixels, as in conventional limb sounders. The study is based on cloud topographies derived from (a) IR brightness temperatures (BT) of geostationary weather satellites in conjunction with ECMWF temperature profiles and (b) ice and liquid water content data of the Consortium for Small-scale Modeling-Europe (COSMO-EU) of the German Weather Service. Limb cloud images are simulated by matching the cloud topography with the limb sounding line of sight (LOS). The analysis of the BT data shows that the reduction of the spatial sampling along the track has hardly any effect on the gain in information. The comparison between BT and COSMO-EU data identifies the strength of both data sets, which are the representation of the horizontal cloud extent for the BT data and the reproduction of the cloud amount for the COSMO-EU data. The results of the analysis of both data sets show the great advantage of the cloud imager. However, because both cloud data sets do not present the complete fine structure of the real cloud fields in the atmosphere it is assumed that the results tend to underestimate the increase in information. In conclusion, real measurements by such an instrument may result in an even higher benefit for tropospheric limb retrievals.

Mobile-bearing medial unicompartmental knee arthroplasty restores limb alignment comparable to that of the unaffected contralateral limb

PubMed Central

Mullaji, Arun B; Shah, Siddharth; Shetty, Gautam M

2017-01-01

Background and purpose — Medial unicompartmental knee arthroplasty (UKA) is undertaken in patients with a passively correctable varus deformity. We investigated whether restoration of natural soft tissue tension would result in a lower limb alignment similar to that of the contralateral unaffected lower limb after mobile-bearing medial UKA. Patients and methods — In this retrospective study, hip-knee-ankle (HKA) angle, position of the weight-bearing axis (WBA), and knee joint line obliquity (KJLO) after mobile-bearing medial UKA was compared with that of the unaffected (clinically and radiologically) contralateral lower limb in 123 patients. Results — Postoperatively, HKA angle was restored to within ±3° of the contralateral lower limb in 87% of the patients and the WBA passed within ±1 Kennedy and White’s tibial zone of the unaffected contralateral lower limb in 95% of the patients. The mean KJLO in the operated limbs was not significantly different from that in the unaffected lower limbs (p = 0.07) and the KJLO in the operated limb was restored to within ±3° of that in the contralateral lower limb in 96% of the patients. Interpretation — Lower limb alignment and knee joint line obliquity after mobile-bearing medial UKA were comparable to that of the unaffected contralateral limb in most patients. Comparison with the contralateral unaffected lower limb is a reliable method for evaluation and validation of limb mechanical alignment after mobile-bearing medial UKA. PMID:27794622

Enhancement of the red emission in CaTiO 3:Pr 3+ by addition of rare earth oxides

NASA Astrophysics Data System (ADS)

Zhang, Xianmin; Zhang, Jiahua; Zhang, Xia; Chen, Li; Luo, Yongshi; Wang, Xiao-jun

2007-02-01

Enhancement of the 1D 2- 3H 4 red emission of CaTiO 3:Pr 3+ with addition of rare earth oxides Ln 2O 3 (Ln = Lu, La, Gd) is reported. Ca 2+ and Ti 4+ in CaTiO 3 can be substituted by Ln 3+ ions as donors and acceptors, respectively. Ca 2+ and Ti 4+ vacancies, as quenching centers in the host, are effectively suppressed by the self-compensation, leading to the increase of lifetimes and then the emission efficiency of 1D 2. The red fluorescence intensity for CaTiO 3:Pr 3+ phosphor co-doped with 5 mol% Lu 2O 3 is nearly 3 times greater than that of the Lu-free samples.

Marine Aerosol Precursor Emissions for Earth System Models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maltrud, Mathew Einar

2016-07-25

Dimethyl sulfide (DMS) is generated by marine ecosystems and plays a major role in cloud formation over the ocean. Currently, Earth System Models use imposed flux of DMS from the ocean to the atmosphere that is independent of the climate state. We have added DMS as a prognostic variable to the Community Earth System Model (CESM) that depends on the distribution of phytoplankton species, and thus changes with climate.

Limb salvage surgery.

PubMed

Kadam, Dinesh

2013-05-01

The threat of lower limb loss is seen commonly in severe crush injury, cancer ablation, diabetes, peripheral vascular disease and neuropathy. The primary goal of limb salvage is to restore and maintain stability and ambulation. Reconstructive strategies differ in each condition such as: Meticulous debridement and early coverage in trauma, replacing lost functional units in cancer ablation, improving vascularity in ischaemic leg and providing stable walking surface for trophic ulcer. The decision to salvage the critically injured limb is multifactorial and should be individualised along with laid down definitive indications. Early cover remains the standard of care, delayed wound coverage not necessarily affect the final outcome. Limb salvage is more cost-effective than amputations in a long run. Limb salvage is the choice of procedure over amputation in 95% of limb sarcoma without affecting the survival. Compound flaps with different tissue components, skeletal reconstruction; tendon transfer/reconstruction helps to restore function. Adjuvant radiation alters tissue characters and calls for modification in reconstructive plan. Neuropathic ulcers are wide and deep often complicated by osteomyelitis. Free flap reconstruction aids in faster healing and provides superior surface for offloading. Diabetic wounds are primarily due to neuropathy and leads to six-fold increase in ulcerations. Control of infections, aggressive debridement and vascular cover are the mainstay of management. Endovascular procedures are gaining importance and have reduced extent of surgery and increased amputation free survival period. Though the standard approach remains utilising best option in the reconstruction ladder, the recent trend shows running down the ladder of reconstruction with newer reliable local flaps and negative wound pressure therapy.

Management of the multiple limb amputee.

PubMed

Davidson, J H; Jones, L E; Cornet, J; Cittarelli, T

2002-09-10

Multiple limb amputations involving at least one upper extremity are very uncommon. The amputation of both an upper and lower limb is even more uncommon. Due to the rarity of these amputations therapists are uncertain regarding the most appropriate treatment methods. While the majority of the protocols used for single limb amputations are appropriate for these multiple limb amputees, there are differences. Loss of multiple limbs creates a problem of overheating for the individual. Loss of an arm and leg results in difficulty donning the prostheses and difficulty using crutches and parallel bars during mobilization. A review is given of 16 multiple limb amputees seen in our rehabilitation centre in the last 15 years. Return to work was seen in one third and was not related to the number of the amputations. A higher proportion of these multiple limb amputations occur through alcoholism or attempted suicide behaviour than occurs with either single upper limb amputations or lower limb amputations. This existing behaviour can create a management problem for the rehabilitation team during rehabilitation. Guidelines as to appropriate prosthetic and preprosthetic care are provided to assist the practitioner who has the acute and long term care of these patients. All multiple limb amputees should be referred to a specialized rehabilitation centre to discuss prosthetic options and long term rehabilitation requirements. This paper does not discuss bilateral lower limb amputations when not combined with an upper limb amputation.

Inductively Coupled Plasma Optical Emission Spectrometry for Rare Earth Elements Analysis

NASA Astrophysics Data System (ADS)

He, Man; Hu, Bin; Chen, Beibei; Jiang, Zucheng

2017-01-01

Inductively coupled plasma optical emission spectrometry (ICP-OES) merits multielements capability, high sensitivity, good reproducibility, low matrix effect and wide dynamic linear range for rare earth elements (REEs) analysis. But the spectral interference in trace REEs analysis by ICP-OES is a serious problem due to the complicated emission spectra of REEs, which demands some correction technology including interference factor method, derivative spectrum, Kalman filtering algorithm and partial least-squares (PLS) method. Matrix-matching calibration, internal standard, correction factor and sample dilution are usually employed to overcome or decrease the matrix effect. Coupled with various sample introduction techniques, the analytical performance of ICP-OES for REEs analysis would be improved. Compared with conventional pneumatic nebulization (PN), acid effect and matrix effect are decreased to some extent in flow injection ICP-OES, with higher tolerable matrix concentration and better reproducibility. By using electrothermal vaporization as sample introduction system, direct analysis of solid samples by ICP-OES is achieved and the vaporization behavior of refractory REEs with high boiling point, which can easily form involatile carbides in the graphite tube, could be improved by using chemical modifier, such as polytetrafluoroethylene and 1-phenyl-3-methyl-4-benzoyl-5-pyrazone. Laser ablation-ICP-OES is suitable for the analysis of both conductive and nonconductive solid samples, with the absolute detection limit of ng-pg level and extremely low sample consumption (0.2 % of that in conventional PN introduction). ICP-OES has been extensively employed for trace REEs analysis in high-purity materials, and environmental and biological samples.

The Floating Upper Limb: Multiple Injuries Involving Ipsilateral, Proximal, Humeral, Supracondylar, and Distal Radial Limb

PubMed Central

Manaan, Qazi; Bashir, Adil; Zahoor, Adnan; Mokhdomi, Taseem A.

2016-01-01

Floating arm injury represents a common yet complicated injury of the childhood severely associated with limb deformation and even morbidity, if not precisely addressed and credibly operated. Here, we report a rare floating upper limb case of a 9-year-old boy with multiple injuries of ipsilateral proximal humeral, supracondylar and distal radial limb. This is the first report to document such a combined floating elbow and floating arm injury in the same limb. In this report, we discuss the surgical procedures used and recovery of the patient monitored to ascertain the effectiveness of the method in limb reorganisation. PMID:27583121

The Floating Upper Limb: Multiple Injuries Involving Ipsilateral, Proximal, Humeral, Supracondylar, and Distal Radial Limb.

PubMed

Manaan, Qazi; Bashir, Adil; Zahoor, Adnan; Mokhdomi, Taseem A; Danish, Qazi

2016-09-01

Floating arm injury represents a common yet complicated injury of the childhood severely associated with limb deformation and even morbidity, if not precisely addressed and credibly operated. Here, we report a rare floating upper limb case of a 9-year-old boy with multiple injuries of ipsilateral proximal humeral, supracondylar and distal radial limb. This is the first report to document such a combined floating elbow and floating arm injury in the same limb. In this report, we discuss the surgical procedures used and recovery of the patient monitored to ascertain the effectiveness of the method in limb reorganisation.

Plasma upflows and microwave emission in hot supra-arcade structure associated with AN M1.6 limb flare

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, S.; Shibasaki, K.; Bain, H.-M.

2014-04-20

We have investigated a supra-arcade structure associated with an M1.6 flare, which occurred on the south-east limb on 2010 November 4. It is observed in EUV with the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory, microwaves at 17 and 34 GHz with the Nobeyama Radioheliograph (NoRH), and soft X-rays of 8-20 keV with RHESSI. Interestingly, we found exceptional properties of the supra-arcade thermal plasma from the AIA 131 Å and the NoRH: (1) plasma upflows along large coronal loops and (2) enhancing microwave emission. RHESSI detected two soft X-ray sources, a broad one in the middle ofmore » the supra-arcade structure and a bright one just above the flare-arcade. We estimated the number density and thermal energy for these two source regions during the decay phase of the flare. In the supra-arcade source, we found that there were increases of the thermal energy and the density at the early and last stages, respectively. On the contrary, the density and thermal energy of the source on the top of the flare-arcade decreases throughout. The observed upflows imply that there is continuous energy supply into the supra-arcade structure from below during the decay phase of the flare. It is hard to explain by the standard flare model in which the energy release site is located high in the corona. Thus, we suggest that a potential candidate of the energy source for the hot supra-arcade structure is the flare-arcade, which has exhibited a predominant emission throughout.« less

FIRST DETECTION OF >100 MeV GAMMA-RAYS ASSOCIATED WITH A BEHIND-THE-LIMB SOLAR FLARE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pesce-Rollins, M.; Omodei, N.; Petrosian, V.

2015-06-01

We report the first detection of >100 MeV gamma-rays associated with a behind-the-limb solar flare, which presents a unique opportunity to probe the underlying physics of high-energy flare emission and particle acceleration. On 2013 October 11 a GOES M1.5 class solar flare occurred ∼9.°9 behind the solar limb as observed by STEREO-B. RHESSI observed hard X-ray (HXR) emission above the limb, most likely from the flare loop-top, as the footpoints were occulted. Surprisingly, the Fermi Large Area Telescope (LAT) detected >100 MeV gamma-rays for ∼30 minutes with energies up to 3 GeV. The LAT emission centroid is consistent with themore » RHESSI HXR source, but its uncertainty does not constrain the source to be located there. The gamma-ray spectra can be adequately described by bremsstrahlung radiation from relativistic electrons having a relatively hard power-law (PL) spectrum with a high-energy exponential cutoff, or by the decay of pions produced by accelerated protons and ions with an isotropic pitch-angle distribution and a PL spectrum with a number index of ∼3.8. We show that high optical depths rule out the gamma-rays originating from the flare site and a high-corona trap model requires very unusual conditions, so a scenario in which some of the particles accelerated by the CME shock travel to the visible side of the Sun to produce the observed gamma-rays may be at work.« less

First detection of >100 MeV gamma-rays associated with a behind-the-limb solar flare

DOE PAGES

Pesce-Rollins, Melissa; Omodei, Nicola; Petrosian, V.; ...

2015-05-28

Here, we report the first detection of >100 MeV gamma-rays associated with a behind-the-limb solar flare, which presents a unique opportunity to probe the underlying physics of high-energy flare emission and particle acceleration. On 2013 October 11 a GOES M1.5 class solar flare occurred ~9°.9 behind the solar limb as observed by STEREO-B. RHESSI observed hard X-ray (HXR) emission above the limb, most likely from the flare loop-top, as the footpoints were occulted. Surprisingly, the Fermi Large Area Telescope (LAT) detected >100 MeV gamma-rays for ~30 minutes with energies up to 3 GeV. The LAT emission centroid is consistent withmore » the RHESSI HXR source, but its uncertainty does not constrain the source to be located there. The gamma-ray spectra can be adequately described by bremsstrahlung radiation from relativistic electrons having a relatively hard power-law (PL) spectrum with a high-energy exponential cutoff, or by the decay of pions produced by accelerated protons and ions with an isotropic pitch-angle distribution and a PL spectrum with a number index of ~3.8. Furthermore, we show that high optical depths rule out the gamma-rays originating from the flare site and a high-corona trap model requires very unusual conditions, so a scenario in which some of the particles accelerated by the CME shock travel to the visible side of the Sun to produce the observed gamma-rays may be at work.« less

On VI /lambda equals 1032 A/ profiles in and above an active region prominence, compared to quiet sun center and limb profiles

NASA Astrophysics Data System (ADS)

Vial, J. C.; Lemaire, P.; Artzner, G.; Gouttebroze, P.

1980-11-01

O VI (λ = 1032 Å) profiles have been measured in and above a filament at the limb, previously analyzed in H I, Mg II, Ca II resonance lines (Vial et al., 1979). They are compared to profiles measured at the quiet Sun center and at the quiet Sun limb. Absolute intensities are found to be about 1.55 times larger than above the quiet limb at the same height (3"); at the top of the prominence (15" above the limb) one finds a maximum blue shift and a minimum line width. The inferred non-thermal velocity (29 km s-1) is about the same as in cooler lines while the approaching line-of-sight velocity (8 km s-1) is lower than in Ca II lines. The O VI profile recorded 30" above the limb outside the filament is wider (FWHM 0.33 Å). It can be interpreted as a coronal emission of 0 VI ions with a temperature of about 106 K, and a non-thermal velocity (NTV) of 49 km s-1. This NTV is twice the NTV of quiet Sun center O VI profiles. Lower NTV require higher temperatures and densities (as suggested by K-coronameter measurements). Computed emission measures for this high temperature regime agree with determinations from disk intensities of EUV lines.

Design of the OMPS limb sensor correction algorithm

NASA Astrophysics Data System (ADS)

Jaross, Glen; McPeters, Richard; Seftor, Colin; Kowitt, Mark

The Sensor Data Records (SDR) for the Ozone Mapping and Profiler Suite (OMPS) on NPOESS (National Polar-orbiting Operational Environmental Satellite System) contains geolocated and calibrated radiances, and are similar to the Level 1 data of NASA Earth Observing System and other programs. The SDR algorithms (one for each of the 3 OMPS focal planes) are the processes by which the Raw Data Records (RDR) from the OMPS sensors are converted into the records that contain all data necessary for ozone retrievals. Consequently, the algorithms must correct and calibrate Earth signals, geolocate the data, and identify and ingest collocated ancillary data. As with other limb sensors, ozone profile retrievals are relatively insensitive to calibration errors due to the use of altitude normalization and wavelength pairing. But the profile retrievals as they pertain to OMPS are not immune from sensor changes. In particular, the OMPS Limb sensor images an altitude range of > 100 km and a spectral range of 290-1000 nm on its detector. Uncorrected sensor degradation and spectral registration drifts can lead to changes in the measured radiance profile, which in turn affects the ozone trend measurement. Since OMPS is intended for long-term monitoring, sensor calibration is a specific concern. The calibration is maintained via the ground data processing. This means that all sensor calibration data, including direct solar measurements, are brought down in the raw data and processed separately by the SDR algorithms. One of the sensor corrections performed by the algorithm is the correction for stray light. The imaging spectrometer and the unique focal plane design of OMPS makes these corrections particularly challenging and important. Following an overview of the algorithm flow, we will briefly describe the sensor stray light characterization and the correction approach used in the code.

Is Atherectomy the Best First-Line Therapy for Limb Salvage in Patients With Critical Limb Ischemia?

PubMed Central

Loor, Gabriel; Skelly, Christopher L.; Wahlgren, Carl-Magnus; Bassiouny, Hisham S.; Piano, Giancarlo; Shaalan, Wael

2010-01-01

Objective To determine the efficacy of atherectomy for limb salvage compared with open bypass in patients with critical limb ischemia. Methods Ninety-nine consecutive bypass and atherectomy procedures performed for critical limb ischemia between January 2003 and October 2006 were reviewed. Results A total of 99 cases involving TASC C (n = 43, 44%) and D (n = 56, 56%) lesions were treated with surgical bypass in 59 patients and atherectomy in 33 patients. Bypass and atherectomy achieved similar 1-year primary patency (64% vs 63%; P = .2). However, the 1-year limb salvage rate was greater in the bypass group (87% vs 69%; P = .004). In the tissue loss subgroup, there was a greater limb salvage rate for bypass patients versus atherectomy (79% vs 60%; P = .04). Conclusions Patients with critical limb ischemia may do better with open bypass compared with atherectomy as first-line therapy for limb salvage. PMID:19640919

Characterizing sampling and quality screening biases in infrared and microwave limb sounding

NASA Astrophysics Data System (ADS)

Millán, Luis F.; Livesey, Nathaniel J.; Santee, Michelle L.; von Clarmann, Thomas

2018-03-01

This study investigates orbital sampling biases and evaluates the additional impact caused by data quality screening for the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) and the Aura Microwave Limb Sounder (MLS). MIPAS acts as a proxy for typical infrared limb emission sounders, while MLS acts as a proxy for microwave limb sounders. These biases were calculated for temperature and several trace gases by interpolating model fields to real sampling patterns and, additionally, screening those locations as directed by their corresponding quality criteria. Both instruments have dense uniform sampling patterns typical of limb emission sounders, producing almost identical sampling biases. However, there is a substantial difference between the number of locations discarded. MIPAS, as a mid-infrared instrument, is very sensitive to clouds, and measurements affected by them are thus rejected from the analysis. For example, in the tropics, the MIPAS yield is strongly affected by clouds, while MLS is mostly unaffected. The results show that upper-tropospheric sampling biases in zonally averaged data, for both instruments, can be up to 10 to 30 %, depending on the species, and up to 3 K for temperature. For MIPAS, the sampling reduction due to quality screening worsens the biases, leading to values as large as 30 to 100 % for the trace gases and expanding the 3 K bias region for temperature. This type of sampling bias is largely induced by the geophysical origins of the screening (e.g. clouds). Further, analysis of long-term time series reveals that these additional quality screening biases may affect the ability to accurately detect upper-tropospheric long-term changes using such data. In contrast, MLS data quality screening removes sufficiently few points that no additional bias is introduced, although its penetration is limited to the upper troposphere, while MIPAS may cover well into the mid-troposphere in cloud-free scenarios. We emphasize that the

Chronic pain associated with upper-limb loss.

PubMed

Hanley, Marisol A; Ehde, Dawn M; Jensen, Mark; Czerniecki, Joseph; Smith, Douglas G; Robinson, Lawrence R

2009-09-01

To describe the prevalence, intensity, and functional impact of the following types of pain associated with upper-limb loss: phantom limb, residual limb, back, neck, and nonamputated-limb pain. Cross-sectional survey; 104 respondents with upper-limb loss at least 6 months postamputation completed measures of pain intensity, interference, disability, and health-related quality-of-life. Nearly all (90%) of the respondents reported pain, with 76% reporting more than one pain type. Phantom-limb pain and residual-limb pain were the most prevalent (79% and 71%, respectively), followed by back (52%), neck (43%), and nonamputated-limb pain (33%). Although nonamputated-limb pain was least prevalent, it was reported to cause the highest levels of interference and pain-related disability days. Self-reported quality-of-life was significantly lower for individuals with each type of pain compared with those without any pain. Age, time since amputation, and cause of amputation were not associated with pain. In addition to pain in the phantom and residual limb, back, neck, and nonamputated-limb pain are also common after upper-limb loss. All of these pain types are associated with significant disability and activity interference for some individuals, suggesting that assessment of multiple pain types in persons with upper-limb amputation may be important.

High-Resolution Spectroscopic Database for the NASA Earth Observing System Program

NASA Technical Reports Server (NTRS)

Rothman, Laurence

2003-01-01

The purpose of this project is to develop and enhance the HITRAN molecular spectroscopic database and associated software to support the observational programs of the Earth Observing System (EOS). In particular, the focus is on the EOS projects: the Atmospheric Infrared Sounder (AIRS), the High-Resolution Dynamics Limb Sounder (HIRDLS), Measurements of Pollution in the Troposphere (MOPITT), the Tropospheric Emission Spectrometer (TES), and the Stratospheric Aerosol and Gas Experiment (SAGE III). The HITRAN program is also involved in the Ozone Monitoring Experiment (OMI). The data requirements of these programs in terms of spectroscopy are varied with respect to constituents being observed, required remote-sensing parameters, and spectral coverage. A general requisite is for additional spectral parameters and improvements to existing molecular bands sufficient for the simulation of the observations leading to retrieval of the atmospheric state. In addition, cross-section data for heavier molecular species must be expanded and made amenable to modeling in remote sensing. The effort in the project also includes developing software and distribution to make access, manipulation, and use of HITRAN functional to the EOS program.

High Resolution Spectroscopic Database for the NASA Earth Observing System Program

NASA Technical Reports Server (NTRS)

Rothman, Laurence

2004-01-01

The purpose of this project has been to develop and enhance the HITRAN molecular spectroscopic database and associated software to support the observational programs of the Earth Observing System (EOS). Emphasis has been on the EOS projects: the Atmospheric Infrared Sounder (AIRS), the High-Resolution Dynamics Limb Sounder (HIRDLS), Measurements of Pollution in the Troposphere (MOPITT), the Tropospheric Emission Spectrometer (TES), and the Stratospheric Aerosol and Gas Experiment (SAGE III). The HITRAN program is also involved in the Ozone Monitoring Experiment (OMI). The data requirements of these programs in terms of spectroscopy are varied with respect to constituents being observed, required remote-sensing parameters, and spectral coverage. A general requisite is for additional spectral parameters and improvements to existing molecular bands sufficient for the simulation of the observations leading to retrieval of the atmospheric state. In addition, cross-section data for heavier molecular species must be expanded and made amenable to modeling in remote sensing. The effort in the project also includes developing software and distribution to make access, manipulation, and use of HITRAN functional to the EOS program.

High-Resolution Spectroscopic Database for the NASA Earth Observing System Program

NASA Technical Reports Server (NTRS)

Rothman, Laurence S.

2004-01-01

The purpose of this project is to develop and enhance the HITRAN molecular spectroscopic database and associated - software to support the observational programs of the Earth observing System (EOS). In particular, the focus is on the EOS projects: the Atmospheric Infrared Sounder (AIRS), the High-Resolution Dynamics Limb Sounder (HIRDLS), Measurements of Pollution in the Troposphere (MOPITT), the Tropospheric Emission Spectrometer (TES), and the Stratospheric Aerosol and Gas Experiment (SAGE III). The HITRAN program is also involved in the Ozone Monitoring Experiment (OMI). The data requirements of these programs in terms of spectroscopy are varied with respect to constituents being observed, required remote-sensing parameters, and spectral coverage. A general requisite is for additional spectral parameters and improvements to existing molecular bands sufficient for the simulation of the observations leading to retrieval of the atmospheric state. In addition cross-section data for heavier molecular species must be expanded and made amenable to modeling in remote sensing. The effort in the project also includes developing software and distribution to make access, manipulation, and use HITRAN functional to the EOS program.

Limb immobilization and corticobasal syndrome.

PubMed

Graff-Radford, Jonathan; Boeve, Bradley F; Drubach, Daniel A; Knopman, David S; Ahlskog, J Eric; Golden, Erin C; Drubach, Dina I; Petersen, Ronald C; Josephs, Keith A

2012-12-01

Recently, we evaluated two patients with corticobasal syndrome (CBS) who reported symptom onset after limb immobilization. Our objective was to investigate the association between trauma, immobilization and CBS. The charts of forty-four consecutive CBS patients seen in the Mayo Clinic Alzheimer Disease Research Center were reviewed with attention to trauma and limb immobilization. 10 CBS patients (23%) had immobilization or trauma on the most affected limb preceding the onset or acceleration of symptoms. The median age at onset was 61. Six patients manifested their first symptoms after immobilization from surgery or fracture with one after leg trauma. Four patients had pre-existing symptoms of limb dysfunction but significantly worsened after immobilization or surgery. 23 percent of patients had immobilization or trauma of the affected limb. This might have implications for management of CBS, for avoiding injury, limiting immobilization and increasing movement in the affected limb. Copyright © 2012 Elsevier Ltd. All rights reserved.

Warfarin-induced Venous Limb Gangrene

PubMed Central

Grim Hostetler, Sarah; Sopkovich, Jennifer; Dean, Steven

2012-01-01

Warfarin is a commonly used anticoagulant that has been associated with several significant cutaneous side effects, most notably warfarin-induced skin necrosis. A lesser known adverse reaction to warfarin is warfarin-induced venous limb gangrene. Both cutaneous adverse effects share the same pathophysiology, but are clinically quite different. The majority of cases of warfarin-induced venous limb gangrene has been in patients with cancer or heparin-induced thrombocytopenia. However, other hypercoagulable disease states, such as the antiphospholipid antibody syndrome, can be associated with venous limb gangrene. In order to increase recognition of this important condition, the authors report a case of warfarin-induced venous limb gangrene in a patient with presumed antiphospholipid antibody syndrome and review the literature on warfarin-induced venous limb gangrene. PMID:23198012

Remote Sounding of the Earth's Atmospheric Limb From a Micro-Satellite Platform: a Feasibility Study of the ALTIUS Mission

NASA Astrophysics Data System (ADS)

Vrancken, D.; Paijmans, B.; Fussen, D.; Neefs, E.; Loodts, N.; Dekemper, E.; Vahellemont, F.; Devos, L.; Moelans, W.; Nevejans, D.; Schroeven-Deceuninck, H.; Bernaerts, D.; Zender, J.

2008-08-01

There is more and more interest in the understanding and the monitoring of the physics and chemistry of the Earth's atmosphere and its impact on the climate change. Currently a significantly high number of sounders provide the required data to monitor the changes in atmosphere composition, but a dramatic drop in operational atmosphere monitoring missions is expected around 2010. This drop is mainly visible in sounders capable of a high vertical resolution. Currently, instruments on ENVISAT and METOP provide relevant data but this is envisaged to be insufficient to ensure full spatial and temporal coverage and redundancy in the measurement data set. ALTIUS (Atmospheric Limb Tracker for the Investigation of the Upcoming Stratosphere) is a remote sounding experiment proposed by the Belgian Institute for Space Aeronomy (BIRA/IASB) for which a feasibility study was initiated with BELSPO (Belgian Science Policy) and ESA support. The main objective of this study phase was to establish a mission concept, to define the required payload and to establish a satellite platform design. The study was led by the BIRA/IASB team and performed in close collaboration with OIP (payload developer) and Verhaert Space (spacecraft developer). The mission scenario includes bright limb observations in basically all directions, solar occultations around the terminator passages and star occultations during eclipse. These observation modes allow imaging the atmosphere with a high vertical resolution. The spacecraft will be operated in a 10:00 sun-synchronous orbit at an altitude of 695 km, allowing a 3-day revisit time. The envisaged payload for the ALTIUS mission is an imaging spectrometer, observing in the UV, the VIS and the NIR spectral ranges. For each spectral range, an AOTF (Acousto-Optical Tunable Filter) will permit to perform observations of selectable small wavelength domains. A typical set of 10 wavelengths will be recorded within 1 second. The different operational modes impose a

The effect of limb amputation on standing weight distribution in the remaining three limbs in dogs.

PubMed

Cole, Grayson Lee; Millis, Darryl

2017-01-16

Despite the fact that limb amputation is a commonly performed procedure in veterinary medicine, quantitative data regarding outcomes are lacking. The intention of this study was to evaluate the effect of limb amputation on weight distribution to the remaining three limbs at a stance in dogs. Ten dogs with a prior forelimb amputation and ten dogs with a prior hindlimb amputation; all of which had no history of orthopaedic or neural disease in the remaining three limbs were included in the study. Standing weight bearing was evaluated with a commercial stance analyzer in all dogs. Five valid trials were obtained and a mean percentage of weight bearing was calculated for each remaining limb. The dogs with a previous forelimb amputation, and also those with a previous hindlimb amputation, had the largest mean increase in weight bearing in the contralateral forelimb. In conclusion, proactive monitoring of orthopaedic disease in the contralateral forelimb may be advisable in dogs with a previous limb amputation. In addition, when determining candidacy for a limb amputation, disease of the contralateral forelimb should be thoroughly evaluated.

Detecting Water on Super-Earths Using JAVST

NASA Technical Reports Server (NTRS)

Deming, D.

2010-01-01

Nearby lower train sequence stars host a class of planets known as Super-Earths, that have no analog in our own solar system. Super-Earths are rocky and/or icy planets with masses up to about 10 Earth masses, They are expected to host atmospheres generated by a number of processes including accretion of chondritic material. Water vapor should be a common constituent of super-Earth atmospheres, and may be detectable in transiting super-Earths using transmission spectroscopy during primar y eclipse, and emission spectroscopy at secondary eclipse. I will discuss the prospects for super-Earth atmospheric measurements using JWST.

Evaluation of Limb-Girdle Muscular Dystrophy

ClinicalTrials.gov

2014-03-06

Becker Muscular Dystrophy; Limb-Girdle Muscular Dystrophy, Type 2A (Calpain-3 Deficiency); Limb-Girdle Muscular Dystrophy, Type 2B (Miyoshi Myopathy, Dysferlin Deficiency); Limb-Girdle Muscular Dystrophy, Type 2I (FKRP-deficiency)

The benefit of limb cloud imaging for infrared limb sounding of tropospheric trace gases

NASA Astrophysics Data System (ADS)

Adams, S.; Spang, R.; Preusse, P.; Heinemann, G.

2009-06-01

Advances in detector technology enable a new generation of infrared limb sounders to measure 2-D images of the atmosphere. A proposed limb cloud imager (LCI) mode will detect clouds with a spatial resolution unprecedented for limb sounding. For the inference of temperature and trace gas distributions, detector pixels of the LCI have to be combined into super-pixels which provide the required signal-to-noise and information content for the retrievals. This study examines the extent to which tropospheric coverage can be improved in comparison to limb sounding using a fixed field of view with the size of the super-pixels, as in conventional limb sounders. The study is based on cloud topographies derived from (a) IR brightness temperatures (BT) of geostationary weather satellites in conjunction with ECMWF temperature profiles and (b) ice and liquid water content data of the Consortium for Small-scale Modeling-Europe (COSMO-EU) of the German Weather Service. Limb cloud images are simulated by matching the cloud topography with the limb sounding line of sight (LOS). The analysis of the BT data shows that the reduction of the spatial sampling along the track has hardly any effect on the gain in information. The comparison between BT and COSMO-EU data identifies the strength of both data sets, which are the representation of the horizontal cloud extent for the BT data and the reproduction of the cloud amount for the COSMO-EU data. The results of the analysis of both data sets show the great advantage of the cloud imager. However, because both cloud data sets do not present the complete fine structure of the real cloud fields in the atmosphere it is assumed that the results tend to underestimate the increase in information. In conclusion, real measurements by such an instrument may result in an even higher benefit for tropospheric limb retrievals.

Limb Darkening and Planetary Transits: Testing Center-to-limb Intensity Variations and Limb-darkening Directly from Model Stellar Atmospheres

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neilson, Hilding R.; Lester, John B.; McNeil, Joseph T.

The transit method, employed by Microvariability and Oscillation of Stars ( MOST ), Kepler , and various ground-based surveys has enabled the characterization of extrasolar planets to unprecedented precision. These results are precise enough to begin to measure planet atmosphere composition, planetary oblateness, starspots, and other phenomena at the level of a few hundred parts per million. However, these results depend on our understanding of stellar limb darkening, that is, the intensity distribution across the stellar disk that is sequentially blocked as the planet transits. Typically, stellar limb darkening is assumed to be a simple parameterization with two coefficients thatmore » are derived from stellar atmosphere models or fit directly. In this work, we revisit this assumption and compute synthetic planetary-transit light curves directly from model stellar atmosphere center-to-limb intensity variations (CLIVs) using the plane-parallel Atlas and spherically symmetric SAtlas codes. We compare these light curves to those constructed using best-fit limb-darkening parameterizations. We find that adopting parametric stellar limb-darkening laws leads to systematic differences from the more geometrically realistic model stellar atmosphere CLIV of about 50–100 ppm at the transit center and up to 300 ppm at ingress/egress. While these errors are small, they are systematic, and they appear to limit the precision necessary to measure secondary effects. Our results may also have a significant impact on transit spectra.« less

The role of GPS in precise earth observation

NASA Technical Reports Server (NTRS)

Yunck, Thomas P.; Lindal, Gunnar F.; Liu, Chao-Han

1988-01-01

The potential of the Global Positioning System (GPS) for precise earth observation is evaluated. It is projected that soon GPS will be utilized to track remote-sensing satellites with subdecimeter accuracy. The first will be Topex/Poseidon, a US/French ocean altimetry mission to be launched in 1991. In addition, it is suggested that developments planned for future platforms may push orbit accuracy near 1 cm within a decade. GPS receivers on some platforms will track the signals down to the earth limb to observe occultation by intervening media. This will provide comprehensive information on global temperature and climate and help detect the possible onset of a greenhouse effect. It is also projected that dual-frequency observations will be used to trace the flow of energy across earth systems through detection of ionospheric gravity waves, and to map the structure of the ionosphere by computer tomography.

The Thermal Emission and Albedo of Super-Earths with Flat Transmission Spectra

NASA Astrophysics Data System (ADS)

Morley, Caroline; Fortney, Jonathan J.; Marley, Mark

2015-01-01

Vast resources have been dedicated to characterizing the handful of planets with radii between Earth's and Neptune's that are accessible to current telescopes. Observations of their transmission spectra have been inconclusive and do not constrain the atmospheric composition. Here, we present a path forward for understanding this class of small planets: by understanding the thermal emission and reflectivity of small planets, we can break these degeneracies and constrain the atmospheric composition.Of the ~five small planets studied to date, four have radii in the near-IR consistent with being constant in wavelength. This suggests either that these planets all have higher mean molecular weight atmospheres than expected for hydrogen-dominated bulk compositions, or that the atmospheres of small planets are consistently enshrouded in thick hazes and clouds. For the particularly well-studied planet GJ 1214b, the measurements made using HST/WFC3 can rule out atmospheres with high mean molecular weights, leaving clouds as the sole explanation for the flat transmission spectrum. We showed in Morley et al. 2013 that these clouds and hazes can be made of salts and sulfides, which condense in the upper atmosphere of a cool H-rich atmosphere like GJ 1214b, or made of photochemical hazes such as soots, which result from methane photodissociation and subsequent carbon chemistry. Here, we explore how clouds thick enough to obscure the transmission spectrum change both thermal emission spectra and albedo spectra. These observations are complementary to transmission spectra measurements. Thermal emission probes deeper layers of the atmosphere, potentially below the high haze layer obscuring the transmission spectra; albedo spectra probe reflected starlight largely from the cloud particles themselves. Crucially, these complementary observations of planets with flat transmission spectra may allow us to break the degeneracies between cloud materials, cloud height and longitude, and

Validation of Suomi NPP OMPS Limb Profiler Ozone Measurements

NASA Astrophysics Data System (ADS)

Buckner, S. N.; Flynn, L. E.; McCormick, M. P.; Anderson, J.

2017-12-01

The Ozone Mapping and Profiler Suite (OMPS) Limb Profiler onboard the Suomi National Polar-Orbiting Partnership satellite (SNPP) makes measurements of limb-scattered solar radiances over Ultraviolet and Visible wavelengths. These measurements are used in retrieval algorithms to create high vertical resolution ozone profiles, helping monitor the evolution of the atmospheric ozone layer. NOAA is in the process of implementing these algorithms to make near-real-time versions of these products. The main objective of this project is to generate estimates of the accuracy and precision of the OMPS Limb products by analysis of matchup comparisons with similar products from the Earth Observing System Microwave Limb Sounder (EOS Aura MLS). The studies investigated the sources of errors, and classified them with respect to height, geographic location, and atmospheric and observation conditions. In addition, this project included working with the algorithm developers in an attempt to develop corrections and adjustments. Collocation and zonal mean comparisons were made and statistics were gathered on both a daily and monthly basis encompassing the entire OMPS data record. This validation effort of the OMPS-LP data will be used to help validate data from the Stratosphere Aerosol and Gas Experiment III on the International Space Station (SAGE III ISS) and will also be used in conjunction with the NOAA Total Ozone from Assimilation of Stratosphere and Troposphere (TOAST) product to develop a new a-priori for the NOAA Unique Combined Atmosphere Processing System (NUCAPS) ozone product. The current NUCAPS ozone product uses a combination of Cross-track Infrared Sounder (CrIS) data for the troposphere and a tropopause based climatology derived from ozonesonde data for the stratosphere a-priori. The latest version of TOAST uses a combination of both CrIS and OMPS-LP data. We will further develop the newest version of TOAST and incorporate it into the NUCAPS system as a new a

SOHO/CDS Measurements of Coronal EUV Polarization above the Limb

NASA Technical Reports Server (NTRS)

Thomas, Roger J.; Oegerle, William R. (Technical Monitor)

2002-01-01

Attempts to measure polarization in coronal EUV emission above the solar limb have been made using the SOHO/CDS normal-incidence spectrometer which has a polarization sensitivity of about 50%, a property that causes variations in intensity response as a function of the spacecraft's roll angle for polarized light. Such observations were made on the disk and up to 0.22 solar radii above the solar limb in a number of EUV lines during two special roll-maneuvers of the SOHO spacecraft. Measurements of intensity gradients were made above a modestly active equatorial region in 1997 and above a relatively cool polar region in 2001. Observed emission lines include He I 584A, He II 304A, 0 IV 555+610A, 0 V 630A, Mg IX 368A, Mg X 610+625A, and Si XI 303A, formed at temperatures that evenly cover the range in logT from 4.1 to 6.2. Near the disk, measured intensities of all lines fall off exponentially at different rates that can be used to determine the density scale-heights of the emitting plasma, since this emission is dominated by collisional excitation with an Ne-squared dependence. Assuming hydrostatic equilibrium, the intensity gradient for each line can then be converted into a 'scale-height temperature', which is found to be closely related to the ionization temperature of each line over the wide range of lines and solar conditions observed. Beyond a certain distance, intensity gradients of the cooler lines switch over to a flatter exponential slope, suggesting that this radiation is dominated by resonance scattering which varies as Ne to the first power. Such radiation should also be linearly polarized in the plane containing the line-of-sight and the solar center, a signature that would strongly confirm this interpretation.

Soft X-ray study of solar wind charge exchange from the Earth's magnetosphere : Suzaku observations and a future X-ray imaging mission concept

NASA Astrophysics Data System (ADS)

Ezoe, Y.; Ishisaki, Y.; Ohashi, T.; Ishikawa, K.; Miyoshi, Y.; Fujimoto, R.; Terada, N.; Kasahara, S.; Fujimoto, M.; Mitsuda, K.; Nishijo, K.; Noda, A.

2013-12-01

Soft X-ray observations of solar wind charge exchange (SWCX) emission from the Earth's magnetosphere using the Japanese X-ray astronomy satellite Suzaku are shown, together with our X-ray imaging mission concept to characterize the solar wind interaction with the magnetosphere. In recent years, the SWCX emission from the Earth's magnetosphere, originally discovered as unexplained noise during the soft X-ray all sky survey (Snowden et al. 1994), is receiving increased attention on studying geospace. The SWCX is a reaction between neutrals in exosphere and highly charged ions in the magnetosphere originated from solar wind. Robertson et al. (2005) modeled the SWCX emission as seen from an observation point 50 Re from Earth. In the resulting X-ray intensities, the magnetopause, bow shock and cusp were clearly visible. High sensitivity soft X-ray observation with CCDs onboard recent X-ray astronomy satellites enables us to resolve SWCX emission lines and investigate time correlation with solar wind as observed with ACE and WIND more accurately. Suzaku is the 5th Japanese X-ray astronomy satellite launched in 2005. The line of sight direction through cusp is observable, while constraints on Earth limb avoidance angle of other satellites often limits observable regions. Suzaku firstly detected the SWCX emission while pointing in the direction of the north ecliptic pole (Fujimoto et al. 2007). Using the Tsyganenko 1996 magnetic field model, the distance to the nearest SWCX region was estimated as 2-8 Re, implying that the line of sight direction can be through magnetospheric cusp. Ezoe et al. (2010) reported SWCX events toward the sub-solar side of the magnetosheath. These cusp and sub-solar side magnetosheath regions are predicted to show high SWCX fluxes by Robertson et al. (2005). On the other hand, Ishikawa et al. (2013) discovered a similarly strong SWCX event when the line of sight direction did not transverse these two regions. Motivated by these detections

Sonic Hedgehog Signaling in Limb Development

PubMed Central

Tickle, Cheryll; Towers, Matthew

2017-01-01

The gene encoding the secreted protein Sonic hedgehog (Shh) is expressed in the polarizing region (or zone of polarizing activity), a small group of mesenchyme cells at the posterior margin of the vertebrate limb bud. Detailed analyses have revealed that Shh has the properties of the long sought after polarizing region morphogen that specifies positional values across the antero-posterior axis (e.g., thumb to little finger axis) of the limb. Shh has also been shown to control the width of the limb bud by stimulating mesenchyme cell proliferation and by regulating the antero-posterior length of the apical ectodermal ridge, the signaling region required for limb bud outgrowth and the laying down of structures along the proximo-distal axis (e.g., shoulder to digits axis) of the limb. It has been shown that Shh signaling can specify antero-posterior positional values in limb buds in both a concentration- (paracrine) and time-dependent (autocrine) fashion. Currently there are several models for how Shh specifies positional values over time in the limb buds of chick and mouse embryos and how this is integrated with growth. Extensive work has elucidated downstream transcriptional targets of Shh signaling. Nevertheless, it remains unclear how antero-posterior positional values are encoded and then interpreted to give the particular structure appropriate to that position, for example, the type of digit. A distant cis-regulatory enhancer controls limb-bud-specific expression of Shh and the discovery of increasing numbers of interacting transcription factors indicate complex spatiotemporal regulation. Altered Shh signaling is implicated in clinical conditions with congenital limb defects and in the evolution of the morphological diversity of vertebrate limbs. PMID:28293554

Elevated vacuum suspension preserves residual-limb skin health in people with lower-limb amputation: Randomized clinical trial.

PubMed

Rink, Cameron; Wernke, Matthew M; Powell, Heather M; Gynawali, Surya; Schroeder, Ryan M; Kim, Jayne Y; Denune, Jeffrey A; Gordillo, Gayle M; Colvin, James M; Sen, Chandan K

2016-01-01

A growing number of clinical trials and case reports support qualitative claims that use of an elevated vacuum suspension (EVS) prosthesis improves residual-limb health on the basis of self-reported questionnaires, clinical outcomes scales, and wound closure studies. Here, we report first efforts to quantitatively assess residual-limb circulation in response to EVS. Residual-limb skin health and perfusion of people with lower-limb amputation (N = 10) were assessed during a randomized crossover study comparing EVS with nonelevated vacuum suspension (control) over a 32 wk period using noninvasive probes (transepidermal water loss, laser speckle imaging, transcutaneous oxygen measurement) and functional hyperspectral imaging approaches. Regardless of the suspension system, prosthesis donning decreased perfusion in the residual limb under resting conditions. After 16 wk of use, EVS improved residual-limb oxygenation during treadmill walking. Likewise, prosthesis-induced reactive hyperemia was attenuated with EVS following 16 wk of use. Skin barrier function was preserved with EVS but disrupted after control socket use. Taken together, outcomes suggest chronic EVS use improves perfusion and preserves skin barrier function in people with lower-limb amputation. ClinicalTrials.gov; "Evaluation of limb health associated with a prosthetic vacuum socket system": NCT01839123; https://clinicaltrials.gov/ct2/show/NCT01839123?term=NCT01839123&rank=1.

Comparison of 2-limb versus 3-limb electrodiagnostic studies in the evaluation of chronic inflammatory demyelinating polyneuropathy.

PubMed

Vo, Mary L; Hanineva, Aneliya; Chin, Russell L; Carey, Bridget T; Latov, Norman; Langsdorf, Jennifer A

2015-04-01

European Federation of Neurological Societies/Peripheral Nerve Society electrodiagnostic (EDx) criteria for the definite diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP) require the presence of demyelinating findings (DF) in at least 2 nerves. Data are lacking, however, regarding the optimal number of nerves to test. We retrospectively reviewed EDx data from 53 patients with CIDP and compared the number of DF found on 2- and 3-limb testing. A median of 3 (range 2-5) DF were found on 2-limb testing compared with 5 (range 4-7) DF when 3 limbs were evaluated. Two-limb EDx studies were sufficient to diagnose definite CIDP in 92.3% of typical, 84.2% of asymmetric, and 66.7% of distal phenotypes. Testing a third limb increased diagnostic certainty in 11 patients (20.8%) to definite CIDP. Three-limb testing may increase diagnostic sensitivity of definite CIDP, especially in patients with atypical phenotypes. Larger prospective studies are needed to better assess the benefit of performing 3-limb EDx studies. © 2014 Wiley Periodicals, Inc.

Advanced upper limb prosthetic devices: implications for upper limb prosthetic rehabilitation.

PubMed

Resnik, Linda; Meucci, Marissa R; Lieberman-Klinger, Shana; Fantini, Christopher; Kelty, Debra L; Disla, Roxanne; Sasson, Nicole

2012-04-01

The number of catastrophic injuries caused by improvised explosive devices in the Afghanistan and Iraq Wars has increased public, legislative, and research attention to upper limb amputation. The Department of Veterans Affairs (VA) has partnered with the Defense Advanced Research Projects Agency and DEKA Integrated Solutions to optimize the function of an advanced prosthetic arm system that will enable greater independence and function. In this special communication, we examine current practices in prosthetic rehabilitation including trends in adoption and use of prosthetic devices, financial considerations, and the role of rehabilitation team members in light of our experiences with a prototype advanced upper limb prosthesis during a VA study to optimize the device. We discuss key challenges in the adoption of advanced prosthetic technology and make recommendations for service provision and use of advanced upper limb prosthetics. Rates of prosthetic rejection are high among upper limb amputees. However, these rates may be reduced with sufficient training by a highly specialized, multidisciplinary team of clinicians, and a focus on patient education and empowerment throughout the rehabilitation process. There are significant challenges emerging that are unique to implementing the use of advanced upper limb prosthetic technology, and a lack of evidence to establish clinical guidelines regarding prosthetic prescription and treatment. Finally, we make recommendations for future research to aid in the identification of best practices and development of policy decisions regarding insurance coverage of prosthetic rehabilitation. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Limb myokymia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Albers, J.W.; Allen, A.A.; Bastron, J.A.

Thirty-eight patients with myokymic discharges localized to limb muscles on needle electromyography had various neurologic lesions, both acute and chronic. Of the 38 patients, 27 had had previous radiation therapy and the clinical diagnosis of radiation-induced plexopathy, myelopathy, or both. For the remaining 11 patients, the diagnoses included multiple sclerosis, inflammatory polyradiculoneuropathy, ischemic neuropathy, inflammatory myopathy, and chronic disorders of the spinal cord and peripheral nerves. The clinical presentations and results of local ischemia, peripheral nerve block, and percutaneous stimulation suggest that most limb myokymic discharges arise focally at the site of a chronic peripheral nerve lesion.

Effects of the Earth Albedo and Thermic Emissivity on Geodetic Satellite Trajectories: a Mean Model from 2000-2016 data sets.

NASA Astrophysics Data System (ADS)

Deleflie, Florent; Sammuneh, Muhammad Ali; Coulot, David; Pollet, Arnaud; Biancale, Richard; Capderou, Michel

2017-04-01

Part of the energy received on the Earth from the Sun is split into two components, a short wave component which corresponds to the visible emissivity of the Earth's surface (albedo), and the long wave part corresponding to the thermic emissivity (infrared wavelengths). These two components induce small non gravitational forces on the orbits of artificial satellites, towards the radial direction (mainly), that we are evaluating to derive a mean model. The first step to evaluate the mean amplitudes and periods of the generaetd perturbations consists in comparing post-fit adjustment of geodetic satellites to SLR data, in two dynamical models accounting or not accounting for empirical forces standing for such effects: the orbits of the geodetic satellite STARLETTE, Stella, Ajisai, Lageos 1 and Lageos 2 are carried out in such a way over the period 2000-2016, with the GINS GRGS orbit computation s/w. We then use three kinds of data sets to investigate the mean amplitudes of the perturbations, and to investigate features on regional spatial scales: (i) Stephens tables, (Stephens, 1980), ECMWF (European Centre for Medium-Range Weather Forecasts ) data sets (that are available at GRGS, Groupe de Recherche de Géodésie Spatiale, France), and CERES (Clouds and the Earth's Radiant Energy System) data sets (publickly available).We analyze what is the data set leading to the lowest residual level. Then, following an approach close to the one developed by Stephens, we propose a set of monthly grids that are averaged over the period 2000-2016, and that is evaluated through the orbit computation of the above-mentioned satellites.

Apparatus for determining changes in limb volume

NASA Technical Reports Server (NTRS)

Bhagat, P. K.; Wu, V. C. (Inventor)

1981-01-01

Measuring apparatus for determining changes in the volume of limbs or other boty extremities by determining the cross-sectional area of such limbs many comprise a transmitter including first and second transducers for positioning on the surface of the limb at a predetermined distance there between, and a receiver including a receiver crystal for positioning on the surface of the limb. The distance between the receiver crystal and the first and second transducers are represented by respective first and second chords of the cross-section of the limb and the predetermined distance between the first and second transducers is represented by a third chord of the limb cross section.

The Sun and Earth

NASA Technical Reports Server (NTRS)

Gopalswamy, Natchimuthuk

2012-01-01

Thus the Sun forms the basis for life on Earth via the black body radiation it emits. The Sun also emits mass in the form of the solar wind and the coronal mass ejections (CMEs). Mass emission also occurs in the form of solar energetic particles (SEPs), which happens during CMEs and solar flares. Both the mass and electromagnetic energy output of the Sun vary over a wide range of time scales, thus introducing disturbances on the space environment that extends from the Sun through the entire heliosphere including the magnetospheres and ionospheres of planets and moons of the solar system. Although our habitat is located in the neutral atmosphere of Earth, we are intimately connected to the non-neutral space environment starting from the ionosphere to the magnetosphere and to the vast interplanetary space. The variability of the solar mass emissions results in the interaction between the solar wind plasma and the magnetospheric plasma leading to huge disturbances in the geospace. The Sun ionizes our atmosphere and creates the ionosphere. The ionosphere can be severely disturbed by the transient energy input from solar flares and the solar wind during geomagnetic storms. The complex interplay between Earth's magnetic field and the solar magnetic field carried by the solar wind presents varying conditions that are both beneficial and hazardous to life on earth. This seminar presents some of the key aspects of this Sun-Earth connection that we have learned since the birth of space science as a scientific discipline some half a century ago.

A Systematic Search for Solar Wind Charge Exchange Emission from the Earth's Exosphere with Suzaku

NASA Astrophysics Data System (ADS)

Ishi, D.; Ishikawa, K.; Ezoe, Y.; Ohashi, T.; Miyoshi, Y.; Terada, N.

2017-10-01

We report on a systematic search of all the Suzaku archival data covering from 2005 August to 2015 May for geocoronal Solar Wind Charge eXchange (SWCX). In the vicinity of Earth, solar wind ions strip an electron from Earth's exospheric neutrals, emitting X-ray photons (e.g., Snowden et al. 1997). The X-ray flux of this geocoronal SWCX can change depending on solar wind condition and line of sight direction. Although it is an immediate background for all the X-ray astronomy observations, the X-ray flux prediction and the dependence on the observational conditions are not clear. Using the X-ray Imaging Spectrometer onboard Suzaku which has one of the highest sensitivities to the geocoronal SWCX, we searched the data for time variation of soft X-ray background. We then checked the solar wind proton flux taken with the WIND satellite and compared it with X-ray light curve. We also analyzed X-ray spectra and fitted them with a charge exchange emission line model constructed by Bodewits et al. (2007). Among 3055 data sets, 90 data showed SWCX features. The event rate seems to correlate with solar activity, while the distribution of SWCX events plotted in the solar magnetic coordinate system was relatively uniform.

Managing residual limb hyperhidrosis in wounded warriors.

PubMed

Pace, Sarah; Kentosh, Joshua

2016-06-01

Residual limb dermatologic problems are a common concern among young active traumatic amputee patients who strive to maintain an active lifestyle. Hyperhidrosis of residual limbs is a recognized inciting factor that often contributes to residual limb dermatoses and is driven by the design of the prosthetic liner covering the residual limb. Treatment of hyperhidrosis in this population presents a unique challenge. Several accepted treatments of hyperhidrosis can offer some relief but have been limited by lack of results or side-effect profiles. Microwave thermal ablation has presented an enticing potential for residual limb hyperhidrosis.

Earth system responses to cumulative carbon emissions

NASA Astrophysics Data System (ADS)

Steinacher, M.; Joos, F.

2015-07-01

Information on the relationship between cumulative fossil carbon emissions and multiple climate targets are essential to design emission mitigation and climate adaptation strategies. In this study, the transient responses in different climate variables are quantified for a large set of multi-forcing scenarios extended to year 2300 towards stabilization and in idealized experiments using the Bern3D-LPJ carbon-climate model. The model outcomes are constrained by 26 physical and biogeochemical observational data sets in a Bayesian, Monte-Carlo type framework. Cumulative fossil emissions of 1000 Gt C result in a global mean surface air temperature change of 1.88 °C (68 % confidence interval (c.i.): 1.28 to 2.69 °C), a decrease in surface ocean pH of 0.19 (0.18 to 0.22), and in steric sea level rise of 20 cm (13 to 27 cm until 2300). Linearity between cumulative emissions and transient response is high for pH and reasonably high for surface air and sea surface temperatures, but less pronounced for changes in Atlantic Meridional Overturning, Southern Ocean and tropical surface water saturation with respect to biogenic structures of calcium carbonate, and carbon stocks in soils. The slopes of the relationships change when CO2 is stabilized. The Transient Climate Response is constrained, primarily by long-term ocean heat observations, to 1.7 °C (68 % c.i.: 1.3 to 2.2 °C) and the Equilibrium Climate Sensitivity to 2.9 °C (2.0 to 4.2 °C). This is consistent with results by CMIP5 models, but inconsistent with recent studies that relied on short-term air temperature data affected by natural climate variability.

THz limb sounder (TLS) for lower thermospheric wind, oxygen density, and temperature

NASA Astrophysics Data System (ADS)

Wu, Dong L.; Yee, Jeng-Hwa; Schlecht, Erich; Mehdi, Imran; Siles, Jose; Drouin, Brian J.

2016-07-01

Neutral winds are one of the most critical measurements in the lower thermosphere and E region ionosphere (LTEI) for understanding complex electrodynamic processes and ion-neutral interactions. We are developing a high-sensitivity, low-power, noncryogenic 2.06 THz Schottky receiver to measure wind profiles at 100-140 km. The new technique, THz limb sounder (TLS), aims to measure LTEI winds by resolving the wind-induced Doppler shift of 2.06 THz atomic oxygen (OI) emissions. As a transition between fine structure levels in the ground electronic state, the OI emission is in local thermodynamic equilibrium (LTE) at altitudes up to 350 km. This LTE property, together with day-and-night capability and small line-of-sight gradient, makes the OI limb sounding a very attractive technique for neutral wind observations. In addition to the wind measurement, TLS can also retrieve [OI] density and neutral temperature in the LTEI region. TLS leverages rapid advances in THz receiver technologies including subharmonically pumped (SHP) mixers and Schottky-diode-based power multipliers. Current SHP Schottky receivers have produced good sensitivity for THz frequencies at ambient environment temperatures (120-150 K), which are achievable through passively cooling in spaceflight. As an emerging technique, TLS can fill the critical data gaps in the LTEI neutral wind observations to enable detailed studies on the coupling and dynamo processes between charged and neutral molecules.

THz Limb Sounder (TLS) for Lower Thermospheric Wind, Oxygen Density, and Temperature

NASA Technical Reports Server (NTRS)

Wu, Dong L.; Yee, Jeng-Hwa; Schlecht, Erich; Mehdi, Imran; Siles, Jose; Drouin, Brian J.

2016-01-01

Neutral winds are one of the most critical measurements in the lower thermosphere and E region ionosphere (LTEI) for understanding complex electrodynamic processes and ion-neutral interactions. We are developing a high-sensitivity, low-power, noncryogenic 2.06 THz Schottky receiver to measure wind profiles at 100-140 km. The new technique, THz limb sounder (TLS), aims to measure LTEI winds by resolving the wind-induced Doppler shift of 2.06 THz atomic oxygen (OI) emissions. As a transition between fine structure levels in the ground electronic state, the OI emission is in local thermodynamic equilibrium(LTE) at altitudes up to 350km. This LTE property, together with day-and-night capability and small line-of-sight gradient, makes the OI limb sounding a very attractive technique for neutral wind observations. In addition to the wind measurement, TLS can also retrieve [OI] density and neutral temperature in the LTEI region. TLS leverages rapid advances in THz receiver technologies including subharmonically pumped (SHP)mixers and Schottky-diode-based power multipliers. Current SHP Schottky receivers have produced good sensitivity for THz frequencies at ambient environment temperatures (120-150 K), which are achievable through passively cooling in spaceflight. As an emerging technique, TLS can fill the critical data gaps in the LTEI neutral wind observations to enable detailed studies on the coupling and dynamo processes between charged and neutral molecules.

View of Moon over Earth limb taken by the Expedition 37 crew.

NASA Image and Video Library

2013-10-19

ISS037-E-017169 (19 Oct. 2013) --- The European Space Agency's fourth Automated Transfer Vehicle (ATV-4), also known as the Albert Einstein, is seen in the foreground of an image featuring the home planet and its moon as photographed by one of Expedition 37 crew members aboard the Earth-orbiting International Space Station.

Biochemical markers of acute limb ischemia, rhabdomyolysis, and impact on limb salvage.

PubMed

Watson, J Devin B; Gifford, Shaun M; Clouse, W Darrin

2014-12-01

Biochemical markers of ischemia reperfusion injury have been of interest to vascular surgeons and researchers for many years. Acute limb ischemia is the quintessential clinical scenario where these markers would seem relevant. The use of biomarkers to preoperatively or perioperatively predict which patients will not tolerate limb-salvage efforts or who will have poor functional outcomes after salvage is of immense interest. Creatinine phosphokinase, myoglobin, lactate, lactate dehydrogenase, potassium, bicarbonate, and neutrophil/leukocyte ratios are a few of the studied biomarkers available. Currently, the most well-studied aspect of ischemia reperfusion injury is rhabdomyolysis leading to acute kidney injury. The last 10 years have seen significant progression and improvement in the treatment of rhabdomyolysis, from minor supportive care to use of continuous renal replacement therapy. Identification of specific biomarkers with predictive outcome characteristics in the setting of ischemia reperfusion injury will help guide therapeutic development and potentially mitigate pathophysiologic changes in acute limb ischemia, including rhabdomyolysis. These may further lead to improvements in short- and long-term surgical outcomes and limb salvage, as well as a better understanding of the timing and selection of intervention. Copyright © 2015 Elsevier Inc. All rights reserved.

Paradigms and challenges for bioapplication of rare earth upconversion luminescent nanoparticles: small size and tunable emission/excitation spectra.

PubMed

Sun, Ling-Dong; Wang, Ye-Fu; Yan, Chun-Hua

2014-04-15

Rare earth (RE) materials, which are excited in the ultraviolet and emit in the visible light spectrum, are widely used as phosphors for lamps and displays. In the 1960's, researchers reported an abnormal emission phenomenon where photons emitted from a RE element carried more energy than those absorbed, owing to the sequential energy transfer between two RE ions--Yb(3+)-sensitized Er(3+) or Tm(3+)--in the solid state. After further study, researchers named this abnormal emission phenomenon upconversion (UC) emission. More recent approaches take advantage of solution-based synthesis, which allows creation of homogenous RE nanoparticles (NPs) with controlled size and structure that are capable of UC emission. Such nanoparticles are useful for many applications, especially in biology. For these applications, researchers seek small NPs with high upconversion emission intensity. These UCNPs have the potential to have multicolor and tunable emissions via various activators. A vast potential for future development remains by developing molecular antennas and energy transfer within RE ions. We expect UCNPs with optimized spectra behavior to meet the increasing demand of potential applications in bioimaging, biological detection, and light conversion. This Account focuses on efforts to control the size and modulate the spectra of UCNPs. We first review efforts in size control. One method is careful control of the synthesis conditions to manipulate particle nucleation and growth, but more recently researchers have learned that the doping conditions can affect the size of UCNPs. In addition, constructing homogeneous core/shell structures can control nanoparticle size by adjusting the shell thickness. After reviewing size control, we consider how diverse applications impose different requirements on excitation and/or emission photons and review recent developments on tuning of UC spectral profiles, especially the extension of excitation/emission wavelengths and the adjustment

Developmental origin of limb size variation in lizards.

PubMed

Andrews, Robin M; Skewes, Sable A

2017-05-01

In many respects, reptile hatchlings are fully functional, albeit miniature, adults. This means that the adult morphology must emerge during embryonic development. This insight emphasizes the connection between the mechanisms that generate phenotypic variation during embryonic development and the action of selection on post-hatching individuals. To determine when species-specific differences in limb and tail lengths emerge during embryonic development, we compared allometric patterns of early limb growth of four distantly related species of lizards. The major questions addressed were whether early embryonic limb and tail growth is characterized by the gradual (continuous allometry) or by the abrupt emergence (transpositional allometry) of size differences among species. Our observations supported transpositional allometry of both limbs and tails. Species-specific differences in limb and tail length were exhibited when limb and tail buds first protruded from the body wall. Genes known to be associated with early limb development of tetrapods are obvious targets for studies on the genetic mechanisms that determine interspecific differences in relative limb length. Broadly comparative studies of gene regulation would facilitate understanding of the mechanisms underlying adaptive variation in limb size, including limb reduction and loss, of squamate reptiles. © 2017 Wiley Periodicals, Inc.

Solar off-limb emission of the O I 7772 Å line

NASA Astrophysics Data System (ADS)

Pazira, H.; Kiselman, D.; Leenaarts, J.

2017-08-01

Aims: The aim of this paper is to understand the formation of the O I line at 7772 Å in the solar chromosphere. Methods: We used SST/CRISP observations to observe O I 7772 Å in several places around the solar limb. We compared the observations with synthetic spectra calculated with the RH code in the one-dimension spherical geometry mode. New accurate hydrogen collisional rates were included for the RH calculations. Results: The observations reveal a dark gap in the lower chromosphere, which is caused by variations in the line opacity as shown by our models. The lower level of the 7772 Å transition is populated by a downward cascade from the continuum. We study the effect of Lyman-β pumping and hydrogen collisions between the triplet and quintet system in O I. Both have a small but non-negligible influence on the line intensity.

Management of Major Limb Injuries

PubMed Central

Langer, Vijay

2014-01-01

Management of major limb injuries is a daunting challenge, especially as many of these patients have severe associated injuries. In trying to save life, often the limb is sacrificed. The existing guidelines on managing such trauma are often confusing. There is scope to lay down such protocols along with the need for urgent transfer of such patients to a multispecialty center equipped to salvage life and limb for maximizing outcome. This review article comprehensively deals with the issue of managing such major injuries. PMID:24511296

X-ray observations of limb flare loops and post-flare coronal arch

NASA Technical Reports Server (NTRS)

Svestka, Zdenek; Smith, Kermit L.; Strong, Keith T.

1992-01-01

Postflare arc observations have been obtained following a May 2, 1985 eruptive flare that was detected in X-ray lines above the western solar limb, constituting a rare opportunity for the isolation of pure spectra of the arch without the disturbing effect of X-ray emission from lower and more intense coronal regions. It remains difficult to decide which portion of the observed shift is due to real motion and which is due to cooling, which is faster at lower altitudes.

Slow Movements of Bio-Inspired Limbs

NASA Astrophysics Data System (ADS)

Babikian, Sarine; Valero-Cuevas, Francisco J.; Kanso, Eva

2016-10-01

Slow and accurate finger and limb movements are essential to daily activities, but the underlying mechanics is relatively unexplored. Here, we develop a mathematical framework to examine slow movements of tendon-driven limbs that are produced by modulating the tendons' stiffness parameters. Slow limb movements are driftless in the sense that movement stops when actuations stop. We demonstrate, in the context of a planar tendon-driven system representing a finger, that the control of stiffness suffices to produce stable and accurate limb postures and quasi-static (slow) transitions among them. We prove, however, that stable postures are achievable only when tendons are pretensioned, i.e., they cannot become slack. Our results further indicate that a non-smoothness in slow movements arises because the precision with which individual stiffnesses need to be altered changes substantially throughout the limb's motion.

Spatial imaging of hydrogen Lyman-alpha emission from Jupiter

NASA Technical Reports Server (NTRS)

Clarke, J. T.; Weaver, H. A.; Feldman, P. D.; Moos, H. W.; Fastie, W. G.; Opal, C. B.

1980-01-01

A sounding rocket measurement of the H I L-alpha emission from Jupiter made on Dec. 1, 1978 shows limb darkening and an average disk brightness of 13 kR. This brightness is significantly higher than in previous measurements, and was confirmed by an IUE observation on Dec. 10, 1978. Comparison with a plane-parallel hydrogen layer model indicates that there is enhanced emission from the equatorial regions, reaching a peak near 80 deg longitude.

The variations of oxygen emissions in corresponding to Earth's aurora in low latitude region under influence of solar wind dynamics

NASA Astrophysics Data System (ADS)

Jamlongkul, P.; Wannawichian, S.

2017-12-01

Earth's aurora in low latitude region was studied via time variations of oxygen emission spectra, simultaneously with solar wind data. The behavior of spectrum intensity, in corresponding with solar wind condition, could be a trace of aurora in low latitude region including some effects of high energetic auroral particles. Oxygen emission spectral lines were observed by Medium Resolution Echelle Spectrograph (MRES) at 2.4-m diameter telescope at Thai National Observatory, Inthanon Mountain, Chiang Mai, Thailand, during 1-5 LT on 5 and 6 February 2017. The observed spectral lines were calibrated via Dech95 - 2D image processing program and Dech-Fits spectra processing program for spectrum image processing and spectrum wavelength calibration, respectively. The variations of observed intensities each day were compared with solar wind parameters, which are magnitude of IMF (|BIMF|) including IMF in RTN coordinate (BR, BT, BN), ion density (ρ), plasma flow pressure (P), and speed (v). The correlation coefficients between oxygen spectral emissions and different solar wind parameters were found to vary in both positive and negative behaviors.

Limb apraxia in aphasic patients.

PubMed

Ortiz, Karin Zazo; Mantovani-Nagaoka, Joana

2017-11-01

Limb apraxia is usually associated with left cerebral hemisphere damage, with numerous case studies involving aphasic patients. The aim of this study was to verify the occurrence of limb apraxia in aphasic patients and analyze its nature. This study involved 44 healthy volunteers and 28 aphasic patients matched for age and education. AH participants were assessed using a limb apraxia battery comprising subtests evaluating lexical-semantic aspects related to the comprehension/production of gestures as well as motor movements. Aphasics had worse performances on many tasks related to conceptual components of gestures. The difficulty found on the imitation of dynamic gesture tasks also indicated that there were specific motor difficulties in gesture planning. These results reinforce the importance of conducting limb apraxia assessment in aphasic patients and also highlight pantomime difficulties as a good predictor for semantic disturbances.

STS-44 Earth observation shows purplish twilight over the Atlantic Ocean

NASA Technical Reports Server (NTRS)

1991-01-01

STS-44 Earth observation taken aboard Atlantis, Orbiter Vehicle (OV) 104, shows twilight over the Atlantic Ocean. OV-104 was at a point in the north Atlantic located at 28 degrees north latitude and 37 degrees west longitude. The spacecraft has just passed sundown on the Earth's surface, but it was still daylight at an altitude of 195 nautical miles. During the mission, the astronauts noted that the limb of the Earth displayed a more purplish tint instead of its normal blue. This effect, according to NASA scientists, is attributed to the high altitude residue (mostly sulfuric acid particles) from the Mount Pinatubo eruptions of mid June 1991. Note the broad band of twilight in the center of the image. This band is another indicator of the upper atmospheric scattering of sunlight caused by this layer of haze that exists between 20 and 30 kilometers above Earth. Sunlight highlights the empty payload bay (PLB), the vertical tail, and orbital maneuvering system (OMS) pods against the black

SPILL ALERT DEVICE FOR EARTH DAM FAILURE WARNING

EPA Science Inventory

A spill alert device for determining earth dam safety based on the monitoring of the acoustic emissions generated in a deforming soil mass was developed and field-tested. The acoustic emissions are related to the basic mechanisms from which soils derive their strength. Laboratory...

Epidemiology of limb loss and congenital limb deficiency: a review of the literature.

PubMed

Ephraim, Patti L; Dillingham, Timothy R; Sector, Mathilde; Pezzin, Liliana E; Mackenzie, Ellen J

2003-05-01

To examine the state of research on population-based studies of the incidence of limb amputation and birth prevalence of limb deficiency. A total of 18 publication databases were searched, including MEDLINE, CINAHL, and the Cochrane Library. The search was performed by using a hierarchical process. Articles were reviewed for inclusion by 3 reviewers. Inclusion criteria included defined catchment area, calculation of population-based incidence rates, defined etiology of limb loss, and English language. Review articles, animal studies, case reports, cohort studies, letters, and editorials were excluded. Figures on the estimated incidence of amputation and birth prevalence of congenital limb deficiency were gleaned from selected reports and assembled into a table format by etiology. The studies varied in scope, quality, and methodology, making comparisons between studies difficult. Incidence rates of acquired amputation varied greatly between and within nations. Rates of all-cause acquired amputation ranged from 1.2 first major amputations per 10,000 women in Japan to 4.4 per 10,000 men in the Navajo Nation in the United States between 1992 and 1997. Consistent among all nations, the risk of amputation was greatest among persons with diabetes mellitus. Surveillance of congenital limb deficiency exists in much of the developed world. Existing studies of acquired amputation suffer from a host of methodologic problems. Future efforts should be directed toward the application of standardized measures and methods to enable trends to be evaluated over time and comparisons to be made within and between countries.

ISAMS and MLS for NASA's Upper Atmosphere Research Satellite

NASA Astrophysics Data System (ADS)

Llewellyn-Jones, D.; Dickinson, P. H. G.

1990-04-01

The primary goal of NASA's Upper Atmosphere Research Satellite (UARS), planned to be launched in 1991, is to compile data about the structure and behavior of the stratospheric ozone layer, and especially about the threat of the chlorine-based pollutants to its stablility. Two of the payload instruments, manufactured in the UK, are described: the Improved Stratospheric and Mesospheric Sounder (ISAMS), a radiometer designed to measure thermal emission from selected atmospheric constituents at the earth's limb, then making it possible to obtain nearly global coverage of the vertical distribution of temperature and composition from 80 deg S to 80 deg N latitude; and the Microwave Limb Sounder (MLS), a limb sounding radiometer, measuring atmospheric thermal emission from selected molecular spectral lines at mm wavelength, in the frequency regions of 63, 183, and 205 GHz.

Driving ability following upper limb amputation.

PubMed

Burger, Helena; Marincek, Crt

2013-10-01

In the existing literature, there is scarce information about subjects with upper limb amputation and driving. The aim of this study was to find out how frequently subjects following upper limb amputation have problems when driving; most frequently proposed adaptations and, when possible, factors that influence driving ability. Retrospective clinical study. Medical records were reviewed of all subjects following upper limb amputation who had been amputated in the last 5 years and those with congenital upper limb deficiency who in the last 5 years turned 17. Out of 37 subjects, 7 did not attend the clinic for assessment of driving abilities. They were significantly older at the time of the amputation (p < 0.001). To the remaining 30 who attended driving assessment, zero to four car adaptations (two on average) were proposed. There were no correlations between the number of suggested car adaptations and the age at the time of the amputation, amputation level, education and severity of phantom limb pain. Type of prosthesis also did not influence the number of car adaptations. Most people following upper limb amputation need at least one car adaptation for safe driving.

2D-model of oxygen emissions lines for Europa

NASA Astrophysics Data System (ADS)

Cessateur, Gaël; Barthelemy, Mathieu; Lilensten, Jean; Rubin, Martin; Maggiolo, Romain; De Keyser, Johan

2017-04-01

The Jovian moon Europa is an interesting case study as an archetype for icy satellites, and will be one of the primary targets of the ESA JUICE mission which should be launched in 2022. Hosting a thin neutral gas atmosphere mainly composed of O2 and H2O, Europa can be studied by its airglow and dayglow emissions. A 1D photochemistry model has first been developed to assess the impact of the solar UV flux on the visible emission, such as the red and green oxygen lines (Cessateur et al. 2016). For limb polar viewing, red line emissions can reach a few hundreds of Rayleigh close to the surface. The impact of the precipitating electrons has also been studied. The density and temperature of the electrons are first derived from the multifluid MHD model from Rubin et al. (2015). A 2D emission model has thus been developed to estimate the airglow emissions. When electrons are the major source of the visible emissions, the solar UV flux can be responsible for up to 15% of those emissions for some specific line of sight. Oxygen emission lines in the UV have also been considered, such as 130.5 and 135.6 nm. For the latter, we did estimate some significant line emissions reaching 700 Rayleigh for a polar limb viewing angle close to the surface. Oxygen emission lines are significant (higher than 10 R) for altitudes lower than 100 km for all lines, except for the red line emissions where emissions are still above 10 R up to 200 km from the surface. A sensitivity study has also been performed in order to assess the impact of the uncertainties relative to the dissociative-excitation cross sections. Cessateur G, Barthelemy M & Peinke I. Photochemistry-emission coupled model for Europa and Ganymede. J. Space Weather Space Clim., 6, A17, 2016 Rubin, M., et al. Self-consistent multifluid MHD simulations of Europa's exospheric interaction with Jupiter's magnetosphere, J. Geophys. Res. Space Physics, 120, 3503-3524, 2015

Genetics Home Reference: limb-girdle muscular dystrophy

MedlinePlus

... age of onset, and features of limb-girdle muscle dystrophy vary among the many subtypes of this condition ... occurs in some people with limb-girdle muscular dystrophy . Weakening of the heart muscle (cardiomyopathy) occurs in some forms of limb-girdle ...

Movement patterns of limb coordination in infant rolling.

PubMed

Kobayashi, Yoshio; Watanabe, Hama; Taga, Gentaro

2016-12-01

Infants must perform dynamic whole-body movements to initiate rolling, a key motor skill. However, little is known regarding limb coordination and postural control in infant rolling. To address this lack of knowledge, we examined movement patterns and limb coordination during rolling in younger infants (aged 5-7 months) that had just begun to roll and in older infants (aged 8-10 months) with greater rolling experience. Due to anticipated difficulty in obtaining measurements over the second half of the rolling sequence, we limited our analysis to the first half. Ipsilateral and contralateral limbs were identified on the basis of rolling direction and were classified as either a stationary limb used for postural stability or a moving limb used for controlled movement. We classified the observed movement patterns by identifying the number of stationary limbs and the serial order of combinational limb movement patterns. Notably, older infants performed more movement patterns that involved a lower number of stationary limbs than younger infants. Despite the wide range of possible movement patterns, a small group of basic patterns dominated in both age groups. Our results suggest that the fundamental structure of limb coordination during rolling in the early acquisition stages remains unchanged until at least 8-10 months of age. However, compared to younger infants, older infants exhibited a greater ability to select an effective rotational movement by positioning themselves with fewer stationary limbs and performing faster limb movements.

Coupling population dynamics with earth system models: the POPEM model.

PubMed

Navarro, Andrés; Moreno, Raúl; Jiménez-Alcázar, Alfonso; Tapiador, Francisco J

2017-09-16

Precise modeling of CO 2 emissions is important for environmental research. This paper presents a new model of human population dynamics that can be embedded into ESMs (Earth System Models) to improve climate modeling. Through a system dynamics approach, we develop a cohort-component model that successfully simulates historical population dynamics with fine spatial resolution (about 1°×1°). The population projections are used to improve the estimates of CO 2 emissions, thus transcending the bulk approach of existing models and allowing more realistic non-linear effects to feature in the simulations. The module, dubbed POPEM (from Population Parameterization for Earth Models), is compared with current emission inventories and validated against UN aggregated data. Finally, it is shown that the module can be used to advance toward fully coupling the social and natural components of the Earth system, an emerging research path for environmental science and pollution research.

Robotics in Lower-Limb Rehabilitation after Stroke

PubMed Central

2017-01-01

With the increase in the elderly, stroke has become a common disease, often leading to motor dysfunction and even permanent disability. Lower-limb rehabilitation robots can help patients to carry out reasonable and effective training to improve the motor function of paralyzed extremity. In this paper, the developments of lower-limb rehabilitation robots in the past decades are reviewed. Specifically, we provide a classification, a comparison, and a design overview of the driving modes, training paradigm, and control strategy of the lower-limb rehabilitation robots in the reviewed literature. A brief review on the gait detection technology of lower-limb rehabilitation robots is also presented. Finally, we discuss the future directions of the lower-limb rehabilitation robots. PMID:28659660

Robotics in Lower-Limb Rehabilitation after Stroke.

PubMed

Zhang, Xue; Yue, Zan; Wang, Jing

2017-01-01

With the increase in the elderly, stroke has become a common disease, often leading to motor dysfunction and even permanent disability. Lower-limb rehabilitation robots can help patients to carry out reasonable and effective training to improve the motor function of paralyzed extremity. In this paper, the developments of lower-limb rehabilitation robots in the past decades are reviewed. Specifically, we provide a classification, a comparison, and a design overview of the driving modes, training paradigm, and control strategy of the lower-limb rehabilitation robots in the reviewed literature. A brief review on the gait detection technology of lower-limb rehabilitation robots is also presented. Finally, we discuss the future directions of the lower-limb rehabilitation robots.

Observations of the 10-micron natural laser emission from the mesospheres of Mars and Venus

NASA Technical Reports Server (NTRS)

Espenak, F.; Deming, D.; Jennings, D.; Kostiuk, T.; Mumma, M.; Zipoy, D.

1983-01-01

Observations of the total flux and center to limb dependence of the nonthermal emission occurring in the cores of the 9.4 and 10.4 micrometers CO2 bands on Mars are compared to a theoretical model based on this mechanism. The model successfully reproduces the observed center to limb dependence of this emission, to within the limits imposed by the spatial resolution of the observations of Mars and Venus. The observed flux from Mars agrees closely with the prediction of the model; the flux observed from Venus is 74 percent of the flux predicted by the model. This emission is used to obtain the kinetic temperatures of the Martian and Venusian mesospheres. For Mars near 70 km altitude, a rotational temperature analysis using five lines gives T = 135 + or - 20 K. The frequency width of the emission is also analyzed to derive a temperature of 126 + or - 6 K. In the case of the Venusian mesosphere near 109 km, the frequency width of the emission gives T = 204 + or - 10 K.

Observations of the 10 micrometer natural laser emission from the mesospheres of Mars and Venus

NASA Technical Reports Server (NTRS)

Deming, D.; Espenak, F.; Jennings, D.; Kostiuk, T.; Mumma, M. J.

1983-01-01

Observations of the total flux and center to limb dependence of the nonthermal emission occurring in the cores of the 9.4 and 10.4 micrometers CO2 bands on Mars are compared to a theoretical model based on this mechanism. The model successfully reproduces the observed center to limb dependence of this emission, to within the limits imposed by the spatial resolution of the observations of Mars and Venus. The observed flux from Mars agrees closely with the prediction of the model; the flux observed from Venus is 74% of the flux predicted by the model. This emission is used to obtain the kinetic temperatures of the Martian and Venusian mesospheres. For Mars near 70 km altitude, a rotational temperature analysis using five lines gives T = 135 + or - 20 K. The frequency width of the emission is also analyzed to derive a temperature of 126 + or - 6 K. In the case of the Venusian mesosphere near 109 km, the frequency width of the emission gives T = 204 + or - 10 K.

Roux limb volvulus in laparoscopic Roux-en-Y gastric bypass due to Roux limb stabilization suture: case series.

PubMed

Marr, Brendan; Yenumula, Panduranga

2012-01-01

Complications after laparoscopic Roux-en-Y gastric bypass surgery may be related to the type of surgical technique employed. One technique, the placement of a Roux limb stabilization suture, presumably prevents kink at the gastrojejunal anastomosis. However, it can have an adverse effect and we studied a series of cases presenting with intestinal obstruction secondary to this stitch. A retrospective review of a prospectively collected database of laparoscopic Roux-en-Y gastric bypass cases who had reoperations for Roux limb volvulus was performed at a single bariatric center by a single surgeon. Out of 199 patients who underwent laparoscopic Roux en Y gastric bypass with placement of Roux limb stabilization suture, 4 patients (2.01%) presented with Roux limb volvulus postoperatively. BMI was 45.35 ± 2.95. The postoperative time to presentation was 11 ± 10.6 months. All four patients required surgical exploration to reduce the volvulus. In all cases, the Roux limb volvulus was directly attributable to the presence of the stabilization suture. In subsequent 250 cases where this suture was eliminated, there was no volvulus of Roux limb seen. The use of a stabilization suture can result in volvulus of the Roux limb causing intestinal obstruction and this complication can be prevented by avoiding this suture.

Cryopreservation and replantation of amputated rat hind limbs

PubMed Central

2014-01-01

Background In spite of the relatively high success rate of limb replantation, many patients cannot undergo replantation surgery because the preservation time of an amputated limb is only about six hours. In addition, although allotransplantation of composite tissues is being performed more commonly with increasingly greater success rates, the shortage of donors limits the number of patients that can be treated. So the purpose of this study is to examine the feasibility of cryopreservation and replantation of limbs in a rat model. Methods Twelve five-month-old Sprague-Dawley rats were divided evenly into group A (above-knee amputation) and group B (Syme’s amputation). One hind limb was amputated from each rat. The limbs were irrigated with cryoprotectant, cooled in a controlled manner to -140°C, and placed in liquid nitrogen. Thawing and replantation were performed 14 days later. Results In group A, the limbs became swollen after restoration of blood flow resulting in blood vessel compression and all replantations failed. In group B, restoration of blood flow was noted in all limbs after replantation. In one case, the rat chewed the replanted limb and replantation failed. The other five rats were followed for three months with no abnormalities noted in the replanted limbs. Conclusions Limbs with a minimal amount of muscle tissue can be successfully cryopreserved and replanted. PMID:24886622

SOHO/CDS Measurements of Coronal EUV Polarization above the Limb

NASA Technical Reports Server (NTRS)

Thomas, Roger J.

2002-01-01

Attempts to measure polarization in coronal extreme ultraviolet (EUV) emission above the solar limb have been made using the SOHO/CDS normal-incidence spectrometer which has a polarization sensitivity of about 50%, a property that causes variations in intensity response as a function of the spacecraft's roll angle for polarized light. Such observations were made on the disk and up to 0.22 solar radii above the solar limb in a number of EUV lines during two special roll-maneuvers of the SOHO spacecraft. Measurements of intensity gradients were made above a modestly active equatorial region in 1997 and above a relatively cool polar region in 2001. Observed emission lines include He I 584 A, He II 304 A, O IV 555+610 A, O V 630 A, Mg IX 368 A, Mg X 610+625 A, and Si XI 303 A, formed at temperatures that evenly cover the range in log T from 4.1 to 6.2. Near the disk, measured intensities of all lines fall off exponentially at different rates that can be used to determine the density scale-heights of the emitting plasma, since this emission is dominated by collisional excitation with an Ne-squared dependence. Assuming hydrostatic equilibrium, the intensity gradient for each line can then be converted into a 'scale-height temperature', which is found to be closely related to the ionization temperature of each line over the wide range of lines and solar conditions observed. Thus the large-scale corona is remarkably uniform, even though clearly displaying a great deal of structure and non-uniformity on smaller spatial scales. Beyond a certain distance, intensity gradients of the cooler lines switch over to a flatter exponential slope, suggesting that this radiation is dominated by resonance scattering which varies as Ne to the first power. Such radiation should also be linearly polarized in the plane containing the line-of-sight and the solar center, a signature that would strongly confirm this interpretation.

Limb-Enhancer Genie: An accessible resource of accurate enhancer predictions in the developing limb

DOE PAGES

Monti, Remo; Barozzi, Iros; Osterwalder, Marco; ...

2017-08-21

Epigenomic mapping of enhancer-associated chromatin modifications facilitates the genome-wide discovery of tissue-specific enhancers in vivo. However, reliance on single chromatin marks leads to high rates of false-positive predictions. More sophisticated, integrative methods have been described, but commonly suffer from limited accessibility to the resulting predictions and reduced biological interpretability. Here we present the Limb-Enhancer Genie (LEG), a collection of highly accurate, genome-wide predictions of enhancers in the developing limb, available through a user-friendly online interface. We predict limb enhancers using a combination of > 50 published limb-specific datasets and clusters of evolutionarily conserved transcription factor binding sites, taking advantage ofmore » the patterns observed at previously in vivo validated elements. By combining different statistical models, our approach outperforms current state-of-the-art methods and provides interpretable measures of feature importance. Our results indicate that including a previously unappreciated score that quantifies tissue-specific nuclease accessibility significantly improves prediction performance. We demonstrate the utility of our approach through in vivo validation of newly predicted elements. Moreover, we describe general features that can guide the type of datasets to include when predicting tissue-specific enhancers genome-wide, while providing an accessible resource to the general biological community and facilitating the functional interpretation of genetic studies of limb malformations.« less

Shared Enhancer Activity in the Limbs and Phallus and Functional Divergence of a Limb-Genital cis-Regulatory Element in Snakes.

PubMed

Infante, Carlos R; Mihala, Alexandra G; Park, Sungdae; Wang, Jialiang S; Johnson, Kenji K; Lauderdale, James D; Menke, Douglas B

2015-10-12

The amniote phallus and limbs differ dramatically in their morphologies but share patterns of signaling and gene expression in early development. Thus far, the extent to which genital and limb transcriptional networks also share cis-regulatory elements has remained unexplored. We show that many limb enhancers are retained in snake genomes, suggesting that these elements may function in non-limb tissues. Consistent with this, our analysis of cis-regulatory activity in mice and Anolis lizards reveals that patterns of enhancer activity in embryonic limbs and genitalia overlap heavily. In mice, deletion of HLEB, an enhancer of Tbx4, produces defects in hindlimbs and genitalia, establishing the importance of this limb-genital enhancer for development of these different appendages. Further analyses demonstrate that the HLEB of snakes has lost hindlimb enhancer function while retaining genital activity. Our findings identify roles for Tbx4 in genital development and highlight deep similarities in cis-regulatory activity between limbs and genitalia. Copyright © 2015 Elsevier Inc. All rights reserved.

Rare Earth Optical Temperature Sensor

NASA Technical Reports Server (NTRS)

Chubb, Donald L. (Inventor); Jenkins, Phillip (Inventor)

2004-01-01

A rare earth optical temperature sensor is disclosed for measuring high temperatures. Optical temperature sensors exist that channel emissions from a sensor to a detector using a light pipe. The invention uses a rare earth emitter to transform the sensed thermal energy into a narrow band width optical signal that travels to a detector using a light pipe. An optical bandpass filter at the detector removes any noise signal outside of the band width of the signal from the emitter.

Second-Generation Six-Limbed Experimental Robot

NASA Technical Reports Server (NTRS)

Kennedy, Brett; Okon, Avi; Aghazarian, Hrand; Robinson, Matthew; Garrett, Michael; Magnone, Lee

2004-01-01

The figure shows the LEMUR II - the second generation of the Limbed Excursion Mechanical Utility Robot (LEMUR), which was described in "Six-Legged Experimental Robot" (NPO-20897), NASA Tech Briefs, Vol. 25, No. 12 (December 2001), page 58. The LEMUR II incorporates a number of improvements, including new features, that extend its capabilities beyond those of its predecessor, which is now denoted the LEMUR I. To recapitulate: the LEMUR I was a six-limbed robot for demonstrating robotic capabilities for assembly, maintenance, and inspection. The LEMUR I was designed to be capable of walking autonomously along a truss structure toward a mechanical assembly at a prescribed location and to perform other operations. The LEMUR I was equipped with stereoscopic video cameras and image-data-processing circuitry for navigation and mechanical operations. It was also equipped with a wireless modem, through which it could be commanded remotely. Upon arrival at a mechanical assembly, the LEMUR I would perform simple mechanical operations with one or both of its front limbs. It could also transmit images to a host computer. Each of the six limbs of the LEMUR I was operated independently. Each of the four rear limbs had three degrees of freedom (DOFs), while each of the front two limbs had four DOFs. The front two limbs were designed to hold, operate, and/or be integrated with tools. The LEMUR I included an onboard computer equipped with an assortment of digital control circuits, digital input/output circuits, analog-to-digital converters for input, and digital-to-analog (D/A) converters for output. Feedback from optical encoders in the limb actuators was utilized for closed-loop microcomputer control of the positions and velocities of the actuators. The LEMUR II incorporates the following improvements over the LEMUR I: a) The drive trains for the joints of the LEMUR II are more sophisticated, providing greater torque and accuracy. b) The six limbs are arranged symmetrically about

The axolotl limb blastema: cellular and molecular mechanisms driving blastema formation and limb regeneration in tetrapods

PubMed Central

McCusker, Catherine; Bryant, Susan V.

2015-01-01

Abstract The axolotl is one of the few tetrapods that are capable of regenerating complicated biological structures, such as complete limbs, throughout adulthood. Upon injury the axolotl generates a population of regeneration‐competent limb progenitor cells known as the blastema, which will grow, establish pattern, and differentiate into the missing limb structures. In this review we focus on the crucial early events that occur during wound healing, the neural−epithelial interactions that drive the formation of the early blastema, and how these mechanisms differ from those of other species that have restricted regenerative potential, such as humans. We also discuss how the presence of cells from the different axes of the limb is required for the continued growth and establishment of pattern in the blastema as described in the polar coordinate model, and how this positional information is reprogrammed in blastema cells during regeneration. Multiple cell types from the mature limb stump contribute to the blastema at different stages of regeneration, and we discuss the contribution of these types to the regenerate with reference to whether they are “pattern‐forming” or “pattern‐following” cells. Lastly, we explain how an engineering approach will help resolve unanswered questions in limb regeneration, with the goal of translating these concepts to developing better human regenerative therapies. PMID:27499868

Effect of Upper Limb Deformities on Gross Motor and Upper Limb Functions in Children with Spastic Cerebral Palsy

ERIC Educational Resources Information Center

Park, Eun Sook; Sim, Eun Geol; Rha, Dong-wook

2011-01-01

The aims of this study were to investigate the nature and extent of upper limb deformities via the use of various classifications, and to analyze the relationship between upper limb deformities and gross motor or upper limb functionality levels. Upper extremity data were collected from 234 children with spastic cerebral palsy (CP) who were…

Limb Preservation With Isolated Limb Infusion for Locally Advanced Nonmelanoma Cutaneous and Soft-Tissue Malignant Neoplasms

PubMed Central

Turaga, Kiran K.; Beasley, Georgia M.; Kane, John M.; Delman, Keith A.; Grobmyer, Stephen R.; Gonzalez, Ricardo J.; Letson, G. Douglas; Cheong, David; Tyler, Douglas S.; Zager, Jonathan S.

2015-01-01

Objective To demonstrate the efficacy of isolated limb infusion (ILI) in limb preservation for patients with locally advanced soft-tissue sarcomas and nonmelanoma cutaneous malignant neoplasms. Background Locally advanced nonmelanoma cutaneous and soft-tissue malignant neoplasms, including soft-tissue sarcomas of the extremities, can pose significant treatment challenges. We report our experience, including responses and limb preservation rates, using ILI in cutaneous and soft-tissue malignant neoplasms. Methods We identified 22 patients with cutaneous and soft-tissue malignant neoplasms who underwent 26 ILIs with melphalan and actinomycin from January 1, 2004, through December 31, 2009, from 5 institutions. Outcome measures included limb preservation and in-field response rates. Toxicity was measured using the Wieberdink scale and serum creatinine phosphokinase levels. Results The median age was 70 years (range, 19-92 years), and 12 patients (55%) were women. Fourteen patients (64%) had sarcomas, 7 (32%) had Merkel cell carcinoma, and 1 (5%) had squamous cell carcinoma. The median length of stay was 5.5 days (interquartile range, 4-8 days). Twenty-five of the 26 ILIs (96%) resulted in Wieberdink grade III or less toxicity, and 1 patient (4%) developed grade IV toxicity. The median serum creatinine phosphokinase level was 127 U/L for upper extremity ILIs and 93 U/L for lower extremity ILIs. Nineteen of 22 patients (86%) underwent successful limb preservation. The 3-month in-field response rate was 79% (21% complete and 58% partial), and the median follow-up was 8.6 months (range, 1-63 months). Five patients underwent resection of disease after an ILI, of whom 80% are disease free at a median of 8.6 months. Conclusions Isolated limb infusion provides an attractive alternative therapy for regional disease control and limb preservation in patients with limb-threatening cutaneous and soft-tissue malignant neoplasms. Short-term response rates appear encouraging, yet

Chandra X-ray Observations of Jovian Low-latitude Emissions: Morphological, Temporal, and Spectral Characteristics

NASA Technical Reports Server (NTRS)

Bhardwaj, Anil; Elsner, Ronald F.; Gladstone, G. Randall; Cravens, Thomas E.; Waiate J. Hunter, Jr.; Branduardi-Raymont, Graziella; Ford, Peter

2004-01-01

Chandra observed X-rays from Jupiter during 24-26 February 2003 for about 40 hours with the ACIS-S and HRC-I instruments. The analysis of Jovian low-latitude "disk" Xray emissions are presented and compared with the high-latitude "auroral" emissions. We report the first Chandra ACIS-S measured X-ray spectrum (0.3-2 keV) of Jupiter's low-latitude disk The disk X-ray emission is harder and extends to higher energies than the auroral spectrum. The temporal variation in the Jovian disk X-rays is on an average consistent with those in the solar X-rays observed by GOES, and TIMED/SSE. Contrary to the auroral X-rays, the disk emissions are uniformly distributed over Jupiter; no indication of longitudinal dependence or correlation with surface magneh field strength is visible. Also, unlike the approx. 40 +/- 20 min periodic oscillations seen in the auroral X-ray emissions, the disk emissions do not show any periodic oscillations. The disk spectrum seems to be consistent with resonant and fluorescent scattering of solar X-rays by the Jovian upper atmosphere. Jupiter's disk is found to be about 50% dimmer in soft X-rays in February 2003 compared that in December 2000, which is consistent with the decrease in solar activity. No evidence of lightning-induced X-rays is seen in the Chandra X-ray data. The Jovian disk spectra observed with Chandra-ACIS is stronger than that observed with XMM-Newton two months later during April 28-29, 2003. The XMM-Newton Xray image of Jupiter shows evidence of limb darkening on the anti-sunward side as seen from Earth, as well as an asymmetry with respect to the subsolar point: suggesting a solar driven process.

Using MERRA-2 analysis fields to simulate limb scattered radiance profiles for inhomogeneous atmospheric lines of sight: Preparation for data assimilation of OMPS LP radiances through 2D single-scattering GSLS radiative transfer model development

NASA Astrophysics Data System (ADS)

Loughman, R. P.; Bhartia, P. K.; Moy, L.; Kramarova, N. A.; Wargan, K.

2016-12-01

Many remote sensing techniques used to monitor the Earth's upper atmosphere fall into the broad category of "limb viewing" (LV) measurements, which includes any method for which the line of sight (LOS) fails to intersect the surface. Occultation, limb emission and limb scattering (LS) measurements are all LV methods that offer strong sensitivity to changes in the atmosphere near the tangent point of the LOS, due to the enhanced geometric path through the tangent layer (where the concentration also typically peaks, for most atmospheric species). But many of the retrieval algorithms used to interpret LV measurements assume that the atmosphere consists of "spherical shells", in which the atmospheric properties vary only with altitude (creating a 1D atmosphere). This assumption simplifies the analysis, but at the possible price of misinterpreting measurements made in the real atmosphere. In this presentation, we focus on the problem of LOS inhomogeneity for LS measurements made by the OMPS Limb Profiler (LP) instrument during the 2015 ozone hole period. The GSLS radiative transfer model (RTM) used in the default OMPS LP algorithms assumes a spherical-shell atmosphere defined at levels spaced 1 km apart, with extinction coefficients assumed to vary linearly with height between levels. Several recent improvements enable an updated single-scattering version of the GSLS RTM to ingest 3D MERRA-2 analysis fields (including temperature, pressure, and ozone concentration) when creating the model atmosphere, by introducing flexible altitude grids, flexible atmospheric specification along the LOS, and improved treatment of the radiative transfer within each atmospheric layer. As a result, the effect of LOS inhomogeneity on the current (1D) OMPS LP retrieval algorithm can now be studied theoretically, using realistic 3D atmospheric profiles. This work also represents a step towards enabling OMPS LP data to be ingested as part of future data assimilation efforts.

Isolated primary lymphedema tarda of the upper limb.

PubMed

Shariati, Farzaneh; Ravari, Hasan; Kazemzadeh, Gholamhossein; Sadeghi, Ramin

2013-03-01

Primary lymphedema tarda is considered as a congenital disease with late presentation. Primary lymphedema tarda usually affects lower limbs, and primary lymphedema tarda of the upper limbs usually accompanies lower limb lymphedema. In the current case report, we present an 80-year-old male patient with isolated left upper limb swelling that lymphoscintigraphy imaging proved to be lymphedema.

Society for Vascular Surgery Wound, Ischemia, foot Infection (WIfI) score correlates with the intensity of multimodal limb treatment and patient-centered outcomes in patients with threatened limbs managed in a limb preservation center.

PubMed

Robinson, William P; Loretz, Lorraine; Hanesian, Colleen; Flahive, Julie; Bostrom, John; Lunig, Nicholas; Schanzer, Andres; Messina, Louis

2017-08-01

The Society for Vascular Surgery Wound, Ischemia, foot Infection (WIfI) system aims to stratify threatened limbs according to their anticipated natural history and estimate the likelihood of benefit from revascularization, but whether it accurately stratifies outcomes in limbs undergoing aggressive treatment for limb salvage is unknown. We investigated whether the WIfI stage correlated with the intensity of limb treatment required and patient-centered outcomes. We stratified limbs from a prospectively maintained database of consecutive patients referred to a limb preservation center according to WIfI stage (October 2013-May 2015). Comorbidities, multimodal limb treatment, including foot operations and revascularization, and patient-centered outcomes (wound healing, limb salvage, amputation-free survival, maintenance of ambulatory and independent living status, and mortality) were compared among WIfI stages. Multivariate analysis was performed to identify predictors of wound healing and limb salvage. We identified 280 threatened limbs encompassing all WIfI stages in 257 consecutive patients: stage 1, 48 (17%); stage 2, 67 (24%); stage 3, 64 (23%); stage 4, 83 (30%); and stage 5 (unsalvageable), 18 (6%). Operative foot débridement, minor amputation, and use of revascularization increased with increasing WIfI stage (P ≤ .04). Revascularization was performed in 106 limbs (39%), with equal use of open and endovascular procedures. Over a median follow-up of 209 days (interquartile range, 95, 340) days, 1-year Kaplan-Meier wound healing cumulative incidence was 71%, and the proportion with complete wound healing decreased with increasing WIfI stage. Major amputation was required in 26 stage 1 to 4 limbs (10%). Increasing WIfI stage was associated with decreased 1-year Kaplan-Meier limb salvage (stage 1: 96%, stage 2: 84%, stage 3: 90%, and stage 4: 78%; P = .003) and amputation-free survival (P = .006). Stage 4 WIfI independently predicted amputation (hazard ratio

Long-term outcome of dogs treated with ulnar rollover transposition for limb-sparing of distal radial osteosarcoma: 27 limbs in 26 dogs.

PubMed

Séguin, Bernard; O'Donnell, Matthew D; Walsh, Peter J; Selmic, Laura E

2017-10-01

To determine outcomes in dogs with distal radial osteosarcoma treated with ulnar rollover transposition (URT) limb-sparing surgery including: viability of the ulnar graft, complications, subjective limb function, disease-free interval (DFI), and survival time (ST). Retrospective case series. Twenty-six client-owned dogs with distal radial osteosarcoma and no involvement of the ulna. Data of dogs treated with URT were collected at the time of surgery and retrospectively from medical records and by contacting owners and referring veterinarians. URT technique was performed on 27 limbs in 26 dogs. The ulnar graft was determined to be viable in 17 limbs, nonviable in 3, and unknown in 7. Complications occurred in 20 limbs. Infection was diagnosed in 12 limbs. Biomechanical complications occurred in 15 and local recurrence in 2 limbs. Limb function graded by veterinarians or owners was poor in 2 limbs, fair in 4, good in 14, excellent in 3, and unknown in 4. Median DFI was 245 days and median ST was 277 days. The URT technique maintained the viability of the ulnar graft. The complication rate was high but limb function appeared acceptable. Although sufficient length of the distal aspect of the ulna must be preserved to perform this technique, local recurrence was not increased compared to other limb-sparing techniques when cases were appropriately selected. © 2017 The American College of Veterinary Surgeons.

Mechanisms of urodele limb regeneration

PubMed Central

2017-01-01

Abstract This review explores the historical and current state of our knowledge about urodele limb regeneration. Topics discussed are (1) blastema formation by the proteolytic histolysis of limb tissues to release resident stem cells and mononucleate cells that undergo dedifferentiation, cell cycle entry and accumulation under the apical epidermal cap. (2) The origin, phenotypic memory, and positional memory of blastema cells. (3) The role played by macrophages in the early events of regeneration. (4) The role of neural and AEC factors and interaction between blastema cells in mitosis and distalization. (5) Models of pattern formation based on the results of axial reversal experiments, experiments on the regeneration of half and double half limbs, and experiments using retinoic acid to alter positional identity of blastema cells. (6) Possible mechanisms of distalization during normal and intercalary regeneration. (7) Is pattern formation is a self‐organizing property of the blastema or dictated by chemical signals from adjacent tissues? (8) What is the future for regenerating a human limb? PMID:29299322

GRACILE: a comprehensive climatology of atmospheric gravity wave parameters based on satellite limb soundings

NASA Astrophysics Data System (ADS)

Ern, Manfred; Trinh, Quang Thai; Preusse, Peter; Gille, John C.; Mlynczak, Martin G.; Russell, James M., III; Riese, Martin

2018-04-01

Gravity waves are one of the main drivers of atmospheric dynamics. The spatial resolution of most global atmospheric models, however, is too coarse to properly resolve the small scales of gravity waves, which range from tens to a few thousand kilometers horizontally, and from below 1 km to tens of kilometers vertically. Gravity wave source processes involve even smaller scales. Therefore, general circulation models (GCMs) and chemistry climate models (CCMs) usually parametrize the effect of gravity waves on the global circulation. These parametrizations are very simplified. For this reason, comparisons with global observations of gravity waves are needed for an improvement of parametrizations and an alleviation of model biases. We present a gravity wave climatology based on atmospheric infrared limb emissions observed by satellite (GRACILE). GRACILE is a global data set of gravity wave distributions observed in the stratosphere and the mesosphere by the infrared limb sounding satellite instruments High Resolution Dynamics Limb Sounder (HIRDLS) and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER). Typical distributions (zonal averages and global maps) of gravity wave vertical wavelengths and along-track horizontal wavenumbers are provided, as well as gravity wave temperature variances, potential energies and absolute momentum fluxes. This global data set captures the typical seasonal variations of these parameters, as well as their spatial variations. The GRACILE data set is suitable for scientific studies, and it can serve for comparison with other instruments (ground-based, airborne, or other satellite instruments) and for comparison with gravity wave distributions, both resolved and parametrized, in GCMs and CCMs. The GRACILE data set is available as supplementary data at https://doi.org/10.1594/PANGAEA.879658.

The relationship between buccofacial and limb apraxia.

PubMed

Raade, A S; Rothi, L J; Heilman, K M

1991-07-01

There are at least two possible models depicting the relationship between buccofacial and limb apraxia. First, apraxia can be viewed as a unitary motor disorder which transcends the output modalities of both buccofacial and limb output. A high degree of similarity between the two types of apraxia would support this model. Alternatively, the relationship between buccofacial and limb apraxia may not include a unitary mechanism. The presence of quantitative and qualitative differences between buccofacial and limb performance would support this nonunitary model. The results of the present study support the nonunitary model.

Power line emission 50/60 Hz and Schumann resonances observed by microsatellite Chibis-M in the Earth's ionosphere

NASA Astrophysics Data System (ADS)

Dudkin, Denys; Pilipenko, Vyacheslav; Dudkin, Fedir; Pronenko, Vira; Klimov, Stanislav

2015-04-01

The overhead power lines are the sources of intense wideband electromagnetic (EM) emission, especially in ELF-VLF range, because of significant length (up to a few thousand kilometers) and strong 50/60 Hz currents with noticeable distortion. The radiation efficiency of the power line emission (PLE) increases with the harmonic order, so they are well observed by ground-based EM sensors. However their observations by low orbiting satellites (LEO) are very rare, particularly at basic harmonic 50/60 Hz, because of the ionospheric plasma opacity in ELF band. The Schumann resonance (SR) is the narrow-band EM noise that occurs due to the global thunderstorm activity in the Earth-ionosphere cavity. The first five eigenmodes of the SR are 7.8, 14.3, 20.8, 27.3 and 33.8 Hz and, thus, SR harmonics are also strongly absorbed by the Earth ionosphere. The published numerical simulations show that the penetration depth of such an ELF emission into the Earth's ionosphere is limited to 50-70 km for electric field and 120-240 km for magnetic field. From this follows, that PLE and SR can hardly ever be detected by LEO satellites, i.e. above the F-layer of ionosphere. In spite of this fact, these emissions were recently observed with use of the electric field antennas placed on the satellites C/NOFS (USA) and Chibis-M (Russia). Microsatellite Chibis-M was launched on January 24, 2012, at 23:18:30 UTC from the cargo ship "Progress M-13M" to circular orbit with altitude ~500 km and inclination ~52° . Chibis-M mass is about 40 kg where one third is a scientific instrumentation. The dimensions of the microsatellite case are 0.26x0.26x0.54 m with the outside mounted solar panels, service and scientific instrumentation. The main scientific objective of Chibis-M is the theoretical model verification for the atmospheric gamma-ray bursts. It requires the study of the accompanying EM processes such as the plasma waves produced by the lightning discharges in the VLF band. Chibis-M decayed on 15

Earth Observations taken by Expedition 30 crewmember

NASA Image and Video Library

2012-01-30

ISS030-E-060478 (30 Jan. 2012) --- The city lights of Madrid (just right of center) stand out in this photograph from the International Space Station. Recorded by one of the Expedition 30 crew members, the view shows almost the entire Iberian Peninsula (both Spain and Portugal) with the Strait of Gibraltar and Morocco appearing at lower left. What is thought to be a blur of the moon appears in upper left corner. The faint gold or brownish line of airglow?caused by ultraviolet radiation exciting the gas molecules in the upper atmosphere?parallels the horizon or Earth limb.

CRISM Limb Observations of Aerosols and Water Vapor

NASA Technical Reports Server (NTRS)

Smith, Michael D.; Wolff, M.J.; Clancy, R.T.; Seelos, F.; Murchie, S.L.

2009-01-01

Near-infrared spectra taken in a limb-viewing geometry by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on-board the Mars Reconnaissance Orbiter (MRO) provide a useful tool for probing atmospheric structure. Here we describe preliminary work on the retrieval of vertical profiles of aerosols and water vapor from the CRISM limb observations. The first full set of CRISM limb observations was taken in July 2009, with subsequent limb observations planned once every two months. Each set of limb observations contains about four dozen scans across the limb giving pole-to-pole coverage for two orbits at roughly 100 and 290 W longitude. Radiative transfer modeling taking account of aerosol scattering in the limb-viewing geometry is used to model the observations. The retrievals show the height to which dust and water vapor extend and the location and height of water ice clouds. Results from the First set of CRISM limb observations (July 2009, Ls=300) show dust aerosol well-mixed to about three scale heights above the surface with thin water ice clouds above the dust near the equator and at mid-northern latitudes. Water vapor is concentrated at high southern latitudes.

ATHLETE: A Limbed Vehicle for Solar System Exploration

NASA Technical Reports Server (NTRS)

Wilcox, Brian H.

2012-01-01

As part of the Human-Robot Systems project funded by NASA, the Jet Propulsion Laboratory has developed a vehicle called ATHLETE: the All-Terrain Hex-Limbed Extra-Terrestrial Explorer. Each vehicle is based on six wheels at the ends of six multi-degree-of-freedom limbs. Because each limb has enough degrees of freedom for use as a general-purpose leg, the wheels can be locked and used as feet to walk out of excessively soft or other extreme terrain. Since the vehicle has this alternative mode of traversing through or at least out of extreme terrain, the wheels and wheel actuators can be sized for nominal terrain. There are substantial mass savings in the wheel and wheel actuators associated with designing for nominal instead of extreme terrain. These mass savings are comparable-to or larger-than the extra mass associated with the articulated limbs. As a result, the entire mobility system, including wheels and limbs, can be about 25% lighter than a conventional mobility chassis. A side benefit of this approach is that each limb has sufficient degrees-of-freedom to use as a general-purpose manipulator (hence the name "limb" instead of "leg"). Our prototype ATHLETE vehicles have quick-disconnect tool adapters on the limbs that allow tools to be drawn out of a "tool belt" and maneuvered by the limb.

Earth-Atmospheric Coupling Prior to Strong Earthquakes Analyzed by IR Remote Sensing Data

NASA Astrophysics Data System (ADS)

Freund, F.; Ouzounov, D.

2001-12-01

Earth-atmosphere interactions during major earthquakes (M>5) are the subject of this study. A mechanism has recently been proposed to account for the appearance of hole-type electronic charge carriers in rocks subjected to transient stress [Freund, 2000]. If such charge carriers are activated in the crust prior to large earthquakes, the predictable consequences are: injection of currents into the rocks, low frequency electromagnetic emission, changes in ground potentials, corona discharges with attendant light emission from high points at the surface of the Earth, and possibly an enhanced emission in the 8-12 μ m region similar to the thermal emission observed during laboratory rock deformation experiments [Geng et al., 1999]. Using data from MODIS (Moderate Resolution Imaging Spectroradiometer) and ASTER (Advanced Spaceborne Thermal Emission & Reflection radiometer) onboard NASA's TERRA satellite launched in Dec. 1999 we have begun analyzing vertical atmospheric profiles, land surface and kinetic temperatures. We looked for correlations between atmospheric dynamics and solid Earth processes prior to the Jan. 13, 2001 earthquake in El Salvador (M=7.6) and the Jan. 26, 2001 Gujarat earth-quake in India (M=7.7). With MODIS covering the entire Earth every 1-2 days in 36 wavelength bands (20 visible and 16 infrared) at different spatial resolutions (250 m, 500 m, and 1 km) we find evidence for a thermal anomaly pattern related to the pre-seismic activity. We also find evidence for changes in the aerosol content and atmospheric instability parameters, possibly due to changes in the ground potential that cause ion emission and lead to the formation of a thin near-ground aerosol layer. We analyze the aerosol content, atmospheric pressure, moisture profile and lifted index.

Upper limb load as a function of repetitive task parameters: part 1--a model of upper limb load.

PubMed

Roman-Liu, Danuta

2005-01-01

The aim of the study was to develop a theoretical indicator of upper limb musculoskeletal load based on repetitive task parameters. As such the dimensionless parameter, Integrated Cycle Load (ICL) was accepted. It expresses upper limb load which occurs during 1 cycle. The indicator is based on a model of a repetitive task, which consists of a model of the upper limb, a model of basic types of upper limb forces and a model of parameters of a repetitive task such as length of the cycle, length of periods of the cycle and external force exerted during each of the periods of the cycle. Calculations of the ICL parameter were performed for 12 different variants of external load characterised by different values of repetitive task parameters. A comparison of ICL, which expresses external load with a physiological indicator of upper limb load, is presented in Part 2 of the paper.

Observations and Operational Products from the Special Sensor Ultraviolet Limb Imager (SSULI)

NASA Astrophysics Data System (ADS)

Dandenault, Patrick; Nicholas, Andrew C.; Coker, Clayton; Budzien, Scott A.; Chua, Damien H.; Finne, Ted T.; Metzler, Christopher A.; Dymond, Kenneth F.

The Naval Research Laboratory (NRL) has developed five ultraviolet remote sensing instru-ments for the Air Force Defense Meteorological Satellite Program (DMSP). These instruments known as SSULI (Special Sensor Ultraviolet Limb Imager) are on the DMSP block of 5D3 satellites, which first launched in 2003. The DMSP satellites are launched in a near-polar, sun-synchronous orbit at an altitude of approximately 830 km. SSULI measures vertical profiles of the natural airglow radiation from atoms, molecules and ions in the upper atmosphere and ionosphere by viewing the earth's limb at a tangent altitude of approximately 50 km to 750 km. Limb observations are made from the extreme ultraviolet (EUV) to the far ultraviolet (FUV) over the wavelength range of 80 nm to 170 nm, with 1.8 nm resolution. An extensive operational data processing system, the SSULI Ground Data Analysis Software (GDAS), has been developed to generate environmental data products from SSULI spectral data in near-real time for use at the Air Force Weather Agency (AFWA). The operational software uses advanced science algorithms developed at NRL and was designed to calibrate data from USAF Raw Sensor Data Records (RSDR) and generate Environmental Data Records (EDRs). Data products from SSULI observations include vertical profiles of electron (Ne) densities, N2, O2, O, O+, Temperature and also vertical Total Electron Content (TEC). On October 18, 2009, the third SSULI sensor launched from Vandenberg Air Force Base, aboard the DMSP F18 spacecraft. An overview of the SSULI operational program and the status of the F18 sensor will be discussed.

Views of Endeavour's payload bay and an Earth limb taken during STS-99

NASA Image and Video Library

2000-02-12

STS099-703-082 (11-22 February 2000) --- Part of the Space Shuttle Endeavour's aft cargo bay, its vertical stabilizer and orbital maneuvering system (OMS) pods are seen in this 70mm frame. Part of Earth's horizon, with an expanse of heavy cloud cover over land and water, is at bottom of frame.

Development of limb volume measuring system

NASA Technical Reports Server (NTRS)

Bhagat, P. K.; Kadaba, P. K.

1983-01-01

The mechanisms underlying the reductions in orthostatic tolerance associated with weightlessness are not well established. Contradictory results from measurements of leg volume changes suggest that altered venomotor tone and reduced blood flow may not be the only contributors to orthostatic intolerance. It is felt that a more accurate limb volume system which is insensitive to environmental factors will aid in better quantification of the hemodynamics of the leg. Of the varous limb volume techniques presently available, the ultrasonic limb volume system has proven to be the best choice. The system as described herein is free from environmental effects, safe, simple to operate and causes negligible radio frequency interference problems. The segmental ultrasonic ultrasonic plethysmograph is expected to provide a better measurement of limb volume change since it is based on cross-sectional area measurements.

[Mirror, mirror of the wall: mirror therapy in the treatment of phantom limbs and phantom limb pain].

PubMed

Casale, Roberto; Furnari, Anna; Lamberti, Raul Coelho; Kouloulas, Efthimios; Hagenberg, Annegret; Mallik, Maryam

2015-01-01

Phantom limb and phantom limb pain control are pivotal points in the sequence of intervention to bring the amputee to functional autonomy. The alterations of perception and sensation, the pain of the residual limb and the phantom limb are therefore aspects of amputation that should be taken into account in the "prise en charge" of these patients. Within the more advanced physical therapies to control phantom and phantom limb pain there is the use of mirrors (mirror therapy). This article willfocus on its use and on the possible side effects induced by the lack of patient selection and a conflict of body schema restoration through mirror therapy with concurrent prosthetic training and trauma acceptance. Advice on the need to select patients before treatment decisions, with regard to their psychological as well as clinical profile (including time since amputation and clinical setting), and the need to be aware of the possible adverse effects matching different and somehow conflicting therapeutic approaches, are put forward. Thus a coordinated sequence of diagnostic, prognostic and therapeutic procedures carried out by an interdisciplinary rehabilitation team that works globally on all patients' problems is fundamental in the management of amputees and phantom limb pain. Further studies and the development of a multidisciplinary network to study this and other applications of mirror therapy are needed.

Reflexology treatment for patients with lower limb amputations and phantom limb pain--an exploratory pilot study.

PubMed

Brown, Christine Ann; Lido, Catherine

2008-05-01

The objectives of the study were to evaluate the possibility of reflexology being used as a non-invasive form of phantom limb pain relief and of empowering patients to maintain any positive results with self-treatment. Prosthetic Services Centre, Herbert Street, Wolverhampton, West Midlands, England. A same-subject, experimental pilot study, recording the intensity of phantom limb pain in weekly pain diaries over a 30-week period, which was divided into five phases: phase 1 gave a baseline of pain, whilst phase 3 was a resting phase. Phases 2, 4 and 5 provided the reflexology interventions. Ten participants with unilateral lower limb amputations and phantom limb pain were selected from the database at the Prosthetic Centre. REFLEXOLOGY INTERVENTIONS: In phase 2, six weekly reflexology treatments were given, which consisted of: full foot reflexology to the remaining foot and full hand reflexology to the hand of the amputated side of the body. In phase 4, six weekly hand reflexology teaching sessions were carried out; patients copied on their own hands what the therapist did on hers. A hand reflexology booklet gave the sequence of the treatment and was used as a reference. In phase 5, the patients self-treated for 6 weeks at home, using the reference material. Over the 30-week period, there was an improvement in the perception of the presence and the intensity of the phantom limb pain, with a corresponding improvement in the duration of the pain and the affect on the person's lifestyle. The improvement was maintained when the clients self-treated. FOLLOW-UP QUESTIONNAIRE: A follow-up questionnaire was carried out in 2007--12 months after the project had ended--to elicit whether the patients had suffered from phantom pain over the previous 12 months, whether they still had relief from phantom limb pain and whether they still self-treated. The project indicated that reflexology treatment, teaching and self-treatment were effective in eradicating or reducing the

Progressive upper limb prosthetics.

PubMed

Lake, Chris; Dodson, Robert

2006-02-01

The field of upper extremity prosthetics is a constantly changing arena as researchers and prosthetists strive to bridge the gap between prosthetic reality and upper limb physiology. With the further development of implantable neurologic sensing devices and targeted muscle innervation (discussed elsewhere in this issue), the challenge of limited input to control vast outputs promises to become a historical footnote in the future annals of upper limb prosthetics. Soon multidextrous terminal devices, such as that found in the iLimb system(Touch EMAS, Inc., Edinburgh, UK), will be a clinical reality (Fig. 22). Successful prosthetic care depends on good communication and cooperation among the surgeon, the amputee, the rehabilitation team, and the scientists harnessing the power of technology to solve real-life challenges. If the progress to date is any indication, amputees of the future will find their dreams limited only by their imagination.

[Psychotherapies for the Treatment of Phantom Limb Pain].

PubMed

Cárdenas, Katherine; Aranda, Mariana

The phantom limb pain has been described as a condition in which patients experience a feeling of itching, spasm or pain in a limb or body part that has been previously amputated. Such pain can be induced by a conflict between the representation of the visual and proprioceptive feedback of the previously healthy limb. The phantom limb pain occurs in at least 42 to 90% of amputees. Regular drug treatment of phantom limb pain is almost never effective. A systematic review of the literature was conducted in Medline and Cochrane using the MESH terms "phantom limb pain" and "psychotherapy", published in the last 10 years, in English and Spanish, finding 49 items. After reviewing the abstracts, 25 articles were excluded for not being related to the objective of the research. Additionally cross references of included articles and literature were reviewed. To describe the psychotherapies used in the management of phantom limb pain, their effectiveness and clinical application reported in the literature. The mechanisms underlying phantom limb pain were initially explained, as were the published studies on the usefulness of some psychotherapies such as mirror visual feedback and immersive virtual reality, visual imagery, desensitization and reprocessing eye movements and hypnosis. The phantom limb pain is a complex syndrome that requires pharmacological and psychotherapeutic intervention. The psychotherapies that have been used the most as adjuvants in the treatment of phantom limb pain are mirror visual feedback, desensitization and reprocessing eye movements, imagery and hypnosis. Studies with more representative samples, specifically randomized trials are required. Copyright © 2016 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Agency over Phantom Limb Enhanced by Short-Term Mirror Therapy.

PubMed

Imaizumi, Shu; Asai, Tomohisa; Koyama, Shinichi

2017-01-01

Most amputees experience phantom limb, whereby they feel that the amputated limb is still present. In some cases, these experiences include pain that can be alleviated by "mirror therapy." Mirror therapy consists of superimposing a mirrored image of the moving intact limb onto the phantom limb. This therapy provides a closed loop between the motor command to the amputated limb and its predicted visual feedback. This loop is also involved in the sense of agency, a feeling of controlling one's own body. However, it is unclear how mirror therapy is related to the sense of agency over a phantom limb. Using mirror therapy, we investigated phantom limb pain and the senses of agency and ownership (i.e., a feeling of having one's own body) of the phantom limb. Nine upper-limb amputees, five of whom reported recent phantom limb pain, underwent a single 15-min trial of mirror therapy. Before and after the trial, the participants completed a questionnaire regarding agency, ownership, and pain related to their phantom limb. They reported that the sense of agency over the phantom limb increased following the mirror therapy trial, while the ownership slightly increased but not as much as did the agency. The reported pain did not change; that is, it was comparably mild before and after the trial. These results suggest that short-term mirror therapy can, at least transiently, selectively enhance the sense of agency over a phantom limb, but may not alleviate phantom limb pain.

49 CFR 572.20 - Limbs.

Code of Federal Regulations, 2010 CFR

2010-10-01

... OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 3-Year-Old Child § 572.20 Limbs. The limbs consist of the assemblies shown on drawing SA 103C 001 as Nos. SA 103C 041, SA 103C 042, SA 103C 051, SA... each of the applicable drawings listed under their respective numbers of the drawing SA 103C 002...

Limb Loss

MedlinePlus

... in amputation. Injuries, including from traffic accidents and military combat Cancer Birth defects Some amputees have phantom pain, which is the feeling of pain in the missing limb. Other physical problems include surgical complications and skin problems, if you ...

Data-driven Simulations of Magnetic Connectivity in Behind-the-Limb Gamma-ray Flares and Associated Coronal Mass Ejections

NASA Astrophysics Data System (ADS)

Jin, M.; Petrosian, V.; Liu, W.; Nitta, N.; Omodei, N.; Rubio da Costa, F.; Effenberger, F.; Li, G.; Pesce-Rollins, M.

2017-12-01

Recent Fermi detection of high-energy gamma-ray emission from the behind-the-limb (BTL) solar flares pose a puzzle on the particle acceleration and transport mechanisms in such events. Due to the large separation between the flare site and the location of gamma-ray emission, it is believed that the associated coronal mass ejections (CMEs) play an important role in accelerating and subsequently transporting particles back to the Sun to produce obseved gamma-rays. We explore this scenario by simulating the CME associated with a well-observed flare on 2014 September 1 about 40 degrees behind the east solar limb and by comparing the simulation and observational results. We utilize a data-driven global magnetohydrodynamics model (AWSoM: Alfven-wave Solar Model) to track the dynamical evolution of the global magnetic field during the event and investigate the magnetic connectivity between the CME/CME-driven shock and the Fermi emission region. Moreover, we derive the time-varying shock parameters (e.g., compression ratio, Alfven Mach number, and ThetaBN) over the area that is magnetically connected to the visible solar disk where Fermi gamma-ray emission originates. Our simulation shows that the visible solar disk develops connections both to the flare site and to the CME-driven shock during the eruption, which indicate that the CME's interaction with the global solar corona is critical for understanding such Fermi BTL events and gamma-ray flares in general. We discuss the causes and implications of Fermi BTL events, in the framework of a potential shift of paradigm on particle acceleration in solar flares/CMEs.

Observations of Ultraviolet Emission from Mg+ in the Lower and Middle Thermosphere

NASA Astrophysics Data System (ADS)

Minschwaner, K.; Shukla, N.; Fortna, C.; Budzien, S.; Dymond, K.; McCoy, R.

2004-12-01

New observations of ionized magnesium dayglow are reported from the Ionospheric Spectroscopy and Atmospheric Chemistry (ISAAC) instrument on the ARGOS satellite. We focused on two periods, October 14-28 1999 and November 15-30 1999, when ISAAC obtained high quality limb spectra between 2600 and 3000 Å and from 85 to 350 km tangent altitude. In addition to the resonant scattering by Mg+ near 2800 Å, these limb spectra also contain signatures of fluorescent scattering by nitric oxide in the gamma bands, emission by molecular nitrogen in the Vergard-Kaplan bands, and atomic emission by oxygen in the 2972 Å line. A retrieval algorithm has been developed to measure the abundance of nitric oxide using the intensity of fluorescent scattering in the γ (1,5) band at 2670 Å. This technique then allows for separating the overlapping emission by nitric oxide in the γ (1,6) band from the Mg+ doublet at 2800 Å. Retrieved Mg+ column densities have been mapped as a function of altitude and geomagnetic latitude.

Clouds above the Martin Limb: Viking observations

NASA Technical Reports Server (NTRS)

Martin, L. J.; Baum, W. A.; Wasserman, L. H.; Kreidl, T. J.

1984-01-01

Whenever Viking Orbiter images included the limb of Mars, they recorded one or more layers of clouds above the limb. The height above the limb and the brightness (reflectivity) of these clouds were determined in a selected group of these images. Normalized individual brightness profiles of three separate traverses across the limb of each image are shown. The most notable finding is that some of these clouds can be very high. Many reach heights of over 60 km, and several are over 70 km above the limb. Statistically, the reflectivity of the clouds increases with phase angle. Reflectivity and height both appear to vary with season, but the selected images spanned only one Martian year, so the role of seasons cannot be isolated. Limb clouds in red-filter images tend to be brighter than violet-filter images, but both season and phase appear to be more dominant factors. Due to the limited sample available, the possible influences of latitude and longitude are less clear. The layering of these clouds ranges from a single layer to five or more layers. Reflectivity gradients range from smooth and gentle to steep and irregular.

Earth Observation

NASA Image and Video Library

2011-07-15

ISS028-E-017123 (16 July 2011) --- Separate atmospheric optical phenomena were captured in this electronic still photograph from the Inernational Space Station. The thin greenish band stretching along the Earth's horizon is airglow; light emitted by the atmosphere from a layer about 30 kilometers thick and about 100 kilometers in altitude. The predominant emission in airglow is the green 5577 Angstrom wavelength light from atomic oxygen atoms. Airglow is always and everywhere present in the atmosphere; it results from the recombination of molecules that have been broken apart by solar radiation during the day. But airglow is so faint that it can only be seen at night by looking "edge on" at the emission layer, such as the view astronauts and cosmonauts have in orbit. The second phenomenon is the appearnce of Aurora Australis.

Limb length inequality: clinical implications for assessment and intervention.

PubMed

Brady, Rebecca J; Dean, John B; Skinner, T Marc; Gross, Michael T

2003-05-01

The purpose of this paper is to review relevant literature concerning limb length inequalities in adults and to make recommendations for assessment and intervention based on the literature and our own clinical experience. Literature searches were conducted in the MEDLINE, PubMed, and CINAHL databases. Limb length inequality and common classification criteria are defined and etiological factors are presented. Common methods of detecting limb length inequality include direct (tape measure methods), indirect (pelvic leveling), and radiological techniques. Interventions include shoe inserts or external shoe lift therapy for mild cases. Surgery may be appropriate in severe cases. Little agreement exists regarding the prevalence of limb length inequality, the degree of limb length inequality that is considered clinically significant, and the reliability and validity of assessment methods. Based on correlational studies, the relationship between limb length inequality and orthopaedic pathologies is questionable. Stronger support for the link between low back pain (LBP) and limb length inequality is provided by intervention studies. Methods involving palpation of pelvic landmarks with block correction have the most support for clinical assessment of limb length inequality. Standing radiographs are suggested when clinical assessment methods are unsatisfactory. Clinicians should exercise caution when undertaking intervention strategies for limb length inequality of less than 5 mm when limb length inequality has been identified with clinical techniques. Recommendations are provided regarding intervention strategies.

Manipulated Changes in Limb Mass and Rotational Inertia in Trotting Dogs (Canis lupus familiaris) and Their Effect on Limb Kinematics.

PubMed

Kilbourne, Brandon M; Carrier, David R

2016-12-01

While the mass distribution of limbs is known to influence the metabolic energy consumed during locomotion, it remains unknown how the mass distribution of limbs may influence overall limb kinematics and whether the influence of limb mass distribution on limb kinematics differs between fore- and hindlimbs. To examine limb mass distribution's influence upon fore- and hindlimb kinematics, temporal stride parameters and swing phase joint kinematics were recorded from four dogs trotting on a treadmill with 0.5% and 1.0% body mass added to each limb, forelimbs alone, and hindlimbs alone, as well as with no added mass. Under all loading conditions, stride period did not differ between fore- and hindlimbs; however, forelimbs exhibited greater duty factors and stance durations, whereas hindlimbs exhibited greater swing durations, which may be related to the hindlimb's greater mass. Changes in forelimb joint and hip range of motion (RoM), flexion, and extension were subject to a high amount of kinematic plasticity among dogs. In contrast, for the knee and ankle, distally loading all four limbs or hindlimbs alone substantially increased joint RoM and flexion. Increased flexion of the knee and ankle has the potential to reduce the hindlimb's rotational inertia during swing phase. The differing response of fore- and hindlimbs with regard to joint kinematics is likely due to differences in their mass and mass distribution and differences in the physiological traits of fore- and hindlimb protractors and joint flexors. © 2017 Wiley Periodicals, Inc.

Agency over Phantom Limb Enhanced by Short-Term Mirror Therapy

PubMed Central

Imaizumi, Shu; Asai, Tomohisa; Koyama, Shinichi

2017-01-01

Most amputees experience phantom limb, whereby they feel that the amputated limb is still present. In some cases, these experiences include pain that can be alleviated by “mirror therapy.” Mirror therapy consists of superimposing a mirrored image of the moving intact limb onto the phantom limb. This therapy provides a closed loop between the motor command to the amputated limb and its predicted visual feedback. This loop is also involved in the sense of agency, a feeling of controlling one’s own body. However, it is unclear how mirror therapy is related to the sense of agency over a phantom limb. Using mirror therapy, we investigated phantom limb pain and the senses of agency and ownership (i.e., a feeling of having one’s own body) of the phantom limb. Nine upper-limb amputees, five of whom reported recent phantom limb pain, underwent a single 15-min trial of mirror therapy. Before and after the trial, the participants completed a questionnaire regarding agency, ownership, and pain related to their phantom limb. They reported that the sense of agency over the phantom limb increased following the mirror therapy trial, while the ownership slightly increased but not as much as did the agency. The reported pain did not change; that is, it was comparably mild before and after the trial. These results suggest that short-term mirror therapy can, at least transiently, selectively enhance the sense of agency over a phantom limb, but may not alleviate phantom limb pain. PMID:29046630

Those Pesky Humans: Emissions and the Future of AnthroGeoscience

NASA Astrophysics Data System (ADS)

Bond, T. C.

2015-12-01

Despite the "Geophysical" word in our society's name, a large fraction of our work is devoted to characterizing how humans influence the Earth system: the discipline of anthrogeoscience.When I joined AGU in 1997, emissions for atmospheric models were treated as "just a flux." Since then, emission inventories have become recognized as core intermediaries to describe how humans, and their use of Earth's resources, connect with Earth's atmosphere. What we know and don't know about emissions often reflects what we know and don't know about people. Emissions and atmospheric pollution become routinely observable and controllable when a society reaches a certain level of technical expertise. The least well-understood emissions of air pollutants occur before this point in societal development, or remain after controls are implemented. Yet the humans who live with these emissions may have enormous health impacts and other elevated risks. The future emission trajectories that we can choose are constrained by human capacity, capital stock, physical infrastructure, and ultimately, political will. Many have hoped to follow a low-impact trajectory, but have yet to understand and commit to the physical and societal changes required. Understanding and choosing the future of the atmosphere will require close-coupled projections of the three-way connection between humans, the built environment, and the Earth system. Responsible stewardship will require us to integrate disciplines ranging from engineering and planning to human behavior and governance. The American Geophysical Union is key to the future of anthrogeoscience. Looking beyond its halls is imperative, as well.

Limb-brightened jet of 3C 84 revealed by the 43 GHz very-long-baseline-array observation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagai, H.; Hada, K.; Haga, T.

2014-04-10

We present a study of the sub-parsec scale radio structure of the radio galaxy 3C 84/NGC 1275 based on the Very Long Baseline Array data at 43 GHz. We discover a limb brightening in the 'restarted' jet that is associated with the 2005 radio outburst. In the 1990s, the jet structure was ridge brightening rather than limb brightening, despite the observations being done with similar angular resolutions. This indicates that the transverse jet structure has recently changed. This change in the morphology reveals an interesting agreement with the γ-ray flux increase, i.e., the γ-ray flux in the 1990s was atmore » least seven times lower than the current one. One plausible explanation for the limb brightening is that the velocity structure of the jet is in the context of the stratified jet, which is a successful scenario that explains the γ-ray emission in some active galactic nuclei. If this is the case, then the change in apparent transverse structure might be caused by the change in the transverse velocity structure. We argue that the transition from ridge brightening to limb brightening is related to the γ-ray time variability on the timescale of decades. We also discuss the collimation profile of the jet.« less

Spatial Coupling Affects Both Homologous and Non-Homologous Limbs

ERIC Educational Resources Information Center

Huh, Carey Y.

2004-01-01

The present study examined the interaction between limb movements in space. The amount of interaction was measured by how much moving one limb affected the movement of another limb. Participants were 24 right-handed university students (19 female, mean AGE=19 years). The task was to draw lines with the right hand while moving another limb in lines…

Europium-doped mesoporous titania thin films: rare-earth locations and emission fluctuations under illumination.

PubMed

Leroy, Celine Marie; Cardinal, Thierry; Jubera, Veronique; Treguer-Delapierre, Mona; Majimel, Jerome; Manaud, Jean Pierre; Backov, Renal; Boissière, Cedric; Grosso, David; Sanchez, Clement; Viana, Bruno; Pellé, Fabienne

2008-10-06

Herein, Eu(III)-doped 3D mesoscopically ordered arrays of mesoporous and nanocrystalline titania are prepared and studied. The rare-earth-doped titania thin films-synthesized via evaporation-induced self-assembly (EISA)-are characterized by using environmental ellipsoporosimetry, electronic microscopy (i.e. high-resolution scanning electron microscopy, HR-SEM, and transmission electron microscopy, HR-TEM), X-ray diffraction, and luminescence spectroscopy. Structural characterizations show that high europium-ion loadings can be incorporated into the titanium-dioxide walls without destroying the mesoporous arrangement. The luminescence properties of Eu(III) are investigated by using steady-state and time-resolved spectroscopy via excitation of the Eu(III) ions through the titania host. Using Eu(III) luminescence as a probe, the europium-ion sites can be addressed with at least two different environments within the mesoporous framework, namely, a nanocrystalline environment and a glasslike one. Emission fluctuations ((5)D(0)-->(7)F(2)) are observed upon continuous UV excitation in the host matrix. These fluctuations are attributed to charge trapping and appear to be strongly dependent on the amount of europium and the level of crystallinity.

Modelling of N2 Vegard-Kaplan and LBH emissions in the planetary atmospheres

NASA Astrophysics Data System (ADS)

Jain, Sonal Kumar; Bhardwaj, Anil

The N_{2} triplet band emissions are common features in the dayglow of Earth. Recent discoveries of N _{2} Vegard-Kaplan (VK) band emissions on Mars by SPICAM/Mars-Express and N _{2} VK and LBH band emissions on Titan by Cassini's UVIS have led planetary scientists to look for the processes governing the N _{2} triplet and singlet band emissions in different planetary atmospheres. We have developed a model to calculate N _{2} triplet and Lyman-Birge-Hopefield (LBH) band emissions in the dayglow of Venus, Mars, Titan, and Pluto. The Steady state photoelectron fluxes and volume excitation rates have been calculated using the Analytical Yield Spectra (AYS) technique. Since interstate cascading is important for triplet and singlet states of N _{2}, the population of any given level of N _{2} triplet and singlet states is calculated under statistical equilibrium considering direct excitation, cascading, and quenching effects. Relative population of all vibrational levels of each triplet and singlet states is calculated in the model. Line of sight intensities and height-integrated overhead intensities have been calculated for VK ( A(3Sigma_u^+) - X(1Sigma^+_g) ), first positive ( B(3Pi_g) - A(3Sigma^+_u) ), second positive ( C(3Pi_u) - B(3Pi_g) ), Wu-Benesch (W(3Delta_u) - B(3Pi_g) ), B '-> B, E -> B, E-> C, E-> A, and LBH (a(1Pi_g) - X(1Sigma^+_g) ) bands of N _{2}. The N _{2} VK band span wavelength range from far ultraviolet to visible, and some transitions even originate at wavelength more than 1000 nm. Our calculations show that the overhead intensity of VK bands in the wavelength range 400-800, 300-190, 200-300, and 150-200 nm are 22%, 39%, 35%, and 4% of the total VK band emission. On Titan, the calculated intensities of N _{2} VK and LBH bands in 150-190 and 120-190 nm wavelength range, respectively, are in good agreement with the Cassini-UVIS observation. On Mars, calculated intensities of N _{2} VK bands are in agreement with the SPICAM observed limb profile of

RESIDUAL LIMB VOLUME CHANGE: SYSTEMATIC REVIEW OF MEASUREMENT AND MANAGEMENT

PubMed Central

Sanders, JE; Fatone, S

2014-01-01

Management of residual limb volume affects decisions regarding timing of fit of the first prosthesis, when a new prosthetic socket is needed, design of a prosthetic socket, and prescription of accommodation strategies for daily volume fluctuations. The purpose of this systematic review was to assess what is known about measurement and management of residual limb volume change in persons with lower-limb amputation. Publications that met inclusion criteria were grouped into three categories: (I) descriptions of residual limb volume measurement techniques; (II) studies on people with lower-limb amputation investigating the effect of residual limb volume change on clinical care; and (III) studies of residual limb volume management techniques or descriptions of techniques for accommodating or controlling residual limb volume. The review showed that many techniques for the measurement of residual limb volume have been described but clinical use is limited largely because current techniques lack adequate resolution and in-socket measurement capability. Overall, there is limited evidence regarding the management of residual limb volume, and the evidence available focuses primarily on adults with trans-tibial amputation in the early post-operative phase. While we can draw some insights from the available research about residual limb volume measurement and management, further research is required. PMID:22068373

A newborn with unilateral limb enlargement.

PubMed

Sharma, Shanel; Maino, Anna P F; Husain, Shad M; Adams, Gill G W

2012-03-01

On routine neonatal examination, a newborn term male was noted to have unilateral enlargement of the right lower limb, loose thickened red skin over the palm and widening of all the fingers on the right hand. His body was pinker and warmer on the right side compared with the left and he had a right undescended testicle and hypoplastic scrotum. Radiological examination of the lower limbs demonstrated the enlargement of the soft tissue of the right lower limb compared to the left (Fig. 1). Therefore, the diagnosis was unclear from this constellation of findings and an ophthalmic assessment was requested.

The UK Earth System Model project

NASA Astrophysics Data System (ADS)

Tang, Yongming

2016-04-01

In this talk we will describe the development and current status of the UK Earth System Model (UKESM). This project is a NERC/Met Office collaboration and has two objectives; to develop and apply a world-leading Earth System Model, and to grow a community of UK Earth System Model scientists. We are building numerical models that include all the key components of the global climate system, and contain the important process interactions between global biogeochemistry, atmospheric chemistry and the physical climate system. UKESM will be used to make key CMIP6 simulations as well as long-time (e.g. millennium) simulations, large ensemble experiments and investigating a range of future carbon emission scenarios.

Forward scattering and backscattering of solar radiation by the stratospheric limb after Mount St. Helens eruption

NASA Technical Reports Server (NTRS)

Ackerman, M.; Lippens, C.

1982-01-01

Stratospheric limb radiance profiles versus altitude of closest approach of the line of sight to the Earth's surface have been measured before and after the Mount St. Helens eruptions by means of photographs taken from a Sun-oriented balloon gondola floating above 35 km altitude over France. Preliminary data were reported for flights in October 1979 and in May and June 1980. The radiance integrated along the line of sight as in-situ radiance (R) can be derived taking into account absorption by ozone and air. The onion peeling inversion method was used to derive the vertical radiance (R) profiles respectively. The values of R were determined in the solar azimuth. The solar elevation angles are chosen larger for the backscattering observation than for the forward scattering observation to deal with as similar illumination conditions as possible despite the Earth's sphericity.

The functional anatomy of suggested limb paralysis.

PubMed

Deeley, Quinton; Oakley, David A; Toone, Brian; Bell, Vaughan; Walsh, Eamonn; Marquand, Andre F; Giampietro, Vincent; Brammer, Michael J; Williams, Steven C R; Mehta, Mitul A; Halligan, Peter W

2013-02-01

Suggestions of limb paralysis in highly hypnotically suggestible subjects have been employed to successfully model conversion disorders, revealing similar patterns of brain activation associated with attempted movement of the affected limb. However, previous studies differ with regard to the executive regions involved during involuntary inhibition of the affected limb. This difference may have arisen as previous studies did not control for differences in hypnosis depth between conditions and/or include subjective measures to explore the experience of suggested paralysis. In the current study we employed functional magnetic resonance imaging (fMRI) to examine the functional anatomy of left and right upper limb movements in eight healthy subjects selected for high hypnotic suggestibility during (i) hypnosis (NORMAL) and (ii) attempted movement following additional left upper limb paralysis suggestions (PARALYSIS). Contrast of left upper limb motor function during NORMAL relative to PARALYSIS conditions revealed greater activation of contralateral M1/S1 and ipsilateral cerebellum, consistent with the engagement of these regions in the completion of movements. By contrast, two significant observations were noted in PARALYSIS relative to NORMAL conditions. In conjunction with reports of attempts to move the paralysed limb, greater supplementary motor area (SMA) activation was observed, a finding consistent with the role of SMA in motor intention and planning. The anterior cingulate cortex (ACC, BA 24) was also significantly more active in PARALYSIS relative to NORMAL conditions - suggesting that ACC (BA 24) may be implicated in involuntary, as well as voluntary inhibition of prepotent motor responses. Copyright © 2012 Elsevier Ltd. All rights reserved.

Imparting regenerative capacity to limbs by progenitor cell transplantation

PubMed Central

Lin, Gufa; Chen, Ying; Slack, Jonathan M.W.

2012-01-01

Summary The frog Xenopus can normally regenerate its limbs at early developmental stages but loses the ability during metamorphosis. This behavior provides a potential gain-of-function model for measures that can enhance limb regeneration. Here we show that frog limbs can be caused to form multidigit regenerates after receiving transplants of larval limb progenitor cells. It is necessary to activate Wnt/β -catenin signaling in the cells, and to add Sonic hedgehog, FGF10 and thymosin β4. These factors promote survival and growth of the grafted cells and also provide pattern information. The eventual regenerates are not composed solely of donor tissue; the host cells also make a substantial contribution despite their lack of regeneration-competence. Cells from adult frog legs or from regenerating tadpole tails do not promote limb regeneration, demonstrating the necessity for limb progenitor cells. These findings have obvious implications for the development of a technology to promote limb regeneration in mammals. PMID:23273877

Advances in Decoding Axolotl Limb Regeneration.

PubMed

Haas, Brian J; Whited, Jessica L

2017-08-01

Humans and other mammals are limited in their natural abilities to regenerate lost body parts. By contrast, many salamanders are highly regenerative and can spontaneously replace lost limbs even as adults. Because salamander limbs are anatomically similar to human limbs, knowing how they regenerate should provide important clues for regenerative medicine. Although interest in understanding the mechanics of this process has never wavered, until recently researchers have been vexed by seemingly impenetrable logistics of working with these creatures at a molecular level. Chief among the problems has been the very large size of salamander genomes, and not a single salamander genome has been fully sequenced to date. Recently the enormous gap in sequence information has been bridged by approaches that leverage mRNA as the starting point. Together with functional experimentation, these data are rapidly enabling researchers to finally uncover the molecular mechanisms underpinning the astonishing biological process of limb regeneration. Copyright © 2017 Elsevier Ltd. All rights reserved.

Mid-Infrared Imaging of Exo-Earths: Impact of Exozodiacal Disk Structures

NASA Technical Reports Server (NTRS)

Defrere, Denis; Absil, O.; Stark, C.; den Hartog, R.; Danchi, W.

2011-01-01

The characterization of Earth-like extrasolar planets in the mid-infrared is a significant observational challenge that could be tackled by future space-based interferometers. The presence of large amounts of exozodiacal dust around nearby main sequence stars represents however a potential hurdle to obtain mid-infrared spectra of Earth-like planets. Whereas the disk brightness only affects the integration time, the emission of resonant dust structures mixes with the planet signal at the output of the interferometer and could jeopardize the spectroscopic analysis of an Earth-like planet. Fortunately, the high angular resolution provided by space-based interferometry is sufficient to spatially distinguish most of the extended exozodiacal emission from the planetary signal and only the dust located near the planet significantly contributes to the noise level. Considering modeled resonant structures created by Earth-like planets, we address in this talk the role of exozodiacal dust in two different cases: the characterization of Super-Earth planets with single space-based Bracewell interferometers (e.g., the FKSI mission) and the characterization of Earth-like planets with 4-telescope space-based nulling interferometers (e.g., the TPF-I and Darwin projects). In each case, we derive constraints on the disk parameters that can be tolerated without jeopardizing the detection of Earth-like planets

Modeling and dynamic simulation of astronaut's upper limb motions considering counter torques generated by the space suit.

PubMed

Li, Jingwen; Ye, Qing; Ding, Li; Liao, Qianfang

2017-07-01

Extravehicular activity (EVA) is an inevitable task for astronauts to maintain proper functions of both the spacecraft and the space station. Both experimental research in a microgravity simulator (e.g. neutral buoyancy tank, zero-g aircraft or a drop tower/tube) and mathematical modeling were used to study EVA to provide guidance for the training on Earth and task design in space. Modeling has become more and more promising because of its efficiency. Based on the task analysis, almost 90% of EVA activity is accomplished through upper limb motions. Therefore, focusing on upper limb models of the body and space suit is valuable to this effort. In previous modeling studies, some multi-rigid-body systems were developed to simplify the human musculoskeletal system, and the space suit was mostly considered as a part of the astronaut body. With the aim to improve the reality of the models, we developed an astronauts' upper limb model, including a torque model and a muscle-force model, with the counter torques from the space suit being considered as a boundary condition. Inverse kinematics and the Maggi-Kane's method was applied to calculate the joint angles, joint torques and muscle force given that the terminal trajectory of upper limb motion was known. Also, we validated the muscle-force model using electromyogram (EMG) data collected in a validation experiment. Muscle force calculated from our model presented a similar trend with the EMG data, supporting the effectiveness and feasibility of the muscle-force model we established, and also, partially validating the joint model in kinematics aspect.

The role of artificial atmospheric CO2 removal in stabilizing Earth's climate

NASA Astrophysics Data System (ADS)

Zickfeld, K.; Tokarska, K.

2014-12-01

The current CO2 emission trend entails a risk that the 2°C target will be missed, potentially causing "dangerous" changes in Earth's climate system. This research explores the role of artificial atmospheric CO2 removal (also referred to as "negative emissions") in stabilizing Earth's climate after overshoot. We designed a range of plausible CO2 emission scenarios, which follow a gradual transition from a fossil fuel driven economy to a zero-emission energy system, followed by a period of negative emissions. The scenarios differ in peak emissions rate and, accordingly, the amount of negative emissions, to reach the same cumulative emissions compatible with the 2°C temperature stabilization target. The climate system components' responses are computed using the University of Victoria Earth System Climate Model of intermediate complexity. Results suggest that negative emissions are effective in reversing the global mean temperature and stabilizing it at a desired level (2°C above pre-industrial) after overshoot. Also, changes in the meridional overturning circulation and sea ice are reversible with the artificial removal of CO2 from the atmosphere. However, sea level continues to rise and is not reversible for several centuries, even under assumption of large amounts of negative emissions. For sea level to decline, atmospheric CO2 needs to be reduced to pre-industrial levels in our simulations. During the negative emission phase, outgassing of CO2 from terrestrial and marine carbon sinks offsets the artificial removal of atmospheric CO2, thereby reducing its effectiveness. On land, the largest CO2 outgassing occurs in the Tropics and is partially compensated by CO2 uptake at northern high latitudes. In the ocean, outgassing occurs mostly in the Southern Ocean, North Atlantic and tropical Pacific. The strongest outgassing occurs for pathways entailing greatest amounts of negative emissions, such that the efficiency of CO2 removal - here defined as the change in

21 CFR 890.3475 - Limb orthosis.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Limb orthosis. 890.3475 Section 890.3475 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3475 Limb orthosis. (a) Identification...

21 CFR 890.3475 - Limb orthosis.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Limb orthosis. 890.3475 Section 890.3475 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3475 Limb orthosis. (a) Identification...

21 CFR 890.3475 - Limb orthosis.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Limb orthosis. 890.3475 Section 890.3475 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3475 Limb orthosis. (a) Identification...

21 CFR 890.3475 - Limb orthosis.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Limb orthosis. 890.3475 Section 890.3475 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3475 Limb orthosis. (a) Identification...

21 CFR 890.3475 - Limb orthosis.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Limb orthosis. 890.3475 Section 890.3475 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3475 Limb orthosis. (a) Identification...

LIMB-DARKENING COEFFICIENTS FOR ECLIPSING WHITE DWARFS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gianninas, A.; Strickland, B. D.; Kilic, Mukremin

2013-03-20

We present extensive calculations of linear and nonlinear limb-darkening coefficients as well as complete intensity profiles appropriate for modeling the light-curves of eclipsing white dwarfs. We compute limb-darkening coefficients in the Johnson-Kron-Cousins UBVRI photometric system as well as the Large Synoptic Survey Telescope (LSST) ugrizy system using the most up to date model atmospheres available. In all, we provide the coefficients for seven different limb-darkening laws. We describe the variations of these coefficients as a function of the atmospheric parameters, including the effects of convection at low effective temperatures. Finally, we discuss the importance of having readily available limb-darkening coefficientsmore » in the context of present and future photometric surveys like the LSST, Palomar Transient Factory, and the Panoramic Survey Telescope and Rapid Response System (Pan-STARRS). The LSST, for example, may find {approx}10{sup 5} eclipsing white dwarfs. The limb-darkening calculations presented here will be an essential part of the detailed analysis of all of these systems.« less

Successful limb salvage through staged bypass combined with free gracilis muscle transfer for critical limb ischemia with osteomyelitis after failed endovascular therapy.

PubMed

Miyake, Keisuke; Kikuchi, Shinsuke; Okuda, Hiroko; Koya, Atsuhiro; Abe, Satomi; Sawa, Yoshiki; Ota, Tetsuo; Azuma, Nobuyoshi

2018-05-02

Critical limb ischemia with osteomyelitis is so difficult to treat that even appropriate revascularization and wound therapy cannot achieve limb salvage because of uncontrollable infection. It is still difficult to judge the possibility of limb salvage before revascularization. A 73-year-old male complained of a small ulcer on his left toe, which was treated with multiple endovascular therapy. After failed endovascular therapy, he suffered extensive tissue loss with tibial osteomyelitis. We carried out staged surgery that was composed of dual bypass to the sural artery and posterior tibial artery. After intensive debridement and wound care, insertion of a subsequent free gracilis muscle flap to cover the exposed tibial bone was performed, achieving functional limb salvage. Even in the threatened limb with extensive tissue loss and osteomyelitis, intensive and multidisciplinary treatment with staged revascularization, muscle transfer, and appropriate wound care achieved functional limb salvage.

Uncertainty in projected climate change arising from uncertain fossil-fuel emission factors

NASA Astrophysics Data System (ADS)

Quilcaille, Y.; Gasser, T.; Ciais, P.; Lecocq, F.; Janssens-Maenhout, G.; Mohr, S.

2018-04-01

Emission inventories are widely used by the climate community, but their uncertainties are rarely accounted for. In this study, we evaluate the uncertainty in projected climate change induced by uncertainties in fossil-fuel emissions, accounting for non-CO2 species co-emitted with the combustion of fossil-fuels and their use in industrial processes. Using consistent historical reconstructions and three contrasted future projections of fossil-fuel extraction from Mohr et al we calculate CO2 emissions and their uncertainties stemming from estimates of fuel carbon content, net calorific value and oxidation fraction. Our historical reconstructions of fossil-fuel CO2 emissions are consistent with other inventories in terms of average and range. The uncertainties sum up to a ±15% relative uncertainty in cumulative CO2 emissions by 2300. Uncertainties in the emissions of non-CO2 species associated with the use of fossil fuels are estimated using co-emission ratios varying with time. Using these inputs, we use the compact Earth system model OSCAR v2.2 and a Monte Carlo setup, in order to attribute the uncertainty in projected global surface temperature change (ΔT) to three sources of uncertainty, namely on the Earth system’s response, on fossil-fuel CO2 emission and on non-CO2 co-emissions. Under the three future fuel extraction scenarios, we simulate the median ΔT to be 1.9, 2.7 or 4.0 °C in 2300, with an associated 90% confidence interval of about 65%, 52% and 42%. We show that virtually all of the total uncertainty is attributable to the uncertainty in the future Earth system’s response to the anthropogenic perturbation. We conclude that the uncertainty in emission estimates can be neglected for global temperature projections in the face of the large uncertainty in the Earth system response to the forcing of emissions. We show that this result does not hold for all variables of the climate system, such as the atmospheric partial pressure of CO2 and the

Projections of oceanic N2O emissions in the 21st century using the IPSL Earth system model

NASA Astrophysics Data System (ADS)

Martinez-Rey, J.; Bopp, L.; Gehlen, M.; Tagliabue, A.; Gruber, N.

2015-07-01

The ocean is a substantial source of nitrous oxide (N2O) to the atmosphere, but little is known about how this flux might change in the future. Here, we investigate the potential evolution of marine N2O emissions in the 21st century in response to anthropogenic climate change using the global ocean biogeochemical model NEMO-PISCES. Assuming nitrification as the dominant N2O formation pathway, we implemented two different parameterizations of N2O production which differ primarily under low-oxygen (O2) conditions. When forced with output from a climate model simulation run under the business-as-usual high-CO2 concentration scenario (RCP8.5), our simulations suggest a decrease of 4 to 12 % in N2O emissions from 2005 to 2100, i.e., a reduction from 4.03/3.71 to 3.54/3.56 TgN yr-1 depending on the parameterization. The emissions decrease strongly in the western basins of the Pacific and Atlantic oceans, while they tend to increase above the oxygen minimum zones (OMZs), i.e., in the eastern tropical Pacific and in the northern Indian Ocean. The reduction in N2O emissions is caused on the one hand by weakened nitrification as a consequence of reduced primary and export production, and on the other hand by stronger vertical stratification, which reduces the transport of N2O from the ocean interior to the ocean surface. The higher emissions over the OMZ are linked to an expansion of these zones under global warming, which leads to increased N2O production, associated primarily with denitrification. While there are many uncertainties in the relative contribution and changes in the N2O production pathways, the increasing storage seems unequivocal and determines largely the decrease in N2O emissions in the future. From the perspective of a global climate system, the averaged feedback strength associated with the projected decrease in oceanic N2O emissions amounts to around -0.009 W m-2 K-1, which is comparable to the potential increase from terrestrial N2O sources. However

Functional specialisation of pelvic limb anatomy in horses (Equus caballus)

PubMed Central

Payne, RC; Hutchinson, JR; Robilliard, JJ; Smith, NC; Wilson, AM

2005-01-01

We provide quantitative anatomical data on the muscle–tendon units of the equine pelvic limb. Specifically, we recorded muscle mass, fascicle length, pennation angle, tendon mass and tendon rest length. Physiological cross sectional area was then determined and maximum isometric force estimated. There was proximal-to-distal reduction in muscle volume and fascicle length. Proximal limb tendons were few and, where present, were relatively short. By contrast, distal limb tendons were numerous and long in comparison to mean muscle fascicle length, increasing potential for elastic energy storage. When compared with published data on thoracic limb muscles, proximal pelvic limb muscles were larger in volume and had shorter fascicles. Distal limb muscle architecture was similar in thoracic and pelvic limbs with the exception of flexor digitorum lateralis (lateral head of the deep digital flexor), the architecture of which was similar to that of the pelvic and thoracic limb superficial digital flexors, suggesting a functional similarity. PMID:15960766

Linear Polarization Measurements of Chromospheric Emission Lines

NASA Technical Reports Server (NTRS)

Sheeley, N. R., Jr.; Keller, C. U.

2003-01-01

We have used the Zurich Imaging Stokes Polarimeter (ZIMPOL I) with the McMath-Pierce 1.5 m main telescope on Kitt Peak to obtain linear polarization measurements of the off-limb chromosphere with a sensitivity better than 1 x 10(exp -5). We found that the off-disk observations require a combination of good seeing (to show the emission lines) and a clean heliostat (to avoid contamination by scattered light from the Sun's disk). When these conditions were met, we obtained the following principal results: 1. Sometimes self-reversed emission lines of neutral and singly ionized metals showed linear polarization caused by the transverse Zeeman effect or by instrumental cross talk from the longitudinal Zeeman effect in chromospheric magnetic fields. Otherwise, these lines tended to depolarize the scattered continuum radiation by amounts that ranged up to 0.2%. 2. Lines previously known to show scattering polarization just inside the limb (such as the Na I lambda5889 D2 and the He I lambda5876 D3 lines) showed even more polarization above the Sun's limb, with values approaching 0.7%. 3. The O I triplet at lambda7772, lambda7774, and lambda7775 showed a range of polarizations. The lambda7775 line, whose maximum intrinsic polarizability, P(sub max), is less than 1%, revealed mainly Zeeman contributions from chromospheric magnetic fields. However, the more sensitive lambda7772 (P(sub max) = 19%) and lambda7774 (P(sub max) = 29%) lines had relatively strong scattering polarizations of approximately 0.3% in addition to their Zeeman polarizations. At times of good seeing, the polarization spectra resolve into fine structures that seem to be chromospheric spicules.

EMISSION MEASUREMENTS OF PARTICLE MASS AND SIZE EMISSION PROFILES FROM CONSTRUCTION ACTIVITIES

EPA Science Inventory

The report gives results from field tests that characterize the amount and size distribution of particulate matter (PM) emissions from operations at construction sites. Of particular interest is the movement of earth by scraper loading and unloading, grading, transit vehicular m...

Phantom Limbs, Neuroprosthetics, and the Developmental Origins of Embodiment.

PubMed

Blumberg, Mark S; Dooley, James C

2017-10-01

Amputees who wish to rid themselves of a phantom limb must weaken the neural representation of the absent limb. Conversely, amputees who wish to replace a lost limb must assimilate a neuroprosthetic with the existing neural representation. Whether we wish to remove a phantom limb or assimilate a synthetic one, we will benefit from knowing more about the developmental process that enables embodiment. A potentially critical contributor to that process is the spontaneous activity - in the form of limb twitches - that occurs exclusively and abundantly during active (REM) sleep, a particularly prominent state in early development. The sensorimotor circuits activated by twitching limbs, and the developmental context in which activation occurs, could provide a roadmap for creating neuroprosthetics that feel as if they are part of the body. Copyright © 2017 Elsevier Ltd. All rights reserved.

Simulating super earth atmospheres in the laboratory

NASA Astrophysics Data System (ADS)

Claudi, R.; Erculiani, M. S.; Galletta, G.; Billi, D.; Pace, E.; Schierano, D.; Giro, E.; D'Alessandro, M.

2016-01-01

Several space missions, such as JWST, TESS and the very recently proposed ARIEL, or ground-based experiments, as SPHERE and GPI, have been proposed to measure the atmospheric transmission, reflection and emission spectra of extrasolar planets. The planet atmosphere characteristics and possible biosignatures will be inferred by studying planetary spectra in order to identify the emission/absorption lines/bands from atmospheric molecules such as water (H2O), carbon monoxide (CO), methane (CH4), ammonia (NH3), etc. In particular, it is important to know in detail the optical characteristics of gases in the typical physical conditions of the planetary atmospheres and how these characteristics could be affected by radiation driven photochemical and biochemical reaction. The main aim of the project `Atmosphere in a Test Tube' is to provide insights on exoplanet atmosphere modification due to biological intervention. This can be achieved simulating planetary atmosphere at different pressure and temperature conditions under the effects of radiation sources, used as proxies of different bands of the stellar emission. We are tackling the characterization of extrasolar planet atmospheres by mean of innovative laboratory experiments described in this paper. The experiments are intended to reproduce the conditions on warm earths and super earths hosted by low-mass M dwarfs primaries with the aim to understand if a cyanobacteria population hosted on a Earth-like planet orbiting an M0 star is able to maintain its photosynthetic activity and produce traceable signatures.

Visual Feedback of the Non-Moving Limb Improves Active Joint-Position Sense of the Impaired Limb in Spastic Hemiparetic Cerebral Palsy

ERIC Educational Resources Information Center

Smorenburg, Ana R. P.; Ledebt, Annick; Deconinck, Frederik J. A.; Savelsbergh, Geert J. P.

2011-01-01

This study examined the active joint-position sense in children with Spastic Hemiparetic Cerebral Palsy (SHCP) and the effect of static visual feedback and static mirror visual feedback, of the non-moving limb, on the joint-position sense. Participants were asked to match the position of one upper limb with that of the contralateral limb. The task…

Feasibility of infrared Earth tracking for deep-space optical communications.

PubMed

Chen, Yijiang; Hemmati, Hamid; Ortiz, Gerry G

2012-01-01

Infrared (IR) Earth thermal tracking is a viable option for optical communications to distant planet and outer-planetary missions. However, blurring due to finite receiver aperture size distorts IR Earth images in the presence of Earth's nonuniform thermal emission and limits its applicability. We demonstrate a deconvolution algorithm that can overcome this limitation and reduce the error from blurring to a negligible level. The algorithm is applied successfully to Earth thermal images taken by the Mars Odyssey spacecraft. With the solution to this critical issue, IR Earth tracking is established as a viable means for distant planet and outer-planetary optical communications. © 2012 Optical Society of America

Ontogenetic scaling of fore limb and hind limb joint posture and limb bone cross-sectional geometry in vervets and baboons.

PubMed

Burgess, M Loring; Schmitt, Daniel; Zeininger, Angel; McFarlin, Shannon C; Zihlman, Adrienne L; Polk, John D; Ruff, Christopher B

2016-09-01

Previous studies suggest that the postures habitually adopted by an animal influence the mechanical loading of its long bones. Relatively extended limb postures in larger animals should preferentially reduce anteroposterior (A-P) relative to mediolateral (M-L) bending of the limb bones and therefore decrease A-P/M-L rigidity. We test this hypothesis by examining growth-related changes in limb bone structure in two primate taxa that differ in ontogenetic patterns of joint posture. Knee and elbow angles of adult and immature vervets (Chlorocebus aethiops, n = 16) were compared to published data for baboons (Papio hamadryas ursinus, n = 33, Patel et al., ). Ontogenetic changes in ratios of A-P/M-L bending rigidity in the femur and humerus were compared in skeletal samples (C. aethiops, n = 28; P. cynocephalus, n = 39). Size changes were assessed with linear regression, and age group differences tested with ANOVA. Only the knee of baboons shows significant postural change, becoming more extended with age and mass. A-P/M-L bending rigidity of the femur decreases during ontogeny in immature and adult female baboons only. Trends in the humerus are less marked. Adult male baboons have higher A-P/M-L bending rigidity of the femur than females. The hypothesized relationship between more extended joints and reduced A-P/M-L bending rigidity is supported by our results for immature and adult female baboon hind limbs, and the lack of significant age changes in either parameter in forelimbs and vervets. Adult males of both species depart from general ontogenetic trends, possibly due to socially mediated behavioral differences between sexes. Am J Phys Anthropol 161:72-83, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Phosphorylation of Lbx1 controls lateral myoblast migration into the limb.

PubMed

Masselink, Wouter; Masaki, Megumi; Sieiro, Daniel; Marcelle, Christophe; Currie, Peter D

2017-10-15

The migration of limb myogenic precursors from limb level somites to their ultimate site of differentiation in the limb is a paradigmatic example of a set of dynamic and orchestrated migratory cell behaviours. The homeobox containing transcription factor ladybird homeobox 1 (Lbx1) is a central regulator of limb myoblast migration, null mutations of Lbx1 result in severe disruptions to limb muscle formation, particularly in the distal region of the limb in mice (Gross et al., 2000). As such Lbx1 has been hypothesized to control lateral migration of myoblasts into the distal limb anlage. It acts as a core regulator of the limb myoblast migration machinery, controlled by Pax3. A secondary role for Lbx1 in the differentiation and commitment of limb musculature has also been proposed (Brohmann et al., 2000; Uchiyama et al., 2000). Here we show that lateral migration, but not differentiation or commitment of limb myoblasts, is controlled by the phosphorylation of three adjacent serine residues of LBX1. Electroporation of limb level somites in the chick embryo with a dephosphomimetic form of Lbx1 results in a specific defect in the lateral migration of limb myoblasts. Although the initial delamination and migration of myoblasts is unaffected, migration into the distal limb bud is severely disrupted. Interestingly, myoblasts undergo normal differentiation independent of their migratory status, suggesting that the differentiation potential of hypaxial muscle is not regulated by the phosphorylation state of LBX1. Furthermore, we show that FGF8 and ERK mediated signal transduction, both critical regulators of the developing limb bud, have the capacity to induce the phosphorylation of LBX1 at these residues. Overall, this suggests a mechanism whereby the phosphorylation of LBX1, potentially through FGF8 and ERK signalling, controls the lateral migration of myoblasts into the distal limb bud. Copyright © 2017. Published by Elsevier Inc.

Transcriptomic insights into the genetic basis of mammalian limb diversity.

PubMed

Maier, Jennifer A; Rivas-Astroza, Marcelo; Deng, Jenny; Dowling, Anna; Oboikovitz, Paige; Cao, Xiaoyi; Behringer, Richard R; Cretekos, Chris J; Rasweiler, John J; Zhong, Sheng; Sears, Karen E

2017-03-23

From bat wings to whale flippers, limb diversification has been crucial to the evolutionary success of mammals. We performed the first transcriptome-wide study of limb development in multiple species to explore the hypothesis that mammalian limb diversification has proceeded through the differential expression of conserved shared genes, rather than by major changes to limb patterning. Specifically, we investigated the manner in which the expression of shared genes has evolved within and among mammalian species. We assembled and compared transcriptomes of bat, mouse, opossum, and pig fore- and hind limbs at the ridge, bud, and paddle stages of development. Results suggest that gene expression patterns exhibit larger variation among species during later than earlier stages of limb development, while within species results are more mixed. Consistent with the former, results also suggest that genes expressed at later developmental stages tend to have a younger evolutionary age than genes expressed at earlier stages. A suite of key limb-patterning genes was identified as being differentially expressed among the homologous limbs of all species. However, only a small subset of shared genes is differentially expressed in the fore- and hind limbs of all examined species. Similarly, a small subset of shared genes is differentially expressed within the fore- and hind limb of a single species and among the forelimbs of different species. Taken together, results of this study do not support the existence of a phylotypic period of limb development ending at chondrogenesis, but do support the hypothesis that the hierarchical nature of development translates into increasing variation among species as development progresses.

Structure design of lower limb exoskeletons for gait training

NASA Astrophysics Data System (ADS)

Li, Jianfeng; Zhang, Ziqiang; Tao, Chunjing; Ji, Run

2015-09-01

Due to the close physical interaction between human and machine in process of gait training, lower limb exoskeletons should be safe, comfortable and able to smoothly transfer desired driving force/moments to the patients. Correlatively, in kinematics the exoskeletons are required to be compatible with human lower limbs and thereby to avoid the uncontrollable interactional loads at the human-machine interfaces. Such requirement makes the structure design of exoskeletons very difficult because the human-machine closed chains are complicated. In addition, both the axis misalignments and the kinematic character difference between the exoskeleton and human joints should be taken into account. By analyzing the DOF(degree of freedom) of the whole human-machine closed chain, the human-machine kinematic incompatibility of lower limb exoskeletons is studied. An effective method for the structure design of lower limb exoskeletons, which are kinematically compatible with human lower limb, is proposed. Applying this method, the structure synthesis of the lower limb exoskeletons containing only one-DOF revolute and prismatic joints is investigated; the feasible basic structures of exoskeletons are developed and classified into three different categories. With the consideration of quasi-anthropopathic feature, structural simplicity and wearable comfort of lower limb exoskeletons, a joint replacement and structure comparison based approach to select the ideal structures of lower limb exoskeletons is proposed, by which three optimal exoskeleton structures are obtained. This paper indicates that the human-machine closed chain formed by the exoskeleton and human lower limb should be an even-constrained kinematic system in order to avoid the uncontrollable human-machine interactional loads. The presented method for the structure design of lower limb exoskeletons is universal and simple, and hence can be applied to other kinds of wearable exoskeletons.

Thermal Emission Spectroscopy (5.2 To 38 Microns) And Analysis Of 10 Near-earth Asteroids

NASA Astrophysics Data System (ADS)

Dave, Riddhi; Emery, J.; Cruikshank, D.; Mueller, M.; Delbo, M.; Trilling, D. E.; Mommert, M.

2010-10-01

Near Earth Asteroids (NEAs- 0.983AUemission spectra[R 60-130] have been fitted with models of the thermal continuum employing the Near Earth Asteroid Thermal Model [NEATM](Harris 1998) and a Thermophysical model. Simultaneous measurements of the asteroid flux in the thermal infrared, combined with a thermal model, allow both the diameter and the albedo to be determined. The sample of Asteroids to be a part of this study are 1602 Geographos, 1580 Betulia, 433 Eros, 2212 Hephaistos, 1685 Toro, 1917 Cuyo, 1566 Icarus, 3200 Phaethon, 7092 Cadmus and 1866 Sisyphus. This study will give in-depth understanding of the applicability of the NEATM for NEAs observed at higher phase angles, having larger thermal inertia than main-belt asteroids, and/or displaying varied geometries. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA.

Delayed amputation following trauma increases residual lower limb infection.

PubMed

Jain, Abhilash; Glass, Graeme E; Ahmadi, Hootan; Mackey, Simon; Simmons, Jon; Hettiaratchy, Shehan; Pearse, Michael; Nanchahal, Jagdeep

2013-04-01

Residual limb infection following amputation is a devastating complication, resulting in delayed rehabilitation, repeat surgery, prolonged hospitalisation and poor functional outcome. The aim of this study was to identify variables predicting residual limb infection following non-salvageable lower limb trauma. All cases of non-salvageable lower limb trauma presenting to a specialist centre over 5 years were evaluated from a prospective database and clinical and management variables correlated with the development of deep infection. Forty patients requiring 42 amputations were identified with a mean age of 49 years (±19.9, 1SD). Amputations were performed for 21 Gustilo IIIB injuries, 12 multi-planar degloving injuries, seven IIIC injuries and one open Schatzker 6 fracture. One limb was traumatically amputated at the scene and surgically revised. Amputation level was transtibial in 32, through-knee in one and transfemoral in nine. Median time from injury to amputation was 4 days (range 0-30 days). Amputation following only one debridement and within 5 days resulted in significantly fewer stump infections (p = 0.026 and p = 0.03, respectively, Fisher's exact test). The cumulative probability of infection-free residual limb closure declined steadily from day 5. Multivariate analyses revealed that neither the nature of the injury nor pre-injury patient morbidity independently influenced residual limb infection. Avoiding residual limb infection is critically dependent on prompt amputation of non-salvageable limbs. Copyright © 2012 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Resolving the mesospheric nighttime 4.3 µm emission puzzle: comparison of the CO2(ν3) and OH(ν) emission models

NASA Astrophysics Data System (ADS)

Panka, Peter A.; Kutepov, Alexander A.; Kalogerakis, Konstantinos S.; Janches, Diego; Russell, James M.; Rezac, Ladislav; Feofilov, Artem G.; Mlynczak, Martin G.; Yiğit, Erdal

2017-08-01

In the 1970s, the mechanism of vibrational energy transfer from chemically produced OH(ν) in the nighttime mesosphere to the CO2(ν3) vibration, OH(ν) ⇒ N2(ν) ⇒ CO2(ν3), was proposed. In later studies it was shown that this "direct" mechanism for simulated nighttime 4.3 µm emissions of the mesosphere is not sufficient to explain space observations. In order to better simulate these observations, an additional enhancement is needed that would be equivalent to the production of 2.8-3 N2(1) molecules instead of one N2(1) molecule in each quenching reaction of OH(ν) + N2(0). Recently a new "indirect" channel of the OH(ν) energy transfer to N2(ν) vibrations, OH(ν) ⇒ O(1D) ⇒ N2(ν), was suggested and then confirmed in a laboratory experiment, where its rate for OH(ν = 9) + O(3P) was measured. We studied in detail the impact of the "direct" and "indirect" mechanisms on CO2(ν3) and OH(ν) vibrational level populations and emissions. We also compared our calculations with (a) the SABER/TIMED nighttime 4.3 µm CO2 and OH 1.6 and 2.0 µm limb radiances of the mesosphere-lower thermosphere (MLT) and (b) with ground- and space-based observations of OH(ν) densities in the nighttime mesosphere. We found that the new "indirect" channel provides a strong enhancement of the 4.3 µm CO2 emission, which is comparable to that obtained with the "direct" mechanism alone but assuming an efficiency that is 3 times higher. The model based on the "indirect" channel also produces OH(ν) density distributions which are in good agreement with both SABER limb OH emission observations and ground and space measurements. This is, however, not true for the model which relies on the "direct" mechanism alone. This discrepancy is caused by the lack of an efficient redistribution of the OH(ν) energy from higher vibrational levels emitting at 2.0 µm to lower levels emitting at 1.6 µm. In contrast, the new  indirect  mechanism efficiently removes at least five

PTSD in Limb Trauma and Recovery

DTIC Science & Technology

2011-10-01

Virtual reality and Motion Analysis to Characterize Disabilities in Lower...Program 4: “ Virtual reality and Motion Analysis to Characterize Disabilities in Lower Limb Injury” (Christopher Rhea, Ph.D., lead investigator). This...ANSI Std. Z39.18 ANNUAL REPORT 10/16/2011 VIRTUAL REALITY AND MOTION ANALYSIS TO CHARACTERIZE DISABILITIES IN LOWER LIMB INJURY PI: SUSAN

Medial knee joint contact force in the intact limb during walking in recently ambulatory service members with unilateral limb loss: a cross-sectional study

PubMed Central

Krupenevich, Rebecca L.; Pruziner, Alison L.; Wolf, Erik J.; Schnall, Barri L.

2017-01-01

Background Individuals with unilateral lower limb amputation have a high risk of developing knee osteoarthritis (OA) in their intact limb as they age. This risk may be related to joint loading experienced earlier in life. We hypothesized that loading during walking would be greater in the intact limb of young US military service members with limb loss than in controls with no limb loss. Methods Cross-sectional instrumented gait analysis at self-selected walking speeds with a limb loss group (N = 10, age 27 ± 5 years, 170 ± 36 days since last surgery) including five service members with transtibial limb loss and five with transfemoral limb loss, all walking independently with their first prosthesis for approximately two months. Controls (N = 10, age 30 ± 4 years) were service members with no overt demographical risk factors for knee OA. 3D inverse dynamics modeling was performed to calculate joint moments and medial knee joint contact forces (JCF) were calculated using a reduction-based musculoskeletal modeling method and expressed relative to body weight (BW). Results Peak JCF and maximum JCF loading rate were significantly greater in limb loss (184% BW, 2,469% BW/s) vs. controls (157% BW, 1,985% BW/s), with large effect sizes. Results were robust to probabilistic perturbations to the knee model parameters. Discussion Assuming these data are reflective of joint loading experienced in daily life, they support a “mechanical overloading” hypothesis for the risk of developing knee OA in the intact limb of limb loss subjects. Examination of the evolution of gait mechanics, joint loading, and joint health over time, as well as interventions to reduce load or strengthen the ability of the joint to withstand loads, is warranted. PMID:28168120

[Venous tone of the limbs. Methods and comparison of 2 areas].

PubMed

Journo, H; London, G; Pannier, B; Safar, M

1989-07-01

The limb venous tone, index of local venous compliance, was studied with mercury strain gauge plethysmography on 28 male normal subjects (40 +/- 17 years, +/- SD) simultaneously on upper and lower limbs. Measurements were done after 20 mn rest in supine position. Venous tone (VT) equals the slope of the pressure-volume curve established by simultaneous recording of the forearm and calf relative volumes for successive steps of pressure lower than or equal to 30 mmHg. Limb venous capacitance was expressed by means of the maximal limb relative volume (V30) reached for a pressure of 30 mmHg applied through cuffs in standardized conditions. The upper limb venous tone was greater than the lower limb venous tone: 24.3 +/- 8.2 mmHg/ml/100 vs 17.5 +/- 7.9 mmHg/ml/100, p = 0.001. V30 was greater in lower limb than in upper limb: 1.5 +/- 0.5 ml/100 vs 1.1 +/- 0.4 ml/100, p = 0.001. In conclusion, it appears that upper and lower limbs venous distensibility and capacitance are different. They are greater in the lower limb in baseline conditions. Thus simultaneous studies of both these limb venous systems seems important for physiological experiments because of their baseline differences.

Regional traumatic limb hypothermia attenuates distant hepatic and renal injury following blast limb trauma in rats.

PubMed

Zhao, Hongzhi; Ning, Jiaolin; Duan, Jiaxiang; Gu, Jianteng; Yi, Bin; Lu, Kaizhi; Mo, Liwen; Lai, Xinan; Hennah, Lindsay; Ma, Daqing

2014-09-01

Blast limb injury was reported to result in distant organ injury including the lungs, which can be attenuated with transient regional hypothermia (RH) to the injured limb. We aimed to further study hepatic and renal injuries following blast limb trauma and also to evaluate the protective effects of regional traumatic limb hypothermia on such injuries in rats. Blast limb trauma (BLT) was created using chartaceous electricity detonators in anesthetized male Sprague-Dawley rats. The BLT rats were randomly allocated to undergo regional traumatic limb hypothermic treatment (RH) for 30 minutes, 60 minutes, or 6 hours immediately after the onset of blast or without RH (n = 8 per group). The severity of hepatic and renal injury was assessed through histologic examination and water content (wet/dry weight) in all animals 6 hours later. The level of plasma tumor necrosis factor α (TNF-α), interleukin 6, hydrogen sulfide (H2S), and myeloperoxidase (MPO) together with hepatic and renal MPO, malondialdehyde (MDA), superoxide dismutase, and total antioxidant capacity were measured 6 hours after the blast injury. Following BLT, hepatic injury was evidenced by histopathologic changes, increased water content, as well as plasma alanine aminotransferase and aspartate aminotransferase. Renal histopathologic but not functional changes were also found. RH treatment for all durations attenuated this distant renal injury, but only RH treatment for 60 minutes and 6 hours attenuated distant hepatic injury following BLT. RH treatment for all durations decreased plasma TNF-α and interleukin 6, reduced liver and kidney MPO activity and kidney MDA, and elevated superoxide dismutase and total antioxidant capacity in both liver and kidneys. RH treatment for 60 minutes is the most effective duration to reduce hepatic MPO activity, plasma TNF-α, and kidney MDA. This study indicates that BLT-induced distant renal and hepatic injury could be attenuated by RH treatment through reduction of

LIMB DEFECTS INDUCED BY RETINOIC ACID SIGNALING ANTAGONISM AND SYNTHESIS INHIBITION ARE CONSISTENT WITH ETHANOL-INDUCED LIMB DEFECTS

EPA Science Inventory

Limb defects induced by retinoic acid signaling antagonism and synthesis inhibition are consistent with ethanol-induced limb defects

Johnson CS1, Sulik KK1,2, Hunter, ES III3
1Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill, NC....

Isolated limb perfusion for the management limb threatening soft tissue sarcomas: The role of histological type on clinical outcomes.

PubMed

Rastrelli, M; Mocellin, S; Stramare, R; Brunello, A; Maruzzo, M; Basso, U; Scarzello, G; Buzzaccarini, M S; Pilati, P; Saadeh, L M; Del Fiore, S P; Tosi, A; Montesco, C; Campana, L G; Tropea, S; Rossi, C R

2017-02-01

Hyperthermic isolated limb perfusion (HILP) is an effective neoadjuvant treatment to avoid amputation in patients with locally advanced extremity soft tissue sarcomas (STS). We aimed to investigate whether STS histological type plays a role in predicting clinical outcomes. This study reports a retrospective analysis of 125 patients with limb threatening STS (liposarcoma, n = 41; malignant peripheral nerve sheath tumor, n = 20; leiomyosarcoma, n = 20; miscellany, n = 44), who underwent HILP from 1990 through 2015 at our institution. The following endpoints were evaluated: tumor response (assessed by radiological imaging and histology), limb sparing rate, local progression-free survival (LPFS) and overall survival (OS). On average, overall (complete + partial) tumor response was significantly greater in patients affected with liposarcoma as compared to those with other histotypes (radiological response rate: 38/41, 92.7% vs 66/84, 78.6%, P-value: 0.048; mean histological necrosis: 83.6% vs 52.9%, P < 0.0001). Limb sparing rate was also higher among patients with liposarcoma as compared to other histotypes (39/41, 95.1% vs 62/84, 73.8%, P-value: 0.005). As regards survival, LPFS was similar across tumor types, whereas OS resulted significantly worse in patients with limb leiomyosarcoma (log-rank P-value: 0.009). HILP is a very effective treatment modality for limb threatening STS. In our series, liposarcoma appears to be the histological type most sensitive to HILP in terms of tumor response and thus limb sparing, which might help clinicians in the patient selection process. Copyright © 2016 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

A Limb Action Detector Enabling People with Multiple Disabilities to Control Environmental Stimulation through Limb Action with a Nintendo Wii Remote Controller

ERIC Educational Resources Information Center

Shih, Ching-Hsiang; Chang, Man-Ling; Shih, Ching-Tien

2010-01-01

This study assessed whether two persons with multiple disabilities would be able to control environmental stimulation using limb action with a Nintendo Wii Remote Controller and a newly developed limb action detection program (LADP, i.e., a new software program that turns a Wii Remote Controller into a precise limb action detector). This study was…

A New Limb Movement Detector Enabling People with Multiple Disabilities to Control Environmental Stimulation through Limb Swing with a Gyration Air Mouse

ERIC Educational Resources Information Center

Shih, Ching-Hsiang; Chang, Man-Ling; Shih, Ching-Tien

2010-01-01

This study assessed whether two persons with multiple disabilities would be able to control environmental stimulation using limb swing with a gyration air mouse and a newly developed limb movement detection program (LMDP, i.e., a new software program that turns a gyration air mouse into a precise limb movement detector). The study was performed…

Earth Observations taken by the Expedition 39 Crew

NASA Image and Video Library

2014-04-02

ISS039-E-009160 (2 April 2014) --- This nighttime view featuring the aurora borealis, the moon and Moscow was photographed by an Expedition 39 crew member on the International Space Station. A thin green line of the aurora borealis crosses the top of this image. The moon appears as a white disc just above the aurora. Airglow appears as a blue-white cusp on Earth's limb. Russia's capital city Moscow makes a splash of yellow (lower left), with its easily recognized radial pattern of highways. Other cities are Nizhni Novgorod (lower center) 400 kilometers from Moscow, St. Petersburg (left) 625 kilometers from Moscow, and Finland?s capital city Helsinki.

Quasi-Periodic Pulsations in the Earth's Ionosphere Synchronized with Solar Flare Emission

NASA Astrophysics Data System (ADS)

Hayes, L.; Gallagher, P.; McCauley, J.; Dennis, B. R.; Ireland, J.; Inglis, A. R.

2017-12-01

Solar flare activity is a powerful factor affecting the geophysical processes in the Earth's ionosphere. In particular, X-ray photons with wavelength < 10 A can penetrate down to the D-region ( 60-90 km in altitude) resulting in a dramatic increase of ionization in this lowest lying region of the Earth's ionosphere. This manifests as a substantial enhancement of electron density height profile at these altitudes to extents large enough to change the propagation conditions for Very Low Frequency (VLF 3-30 kHz) radio waves that travel in the waveguide formed by the Earth and the lower ionosphere. Recently, it has become clear that flares exhibit quasi-periodic pulsations with periods of seconds to minutes at EUV, X-ray and gamma-ray wavelengths. To date, it has not been known if the Earth's ionosphere is sensitive to these dynamic solar pulsations. Here, we report ionospheric pulsations with periods of 20 minutes that are synchronized with a set of pulsating flare loops using VLF observations of the ionospheric D-layer together with X-ray and EUV observations of a solar flare from the NOAA/GOES and NASA/SDO satellites. Modeling of the ionosphere show that the D-region electron density varies by up to an order of magnitude over the timescale of the pulsations. Our results show that the Earth's ionosphere is more sensitive to small-scale changes in solar activity than previously thought.

Absorption and emission spectra of Ga1.7Ge25As8.3S65 glasses doped with rare-earth ions

NASA Astrophysics Data System (ADS)

Lupan, E. V.; Iaseniuc, O. V.; Ciornea, V. I.; Iovu, M. S.

2016-12-01

Excellent optical properties of chalcogenide glasses make them interesting for optoelectronic devices in the visible (VIS) and, especially, in the near- and mid-infrared (NIR and MIR) spectral regions. The rare-earth (RE3+) doped Ga17Ge25As8.3S65 glasses were prepared in evacuated ( 10-5 Pa) silica-glass ampoules which were heated up to 1000 °C at 2-4°C min-1, and then the melt was quenched. The absorption and photoluminescence spectra in the visible and near IR regions for GA1.7Ge25As8.3S65 doped with rare-earth RE+) ions (Sm3+, Nd3+, Pr3+, Dy3+ and co-doped with Ho3++Dy3+) are investigated. The energy transfer of the absorbed light in the broad band Urbach region of the host glass to the RE3+ ions is suggested for increasing the emission efficiency. The investigated Ga17Ge25As8.3S65 glasses doped with RE3+ ions are promising materials for optical amplifiers operating at 1300 and 1500 nm telecommunication windows.

Reasonable classical concepts in human lower limb anatomy from the viewpoint of the primitive persistent sciatic artery and twisting human lower limb.

PubMed

Kawashima, Tomokazu; Sasaki, Hiroshi

2010-11-01

The main aim of this review is (1) to introduce the two previous studies we published human lower limb anatomy based on the conventional macroscopic anatomical [corrected] criteria with hazardous recognition of this description, (2) to activate the discussion whether the limb homology exists, and (3) to contribute to future study filling the gap between the gross anatomy and embryology. One of the topics we discussed was the human persistent sciatic artery. To date, numerous human cases of persistent sciatic artery have been reported in which the anomalous artery was present in the posterior compartment of the thigh alongside the sciatic nerve. As one of the important criteria for assessing the human primitive sciatic artery, its ventral arterial position with respect to the sciatic nerve is reasonable based on the initial positional relationship between ventral arterial and dorsal nervous systems and comparative anatomical findings. We also discuss ways of considering the topography of muscles of the lower limb and their innervations compared to those of the upper limb. We propose a schema of the complex anatomical characteristics of the lower limb based on the vertebrate body plan. According to this reasonable schema, the twisted anatomy of the lower limb can be understood more easily. These two main ideas discussed in this paper will be useful for further understanding of the anatomy of the lower limb and as a first step for future. We hope that the future study in lower limb will be further developed by both viewpoints of the classical gross anatomy and recent embryology.

Lower limb strength in sports-active transtibial amputees.

PubMed

Nolan, Lee

2009-09-01

The aim of this study was to compare hip strength in sports-active transtibial (TT) amputees, sedentary TT amputees and sports-active non-amputees. Three 'active' (exercising recreationally at least three times per week) TT amputees, four 'inactive' or sedentary TT amputees and nine 'active' able-bodied persons (AB) underwent concentric and eccentric hip flexion and extension strength testing on both limbs on an isokinetic dynamometer at 60 and 120 degrees /s. Little strength asymmetry was noted between the limbs of the active TT amputees (8% and 14% at 60 and 120 degrees /s, respectively), their residual limb being slightly stronger. Inactive TT amputees demonstrated up to 49% strength asymmetry, their intact limb being the stronger. Active TT amputees demonstrated greater peak hip torques (Nm/kg) for all conditions and speeds compared to inactive TT amputees. Peak hip torques (Nm/kg), were greater in the active TT amputees' residual limb compared to AB. While inactive TT amputees and AB had similar flexion/extension ratios, active TT amputees exhibited a lower ratio indicating overdeveloped hip extensors with respect to their hip flexors. It is not known whether this is due to the demands of sport or exercise with a prosthetic limb, or remaining residual thigh atrophy.

3D ion-scale dynamics of BBFs and their associated emissions in Earth's magnetotail using 3D hybrid simulations and MMS multi-spacecraft observations

NASA Astrophysics Data System (ADS)

Breuillard, H.; Aunai, N.; Le Contel, O.; Catapano, F.; Alexandrova, A.; Retino, A.; Cozzani, G.; Gershman, D. J.; Giles, B. L.; Khotyaintsev, Y. V.; Lindqvist, P. A.; Ergun, R.; Strangeway, R. J.; Russell, C. T.; Magnes, W.; Plaschke, F.; Nakamura, R.; Fuselier, S. A.; Turner, D. L.; Schwartz, S. J.; Torbert, R. B.; Burch, J.

2017-12-01

Transient and localized jets of hot plasma, also known as Bursty Bulk Flows (BBFs), play a crucial role in Earth's magnetotail dynamics because the energy input from the solar wind is partly dissipated in their vicinity, notably in their embedded dipolarization front (DF). This dissipation is in the form of strong low-frequency waves that can heat and accelerate energetic particles up to the high-latitude plasma sheet. The ion-scale dynamics of BBFs have been revealed by the Cluster and THEMIS multi-spacecraft missions. However, the dynamics of BBF propagation in the magnetotail are still under debate due to instrumental limitations and spacecraft separation distances, as well as simulation limitations. The NASA/MMS fleet, which features unprecedented high time resolution instruments and four spacecraft separated by kinetic-scale distances, has also shown recently that the DF normal dynamics and its associated emissions are below the ion gyroradius scale in this region. Large variations in the dawn-dusk direction were also observed. However, most of large-scale simulations are using the MHD approach and are assumed 2D in the XZ plane. Thus, in this study we take advantage of both multi-spacecraft observations by MMS and large-scale 3D hybrid simulations to investigate the 3D dynamics of BBFs and their associated emissions at ion-scale in Earth's magnetotail, and their impact on particle heating and acceleration.

7 CFR 51.1220 - Leaf or limb rub injury.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 2 2014-01-01 2014-01-01 false Leaf or limb rub injury. 51.1220 Section 51.1220 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... Leaf or limb rub injury. “Leaf or limb rub injury” means that the scarring is not smooth, not light...

7 CFR 51.1220 - Leaf or limb rub injury.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 2 2013-01-01 2013-01-01 false Leaf or limb rub injury. 51.1220 Section 51.1220 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards... Leaf or limb rub injury. “Leaf or limb rub injury” means that the scarring is not smooth, not light...

Sonic hedgehog: restricted expression and limb dysmorphologies

PubMed Central

Hill, Robert E; Heaney, Simon JH; Lettice, Laura A

2003-01-01

Sonic hedgehog, SHH, is required for patterning the limb. The array of skeletal elements that compose the hands and feet, and the ordered arrangement of these bones to form the pattern of fingers and toes are dependent on SHH. The mechanism of action of SHH in the limb is not fully understood; however, an aspect that appears to be important is the localized, asymmetric expression of Shh. Shh is expressed in the posterior margin of the limb bud in a region defined as the zone of polarizing activity (ZPA). Analysis of mouse mutants which have polydactyly (extra toes) shows that asymmetric expression of Shh is lost due to the appearance of an ectopic domain of expression in the anterior limb margin. One such polydactylous mouse mutant, sasquatch (Ssq), maps to the corresponding chromosomal region of the human condition pre-axial polydactyly (PPD) and thus represents a model for this condition. The mutation responsible for Ssq is located 1 Mb away from the Shh gene; however, the mutation disrupts a long-range cis-acting regulator of Shh expression. By inference, human pre-axial polydactyly results from a similar disruption of Shh expression. Other human congenital abnormalities also map near the pre-axial polydactyly locus, suggesting a major chromosomal region for limb dysmorphologies. The distinct phenotypes range from loss of all bones of the hands and feet to syndactyly of the soft tissue and fusion of the digits. We discuss the role played by Shh expression in mouse mutant phenotypes and the human limb dysmorphologies. PMID:12587915

A novel methodology for rapid digestion of rare earth element ores and determination by microwave plasma-atomic emission spectrometry and dynamic reaction cell-inductively coupled plasma-mass spectrometry.

PubMed

Helmeczi, Erick; Wang, Yong; Brindle, Ian D

2016-11-01

Short-wavelength infrared radiation has been successfully applied to accelerate the acid digestion of refractory rare-earth ore samples. Determinations were achieved with microwave plasma-atomic emission spectrometry (MP-AES) and dynamic reaction cell - inductively coupled plasma-mass spectrometry (DRC-ICP-MS). The digestion method developed was able to tackle high iron-oxide and silicate matrices using only phosphoric acid in a time frame of only 8min, and did not require perchloric or hydrofluoric acid. Additionally, excellent recoveries and reproducibilities of the rare earth elements, as well as uranium and thorium, were achieved. Digestions of the certified reference materials OREAS-465 and REE-1, with radically different mineralogies, delivered results that mirror those obtained by fusion processes. For the rare-earth CRM OKA-2, whose REE data are provisional, experimental data for the rare-earth elements were generally higher than the provisional values, often exceeding z-values of +2. Determined values for Th and U in this reference material, for which certified values are available, were in excellent agreement. Copyright © 2016 Elsevier B.V. All rights reserved.

Management Approach for Earth Venture Instrument

NASA Technical Reports Server (NTRS)

Hope, Diane L.; Dutta, Sanghamitra

2013-01-01

The Earth Venture Instrument (EVI) element of the Earth Venture Program calls for developing instruments for participation on a NASA-arranged spaceflight mission of opportunity to conduct innovative, integrated, hypothesis or scientific question-driven approaches to pressing Earth system science issues. This paper discusses the EVI element and the management approach being used to manage both an instrument development activity as well as the host accommodations activity. In particular the focus will be on the approach being used for the first EVI (EVI-1) selected instrument, Tropospheric Emissions: Monitoring of Pollution (TEMPO), which will be hosted on a commercial GEO satellite and some of the challenges encountered to date and corresponding mitigations that are associated with the management structure for the TEMPO Mission and the architecture of EVI.

Prevalence of upper limb disorders among female librarians.

PubMed

Pandy, R

2013-09-01

Work as a librarian involves exposure to potential risk factors for developing upper limb disorders. The prevalence of upper limb symptoms has, however, not previously been assessed in this occupational group. To estimate the 7-day and annual prevalence of self-reported neck and upper limb symptoms in librarians and to examine associations with specific tasks and ergonomic risk factors. A cross-sectional study using components of the standardized Nordic questionnaire. The study population consisted of librarians employed by a large local authority, and data collection was by means of a self-administered questionnaire. from studies on keyboard workers and on the general population were used as comparators. The 7-day prevalence of self-reported neck and upper limb pain in female librarians was 42% (95% confidence interval (CI) 33.7-50.5) and the annual prevalence was 65% (95% CI 56.6-72.8). The prevalence of reported wrist and hand pain increased with increased working involving a wide thumb-index span (P < 0.05) with a significant linear trend in prevalence with increasing exposure (P < 0.01). There was a strong association between reporting hand and/or wrist pain and awareness of work-related upper limb disorder (P < 0.05). The annual prevalence of self-reported upper limb symptoms among female librarians was high, but there was insufficient evidence to confirm whether the prevalence was higher than in the general population or among keyboard workers. Working with a wide thumb-index span was associated with reporting upper limb symptoms.

Risk factors in limb reduction defects.

PubMed

Stoll, C; Alembik, Y; Dott, B; Roth, M P

1992-07-01

Risk factors were studied in 123 children with limb reduction defects (LRD) from 118,265 consecutive births of known outcome during the period from 1979 to 1987 in the area which is covered by our registry of congenital malformations. For each case a control was studied. The LRD was localised and classified according to the EUROCAT guide for the description and classification of limb defects. The prevalence of LRD was 1.04 per thousand: 82.9% of the babies were liveborn, 13.0% were late spontaneous abortion or stillborn and termination was performed in 4.0% of the cases. The proportion of males was 0.55. The most common malformations in the 51.2% of children who had at least one other anomaly than LRD were associated cardiac, digestive and renal anomalies. The pregnancy with limb anomalies was more often complicated by oligohydramnios, polyhydramnios and threatened abortion but there were no differences in parental characteristics. However, 9.7% of marriages were consanguineous (P less than 0.01) and the incidence of LRD in first-degree relatives of the children with LRD was high. First-degree relatives also had more non-limb malformations than did those of controls.

Limb bone morphology, bone strength, and cursoriality in lagomorphs

PubMed Central

Young, Jesse W; Danczak, Robert; Russo, Gabrielle A; Fellmann, Connie D

2014-01-01

The primary aim of this study is to broadly evaluate the relationship between cursoriality (i.e. anatomical and physiological specialization for running) and limb bone morphology in lagomorphs. Relative to most previous studies of cursoriality, our focus on a size-restricted, taxonomically narrow group of mammals permits us to evaluate the degree to which ‘cursorial specialization’ affects locomotor anatomy independently of broader allometric and phylogenetic trends that might obscure such a relationship. We collected linear morphometrics and μCT data on 737 limb bones covering three lagomorph species that differ in degree of cursoriality: pikas (Ochotona princeps, non-cursorial), jackrabbits (Lepus californicus, highly cursorial), and rabbits (Sylvilagus bachmani, level of cursoriality intermediate between pikas and jackrabbits). We evaluated two hypotheses: cursoriality should be associated with (i) lower limb joint mechanical advantage (i.e. high ‘displacement advantage’, permitting more cursorial species to cycle their limbs more quickly) and (ii) longer, more gracile limb bones, particularly at the distal segments (as a means of decreasing rotational inertia). As predicted, highly cursorial jackrabbits are typically marked by the lowest mechanical advantage and the longest distal segments, non-cursorial pikas display the highest mechanical advantage and the shortest distal segments, and rabbits generally display intermediate values for these variables. Variation in long bone robusticity followed a proximodistal gradient. Whereas proximal limb bone robusticity declined with cursoriality, distal limb bone robusticity generally remained constant across the three species. The association between long, structurally gracile limb bones and decreased maximal bending strength suggests that the more cursorial lagomorphs compromise proximal limb bone integrity to improve locomotor economy. In contrast, the integrity of distal limb bones is maintained with

Running With an Elastic Lower Limb Exoskeleton.

PubMed

Cherry, Michael S; Kota, Sridhar; Young, Aaron; Ferris, Daniel P

2016-06-01

Although there have been many lower limb robotic exoskeletons that have been tested for human walking, few devices have been tested for assisting running. It is possible that a pseudo-passive elastic exoskeleton could benefit human running without the addition of electrical motors due to the spring-like behavior of the human leg. We developed an elastic lower limb exoskeleton that added stiffness in parallel with the entire lower limb. Six healthy, young subjects ran on a treadmill at 2.3 m/s with and without the exoskeleton. Although the exoskeleton was designed to provide ~50% of normal leg stiffness during running, it only provided 24% of leg stiffness during testing. The difference in added leg stiffness was primarily due to soft tissue compression and harness compliance decreasing exoskeleton displacement during stance. As a result, the exoskeleton only supported about 7% of the peak vertical ground reaction force. There was a significant increase in metabolic cost when running with the exoskeleton compared with running without the exoskeleton (ANOVA, P < .01). We conclude that 2 major roadblocks to designing successful lower limb robotic exoskeletons for human running are human-machine interface compliance and the extra lower limb inertia from the exoskeleton.

Emission properties of Ce-doped alkaline earth borate glasses for scintillator applications

NASA Astrophysics Data System (ADS)

Torimoto, Aya; Masai, Hirokazu; Okada, Go; Kawaguchi, Noriaki; Yanagida, Takayuki

2017-11-01

We investigate the photoluminescence (PL) and X-ray-induced luminescence properties of 0.1 mol% Ce-doped MO-B2O3 (M = Ca, Sr, and Ba) glasses. We also determine the Ce3+/(Ce3++Ce4+) ratio by X-ray absorption near-edge structure analyses. The emission intensities of PL, X-ray scintillation, and thermally stimulated luminescence (TSL) depend on the host glass composition. The order of the PL intensity from highest to lowest is as follows: Ca-substituted glass, Ba-substituted glass, and Sr-substituted glass. Our results suggest that the optical absorption edge and quantum yield (QY) are influenced by the local coordination state of Ce3+, which, in turn, is likely to be affected by the optical basicity. The order of the X-ray scintillation intensity from highest to lowest is reverse of that of the PL intensity. This is probably because the interaction probability of X-rays with matter depends on the effective atomic number of the material and the effective atomic number has a stronger influence on the scintillation intensity than does the QY. Though the TSL glow curves reveal that the density and energy depth of the trap sites depend on the substituted alkaline earth oxides, we are unable to correlate the electron spin resonance (ESR) spectra with the TSL results. Therefore, it is considered that the ESR active sites are not responsible for the TSL in these systems.

Temporal Arctic longwave surface emissivity feedbacks in the Community Earth System Model

NASA Astrophysics Data System (ADS)

Kuo, C.; Feldman, D.; Huang, X.; Flanner, M.; Yang, P.; Chen, X.

2017-12-01

We have investigated how the inclusion of realistic and consistent surface emissivity in both land-surface and atmospheric components of the CESM coupled-climate model affects a wide range of climate variables. We did this by replacing the unit emissivity values in RRTMG_LW for water, fine-grained snow, and desert scenes with spectral emissivity values, and by replacing broadband emissivity values in surface components with the Planck-curve weighted counterparts. We find that this harmonized treatment of surface emissivity within CESM can be important for reducing high-latitude temperature biases. We also find that short-term effects of atmospheric dynamics and spectral information need to be considered to understand radiative effects in higher detail, and are possible with radiative kernels computed for every grid and time point for the entire model integration period. We find that conventional climatological feedback calculations indicate that sea-ice emissivity feedback is positive in sign, but that the radiative effects of the difference in emissivity between frozen and unfrozen surfaces exhibit seasonal dependence. Furthermore, this seasonality itself exhibits meridional asymmetry due to differences in sea-ice response to climate forcing between the Arctic and the Antarctic. In the Arctic, this seasonal, temporally higher order analysis exhibits increasing outgoing surface emissivity radiative response in a warming climate. While the sea-ice emissivity feedback and seasonal sea-ice emissivity radiative response amplitudes are a few percent of surface albedo feedbacks, the feedback analysis methods outlined in this work demonstrate that spatially and temporally localized feedback analysis can give insight into the mechanisms at work on those scales which differ in amplitude and sign from conventional climatological analyses. We note that the inclusion of this realistic physics leads to improved agreement between CESM model results and Arctic surface

7 CFR 51.1220 - Leaf or limb rub injury.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false Leaf or limb rub injury. 51.1220 Section 51.1220... STANDARDS) United States Standards for Grades of Peaches Definitions § 51.1220 Leaf or limb rub injury. “Leaf or limb rub injury” means that the scarring is not smooth, not light colored, or aggregates more...

7 CFR 51.1220 - Leaf or limb rub injury.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 2 2011-01-01 2011-01-01 false Leaf or limb rub injury. 51.1220 Section 51.1220... STANDARDS) United States Standards for Grades of Peaches Definitions § 51.1220 Leaf or limb rub injury. “Leaf or limb rub injury” means that the scarring is not smooth, not light colored, or aggregates more...

7 CFR 51.1220 - Leaf or limb rub injury.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 2 2012-01-01 2012-01-01 false Leaf or limb rub injury. 51.1220 Section 51.1220... STANDARDS) United States Standards for Grades of Peaches Definitions § 51.1220 Leaf or limb rub injury. “Leaf or limb rub injury” means that the scarring is not smooth, not light colored, or aggregates more...

STS-30 aft flight deck onboard view of overhead window, Earth limb, cow photo

NASA Image and Video Library

1989-05-08

STS030-10-008 (4-8 May 1989) --- Since the beginning manned space travel, astronauts have taken with them items of personal sentiment. In case of Mark C. Lee, STS-30 mission specialist, a picture of a cow testifies to his background as one reared on a Wisconsin farm. The scene, through a flight deck aft window, also shows Earth some 160 nautical miles away.

Neural mechanisms of limb position estimation in the primate brain.

PubMed

Shi, Ying; Buneo, Christopher A

2011-01-01

Understanding the neural mechanisms of limb position estimation is important both for comprehending the neural control of goal directed arm movements and for developing neuroprosthetic systems designed to replace lost limb function. Here we examined the role of area 5 of the posterior parietal cortex in estimating limb position based on visual and somatic (proprioceptive, efference copy) signals. Single unit recordings were obtained as monkeys reached to visual targets presented in a semi-immersive virtual reality environment. On half of the trials animals were required to maintain their limb position at these targets while receiving both visual and non-visual feedback of their arm position, while on the other trials visual feedback was withheld. When examined individually, many area 5 neurons were tuned to the position of the limb in the workspace but very few neurons modulated their firing rates based on the presence/absence of visual feedback. At the population level however decoding of limb position was somewhat more accurate when visual feedback was provided. These findings support a role for area 5 in limb position estimation but also suggest that visual signals regarding limb position are only weakly represented in this area, and only at the population level.

Mercury Emissions: The Global Context

EPA Pesticide Factsheets

Mercury emissions are a global problem that knows no national or continental boundaries. Mercury that is emitted to the air can travel thousands of miles in the atmosphere before it is eventually deposited back to the earth.

Effects of postural changes of the upper limb on reflex transmission in the lower limb. Cervicolumbar reflex interactions in man.

PubMed

Delwaide, P J; Figiel, C; Richelle, C

1977-06-01

The influence of passive changes in upper limb position on the excitability of three myotatic arc reflexes (soleus, quadriceps, and biceps femoris) of the lower limb has been explored on 42 volunteers. The results indicate that the excitability of the three myotatic arcs can be influenced at a distance by postural modifications of the upper limb. When the ipsilateral upper limb is forwards or the contralateral backwards, a facilitation of both soleus and quadriceps tendon reflexes is observed while the biceps femoris reflexes are reduced. This pattern of facilitation and inhibition is reversed when the ipsilateral upper limb is backwards or the contralateral forwards. The facilitations as well as inhibitions of proximal myotatic arc reflexes are quantitatively more marked than that of the soleus reflex. Facilitation and inhibition are not linearly related to the angle of the arm with the trunk. Effects begin at a considerable angle, become maximal at 45 degrees, and progressively disappear for greater values. It is suggested that the distinct pattern of facilitation and inhibition which is exerted in reciprocal fashion on extensor and flexor motor nuclei might depend on the long propriospinal neurones connecting cervical and lumbar enlargements.

Morphological Variation in Anuran Limbs: Constraints and Novelties.

PubMed

Fabrezi, Marissa; Goldberg, Javier; Chuliver Pereyra, Mariana

2017-09-01

Anurans have three primary types of locomotion: walking, jumping, and swimming. Additionally, they may dig, climb, grasp, etc. All adult anurans have four limbs, with four fingers on the hands and five toes on the feet. We summarized and updated knowledge on the interspecific variation within anuran limbs, then discuss how developmental constraints (e.g., in size) and novelties may have influenced anuran diversification through the locomotion. We analyze morphological variation from limb bud stages up to the final limb form resulting from certain skeletal organization and growth. We find limited morphometric variations in the skeleton of different developmental modules (i.e., skull, trunk, urostyle, limbs) indicate that the anuran body shape is largely constrained. We identify specializations of the stylopodium, zeugopodium, and proximal carpals/tarsals that have evolved to facilitiate saltatorial locomotion. We show that the anuran prepollex and prehallux are not vestigial digits and that they have come to serve specialized function. Medial rotation of the manus in anurans appears to have evolved to help distribute the force of impact upon landing at the end of a jump. Additional skeletal elements in anuran limbs are intercalary elements and sesamoids. The intercalary elements appear within neobatrachians and are integrated with digital pads in lineages capable of locomotion on smooth vertical surfaces. They have allowed arboreal anurans to occupy a wide range of arboreal habitats. © 2017 Wiley Periodicals, Inc.

Functional analysis of limb enhancers in the developing fin

PubMed Central

Booker, Betty M.; Murphy, Karl K.

2013-01-01

Despite diverging ~365 million years ago, tetrapod limbs and pectoral fins express similar genes that could be regulated by shared regulatory elements. In this study, we set out to analyze the ability of enhancers to maintain tissue specificity in these two divergent structures. We tested 22 human sequences that were previously reported as mouse limb enhancers for their enhancer activity in zebrafish (Danio rerio). Using a zebrafish enhancer assay, we found that 10/22 (45 %) were positive for pectoral fin activity. Analysis of the various criteria that correlated with positive fin activity found that both spatial limb activity and evolutionary conservation are not good predictors of fin enhancer activity. These results suggest that zebrafish enhancer assays may be limited in detecting human limb enhancers, and this limitation does not improve by the use of limb spatial expression or evolutionary conservation. PMID:24068387

Tharsis Limb Cloud

NASA Technical Reports Server (NTRS)

2005-01-01

[figure removed for brevity, see original site] Annotated image of Tharsis Limb Cloud

7 September 2005 This composite of red and blue Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) daily global images acquired on 6 July 2005 shows an isolated water ice cloud extending more than 30 kilometers (more than 18 miles) above the martian surface. Clouds such as this are common in late spring over the terrain located southwest of the Arsia Mons volcano. Arsia Mons is the dark, oval feature near the limb, just to the left of the 'T' in the 'Tharsis Montes' label. The dark, nearly circular feature above the 'S' in 'Tharsis' is the volcano, Pavonis Mons, and the other dark circular feature, above and to the right of 's' in 'Montes,' is Ascraeus Mons. Illumination is from the left/lower left.

Season: Northern Autumn/Southern Spring

Research Priorities in Limb and Task-Specific Dystonias.

PubMed

Pirio Richardson, Sarah; Altenmüller, Eckart; Alter, Katharine; Alterman, Ron L; Chen, Robert; Frucht, Steven; Furuya, Shinichi; Jankovic, Joseph; Jinnah, H A; Kimberley, Teresa J; Lungu, Codrin; Perlmutter, Joel S; Prudente, Cecília N; Hallett, Mark

2017-01-01

Dystonia, which causes intermittent or sustained abnormal postures and movements, can present in a focal or a generalized manner. In the limbs, focal dystonia can occur in either the upper or lower limbs and may be task-specific causing abnormal motor performance for only a specific task, such as in writer's cramp, runner's dystonia, or musician's dystonia. Focal limb dystonia can be non-task-specific and may, in some circumstances, be associated with parkinsonian disorders. The true prevalence of focal limb dystonia is not known and is likely currently underestimated, leaving a knowledge gap and an opportunity for future research. The pathophysiology of focal limb dystonia shares some commonalities with other dystonias with a loss of inhibition in the central nervous system and a loss of the normal regulation of plasticity, called homeostatic plasticity. Functional imaging studies revealed abnormalities in several anatomical networks that involve the cortex, basal ganglia, and cerebellum. Further studies should focus on distinguishing cause from effect in both physiology and imaging studies to permit focus on most relevant biological correlates of dystonia. There is no specific therapy for the treatment of limb dystonia given the variability in presentation, but off-label botulinum toxin therapy is often applied to focal limb and task-specific dystonia. Various rehabilitation techniques have been applied and rehabilitation interventions may improve outcomes, but small sample size and lack of direct comparisons between methods to evaluate comparative efficacy limit conclusions. Finally, non-invasive and invasive therapeutic modalities have been explored in small studies with design limitations that do not yet clearly provide direction for larger clinical trials that could support new clinical therapies. Given these gaps in our clinical, pathophysiologic, and therapeutic knowledge, we have identified priorities for future research including: the development of

Research Priorities in Limb and Task-Specific Dystonias

PubMed Central

Pirio Richardson, Sarah; Altenmüller, Eckart; Alter, Katharine; Alterman, Ron L.; Chen, Robert; Frucht, Steven; Furuya, Shinichi; Jankovic, Joseph; Jinnah, H. A.; Kimberley, Teresa J.; Lungu, Codrin; Perlmutter, Joel S.; Prudente, Cecília N.; Hallett, Mark

2017-01-01

Dystonia, which causes intermittent or sustained abnormal postures and movements, can present in a focal or a generalized manner. In the limbs, focal dystonia can occur in either the upper or lower limbs and may be task-specific causing abnormal motor performance for only a specific task, such as in writer’s cramp, runner’s dystonia, or musician’s dystonia. Focal limb dystonia can be non-task-specific and may, in some circumstances, be associated with parkinsonian disorders. The true prevalence of focal limb dystonia is not known and is likely currently underestimated, leaving a knowledge gap and an opportunity for future research. The pathophysiology of focal limb dystonia shares some commonalities with other dystonias with a loss of inhibition in the central nervous system and a loss of the normal regulation of plasticity, called homeostatic plasticity. Functional imaging studies revealed abnormalities in several anatomical networks that involve the cortex, basal ganglia, and cerebellum. Further studies should focus on distinguishing cause from effect in both physiology and imaging studies to permit focus on most relevant biological correlates of dystonia. There is no specific therapy for the treatment of limb dystonia given the variability in presentation, but off-label botulinum toxin therapy is often applied to focal limb and task-specific dystonia. Various rehabilitation techniques have been applied and rehabilitation interventions may improve outcomes, but small sample size and lack of direct comparisons between methods to evaluate comparative efficacy limit conclusions. Finally, non-invasive and invasive therapeutic modalities have been explored in small studies with design limitations that do not yet clearly provide direction for larger clinical trials that could support new clinical therapies. Given these gaps in our clinical, pathophysiologic, and therapeutic knowledge, we have identified priorities for future research including: the development of

Earth Observations taken by the Expedition 27 Crew

NASA Image and Video Library

2011-04-12

ISS027-E-012224 (12 April 2011) --- Sunset over western South America is featured in this image photographed by an Expedition 27 crew member on the International Space Station. Crew members onboard the space station see, on average, sixteen sunrises and sunsets during a 24-hour orbital period. Each changeover between day and night on the ground is marked by the terminator, or line separating the sunlit side of Earth from the side in darkness. While the terminator is conceptualized as a hard boundary?and is frequently presented as such in graphics and visualizations?in reality the boundary between light and dark is diffuse due to scattering of light by Earth?s atmosphere. This zone of diffuse lighting is experienced as dusk or twilight on the ground ? while the sun is no longer visible, some illumination is still present due to light scattering over the local horizon. The terminator is visible in this photograph trending across the image from lower left to upper right. This panoramic view across central South America, looking towards the northeast, was acquired at approximately 7:37 p.m. local time. Layers of Earth?s atmosphere, colored bright white to deep blue, are visible extending across the horizon (or limb). The highest cloud tops have a reddish glow from the direct light of the setting sun while lower clouds are in twilight. The Salar de Coipasa, a large salt lake in Bolivia, is dimly visible on the night side of the terminator. The salar provides a geographic reference point that allows the location and viewing orientation of the image to be determined.

Facts about Upper and Lower Limb Reduction Defects

MedlinePlus

... its normal size or is missing. What We Know About Upper and Lower Limb Reduction Defects How ... and productive lives. What We Still Do Not Know About Upper and Lower Limb Reduction Defects What ...

Particle size distribution of the stratospheric aerosol from SCIAMACHY limb measurements

NASA Astrophysics Data System (ADS)

Rozanov, Alexei; Malinina, Elizaveta; Bovensmann, Heinrich; Burrows, John

2017-04-01

A crucial role of the stratospheric aerosols for the radiative budget of the Earth's atmosphere and the consequences for the climate change are widely recognized. A reliable knowledge on physical and optical properties of the stratospheric aerosols as well as on their vertical and spatial distributing is a key issue to assure a proper initialization and running conditions for climate models. On a global scale this information can only be gained from space borne measurements. While a series of past, present and future instruments provide extensive date sets of such aerosol characteristics as extinction coefficient or backscattering ratio, information on a size distribution of the stratospheric aerosols is sparse. One of the important sources on vertically and spatially resolved information on the particle size distribution of stratospheric aerosols is provided by space borne measurements of the scattered solar light in limb viewing geometry performed in visible, near-infrared and short-wave infrared spectral ranges. SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) instrument operated on the European satellite Envisat from 2002 to 2102 was capable of providing spectral information needed to retrieve parameters of aerosol particle size distributions. In this presentation we discuss the retrieval method, present first validation results with SAGE II data and analyze first data sets of stratospheric aerosol particle size distribution parameters obtained from SCIAMACHY limb measurements. The research work was performed in the framework of ROMIC (Role of the middle atmosphere in climate) project.

Scale effects between body size and limb design in quadrupedal mammals.

PubMed

Kilbourne, Brandon M; Hoffman, Louwrens C

2013-01-01

Recently the metabolic cost of swinging the limbs has been found to be much greater than previously thought, raising the possibility that limb rotational inertia influences the energetics of locomotion. Larger mammals have a lower mass-specific cost of transport than smaller mammals. The scaling of the mass-specific cost of transport is partly explained by decreasing stride frequency with increasing body size; however, it is unknown if limb rotational inertia also influences the mass-specific cost of transport. Limb length and inertial properties--limb mass, center of mass (COM) position, moment of inertia, radius of gyration, and natural frequency--were measured in 44 species of terrestrial mammals, spanning eight taxonomic orders. Limb length increases disproportionately with body mass via positive allometry (length ∝ body mass(0.40)); the positive allometry of limb length may help explain the scaling of the metabolic cost of transport. When scaled against body mass, forelimb inertial properties, apart from mass, scale with positive allometry. Fore- and hindlimb mass scale according to geometric similarity (limb mass ∝ body mass(1.0)), as do the remaining hindlimb inertial properties. The positive allometry of limb length is largely the result of absolute differences in limb inertial properties between mammalian subgroups. Though likely detrimental to locomotor costs in large mammals, scale effects in limb inertial properties appear to be concomitant with scale effects in sensorimotor control and locomotor ability in terrestrial mammals. Across mammals, the forelimb's potential for angular acceleration scales according to geometric similarity, whereas the hindlimb's potential for angular acceleration scales with positive allometry.

Scale Effects between Body Size and Limb Design in Quadrupedal Mammals

PubMed Central

Kilbourne, Brandon M.; Hoffman, Louwrens C.

2013-01-01

Recently the metabolic cost of swinging the limbs has been found to be much greater than previously thought, raising the possibility that limb rotational inertia influences the energetics of locomotion. Larger mammals have a lower mass-specific cost of transport than smaller mammals. The scaling of the mass-specific cost of transport is partly explained by decreasing stride frequency with increasing body size; however, it is unknown if limb rotational inertia also influences the mass-specific cost of transport. Limb length and inertial properties – limb mass, center of mass (COM) position, moment of inertia, radius of gyration, and natural frequency – were measured in 44 species of terrestrial mammals, spanning eight taxonomic orders. Limb length increases disproportionately with body mass via positive allometry (length ∝ body mass0.40); the positive allometry of limb length may help explain the scaling of the metabolic cost of transport. When scaled against body mass, forelimb inertial properties, apart from mass, scale with positive allometry. Fore- and hindlimb mass scale according to geometric similarity (limb mass ∝ body mass1.0), as do the remaining hindlimb inertial properties. The positive allometry of limb length is largely the result of absolute differences in limb inertial properties between mammalian subgroups. Though likely detrimental to locomotor costs in large mammals, scale effects in limb inertial properties appear to be concomitant with scale effects in sensorimotor control and locomotor ability in terrestrial mammals. Across mammals, the forelimb's potential for angular acceleration scales according to geometric similarity, whereas the hindlimb's potential for angular acceleration scales with positive allometry. PMID:24260117

Smouldering Fires in the Earth System

NASA Astrophysics Data System (ADS)

Rein, G.

2012-04-01

Smouldering fires, the slow, low-temperature, flameless burning, represent the most persistent type of combustion phenomena and the longest continuously fires on Earth system. Indeed, smouldering mega-fires of peatlands occur with some frequency during the dry session in, for example, Indonesia, Canada, Russia, UK and USA. Smouldering fires propagate slowly through organic layers of the ground and can reach depth >5 m if large cracks, natural piping or channel systems exist. It threatens to release sequestered carbon deep into the soil. Once ignited, they are particularly difficult to extinguish despite extensive rains, weather changes or fire-fighting attempts, and can persist for long periods of time (months, years) spreading deep and over extensive areas. Recent figures at the global scale estimate that average annual greenhouse gas emissions from smouldering fires are equivalent to 15% of man-made emissions. These fires are difficult or impossible to detect with current remote sensing methods because the chemistry is significantly different, their thermal radiation signature is much smaller, and the plume is much less buoyant. These wildfires burn fossil fuels and thus are a carbon-positive fire phenomena. This creates feedbacks in the climate system because soil moisture deficit and self-heating are enchanted under warmer climate scenarios and lead to more frequent fires. Warmer temperatures at high latitudes are resulting in more frequent Artic fires. Unprecedented permafrost thaw is leaving large soil carbon pools exposed to smouldering fires for the fist time since millennia. Although interactions between flaming fires and the Earth system have been a central focus, smouldering fires are as important but have received very little attention. DBut differences with flaming fires are important. This paper reviews the current knowledge on smouldering fires in the Earth system regarding combustion dynamics, damage to the soil, emissions, remote sensing and

Artificial limb connection

NASA Technical Reports Server (NTRS)

Owens, L. J.

1974-01-01

Connection simplifies and eases donning and removing artificial limb; eliminates harnesses and clamps; and reduces skin pressures by allowing bone to carry all tensile and part of compressive loads between prosthesis and stump. Because connection is modular, it is easily modified to suit individual needs.

Regeneration and repair of human digits and limbs: fact and fiction

PubMed Central

Cheng, Tsun‐Chih

2015-01-01

Abstract A variety of digit and limb repair and reconstruction methods have been used in different clinical settings, but regeneration remains an item on every plastic surgeon's “wish list.” Although surgical salvage techniques are continually being improved, unreplantable digits and limbs are still abundant. We comprehensively review the structural and functional salvage methods in clinical practice, from the peeling injuries of small distal fingertips to multisegmented amputated limbs, and the developmental and tissue engineering approaches for regenerating human digits and limbs in the laboratory. Although surgical techniques have forged ahead, there are still situations in which digits and limbs are unreplantable. Advances in the field are delineated, and the regeneration processes of salamander limbs, lizard tails, and mouse digits and each component of tissue engineering approaches for digit‐ and limb‐building are discussed. Although the current technology is promising, there are many challenges in human digit and limb regeneration. We hope this review inspires research on the critical gap between clinical and basic science, and leads to more sophisticated digit and limb loss rescue and regeneration innovations. PMID:27499873

A limb action detector enabling people with multiple disabilities to control environmental stimulation through limb action with a Nintendo Wii Remote Controller.

PubMed

Shih, Ching-Hsiang; Chang, Man-Ling; Shih, Ching-Tien

2010-01-01

This study assessed whether two persons with multiple disabilities would be able to control environmental stimulation using limb action with a Nintendo Wii Remote Controller and a newly developed limb action detection program (LADP, i.e., a new software program that turns a Wii Remote Controller into a precise limb action detector). This study was carried out according to an ABAB sequence in which A represented baseline and B represented intervention phases. Data showed that both participants significantly increased their target response, thus increasing the level of environmental stimulation by activating the control system through limb action, during the intervention phases. Practical and developmental implications of the findings are discussed. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Scavenging energy from human limb motions

NASA Astrophysics Data System (ADS)

Fan, Kangqi; Yu, Bo; Tang, Lihua

2017-04-01

This paper proposes a nonlinear piezoelectric energy harvester (PEH) to scavenge energy from human limb motions. The proposed PEH is composed of a ferromagnetic ball, a sleeve, and two piezoelectric cantilever beams each with a magnetic tip mass. The ball is used to sense the swing motions of human limbs and excite the beams to vibrate. The two beams, which are sensitive to the excitation along the radialis or tibial axis, generate electrical outputs. Theoretical and experimental studies are carried out to examine the performance of the proposed PEH when it is fixed at the wrist, thigh and ankle of a male who travels at constant velocities of 2 km/h, 4 km/h, 6 km/h, and 8 km/h on a treadmill. The results indicate that the low-frequency swing motions of human limbs are converted to higher-frequency vibrations of piezoelectric beams. During each gait cycle, different excitations produced by human limbs can be superposed and multiple peaks in the voltage output can be generated by the proposed PEH. Moreover, the voltage outputs of the PEH increase monotonously with the walking speed, and the maximum effective voltage is obtained when the PEH is mounted at the ankle under the walking speed of 8 km/h.

Upper limb injury in rugby union football: results of a cohort study.

PubMed

Usman, Juliana; McIntosh, Andrew Stuart

2013-04-01

There have been few in-depth studies of upper limb injury epidemiology in rugby union football, despite reports that they accounted for between 14% and 28% of all rugby injuries. To report on upper limb injury incidence, injury severity and to identify the risk factors associated with upper limb injuries, for example, level of play, season (years) and playing position. Prospective cohort study across five rugby seasons from 2004 to 2008. Formal rugby competitions-suburban, provincial and international. 1475 adult male rugby players in Colts, Grade and Elite competitions. An upper limb injury resulting in a missed game and its characteristics. A total of 61 598 athletic exposures (AE) and 606 upper limb injuries were recorded. About 66% of the injuries were to the shoulder. The overall upper limb injury incidence rate (IIR) was 9.84 injuries/1000 AE (95% CI 9.06 to 10.62). Statistically significant associations were found between upper limb injuries and level of play; and between shoulder injuries and playing position (p<0.05). No association was found between upper limb and shoulder injuries and study year. The overall upper limb IIR decreased as the level of play increased; 10.74 upper limb injuries/1000 AE (95% CI 9.93 to 11.56) in Colts to 6.07 upper limb injuries/1000 AE (95% CI 5.46 to 6.69) in Elite. The upper limb IIR decreased as the level of play increased indicating that age, level of skill and playing experience may be risk factors for upper limb injury.

Limb-use by foraging marine turtles, an evolutionary perspective

PubMed Central

McLeish, Don; Brooks, Andrew J.; Gaskell, John; Van Houtan, Kyle S.

2018-01-01

The use of limbs for foraging is documented in both marine and terrestrial tetrapods. These behaviors were once believed to be less likely in marine tetrapods due to the physical constraints of body plans adapted to locomotion in a fluid environment. Despite these obstacles, ten distinct types of limb-use while foraging have been previously reported in nine marine tetrapod families. Here, we expand the types of limb-use documented in marine turtles and put it in context with the diversity of marine tetrapods currently known to use limbs for foraging. Additionally, we suggest that such behaviors could have occurred in ancestral turtles, and thus, possibly extend the evolutionary timeline of limb-use behavior in marine tetrapods back approximately 70 million years. Through direct observation in situ and crowd-sourcing, we document the range of behaviors across habitats and prey types, suggesting its widespread occurrence. We argue the presence of these behaviors among marine tetrapods may be limited by limb mobility and evolutionary history, rather than foraging ecology or social learning. These behaviors may also be remnant of ancestral forelimb-use that have been maintained due to a semi-aquatic life history. PMID:29610708

Limb-use by foraging marine turtles, an evolutionary perspective.

PubMed

Fujii, Jessica A; McLeish, Don; Brooks, Andrew J; Gaskell, John; Van Houtan, Kyle S

2018-01-01

The use of limbs for foraging is documented in both marine and terrestrial tetrapods. These behaviors were once believed to be less likely in marine tetrapods due to the physical constraints of body plans adapted to locomotion in a fluid environment. Despite these obstacles, ten distinct types of limb-use while foraging have been previously reported in nine marine tetrapod families. Here, we expand the types of limb-use documented in marine turtles and put it in context with the diversity of marine tetrapods currently known to use limbs for foraging. Additionally, we suggest that such behaviors could have occurred in ancestral turtles, and thus, possibly extend the evolutionary timeline of limb-use behavior in marine tetrapods back approximately 70 million years. Through direct observation in situ and crowd-sourcing, we document the range of behaviors across habitats and prey types, suggesting its widespread occurrence. We argue the presence of these behaviors among marine tetrapods may be limited by limb mobility and evolutionary history, rather than foraging ecology or social learning. These behaviors may also be remnant of ancestral forelimb-use that have been maintained due to a semi-aquatic life history.

Upper Limb Posture Estimation in Robotic and Virtual Reality-Based Rehabilitation

PubMed Central

Cortés, Camilo; Ardanza, Aitor; Molina-Rueda, F.; Cuesta-Gómez, A.; Ruiz, Oscar E.

2014-01-01

New motor rehabilitation therapies include virtual reality (VR) and robotic technologies. In limb rehabilitation, limb posture is required to (1) provide a limb realistic representation in VR games and (2) assess the patient improvement. When exoskeleton devices are used in the therapy, the measurements of their joint angles cannot be directly used to represent the posture of the patient limb, since the human and exoskeleton kinematic models differ. In response to this shortcoming, we propose a method to estimate the posture of the human limb attached to the exoskeleton. We use the exoskeleton joint angles measurements and the constraints of the exoskeleton on the limb to estimate the human limb joints angles. This paper presents (a) the mathematical formulation and solution to the problem, (b) the implementation of the proposed solution on a commercial exoskeleton system for the upper limb rehabilitation, (c) its integration into a rehabilitation VR game platform, and (d) the quantitative assessment of the method during elbow and wrist analytic training. Results show that this method properly estimates the limb posture to (i) animate avatars that represent the patient in VR games and (ii) obtain kinematic data for the patient assessment during elbow and wrist analytic rehabilitation. PMID:25110698

Spectroscopic identification of rare earth elements in phosphate glass

NASA Astrophysics Data System (ADS)

Devangad, Praveen; Tamboli, Maktum; Muhammed Shameem, K. M.; Nayak, Rajesh; Patil, Ajeetkumar; Unnikrishnan, V. K.; Santhosh, C.; Kumar, G. A.

2018-01-01

In this work, rare earth-doped phosphate glasses were synthesized and characterized using three different spectroscopic techniques. The absorption spectra of the prepared praseodymium (Pr) and samarium (Sm) doped glasses, recorded by a UV-VIS-NIR spectrophotometer, show the characteristic absorption bands of these elements. To confirm this inference, laser-induced fluorescence spectra of Pr and Sm were obtained at a laser excitation of 442 nm. Their emission bands are reported here. The elemental analysis of these samples was carried out using a laser-induced breakdown spectroscopy (LIBS) system. Characteristic emission lines of Pr and Sm have been identified and reported by the recorded LIBS spectra of glass samples. Results prove that using these three complimentary spectroscopic techniques (absorption, fluorescence and LIBS), we can meaningfully characterize rare earth-doped glass samples.

Earth Observations taken by Expedition 30 crewmember

NASA Image and Video Library

2012-01-29

ISS030-E-055569 (29 Jan. 2012) --- Southeastern USA at night is featured in this image photographed by an Expedition 30 crew member on the International Space Station. The brightly lit metropolitan areas of Atlanta, GA (center) and Jacksonville, FL (lower right) appear largest in the image with numerous other urban areas forming an interconnected network of light across the region. A large dark region to the northwest of Jacksonville, FL is the Okefenokee National Wildlife Refuge; likewise the ridges of the Appalachian Mountains form dark swaths to the north of Atlanta, GA and west of Charlotte, NC (center). The faint gold and green line of airglow—caused by ultraviolet radiation exciting the gas molecules in the upper atmosphere—parallels the horizon (or Earth limb).

Automatic limb identification and sleeping parameters assessment for pressure ulcer prevention.

PubMed

Baran Pouyan, Maziyar; Birjandtalab, Javad; Nourani, Mehrdad; Matthew Pompeo, M D

2016-08-01

Pressure ulcers (PUs) are common among vulnerable patients such as elderly, bedridden and diabetic. PUs are very painful for patients and costly for hospitals and nursing homes. Assessment of sleeping parameters on at-risk limbs is critical for ulcer prevention. An effective assessment depends on automatic identification and tracking of at-risk limbs. An accurate limb identification can be used to analyze the pressure distribution and assess risk for each limb. In this paper, we propose a graph-based clustering approach to extract the body limbs from the pressure data collected by a commercial pressure map system. A robust signature-based technique is employed to automatically label each limb. Finally, an assessment technique is applied to evaluate the experienced stress by each limb over time. The experimental results indicate high performance and more than 94% average accuracy of the proposed approach. Copyright © 2016 Elsevier Ltd. All rights reserved.

Systems and Methods for Providing Energy to Support Missions in Near Earth Space

NASA Technical Reports Server (NTRS)

Fork, Richard (Inventor)

2015-01-01

A system has a plurality of spacecraft in orbit around the earth for collecting energy from the Sun in space, using stimulated emission to configure that energy as well defined states of the optical field and delivering that energy efficiently throughout the region of space surrounding Earth.

The Near-Earth Object Camera

NASA Astrophysics Data System (ADS)

Mainzer, Amy K.; NEOCam Science Team

2017-10-01

The Near-Earth Object Camera (NEOCam) is a NASA mission in formulation designed to find, track, and provide basic physical characterization of asteroids and comets that make close approaches to Earth. Its goal is to reduce the risk of impacts from undetected near-Earth objects (NEOs) capable of causing global and regional disasters. NEOCam consists of a 50 cm telescope operating at two channels dominated by NEO thermal emission, 4.2-5.0um and 6-10um, in order to better constrain the objects' temperatures and diameters. Orbiting the Sun-Earth L1 Lagrange point, the mission would find hundreds of thousands of NEOs and would make significant progress toward the Congressional objective of discovering more than 90% of NEOs larger than 140 m during its five-year lifetime. The mission uses novel 2048x2048 HgCdTe detectors that extend the wavelength cutoff beyond 10um at an operating temperature of 40K (Dorn et al. 2016). Both the optical system and the detectors are cooled passively using radiators and thermal shields to enable long mission life and to avoid the complexity of cryocoolers or cryogens. NEOCam is currently in an extended Phase A.

Mid-Infrared Ethane Emission on Neptune: 2005-2009

NASA Astrophysics Data System (ADS)

Hammel, Heidi B.; Sitko, M. L.; Russell, R. W.; Lynch, D. K.; Bernstein, L. S.; Perry, R. B.

2009-09-01

Hammel et al. (2006, ApJ 644, 1326) reported 8- to 13-micron spectral observations of Neptune spanning more than a decade. Those data indicated a steady increase in Neptune's 12-micron atmospheric ethane emission from 1985 to 2003, followed by a slight decrease in 2004. The simplest explanation for the intensity variation was an increase in stratospheric effective temperature from 155 K in 1985 to 176 K in 2003 (an average rate of 1.2 K/year), and subsequent decrease to 165 K in 2004 (uncertainties +/- 3 K). Later disk-resolved 12-micron images (Hammel et al. 2007, AJ 134, 637; Orton et al. 2007, AA 473, L5) showed Neptune's ethane emission arose mainly from two regions: emission distributed nearly uniformly around the planet's limb and emission near the south pole. Because much of the non-limb emission was confined to the near-polar region, seasonal variation may play some role in the long-term mid-infrared brightness variations: i.e., more of that region was revealed as Neptune neared solstice in 2005. We will report the results of an additional half decade of mid-infrared spectroscopic observations, from 2005 through 2009, using the Broadband Array Spectrograph System on the NASA Infrared Telescope Facility (IRTF). These post-solstice data should elucidate whether the variations are intrinsic, or due to changes in viewing angle. HBH acknowledges support from NASA grants NNX06AD12G and NNA07CN65A. This work was supported at The Aerospace Corporation by the Independent Research and Development Program. LSB acknowledges the support of Spectral Sciences, Inc. IR and D funding. We also gratefully acknowledge D. Kim (The Aerospace Corporation) for BASS technical support, as well as the support of IRTF staff and telescope operators. We recognize the significant cultural role of Mauna Kea within the indigenous Hawaiian community, and we appreciate the opportunity to conduct observations from this revered site.

Energetic benefits and adaptations in mammalian limbs: Scale effects and selective pressures.

PubMed

Kilbourne, Brandon M; Hoffman, Louwrens C

2015-06-01

Differences in limb size and shape are fundamental to mammalian morphological diversity; however, their relevance to locomotor costs has long been subject to debate. In particular, it remains unknown if scale effects in whole limb morphology could partially underlie decreasing mass-specific locomotor costs with increasing limb length. Whole fore- and hindlimb inertial properties reflecting limb size and shape-moment of inertia (MOI), mass, mass distribution, and natural frequency-were regressed against limb length for 44 species of quadrupedal mammals. Limb mass, MOI, and center of mass position are negatively allometric, having a strong potential for lowering mass-specific locomotor costs in large terrestrial mammals. Negative allometry of limb MOI results in a 40% reduction in MOI relative to isometry's prediction for our largest sampled taxa. However, fitting regression residuals to adaptive diversification models reveals that codiversification of limb mass, limb length, and body mass likely results from selection for differing locomotor modes of running, climbing, digging, and swimming. The observed allometric scaling does not result from selection for energetically beneficial whole limb morphology with increasing size. Instead, our data suggest that it is a consequence of differing morphological adaptations and body size distributions among quadrupedal mammals, highlighting the role of differing limb functions in mammalian evolution. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

Contribution of emissions to concentrations: the TAGGING 1.0 submodel based on the Modular Earth Submodel System (MESSy 2.52)

NASA Astrophysics Data System (ADS)

Grewe, Volker; Tsati, Eleni; Mertens, Mariano; Frömming, Christine; Jöckel, Patrick

2017-07-01

Questions such as what is the contribution of road traffic emissions to climate change? or what is the impact of shipping emissions on local air quality? require a quantification of the contribution of specific emissions sectors to the concentration of radiatively active species and air-quality-related species, respectively. Here, we present a diagnostics package, implemented in the Modular Earth Submodel System (MESSy), which keeps track of the contribution of source categories (mainly emission sectors) to various concentrations. The diagnostics package is implemented as a submodel (TAGGING) of EMAC (European Centre for Medium-Range Weather Forecasts - Hamburg (ECHAM)/MESSy Atmospheric Chemistry). It determines the contributions of 10 different source categories to the concentration of ozone, nitrogen oxides, peroxyacytyl nitrate, carbon monoxide, non-methane hydrocarbons, hydroxyl, and hydroperoxyl radicals ( = tagged tracers). The source categories are mainly emission sectors and some other sources for completeness. As emission sectors, road traffic, shipping, air traffic, anthropogenic non-traffic, biogenic, biomass burning, and lightning are considered. The submodel obtains information on the chemical reaction rates, online emissions, such as lightning, and wash-out rates. It then solves differential equations for the contribution of a source category to each of the seven tracers. This diagnostics package does not feed back to any other part of the model. For the first time, it takes into account chemically competing effects: for example, the competition between NOx, CO, and non-methane hydrocarbons (NMHCs) in the production and destruction of ozone. We show that the results are in-line with results from other tagging schemes and provide plausibility checks for concentrations of trace gases, such as OH and HO2, which have not previously been tagged. The budgets of the tagged tracers, i.e. the contribution from individual source categories (mainly

Review: Biological and Molecular Differences between Tail Regeneration and Limb Scarring in Lizard: An Inspiring Model Addressing Limb Regeneration in Amniotes.

PubMed

Alibardi, Lorenzo

2017-09-01

Tissue regeneration in lizards represents a unique model of regeneration and scarring in amniotes. The tail and limb contain putative stem cells but also dedifferentiating cells contribute to regeneration. Following tail amputation, inflammation is low and cell proliferation high, leading to regeneration while the intense inflammation in the limb leads to low proliferation and scarring. FGFs stimulate tail and limb regeneration and are present in the wound epidermis and blastema while they disappear in the limb wound epidermis 2-3 weeks postamputation in the scarring outgrowth. FGFs localize in the tail blastema and the apical epidermal peg (AEP), an epidermal microregion that allows tail growth but is absent in the limb. Inflammatory cells invade the limb blastema and wound epidermis, impeding the formation of an AEP. An embryonic program of growth is activated in the tail, dominated by Wnt-positive and -negative regulators of cell proliferation and noncoding RNAs, that represent the key regenerative genes. The balanced actions of these regulators likely impede the formation of a tumor in the tail tip. Genes for FACIT and fibrillar collagens, protease inhibitors, and embryonic keratins are upregulated in the regenerating tail blastema. A strong downregulation of genes for both B and T-lymphocyte activation suggests the regenerating tail blastema is a temporal immune-tolerated organ, whereas a scarring program is activated in the limb. Wnt inhibitors, pro-inflammatory genes, negative regulators of cell proliferation, downregulation of myogenic genes, proteases, and oxidases favoring scarring are upregulated. The evolution of an efficient immune system may be the main limiting barrier for organ regeneration in amniotes, and the poor regeneration of mammals and birds is associated with the efficiency of their mature immune system. This does not tolerate embryonic antigens formed in reprogrammed embryonic cells (as for neoplastic cells) that are consequently

Positional information in axolotl and mouse limb extracellular matrix is mediated via heparan sulfate and fibroblast growth factor during limb regeneration in the axolotl (Ambystoma mexicanum).

PubMed

Phan, Anne Q; Lee, Jangwoo; Oei, Michelle; Flath, Craig; Hwe, Caitlyn; Mariano, Rachele; Vu, Tiffany; Shu, Cynthia; Dinh, Andrew; Simkin, Jennifer; Muneoka, Ken; Bryant, Susan V; Gardiner, David M

2015-08-01

Urodele amphibians are unique among adult vertebrates in their ability to regenerate complex body structures after traumatic injury. In salamander regeneration, the cells maintain a memory of their original position and use this positional information to recreate the missing pattern. We used an in vivo gain-of-function assay to determine whether components of the extracellular matrix (ECM) have positional information required to induce formation of new limb pattern during regeneration. We discovered that salamander limb ECM has a position-specific ability to either inhibit regeneration or induce de novo limb structure, and that this difference is dependent on heparan sulfates that are associated with differential expression of heparan sulfate sulfotransferases. We also discovered that an artificial ECM containing only heparan sulfate was sufficient to induce de novo limb pattern in salamander limb regeneration. Finally, ECM from mouse limbs is capable of inducing limb pattern in axolotl blastemas in a position-specific, developmental-stage-specific, and heparan sulfate-dependent manner. This study demonstrates a mechanism for positional information in regeneration and establishes a crucial functional link between salamander regeneration and mammals.

Land use effects on gaseous nitrogen emissions and gross nitrogen transformations in Amazonian Dark Earth

NASA Astrophysics Data System (ADS)

Barbosa Lima, Amanda; Westphal Muniz, Aleksander; Lenhart, Katharina; Moser, Gerald; Brenzinger, Kristof; Ha, Mi-Kyung; Eckhardt, Christian; Steffens, Diedrich; Kammann, Claudia; Müller, Christoph

2017-04-01

Amazonian Dark Earth (ADE) in the Brazilian Amazon provide a strong indication that soils lacking in nutrients can be converted into highly fertile land. These soils have been considered as a model soil when compared to the surrounding soil due to the high concentrations of P, Ca, Mg, Zn, Mn, stable organic matter and soil organic C (SOC). Soils with high SOC contents can lead to extensive emissions of the greenhouse gas N2O. In this context, we measured the fluxes of CO2, N2O and CH4 in ADE and adjacent (ADJ) soils under secondary forest and manioc plantation. Moreover, we added 15N-NH4+ and -NO3- and measured N2O emissions and gross-N transformations of the different N species for two weeks (15N signal, N concentrations; work on-going), to quantify the simultaneousyl operating N transformation rates (method see: Müller et al. (2004; 2007). We observed higher amounts of NO3- in both ADE and ADJ soils under forest. High consumption rates for NH4+ were shown by both ADE soils under forest followed by manioc plantation. CO2 effluxes from ADJ were higher than from ADE soils, and higher from the forest compared to the manioc plantation. N2O fluxes were much lower in ADE under forest and higher in the other soils. The results of the gross N transformations are distinctively different among ADE and Adjacent sites, providing a strong indication how the dynamics of the individual N transformation rates have been affected by the long-term management. References cited Müller et al. (2004) A 15N tracing model to analyse N-transformations in old grassland soil. SBB 36:619-632. Müller et al. (2007) Estimation of parameters in complex 15N tracing models by Monte Carlo sampling. SBB 39:715-726.

Limb lengthening over plate

PubMed Central

Kulkarni, Ruta; Singh, Nishant; Kulkarni, Govind S; Kulkarni, Milind; Kulkarni, Sunil; Kulkarni, Vidisha

2012-01-01

Background: The limb lengthening over plate eliminates the associated risk of infection with limb lengthening over intramedullary nail. We present our experience of limb lengthening in 15 patients with a plate fixed on the proximal segment, followed by corticotomy and application of external fixator. Materials and Methods: 15 patients (7 females, 8 males) were included in this consecutive series. The average age was 18.1 years (range 8–35 years). Fifteen tibiae and one femur were lengthened in 15 patients. Lengthening was achieved at 1 mm/day followed by distal segment fixation with three or four screws on reaching the target length. Results: The preoperative target length was successfully achieved in all patients at a mean of 4.1 cm (range 1.8–6.5 cm). The mean duration of external fixation was 75.3 days (range 33–116 days) with the mean external fixation index at 19.2 days/cm (range 10.0–38.3 days/cm). One patient suffered deep infection up to the plate, three patients had mild procurvatum deformities, and one patient developed mild tendo achilles contracture. Conclusion: Lengthening over a plate allows early removal of external fixator and eliminates the risk of creating deep intramedullary infection as with lengthening over nail. Lengthening over plate is also applicable to children with open physis. PMID:22719123

A comparison of upper limb amputees and patients with upper limb injuries using the Disability of the Arm, Shoulder and Hand (DASH).

PubMed

Davidson, Judith

To use the Disability of the Arm Shoulder and Hand (DASH) scale to measure the disability of patients with upper limb amputation(s) and to compare these to other upper limb injuries. All 274 patients over the age of 18 years presenting to Prince Henry Hospital in Sydney over a 4-year time frame were given the DASH assessment tool and asked to complete it under supervision of the Occupational Therapist. Patients with brachial plexus injuries, Complex Regional Pain Syndrome and bilateral upper limb amputations demonstrated significantly higher levels of disability to patients with unilateral upper limb amputations. Partial hand amputees reported a higher level of disability than major unilateral upper limb amputees. For the 48 patients who completed pre- and post-treatment assessments, there was a significant improvement in their health status. Further research is required to understand the factors that affect a patient's perceptions of their disability. Perhaps the definitive nature of an amputation and the immediate involvement of highly skilled health professionals serve to assist patients to accept their injury and therefore minimizes the level of disability.

Earth Observations taken by Expedition 34 crewmember

NASA Image and Video Library

2013-02-14

ISS034-E-48455 (14 Feb. 2013) --- Looking out at Earth?s surface from the International Space Station (ISS), astronauts and cosmonauts frequently observe sunglint highlighting both ocean and inland water surfaces. The Atlantic Ocean, including Cape Cod Bay and Buzzards Bay, along the coastlines of Massachusetts and Rhode Island, has a burnished, mirror-like appearance in this image. This is due to sunlight reflected off the water surface back towards the station crew member who took the photo. The peak reflection point is towards the right side of the image, lending the waters of Long Island Sound and the upper Massachusetts coastline an even brighter appearance. Sunglint also illuminates the surface waters of Chesapeake Bay, located over 400 kilometers (250 miles) to the southwest of the tip of Long Island. This suggests that the Sun was low on the horizon due to the observed extent of the sunglint effect. The time of image acquisition, approximately 4:26 p.m. Eastern Standard Time, was about one hour before local sunset. There is little in this image to indicate that the region was still recovering from a major winter storm that dropped almost one meter (three feet) of snow over much of the northeastern USA less than a week earlier. The high viewing angle from the space station also allows Earth?s curvature, or limb, to be seen; blue atmospheric layers gradually fade into the darkness of space across the top part of the image. Low clouds near Cape Cod, Long Island, and further down the Atlantic coastline cast shadows over the water surfaces, reducing the sunglint in some areas.

Rare Earth Optical Temperature Sensor

NASA Technical Reports Server (NTRS)

Chubb, Donald L.; Wolford, David S.

2000-01-01

A new optical temperature sensor suitable for high temperatures (greater than 1700 K) and harsh environments is introduced. The key component of the sensor is the rare earth material contained at the end of a sensor that is in contact with the sample being measured. The measured narrow wavelength band emission from the rare earth is used to deduce the sample temperature. A simplified relation between the temperature and measured radiation was verified experimentally. The upper temperature limit of the sensor is determined by material limits to be approximately 2000 C. The lower limit, determined by the minimum detectable radiation, is found to be approximately 700 K. At high temperatures 1 K resolution is predicted. Also, millisecond response times are calculated.

Different regulation of limb development by p63 transcript variants.

PubMed

Kawata, Manabu; Taniguchi, Yuki; Mori, Daisuke; Yano, Fumiko; Ohba, Shinsuke; Chung, Ung-Il; Shimogori, Tomomi; Mills, Alea A; Tanaka, Sakae; Saito, Taku

2017-01-01

The apical ectodermal ridge (AER), located at the distal end of each limb bud, is a key signaling center which controls outgrowth and patterning of the proximal-distal axis of the limb through secretion of various molecules. Fibroblast growth factors (FGFs), particularly Fgf8 and Fgf4, are representative molecules produced by AER cells, and essential to maintain the AER and cell proliferation in the underlying mesenchyme, meanwhile Jag2-Notch pathway negatively regulates the AER and limb development. p63, a transcription factor of the p53 family, is expressed in the AER and indispensable for limb formation. However, the underlying mechanisms and specific roles of p63 variants are unknown. Here, we quantified the expression of p63 variants in mouse limbs from embryonic day (E) 10.5 to E12.5, and found that ΔNp63γ was strongly expressed in limbs at all stages, while TAp63γ expression was rapidly increased in the later stages. Fluorescence-activated cell sorting analysis of limb bud cells from reporter mouse embryos at E11.5 revealed that all variants were abundantly expressed in AER cells, and their expression was very low in mesenchymal cells. We then generated AER-specific p63 knockout mice by mating mice with a null and a flox allele of p63, and Msx2-Cre mice (Msx2-Cre;p63Δ/fl). Msx2-Cre;p63Δ/fl neonates showed limb malformation that was more obvious in distal elements. Expression of various AER-related genes was decreased in Msx2-Cre;p63Δ/fl limb buds and embryoid bodies formed by p63-knockdown induced pluripotent stem cells. Promoter analyses and chromatin immunoprecipitation assays demonstrated Fgf8 and Fgf4 as transcriptional targets of ΔNp63γ, and Jag2 as that of TAp63γ. Furthermore, TAp63γ overexpression exacerbated the phenotype of Msx2-Cre;p63Δ/fl mice. These data indicate that ΔNp63 and TAp63 control limb development through transcriptional regulation of different target molecules with different roles in the AER. Our findings contribute to

Atmospheric Expression of Seasonality on the Early Earth and Earth-like Exoplanets

NASA Astrophysics Data System (ADS)

Olson, S. L.; Schwieterman, E. W.; Reinhard, C. T.; Ridgwell, A.; Lyons, T. W.

2017-12-01

Biologically modulated seasonality impacts nearly every chemical constituent of Earth's atmosphere. For example, seasonal shifts in the balance of photosynthesis and respiration manifest as striking oscillation in the atmospheric abundance of CO2 and O2. Similar temporal variability is likely on other inhabited worlds, and seasonality is often regarded as a potential exoplanetary biosignature. Seasonality is a particularly intriguing biosignature because it may allow us to identify life through the abundance of spectrally active gases that are not uniquely biological in origin (e.g., CO2 or CH4). To date, however, the discussion of seasonality as a biosignature has been exclusively qualitative. We lack both quantitative constraints on the likelihood of spectrally detectable seasonality elsewhere and a framework for evaluating potential false positive scenarios (e.g., seasonal CO2 ice sublimation). That is, we do not yet know for which gases, and under which conditions, we could expect to detect seasonality and reliably infer the presence of an active biosphere. The composition of Earth's atmosphere has changed dramatically through time, and consequently, the atmospheric expression of seasonality has necessarily changed throughout Earth history as well. Thus, Earth offers several case studies for examining the potential for observable seasonality on chemically and tectonically diverse exoplanets. We outline an approach for exploring the history of seasonality on Earth via coupled biogeochemical and photochemical models, with particular emphasis on the seasonal cycles of CO2, CH4, and O2/O3. We also discuss the remote detectability of these seasonal signals on directly imaged exoplanets via reflectance and emission spectra. We suggest that seasonality in O2 on the early Earth was biogeochemically significant—and that seasonal cycles in O3, an indirect biological product coupled to biogenic O2, may be a readily detectable fingerprint of life in the absence of

STS-30 aft flight deck onboard view of overhead window, Earth limb, cow photo

NASA Technical Reports Server (NTRS)

1989-01-01

Since the beginning of manned space travel, astronauts have taken onboard with them items of person sentiment. During STS-30 onboard Atlantis, Orbiter Vehicle (OV) 104, Mission Specialist Mark C. Lee brought along a photograph of a cow. The photo testifies to his background as one reared on a Wisconsin farm and is displayed on aft flight deck alongside an overhead window. Outside the window, some 160 nautical miles away, is the cloud-covered Earth surface.

Coherent emission mechanisms in astrophysical plasmas

NASA Astrophysics Data System (ADS)

Melrose, D. B.

2017-12-01

Three known examples of coherent emission in radio astronomical sources are reviewed: plasma emission, electron cyclotron maser emission (ECME) and pulsar radio emission. Plasma emission is a multi-stage mechanism with the first stage being generation of Langmuir waves through a streaming instability, and subsequent stages involving partial conversion of the Langmuir turbulence into escaping radiation at the fundamental (F) and second harmonic (H) of the plasma frequency. The early development and subsequent refinements of the theory, motivated by application to solar radio bursts, are reviewed. The driver of the instability is faster electrons outpacing slower electrons, resulting in a positive gradient ({d}f(v_allel )/{d}v_allel >0) at the front of the beam. Despite many successes of the theory, there is no widely accepted explanation for type I bursts and various radio continua. The earliest models for ECME were purely theoretical, and the theory was later adapted and applied to Jupiter (DAM), the Earth (AKR), solar spike bursts and flare stars. ECME strongly favors the x mode, whereas plasma emission favors the o mode. Two drivers for ECME are a ring feature (implying {d}f(v)/{d}v>0) and a loss-cone feature. Loss-cone-driven ECME was initially favored for all applications. The now favored driver for AKR is the ring-feature in a horseshoe distribution, which results from acceleration by a parallel electric on converging magnetic field lines. The driver in DAM and solar and stellar applications is uncertain. The pulsar radio emission mechanism remains an enigma. Ingredients needed in discussing possible mechanisms are reviewed: general properties of pulsars, pulsar electrodynamics, the properties of pulsar plasma and wave dispersion in such plasma. Four specific emission mechanisms (curvature emission, linear acceleration emission, relativistic plasma emission and anomalous Doppler emission) are discussed and it is argued that all encounter difficulties. Coherent

Cut your losses: self-amputation of injured limbs increases survival.

PubMed

Emberts, Zachary; Miller, Christine W; Kiehl, Daniel; St Mary, Colette M

2017-01-01

Autotomy, self-induced limb loss, is an extreme trait observed throughout the animal kingdom; lizards drop their tails, crickets release their legs, and crabs drop their claws. These repeated evolutionary origins suggest that autotomy is adaptive. Yet, we do not have a firm understanding of the selective pressures that promote and maintain this extreme trait. Although multiple adaptive hypotheses exist, research has generally focused on autotomy's adaptive value as a form of predator escape. However, autotomy could also be selected to reduce the cost of an injured limb, which we investigate here. Previously, this alternative hypothesis has been challenging to directly test because when an injury occurs on an autotomizable limb, that limb is almost always dropped (i.e., autotomy is behaviorally fixed within populations). Recently, however, we have identified a species, Narnia femorata (Insecta: Hemiptera: Coreidae), where some individuals autotomize limbs in response to injury, but some do not. This natural variation allowed us to investigate both the survival costs of retaining an injured limb and the benefits of autotomizing it. In this study, we find a positive association between autotomizing injured limbs and survival, thereby quantifying a new and likely widespread benefit of autotomy-reducing the cost of injury.

Cut your losses: self-amputation of injured limbs increases survival

PubMed Central

Miller, Christine W; Kiehl, Daniel; St. Mary, Colette M

2017-01-01

Abstract Autotomy, self-induced limb loss, is an extreme trait observed throughout the animal kingdom; lizards drop their tails, crickets release their legs, and crabs drop their claws. These repeated evolutionary origins suggest that autotomy is adaptive. Yet, we do not have a firm understanding of the selective pressures that promote and maintain this extreme trait. Although multiple adaptive hypotheses exist, research has generally focused on autotomy’s adaptive value as a form of predator escape. However, autotomy could also be selected to reduce the cost of an injured limb, which we investigate here. Previously, this alternative hypothesis has been challenging to directly test because when an injury occurs on an autotomizable limb, that limb is almost always dropped (i.e., autotomy is behaviorally fixed within populations). Recently, however, we have identified a species, Narnia femorata (Insecta: Hemiptera: Coreidae), where some individuals autotomize limbs in response to injury, but some do not. This natural variation allowed us to investigate both the survival costs of retaining an injured limb and the benefits of autotomizing it. In this study, we find a positive association between autotomizing injured limbs and survival, thereby quantifying a new and likely widespread benefit of autotomy—reducing the cost of injury. PMID:29622925

In vivo locomotor strain in the hindlimb bones of alligator mississippiensis and iguana iguana: implications for the evolution of limb bone safety factor and non-sprawling limb posture

PubMed

Blob; Biewener

1999-05-01

Limb postures of terrestrial tetrapods span a continuum from sprawling to fully upright; however, most experimental investigations of locomotor mechanics have focused on mammals and ground-dwelling birds that employ parasagittal limb kinematics, leaving much of the diversity of tetrapod locomotor mechanics unexplored. This study reports measurements of in vivo locomotor strain from the limb bones of lizard (Iguana iguana) and crocodilian (Alligator mississippiensis) species, animals from previously unsampled phylogenetic lineages with non-parasagittal limb posture and kinematics. Principal strain orientations and shear strain magnitudes indicate that the limb bones of these species experience considerable torsion during locomotion. This contrasts with patterns commonly observed in mammals, but matches predictions from kinematic observations of axial rotation in lizard and crocodilian limbs. Comparisons of locomotor load magnitudes with the mechanical properties of limb bones in Alligator and Iguana indicate that limb bone safety factors in bending for these species range from 5.5 to 10.8, as much as twice as high as safety factors previously calculated for mammals and birds. Limb bone safety factors in shear (3.9-5.4) for Alligator and Iguana are also moderately higher than safety factors to yield in bending for birds and mammals. Finally, correlations between limb posture and strain magnitudes in Alligator show that at some recording locations limb bone strains can increase during upright locomotion, in contrast to expectations based on size-correlated changes in posture among mammals that limb bone strains should decrease with the use of an upright posture. These data suggest that, in some lineages, strain magnitudes may not have been maintained at constant levels through the evolution of a non-sprawling posture unless the postural change was accompanied by a shift to parasagittal kinematics or by an evolutionary decrease in body size.

Navigating the Return Trip from the Moon Using Earth-Based Ground Tracking and GPS

NASA Technical Reports Server (NTRS)

Berry, Kevin; Carpenter, Russell; Moreau, Michael C.; Lee, Taesul; Holt, Gregg N.

2009-01-01

NASA s Constellation Program is planning a human return to the Moon late in the next decade. From a navigation perspective, one of the most critical phases of a lunar mission is the series of burns performed to leave lunar orbit, insert onto a trans-Earth trajectory, and target a precise re-entry corridor in the Earth s atmosphere. A study was conducted to examine sensitivity of the navigation performance during this phase of the mission to the type and availability of tracking data from Earth-based ground stations, and the sensitivity to key error sources. This study also investigated whether GPS measurements could be used to augment Earth-based tracking data, and how far from the Earth GPS measurements would be useful. The ability to track and utilize weak GPS signals transmitted across the limb of the Earth is highly dependent on the configuration and sensitivity of the GPS receiver being used. For this study three GPS configurations were considered: a "standard" GPS receiver with zero dB antenna gain, a "weak signal" GPS receiver with zero dB antenna gain, and a "weak signal" GPS receiver with an Earth-pointing direction antenna (providing 10 dB additional gain). The analysis indicates that with proper selection and configuration of the GPS receiver on the Orion spacecraft, GPS can potentially improve navigation performance during the critical final phases of flight prior to Earth atmospheric entry interface, and may reduce reliance on two-way range tracking from Earth-based ground stations.

The Inclusion of Thermal Emissions Within the SASKTRAN Framework

NASA Astrophysics Data System (ADS)

Jensen, K. L.; Bourassa, A. E.; Lloyd, N. D.; Degenstein, D. A.

2013-12-01

The SASKTRAN radiative transfer model developed at the University of Saskatchewan has a long heritage associated with simulations of spectrally dispersed limb scattered sunlight. Recent advancements in the SASKTRAN model have allowed for the inclusion of thermal emissions, as a new source of light, originating within the atmosphere and from the ground. Within the model these thermal emissions are then subsequently propagated through the atmosphere while being scattered and absorbed in the exact same fashion as if sunlight were the source of photons. This development allows for the use of the existing and elaborate SASKTRAN infrastructure in the near infrared where scattering of sunlight and thermal emissions contribute with similar fractions to the total intensity of any atmospheric radiance measurement. This paper details the changes to the SASKTRAN model required to accurately simulate scattered thermal emissions and presents results related to the remote sensing of atmospheric constituents such as carbon dioxide, carbon monoxide and methane from satellite platforms.

[Limb lengthening in dwarfism].

PubMed

Correll, J; Held, P

2000-09-01

Limb lengthening in dwarfism has become a standardised procedure with a good prognosis. In most cases external fixation is used. Gain of leg length up to 15 cm and more is possible in the lower leg and the femur and 8.5 cm in the humerus. Limb lengthening is useful in many cases of dwarfism due to skeletal dysplasia. There are a number of risks and possible complications involved and the procedure also requires considerable time. We report the results of 48 patients with dwarfism operated on in the Orthopädische Kinderklinik Aschau (Orthopaedic Hospital for Children). It must not be recommended as a normal tool in handling the problems of dwarfism, but it makes sense in some cases of dwarfism. We describe and discuss the prerequisites for the operative treatment.

Update on embryology of the upper limb.

PubMed

Al-Qattan, Mohammad M; Kozin, Scott H

2013-09-01

Current concepts in the steps of upper limb development and the way the limb is patterned along its 3 spatial axes are reviewed. Finally, the embryogenesis of various congenital hand anomalies is delineated with an emphasis on the pathogenetic basis for each anomaly. Copyright © 2013 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Twilight Limb Observations of the Martian North Polar Hood by MAVEN IUVS

NASA Astrophysics Data System (ADS)

Lo, Daniel; Yelle, Roger; Schneider, Nicholas M.; Jain, Sonal Kumar; Stewart, Ian; Deighan, Justin; Stiepen, Arnaud; Evans, Scott; Stevens, Michael H.; Chaffin, Michael S.; Crismani, Matteo; McClintock, William; Clarke, John T.; Holsclaw, Gregory; Lefevre, Franck; Jacosky, Bruce

2016-10-01

In northern winter, a broad distribution of ice aerosols appears in the north polar atmosphere of Mars, commonly referred to as the North Polar Hood (NPH). The NPH is thought to be formed as a result of condensation from lowered temperatures associated with both seasonal and diurnal variations in solar heating. The spatial extent and density of the NPH is highly variable, with a maximum latitudinal extent spanning 30-80°N, and a maximum density at 10-30 km altitude.The NPH has been extensively observed by both ground-based telescopes and instruments in orbit around Mars. However, the majority of these observations are nadir-pointing. This observation geometry has two significant limitations. Firstly, they poorly probe the vertical structure of the NPH. Secondly, column densities are determined by monitoring the intensity of various spectral features associated with the ice composing the NPH, against a strong background with similar features from the frost that has condensed on the surface in the winter season, resulting in low sensitivities. Limb observations removes both limitations, allowing us to study the vertical distribution of the aerosols that make up the NPH at high sensitivities.We present new limb observations of the NPH by IUVS (Imaging Ultraviolet Spectrograph) on the MAVEN (Mars Atmospheric and Volatile Evolution) spacecraft. These observations represent the first ultraviolet limb observations of the NPH, opening a new window for understanding the structure and composition of the NPH. The observations are also of the twilight limb, with sunlight being scattered from the dayside into the nightside over large solar zenith angles. This illumination geometry allows us to avoid the high dayside intensities that would drown out the signal from the thinner sections of the NPH. We determine the latitudinal extent of the NPH to be 30-60°N. We also find that an exponential altitude distribution of aerosols is able to reproduce the observed intensities, with a

integrated Earth System Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Andew; Di Vittorio, Alan; Collins, William

The integrated Earth system model (iESM) has been developed as a new tool for projecting the joint human/climate system. The iESM is based upon coupling an integrated assessment model (IAM) and an Earth system model (ESM) into a common modeling infrastructure. IAMs are the primary tool for describing the human-Earth system, including the sources of global greenhouse gases (GHGs) and short-lived species (SLS), land use and land cover change (LULCC), and other resource-related drivers of anthropogenic climate change. ESMs are the primary scientific tools for examining the physical, chemical, and biogeochemical impacts of human-induced changes to the climate system. Themore » iESM project integrates the economic and human-dimension modeling of an IAM and a fully coupled ESM within a single simulation system while maintaining the separability of each model if needed. Both IAM and ESM codes are developed and used by large communities and have been extensively applied in recent national and international climate assessments. By introducing heretofore-omitted feedbacks between natural and societal drivers, we can improve scientific understanding of the human-Earth system dynamics. Potential applications include studies of the interactions and feedbacks leading to the timing, scale, and geographic distribution of emissions trajectories and other human influences, corresponding climate effects, and the subsequent impacts of a changing climate on human and natural systems.« less

Ectopic expression of Msx-2 in posterior limb bud mesoderm impairs limb morphogenesis while inducing BMP-4 expression, inhibiting cell proliferation, and promoting apoptosis.

PubMed

Ferrari, D; Lichtler, A C; Pan, Z Z; Dealy, C N; Upholt, W B; Kosher, R A

1998-05-01

During early stages of chick limb development, the homeobox-containing gene Msx-2 is expressed in the mesoderm at the anterior margin of the limb bud and in a discrete group of mesodermal cells at the midproximal posterior margin. These domains of Msx-2 expression roughly demarcate the anterior and posterior boundaries of the progress zone, the highly proliferating posterior mesodermal cells underneath the apical ectodermal ridge (AER) that give rise to the skeletal elements of the limb and associated structures. Later in development as the AER loses its activity, Msx-2 expression expands into the distal mesoderm and subsequently into the interdigital mesenchyme which demarcates the developing digits. The domains of Msx-2 expression exhibit considerably less proliferation than the cells of the progress zone and also encompass several regions of programmed cell death including the anterior and posterior necrotic zones and interdigital mesenchyme. We have thus suggested that Msx-2 may be in a regulatory network that delimits the progress zone by suppressing the morphogenesis of the regions of the limb mesoderm in which it is highly expressed. In the present study we show that ectopic expression of Msx-2 via a retroviral expression vector in the posterior mesoderm of the progress zone from the time of initial formation of the limb bud severely impairs limb morphogenesis. Msx-2-infected limbs are typically very narrow along the anteroposterior axis, are occasionally truncated, and exhibit alterations in the pattern of formation of skeletal elements, indicating that as a consequence of ectopic Msx-2 expression the morphogenesis of large portions of the posterior mesoderm has been suppressed. We further show that Msx-2 impairs limb morphogenesis by reducing cell proliferation and promoting apoptosis in the regions of the posterior mesoderm in which it is ectopically expressed. The domains of ectopic Msx-2 expression in the posterior mesoderm also exhibit ectopic

Phase Curve Analysis of Super-Earth 55 Cancri e

NASA Astrophysics Data System (ADS)

Angelo, Isabel; Hu, Renyu

2018-01-01

One of the primary questions when characterizing Earth-sized and super-Earth-sized exoplanets is whether they have a substantial atmosphere like Earth and Venus, or a bare-rock surface that may come with a tenuous atmosphere like Mercury. Phase curves of the planets in thermal emission provide clues to this question, because a substantial atmosphere would transport heat more efficiently than a bare-rock surface. Analyzing phase curve photometric data around secondary eclipse has previously been used to study energy transport in the atmospheres of hot Jupiters. Here we use phase curve, Spitzer time-series photometry to study the thermal emission properties of the super-Earth exoplanet 55 Cancri e. We utilize a previously developed semi-analytical framework to fit a physical model to infrared photometric data of host star 55 Cancri from the Spitzer telescope IRAC 2 band at 4.5 μm. The model uses various parameters of planetary properties including Bond albedo, heat redistribution efficiency (i.e., the ratio between the radiative timescale and advective timescale of the photosphere), and atmospheric greenhouse factor. The phase curve of 55 Cancri e is dominated by thermal emission with an eastward-shifted hot spot located on the planet surface. We determine the heat redistribution efficiency to be ≈1.47, which implies that the advective timescale is on the same order as the radiative timescale. This requirement from the phase curve cannot be met by the bare-rock planet scenario, because heat transport by currents of molten lava would be too slow. The phase curve thus favors the scenario with a substantial atmosphere. Our constraints on the heat redistribution efficiency translate to a photosphere pressure of ~1.4 bar. The Spitzer IRAC 2 band is thus a window into the deep atmosphere of the planet 55 Cancri e.

Expression of Msx genes in regenerating and developing limbs of axolotl.

PubMed

Koshiba, K; Kuroiwa, A; Yamamoto, H; Tamura, K; Ide, H

1998-12-15

Msx genes, homeobox-containing genes, have been isolated as homologues of the Drosophila msh gene and are thought to play important roles in the development of chick or mouse limb buds. We isolated two Msx genes, Msx1 and Msx2, from regenerating blastemas of axolotl limbs and examined their expression patterns using Northern blot and whole mount in situ hybridization during regeneration and development. Northern blot analysis revealed that the expression level of both Msx genes increased during limb regeneration. The Msx2 expression level increased in the blastema at the early bud stage, and Msx1 expression level increased at the late bud stage. Whole mount in situ hybridization revealed that Msx2 was expressed in the distal mesenchyme and Msx1 in the entire mesenchyme of the blastema at the late bud stage. In the developing limb bud, Msx1 was expressed in the entire mesenchyme, while Msx2 was expressed in the distal and peripheral mesenchyme. The expression patterns of Msx genes in the blastemas and limb buds of the axolotl were different from those reported for chick or mouse limb buds. These expression patterns of axolotl Msx genes are discussed in relation to the blastema or limb bud morphology and their possible roles in limb patterning.

Detection of Genes Regulated by Lmx1b During Limb Dorsalization

PubMed Central

Feenstra, Jennifer M.; Kanaya, Kohei; Pira, Charmaine U; Hoffman, Sarah E.; Eppey, Richard J.; Oberg, Kerby C.

2012-01-01

Lmx1b is a homeodomain transcription factor that regulates dorsal identity during limb development. Lmx1b knockout (KO) mice develop distal ventral-ventral limbs. Although induction of Lmx1b is linked to Wnt7a expression in the dorsal limb ectoderm, the downstream targets of Lmx1b that accomplish limb dorsalization are unknown. To identify genes targeted by Lmx1b, we compared gene arrays from Lmx1b KO and wildtype mouse limbs during limb dorsalization, i.e., 11.5, 12.5, and 13.5 days post coitum. We identified 54 target genes differentially expressed in all three stages. Several skeletal targets, including Emx2, Matrilin1 and Matrilin4, demonstrated a loss of scapular expression in the Lmx1b KO mice, supporting a role for Lmx1b in scapula development. Furthermore, the relative abundance of extracellular matrix-related soft tissue targets regulated by Lmx1b, such as collagens and proteoglycans, suggests a mechanism which includes changes in the extracellular matrix composition to accomplish limb dorsalization. Our study provides the most comprehensive characterization of genes regulated by Lmx1b during limb development to-date and provides targets for further investigation. PMID:22417325

Does Aerosol Geoengineering the Earth's Climate Pass a Cost-Benefit Test?

NASA Astrophysics Data System (ADS)

Keller, K.; Urban, N.; Tuana, N.

2007-12-01

Anthropogenic carbon dioxide (CO2) emissions are changing the Earth's climate with potentially dangerous consequences. Ratified international agreements call for a reduction of CO2 emissions to avoid dangerous anthropogenic interference with the climate system. Recent studies have, however, proposed an alternative strategy: to geoengineer Earth's climate by injecting aerosol precursors into the stratosphere. It is often claimed that aerosol geoengineering would provide net economic benefits because geoengineering requires far lower near-term investments compared to deep cuts in CO2 emissions. However, aerosol geoengineering projects can also cause nontrivial economic costs. This is because aerosol geoengineering hinges on successfully counterbalancing the forcing effects of CO2 emissions (which decay over centuries) with the forcing effects of aerosol emissions (which decay within years). A failure to maintain this delicate balance can lead to abrupt climatic changes, with potentially substantial economic damages. Deferring cuts in CO2 emissions in favor of aerosol geoengineering is hence a deeply uncertain gamble, as it requires so far unknown institutions to reliably control aerosol forcings over centuries. Here we use a simple economic model to evaluate potential costs and benefits of aerosol geoengineering for a wide range of the deeply uncertain parameters. We show that aerosol geoengineering projects may cause economic damages that can far exceed the benefits and may hence fail a cost-benefit test.

Positional information in axolotl and mouse limb extracellular matrix is mediated via heparan sulfate and fibroblast growth factor during limb regeneration in the axolotl (Ambystoma mexicanum)

PubMed Central

Phan, Anne Q.; Lee, Jangwoo; Oei, Michelle; Flath, Craig; Hwe, Caitlyn; Mariano, Rachele; Vu, Tiffany; Shu, Cynthia; Dinh, Andrew; Simkin, Jennifer; Muneoka, Ken; Bryant, Susan V.

2015-01-01

Abstract Urodele amphibians are unique among adult vertebrates in their ability to regenerate complex body structures after traumatic injury. In salamander regeneration, the cells maintain a memory of their original position and use this positional information to recreate the missing pattern. We used an in vivo gain‐of‐function assay to determine whether components of the extracellular matrix (ECM) have positional information required to induce formation of new limb pattern during regeneration. We discovered that salamander limb ECM has a position‐specific ability to either inhibit regeneration or induce de novo limb structure, and that this difference is dependent on heparan sulfates that are associated with differential expression of heparan sulfate sulfotransferases. We also discovered that an artificial ECM containing only heparan sulfate was sufficient to induce de novo limb pattern in salamander limb regeneration. Finally, ECM from mouse limbs is capable of inducing limb pattern in axolotl blastemas in a position‐specific, developmental‐stage‐specific, and heparan sulfate‐dependent manner. This study demonstrates a mechanism for positional information in regeneration and establishes a crucial functional link between salamander regeneration and mammals. PMID:27499874

MEaSUReS Land Surface Temperature and Emissivity data records

NASA Astrophysics Data System (ADS)

Cawse-Nicholson, K.; Hook, S. J.; Gulley, G.; Borbas, E. E.; Knuteson, R. O.

2017-12-01

The NASA MEaSUReS program was put into place to produce long-term, well calibrated and validated data records for Earth Science research. As part of this program, we have developed three Earth System Data Records (ESDR) to measure Land Surface Temperature (LST) and emissivity: a high spatial resolution (1km) LST product using Low Earth Orbiting (LEO) satellites; a high temporal resolution (hourly over North America) LST product using Geostationary (GEO) satellites; and a Combined ASTER MODIS Emissivity for Land (CAMEL) ESDR. CAMEL was produced by merging two state-of-the-art emissivity datasets: the UW-Madison MODIS Infrared emissivity dataset (UWIREMIS), and the JPL ASTER Global Emissivity Dataset v4 (GEDv4). The CAMEL ESDR is currently available for download, and is being tested in sounder retrieval schemes (e.g. CrIS, IASI, AIRS) to reduce uncertainties in water vapor retrievals, and has already been implemented in the radiative transfer software RTTOV v12 for immediate use in numerical weather modeling and data assimilation systems. The LEO-LST product combines two existing MODIS products, using an uncertainty analysis approach to optimize accuracy over different landcover classes. Validation of these approaches for retrieving LST have shown that they are complementary, with the split-window approach (MxD11) being more stable over heavily vegetated regions and the physics-based approach (MxD21) demonstrating higher accuracy in semi-arid and arid regions where the largest variations in emissivity exist, both spatially and spectrally. The GEO LST-ESDR product uses CAMEL ESDR for improved temperature-emissivity separation, and the same atmospheric correction as the LEO LST product to ensure consistency across all three data records.

Vascular access in critical limb ischemia.

PubMed

Kang, Won Yu; Campia, Umberto; Ota, Hideaki; Didier, Romain J; Negi, Smita I; Kiramijyan, Sarkis; Koifman, Edward; Baker, Nevin C; Magalhaes, Marco A; Lipinski, Michael J; Escarcega, Ricardo O; Torguson, Rebecca; Waksman, Ron; Bernardo, Nelson L

2016-01-01

Currently, percutaneous endovascular intervention is considered a first line of therapy for treating patients with critical limb ischemia. As the result of remarkable development of techniques and technologies, percutaneous endovascular intervention has led to rates of limb salvage comparable to those achieved with bypass surgery, with fewer complications, even in the presence of lower rates of long-term patency. Currently, interventionalists have a multiplicity of access routes including smaller arteries, with both antegrade and retrograde approaches. Therefore, the choice of the optimal access site has become an integral part of the success of the percutaneous intervention. By understanding the technical aspects, as well as the advantages and limitations of each approach, the interventionalists can improve clinical outcomes in patients with severe peripheral arterial disease. This article reviews the access routes in critical limb ischemia, their advantages and disadvantages, and the clinical outcomes of each. Copyright © 2016 Elsevier Inc. All rights reserved.

Sall4-Gli3 system in early limb progenitors is essential for the development of limb skeletal elements.

PubMed

Akiyama, Ryutaro; Kawakami, Hiroko; Wong, Julia; Oishi, Isao; Nishinakamura, Ryuichi; Kawakami, Yasuhiko

2015-04-21

Limb skeletal elements originate from the limb progenitor cells, which undergo expansion and patterning to develop each skeletal element. Posterior-distal skeletal elements, such as the ulna/fibula and posterior digits develop in a Sonic hedgehog (Shh)-dependent manner. However, it is poorly understood how anterior-proximal elements, such as the humerus/femur, the radius/tibia and the anterior digits, are developed. Here we show that the zinc finger factors Sall4 and Gli3 cooperate for proper development of the anterior-proximal skeletal elements and also function upstream of Shh-dependent posterior skeletal element development. Conditional inactivation of Sall4 in the mesoderm before limb outgrowth caused severe defects in the anterior-proximal skeletal elements in the hindlimb. We found that Gli3 expression is reduced in Sall4 mutant hindlimbs, but not in forelimbs. This reduction caused posteriorization of nascent hindlimb buds, which is correlated with a loss of anterior digits. In proximal development, Sall4 integrates Gli3 and the Plzf-Hox system, in addition to proliferative expansion of cells in the mesenchymal core of nascent hindlimb buds. Whereas forelimbs developed normally in Sall4 mutants, further genetic analysis identified that the Sall4-Gli3 system is a common regulator of the early limb progenitor cells in both forelimbs and hindlimbs. The Sall4-Gli3 system also functions upstream of the Shh-expressing ZPA and the Fgf8-expressing AER in fore- and hindlimbs. Therefore, our study identified a critical role of the Sall4-Gli3 system at the early steps of limb development for proper development of the appendicular skeletal elements.

In situ saphenous vein bypass for limb salvage.

PubMed

Sarcina, A; Carlesi, R; Bellosta, R; Agrifoglio, G

1993-02-01

A total of 130 infrapopliteal in situ saphenous vein bypasses were performed in 128 patients between January 1980 and June 1991. The indication for surgery was critical ischaemia with impending limb loss in 121 patients; seven suffered from severe claudication. The distal anastomosis was to the popliteal artery below the knee in 60 cases (46.2%) and in 70 (53.8%) to the tibioperoneal arteries. The results, in terms of secondary patency and limb salvage rates, of the first 68 procedures (1980-1985) and subsequent 62 (1986-June 1991) were compared. In the first period, a secondary patency rate of 42.6% and a limb salvage rate of 67.0% were obtained, compared with 71.3 and 80.8% respectively in the second. These differences are significant for patency (P < 0.005) and limb salvage (P < 0.01). These results show that the in situ technique can give acceptable results but a learning period with a high percentage of early failures is to be expected.

Earth-Atmospheric Coupling During Strong Earthquakes by Analyzing MODIS Data

NASA Technical Reports Server (NTRS)

Ouzounov, Dimitar; Williams, Robin G.; Freund, Friedemann

2001-01-01

Interactions between the Earth and the atmosphere during major earthquakes (M greater than 5) are the subject of this investigation. Recently a mechanism has been proposed predicting the build-up of positive ground potentials prior to strong earthquake activity. Connected phenomena include: transient conductivity of rocks, injection of currents, possibly also electromagnetic emission and light emission from high points at the surface of the Earth. To understand this process we analyze vertical atmospheric profiles, land surface and brightness (temperature) data, using the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard NASA's Terra satellite launched in December 1999. MODIS covers the entire Earth every 1-2 days in 36 wavelength bands (20 visible and 16 infrared) at different spatial resolutions (250 m, 500 m, and 1 km). Using MODIS data we look for correlations between the atmospheric dynamics and solid Earth processes for the January 2001 strong earthquakes in San Salvador and India. As part of the build-up of positive grounds potential, an IR luminescence is predicted to occur in the 8-12 micrometer band. We use the MODIS data to differentiate between true "thermal" signals and IR luminescence. Indeed, on the basis of a temporal and spatial distribution analysis, a thermal anomaly pattern is found that appears to be related to the seismic activity. Aerosol content and atmospheric instability parameters also change when ground charges build up causing ion emission and leading to a thin aerosol layer over land. We analyze the aerosol content, atmospheric pressure, moisture profile and lifted index. Anomalous trends have been identified in few days prior to the main shocks. The significance of this observation should be explored further using other data sets.

Skeletal muscle responses to lower limb suspension in humans

NASA Technical Reports Server (NTRS)

Hather, Bruce M.; Adams, Gregory R.; Tesch, Per A.; Dudley, Gary A.

1992-01-01

The morphological responses of human skeletal muscle to unweighting were assessed by analyzing multiple transaxial magnetic resonance (MR) images of both lower limbs and skeletal muscle biopsies of the unweighted lower limb before and after six weeks of unilaterial (left) lower limb suspension (ULLS). Results indicated that, as a results of 6 weeks of unweighting (by the subjects walking on crutches using only one limb), the cross sectional area (CSA) of the thigh muscle of the unweighted left limb decreased 12 percent, while the CSA of the right thigh muscle did not change. The decrease was due to a twofold greater response of the knee extensors than the knee flexors. The pre- and post-ULLS biopsies of the left vastus lateralis showed a 14 percent decrease in average fiber CSA due to unweighting. The number of capillaries surrounding the different fiber types was unchanged after ULLS. Results showed that the adaptive responses of human skeletal muscle to unweighting are qualitatively, but not quantitatively, similar to those of lower mammals and not necessarily dependent on the fiber-type composition.

Collagen reconstitution is inversely correlated with induction of limb regeneration in Ambystoma mexicanum.

PubMed

Satoh, Akira; Hirata, Ayako; Makanae, Aki

2012-03-01

Amphibians can regenerate missing body parts, including limbs. The regulation of collagen has been considered to be important in limb regeneration. Collagen deposition is suppressed during limb regeneration, so we investigated collagen deposition and apical epithelial cap (AEC) formation during axolotl limb regeneration. The accessory limb model (ALM) has been developed as an alternative model for studying limb regeneration. Using this model, we investigated the relationship between nerves, epidermis, and collagen deposition. We found that Sp-9, an AEC marker gene, was upregulated by direct interaction between nerves and epidermis. However, collagen deposition hindered this interaction, and resulted in the failure of limb regeneration. During wound healing, an increase in deposition of collagen caused a decrease in the blastema induction rate in ALM. Wound healing and limb regeneration are alternate processes.

Observations of EMIC Triggered Emissions off the Magnetic Equatorial Plane

NASA Astrophysics Data System (ADS)

Grison, B.; Breuillard, H.; Santolik, O.; Cornilleau-Wehrlin, N.

2016-12-01

On 19/08/2005 Cluster spacecraft had their perigee close to the dayside of the Earth magnetic equatorial plane, at about 14 hours Magnetic Local Time. The spacecraft crossed the equator from the southern hemisphere toward the northern hemisphere. In the Southern hemisphere, at about -23° magnetic latitude (MLAT) and at distance of 5.25 Earth Radii from Earth, Cluster 3 observes an EMIC triggered emission between the He+ and the proton local gyrofrequencies. The magnetic waveform (STAFF instrument data) is transformed into the Fourier space for a study based on single value decomposition (SVD) analysis. The emission lasts about 30s. The emission frequency rises from 1Hz up to 1.9Hz. The emission polarization is left-hand, its coherence value is high and the propagation angle is field aligned (lower than 30º). The Poynting flux orientation could not be established. Based on previous study results, these properties are indicative of an observation in vicinity of the source region of the triggered emission. From our knowledge this is the first time that EMIC triggered emission are observed off the magnetic equator. In order to identify the source region we study two possibilities: a source region at higher latitudes than the observations (and particles orbiting in "Shabansky" orbits) and a source region close to the magnetic equatorial plane, as reported in previous studies. We propose to identify the source region from ray tracing analysis and to compare the observed propagation angle in several frequency ranges to the ray tracing results.

Image Processing for Planetary Limb/Terminator Extraction

NASA Technical Reports Server (NTRS)

Udomkesmalee, S.; Zhu, D. Q.; Chu, C. -C.

1995-01-01

A novel image segmentation technique for extracting limb and terminator of planetary bodies is proposed. Conventional edge- based histogramming approaches are used to trace object boundaries. The limb and terminator bifurcation is achieved by locating the harmonized segment in the two equations representing the 2-D parameterized boundary curve. Real planetary images from Voyager 1 and 2 served as representative test cases to verify the proposed methodology.

Aurora over Earth limb

NASA Image and Video Library

1994-04-10

STS059-52-029 (9-20 April 1994) --- The constellation Orion is backdropped against a colorful display of the Southern Lights (aurora australis) in this 35mm image. Six NASA astronauts went on to spend a week and a half aboard the Space Shuttle Endeavour in support of the Space Radar Laboratory (SRL-1) mission.

Body image and self-esteem in lower-limb amputees.

PubMed

Holzer, Lukas A; Sevelda, Florian; Fraberger, Georg; Bluder, Olivia; Kickinger, Wolfgang; Holzer, Gerold

2014-01-01

Limb amputation is often an inevitable procedure in the advanced condition of various diseases and poses a dramatic impact on a patient's life. The aim of the present study is to analyze the impact of lower-limb amputations on aesthetic factors such as body image and self-esteem as well as quality of life (QoL). 298 patients (149 uni- or bilateral lower-limb amputees and 149 controls) were included in this cross-sectional study in three centers. Demographic data was collected and patients received a 118-item questionnaire including the Multidimensional Body-Self Relations Questionnaire (MBSRQ), the Rosenberg Self-esteem (RSE) scale and the SF-36 Health Survey (QoL). ANOVA and student's t-test were used for statistical analysis. Unilateral lower-limb amputees showed a significant lower MBSRQ score of 3.07±0.54 compared with 3.41±0.34 in controls (p<0.001) and a lower score in the RSE compared to controls (21.63±4.72 vs. 21.46±5.86). However, differences were not statistically significant (p = 0.36). Patients with phantom pain sensation had a significantly reduced RSE (p = 0.01). The SF-36 health survey was significantly lower in patients with lower-limb amputation compared to controls (42.17±14.47 vs. 64.05±12.39) (p<0.001). This study showed that lower-limb amputations significantly influence patients' body image and QoL. Self-esteem seems to be an independent aspect, which is not affected by lower-limb amputation. However, self-esteem is influenced significantly by phantom pain sensation.

The Earth and Moon As Seen by 2001 Mars Odyssey Thermal Emission Imaging System

NASA Image and Video Library

2001-05-01

NASA Mars Odyssey spacecraft took this portrait of the Earth and its companion Moon. It was taken at a distance of 3,563,735 kilometers more than 2 million miles on April 19, 2001 as the 2001 Mars Odyssey spacecraft left the Earth.

Network based transcription factor analysis of regenerating axolotl limbs

PubMed Central

2011-01-01

Background Studies on amphibian limb regeneration began in the early 1700's but we still do not completely understand the cellular and molecular events of this unique process. Understanding a complex biological process such as limb regeneration is more complicated than the knowledge of the individual genes or proteins involved. Here we followed a systems biology approach in an effort to construct the networks and pathways of protein interactions involved in formation of the accumulation blastema in regenerating axolotl limbs. Results We used the human orthologs of proteins previously identified by our research team as bait to identify the transcription factor (TF) pathways and networks that regulate blastema formation in amputated axolotl limbs. The five most connected factors, c-Myc, SP1, HNF4A, ESR1 and p53 regulate ~50% of the proteins in our data. Among these, c-Myc and SP1 regulate 36.2% of the proteins. c-Myc was the most highly connected TF (71 targets). Network analysis showed that TGF-β1 and fibronectin (FN) lead to the activation of these TFs. We found that other TFs known to be involved in epigenetic reprogramming, such as Klf4, Oct4, and Lin28 are also connected to c-Myc and SP1. Conclusions Our study provides a systems biology approach to how different molecular entities inter-connect with each other during the formation of an accumulation blastema in regenerating axolotl limbs. This approach provides an in silico methodology to identify proteins that are not detected by experimental methods such as proteomics but are potentially important to blastema formation. We found that the TFs, c-Myc and SP1 and their target genes could potentially play a central role in limb regeneration. Systems biology has the potential to map out numerous other pathways that are crucial to blastema formation in regeneration-competent limbs, to compare these to the pathways that characterize regeneration-deficient limbs and finally, to identify stem cell markers in

100 top-cited scientific papers in limb prosthetics.

PubMed

Eshraghi, Arezoo; Osman, Noor Azuan Abu; Gholizadeh, Hossein; Ali, Sadeeq; Shadgan, Babak

2013-11-17

Research has tremendously contributed to the developments in both practical and fundamental aspects of limb prosthetics. These advancements are reflected in scientific articles, particularly in the most cited papers. This article aimed to identify the 100 top-cited articles in the field of limb prosthetics and to investigate their main characteristics. Articles related to the field of limb prosthetics and published in the Web of Knowledge database of the Institute for Scientific Information (ISI) from the period of 1980 to 2012. The 100 most cited articles in limb prosthetics were selected based on the citation index report. All types of articles except for proceedings and letters were included in the study. The study design and level of evidence were determined using Sackett's initial rules of evidence. The level of evidence was categorized either as a systematic review or meta-analysis, randomized controlled trial, cohort study, case-control study, case series, expert opinion, or design and development. The top cited articles in prosthetics were published from 1980 to 2012 with a citation range of 11 to 90 times since publication. The mean citation rate was 24.43 (SD 16.7) times. Eighty-four percent of the articles were original publications and were most commonly prospective (76%) and case series studies (67%) that used human subjects (96%) providing level 4 evidence. Among the various fields, rehabilitation (47%), orthopedics (29%), and sport sciences (28%) were the most common fields of study. The study established that studies conducted in North America and were written in English had the highest citations. Top cited articles primarily dealt with lower limb prosthetics, specifically, on transtibial and transradial prosthetic limbs. Majority of the articles were experimental studies.

Limb-girdle muscular dystrophy subtypes: First-reported cohort from northeastern China

PubMed Central

Mahmood, Omar Abdulmonem; Jiang, Xinmei; Zhang, Qi

2013-01-01

The relative frequencies of different subtypes of limb-girdle muscular dystrophies vary widely among different populations. We estimated the percentage of limb-girdle muscular dystrophy subtypes in Chinese people based on 68 patients with limb-girdle muscular dystrophy from the Myology Clinic, Neurology Department, First Hospital of Jilin University, China. A diagnosis of calpainopathy was made in 12 cases (17%), and dysferlin deficiency in 10 cases (15%). Two biopsies revealed α-sarcoglycan deficiency (3%), and two others revealed a lack of caveolin-3 (3%). A diagnosis of unclassified limb-girdle muscular dystrophy was made in the remaining patients (62%). The appearances of calpain 3- and dysferlin-deficient biopsies were similar, though rimmed vacuoles were unique to dysferlinopathy, while inflammatory infiltrates were present in both these limb-girdle muscular dystrophy type 2D biopsies. Macrophages were detected in seven dysferlinopathy biopsies. The results of this study suggest that the distribution of limb-girdle muscular dystrophy subtypes in the Han Chinese population is similar to that reported in the West. The less necrotic, regenerating and inflammatory appearance of limb-girdle muscular dystrophy type 2A, but with more lobulated fibers, supports the idea that calpainopathy is a less active, but more chronic disease than dysferlinopathy. Unusual features indicated an extended limb-girdle muscular dystrophy disease spectrum. The use of acid phosphatase stain should be considered in suspected dysferlinopathies. To the best of our knowledge, this is the first report to define the relative proportions of the various forms of limb-girdle muscular dystrophy in China, based on protein testing. PMID:25206500

Detection of genes regulated by Lmx1b during limb dorsalization.

PubMed

Feenstra, Jennifer M; Kanaya, Kohei; Pira, Charmaine U; Hoffman, Sarah E; Eppey, Richard J; Oberg, Kerby C

2012-05-01

Lmx1b is a homeodomain transcription factor that regulates dorsal identity during limb development. Lmx1b knockout (KO) mice develop distal ventral-ventral limbs. Although induction of Lmx1b is linked to Wnt7a expression in the dorsal limb ectoderm, the downstream targets of Lmx1b that accomplish limb dorsalization are unknown. To identify genes targeted by Lmx1b, we compared gene arrays from Lmx1b KO and wild type mouse limbs during limb dorsalization, i.e., 11.5, 12.5, and 13.5 days post coitum. We identified 54 target genes that were differentially expressed in all three stages. Several skeletal targets, including Emx2, Matrilin1 and Matrilin4, demonstrated a loss of scapular expression in the Lmx1b KO mice, supporting a role for Lmx1b in scapula development. Furthermore, the relative abundance of extracellular matrix-related soft tissue targets regulated by Lmx1b, such as collagens and proteoglycans, suggests a mechanism that includes changes in the extracellular matrix composition to accomplish limb dorsalization. Our study provides the most comprehensive characterization of genes regulated by Lmx1b during limb development to-date and provides targets for further investigation. © 2012 The Authors. Development, Growth & Differentiation © 2012 Japanese Society of Developmental Biologists.

Limb anomalies in DiGeorge and CHARGE syndromes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prasad, C.; Quackenbush, E.J.; Whiteman, D.

1997-01-20

Limb anomalies are not common in the DiGeorge or CHARGE syndromes. We describe limb anomalies in two children, one with DiGeorge and the other with CHARGE syndrome. Our first patient had a bifid left thumb, Tetralogy of Fallot, absent thymus, right facial palsy, and a reduced number of T-cells. A deletion of 22q11 was detected by fluorescence in situ hybridization (FISH). The second patient, with CHARGE syndrome, had asymmetric findings that included right fifth finger clinodactyly, camptodactyly, tibial hemimelia and dimpling, and severe club-foot. The expanded spectrum of the DiGeorge and CHARGE syndromes includes limb anomalies. 14 refs., 4 figs.

The Production of Titan's Ultraviolet Nitrogen Airglow

NASA Astrophysics Data System (ADS)

Stevens, Michael H.; Gustin, J.; Ajello, J. M.; Evans, J. S.; Meier, R. R.; Stewart, A. I. F.; Esposito, L. W.; McClintock, W. E.; Stephan, A. W.

2010-10-01

The Cassini Ultraviolet Imaging Spectrograph (UVIS) observed Titan's dayside limb on 22 June, 2009, obtaining high quality extreme ultraviolet (EUV) and far ultraviolet (FUV) spectra from a distance of only 60,000 km (23 Titan radii). The observations reveal the same EUV and FUV emissions arising from photoelectron excitation and photofragmentation of molecular nitrogen (N2) on Earth but with the altitude of peak emission much higher on Titan near 1000 km altitude. In the EUV, emission bands from the photoelectron excited N2 Carroll-Yoshino c4'-X system and N I and N II multiplets arising from photofragmentation of N2 dominate, with no detectable c4'(0,0) emission near 958 Å, contrary to many interpretations of the lower resolution Voyager 1 Ultraviolet Spectrometer data. The FUV is dominated by emission bands from the N2 Lyman-Birge-Hopfield a-X system and additional N I multiplets. We also identify several N2 Vegard-Kaplan A-X bands between 1500-1900 Å, two of which are located near 1561 and 1657 Å where C I multiplets were previously identified from a separate UVIS disk observation. We compare these limb emissions to predictions from a terrestrial airglow model adapted to Titan that uses a solar spectrum appropriate for these June, 2009 observations. Volume production rates and limb radiances are calculated, including extinction by methane and allowance for multiple scattering within the readily excited c4'(0,v') system, and compared to UVIS observations. We find that for these airglow data only emissions arising from processes involving N2 are present.

Gender differences in limited duty time for lower limb injury.

PubMed

Holsteen, K K; Choi, Y S; Bedno, S A; Nelson, D A; Kurina, L M

2018-02-16

Among active-duty military personnel, lower limb musculoskeletal injuries and related conditions (injuries) frequently arise as unintended consequences of physical training. These injuries are particularly common among women. The practical impact of such injuries on temporary military occupational disability has not been estimated with precision on a large scale. To determine the proportion of service time compromised by limited duty days attributable to lower limb injuries, characterize the time affected by these limitations in terms of specific lower limb region and compare the limited duty time between male and female soldiers. Administrative data and individual limited duty assignments (profiles) were obtained for active-duty US Army personnel who served in 2014. Lower limb injury-related profiles were used to calculate the percent of person-time requiring duty limitations by gender and body region. The study group was 568 753 soldiers of whom 14% were women. Nearly 13% of service days for active-duty US Army soldiers required limited duty for lower limb injuries during 2014. Knee injuries were responsible for 45% of those days. Within integrated military occupations, female soldiers experienced 27-57% more time on limited duty for lower limb injuries compared with men. The substantial amount of limited duty for lower limb musculoskeletal injuries among soldiers highlights the need for improvement in training-related injury screening, prevention and timely treatment with particular attention to knee injuries. The excessive impact of lower limb injuries on female soldiers' occupational functions should be a surveillance priority in the current environment of expanding gender-integrated training. Published by Oxford University Press on behalf of The Society of Occupational Medicine 2017.

Remote sensing of the troposphere by infrared emission spectroscopy

NASA Technical Reports Server (NTRS)

Beer, Reinhard; Glavich, Thomas A.

1989-01-01

This paper describes the concept of a cryogenic IR imaging Fourier transform spectrometer, called the Tropospheric Emission Spectrometer (TES), designed for observations of the troposphere and lower stratosphere from a near-earth orbit, using natural thermal emission and reflected sunlight. The principal molecular species to be measured by TES are O3, CO, CO2, N2O, H2O, H2O2, NO, NO2, HNO3, NH3, CH4, C2H6, C2H2, SO2, COS, CFCl3, and CF2Cl2. The TES is scheduled for a launch on the second polar platform of the Earth Observing System in 1998.

Deep-time evolution of regeneration and preaxial polarity in tetrapod limb development.

PubMed

Fröbisch, Nadia B; Bickelmann, Constanze; Olori, Jennifer C; Witzmann, Florian

2015-11-12

Among extant tetrapods, salamanders are unique in showing a reversed preaxial polarity in patterning of the skeletal elements of the limbs, and in displaying the highest capacity for regeneration, including full limb and tail regeneration. These features are particularly striking as tetrapod limb development has otherwise been shown to be a highly conserved process. It remains elusive whether the capacity to regenerate limbs in salamanders is mechanistically and evolutionarily linked to the aberrant pattern of limb development; both are features classically regarded as unique to urodeles. New molecular data suggest that salamander-specific orphan genes play a central role in limb regeneration and may also be involved in the preaxial patterning during limb development. Here we show that preaxial polarity in limb development was present in various groups of temnospondyl amphibians of the Carboniferous and Permian periods, including the dissorophoids Apateon and Micromelerpeton, as well as the stereospondylomorph Sclerocephalus. Limb regeneration has also been reported in Micromelerpeton, demonstrating that both features were already present together in antecedents of modern salamanders 290 million years ago. Furthermore, data from lepospondyl 'microsaurs' on the amniote stem indicate that these taxa may have shown some capacity for limb regeneration and were capable of tail regeneration, including re-patterning of the caudal vertebral column that is otherwise only seen in salamander tail regeneration. The data from fossils suggest that salamander-like regeneration is an ancient feature of tetrapods that was subsequently lost at least once in the lineage leading to amniotes. Salamanders are the only modern tetrapods that retained regenerative capacities as well as preaxial polarity in limb development.

Lessons from our Own Solar System: Generation Mechanisms of Radio Emissions from Earth, Saturn and Jupiter and Atmospheric Loss from Magnetized versus non-magnetized planets

NASA Astrophysics Data System (ADS)

Brandt, Pontus

2017-05-01

The understanding of the engines and mechanisms behind kilometric and decametric radio emissions from the planets in our own solar system have taken great leaps with missions such as the NASA/Cassini, IMAGE and Galileo missions. The periodic Saturn Kilometric Radiation (SKR), the Auroral Kilometric Radiation (AKR) at Earth and the periodic decametric radio emissions from Jupiter all point to the same generation mechanisms: very large-scale explosive plasma heating events in the magnetotail of each of the planets. The character and periodicity of the associated radio emissions not only tells us about the presence of a magnetic field but also about the plasma content and size of the planetary magnetosphere, and the nature of the interaction with the solar wind.The presence of a planetary magnetic field, as could be established for exoplanets by the positive detection of low-frequency exoplanetary radio emissions, has been thought to shield a planet from atmospheric loss to space. However, recent data from Mars Express, MAVEN, and Venus Express, together with the wealth of terrestrial measurements of atmospheric escape to space has brought a surprising question in to light: Does a planetary magnetic field suppress or enhance atmospheric loss? While at the non-magnetized planets such as Mars and Venus, the solar wind has a more direct access to the ionized upper atmosphere, these planets do set up self shielding currents that do limit escape. Furthermore, it is not clear if Mars have lost the majority of its atmosphere by condensation in to surface and sub-surface frost, or through atmospheric escape. At Earth, the geomagnetic field sets up a relatively large cross section to the solar wind, that allows the induced solar-wind electric field to transfer substantial energy to the upper ionosphere and atmosphere resulting in substantial loss. It is therefore not clear how a planetary magnetic field correlates to the atmospheric loss, or if it does at all.In this

STUDY OF THE 3D GEOMETRIC STRUCTURE AND TEMPERATURE OF A CORONAL CAVITY USING THE LIMB SYNOPTIC MAP METHOD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karna, N.; Pesnell, W. Dean; Webber, S. A. Hess

2015-09-10

We present the three-dimensional geometric structure and thermal properties of a coronal cavity deduced from limb synoptic maps. The observations are extreme ultraviolet images from the Atmospheric Imager Assembly (AIA) and magnetic images from the Helioseismic Magnetic Imager instruments on board the Solar Dynamics Observatory. We describe a limb synoptic-map method used to effectively identify and measure cavities from annuli of radiance above the solar limb. We find that cavities are best seen in the 211, 193, and 171 Å passbands. The prominence associated with each cavity is best seen in the 304 Å synoptic maps. We also estimate themore » thermal properties of the cavity and surrounding plasma by combining the AIA radiances with a differential emission measure analysis. This paper focuses on one long cavity from a catalog of coronal cavities that we are developing. Cavities in this catalog are designated by a coded name using the Carrington Rotation number and position. Cavity C211347177N was observed during Carrington Rotation 2113 at the northwestern limb of the solar disk with an average latitude of 47° N and a central longitude of 177°. We showed the following. (1) The cavity is a long tube with an elliptical cross-section with ratios of the length to width and the length to height of 11:1 and 7:1, respectively. (2) The cavity is about 1360 Mm long, or 170° in longitude. (3) It is tilted in latitude. (4) And it is slightly hotter than its surroundings.« less

Six-degree-of-freedom parallel minimanipulator with three inextensible limbs

NASA Technical Reports Server (NTRS)

Tahmasebi, Farhad (Inventor); Tsai, Lung-Wen (Inventor)

1994-01-01

A Six-Degree-of-Freedom Parallel-Manipulator having three inextensible limbs for manipulating a platform is described. The three inextensible limbs are attached via universal joints to the platform at non-collinear points. Each of the inextensible limbs is also attached via universal joints to a two-degree-of-freedom parallel driver such as a five-bar linkage, a pantograph, or a bidirectional linear stepper motor. The drivers move the lower ends of the limbs parallel to a fixed base and thereby provide manipulation of the platform. The actuators are mounted on the fixed base without using any power transmission devices such as gears or belts.

The effects of prism glasses and intensive upper limb exercise on hemineglect, upper limb function, and activities of daily living in stroke patients: a case series.

PubMed

Oh, Se-Il; Kim, Jin-Kyung; Park, So-Yeon

2015-12-01

[Purpose] This study aimed to examine the effects of visual field with prism glasses, and intensive upper limb functional training on reduction of hemineglect and improvement in upper limb function and activities of daily living in three stroke patients with hemineglect. [Subjects] This study included three stroke patients hospitalized in a sanatorium. [Methods] Intervention treatment involving prism glass use for 12 hours and 30 minutes and paretic side upper limb training was conducted 5 days a week for 15 weeks. Three upper limb training tasks (hitting a balloon, passing through a ring, and reading a newspaper) were performed for 10 minutes each session, for a total of 30 minutes. Line by Section, Motor-Free Visual Perception Test-3 (MVPT-3), Manual Function Test (MFT), Box & Block Test (BBT), and Assessment of Motor and Process Skills (AMPS) were conducted before and after intervention. [Results] Subjects' hemineglect decreased and upper limb function on the paretic side improved after intervention, which enhanced activities of daily living. [Conclusion] Prism glass use and paretic upper limb functional training effectively ameliorated stroke patients' hemineglect and improved upper limb function. Future research should focus on prism glasses that provide a wide visual field for use in patients with different conditions.

Outcomes of lower extremity bypass performed for acute limb ischemia

PubMed Central

Baril, Donald T.; Patel, Virendra I.; Judelson, Dejah R.; Goodney, Philip P.; McPhee, James T.; Hevelone, Nathanael D.; Cronenwett, Jack L.; Schanzer, Andres

2013-01-01

Objective Acute limb ischemia remains one of the most challenging emergencies in vascular surgery. Historically, outcomes following interventions for acute limb ischemia have been associated with high rates of morbidity and mortality. The purpose of this study was to determine contemporary outcomes following lower extremity bypass performed for acute limb ischemia. Methods All patients undergoing infrainguinal lower extremity bypass between 2003 and 2011 within hospitals comprising the Vascular Study Group of New England were identified. Patients were stratified according to whether or not the indication for lower extremity bypass was acute limb ischemia. Primary end points included bypass graft occlusion, major amputation, and mortality at 1 year postoperatively as determined by Kaplan-Meier life table analysis. Multivariable Cox proportional hazards models were constructed to evaluate independent predictors of mortality and major amputation at 1 year. Results Of 5712 lower extremity bypass procedures, 323 (5.7%) were performed for acute limb ischemia. Patients undergoing lower extremity bypass for acute limb ischemia were similar in age (66 vs 67; P = .084) and sex (68% male vs 69% male; P = .617) compared with chronic ischemia patients, but were less likely to be on aspirin (63% vs 75%; P < .0001) or a statin (55% vs 68%; P < .0001). Patients with acute limb ischemia were more likely to be current smokers (49% vs 39%; P < .0001), to have had a prior ipsilateral bypass (33% vs 24%; P = .004) or a prior ipsilateral percutaneous intervention (41% vs 29%; P = .001). Bypasses performed for acute limb ischemia were longer in duration (270 vs 244 minutes; P = .007), had greater blood loss (363 vs 272 mL; P < .0001), and more commonly utilized prosthetic conduits (41% vs 33%; P = .003). Acute limb ischemia patients experienced increased in-hospital major adverse events (20% vs 12%; P < .0001) including myocardial infarction, congestive heart failure exacerbation

Outcomes of lower extremity bypass performed for acute limb ischemia.

PubMed

Baril, Donald T; Patel, Virendra I; Judelson, Dejah R; Goodney, Philip P; McPhee, James T; Hevelone, Nathanael D; Cronenwett, Jack L; Schanzer, Andres

2013-10-01

Acute limb ischemia remains one of the most challenging emergencies in vascular surgery. Historically, outcomes following interventions for acute limb ischemia have been associated with high rates of morbidity and mortality. The purpose of this study was to determine contemporary outcomes following lower extremity bypass performed for acute limb ischemia. All patients undergoing infrainguinal lower extremity bypass between 2003 and 2011 within hospitals comprising the Vascular Study Group of New England were identified. Patients were stratified according to whether or not the indication for lower extremity bypass was acute limb ischemia. Primary end points included bypass graft occlusion, major amputation, and mortality at 1 year postoperatively as determined by Kaplan-Meier life table analysis. Multivariable Cox proportional hazards models were constructed to evaluate independent predictors of mortality and major amputation at 1 year. Of 5712 lower extremity bypass procedures, 323 (5.7%) were performed for acute limb ischemia. Patients undergoing lower extremity bypass for acute limb ischemia were similar in age (66 vs 67; P = .084) and sex (68% male vs 69% male; P = .617) compared with chronic ischemia patients, but were less likely to be on aspirin (63% vs 75%; P < .0001) or a statin (55% vs 68%; P < .0001). Patients with acute limb ischemia were more likely to be current smokers (49% vs 39%; P < .0001), to have had a prior ipsilateral bypass (33% vs 24%; P = .004) or a prior ipsilateral percutaneous intervention (41% vs 29%; P = .001). Bypasses performed for acute limb ischemia were longer in duration (270 vs 244 minutes; P = .007), had greater blood loss (363 vs 272 mL; P < .0001), and more commonly utilized prosthetic conduits (41% vs 33%; P = .003). Acute limb ischemia patients experienced increased in-hospital major adverse events (20% vs 12%; P < .0001) including myocardial infarction, congestive heart failure exacerbation, deterioration in renal function

A NASA Space Sleuth Hunts the Trail of Earth Water

NASA Image and Video Library

2009-08-13

This vertical profile view from the Tropospheric Emission Spectrometer TES instrument on NASA Aura satellite depicts the distribution of water vapor molecules over Earth tropics across one transect of the satellite orbit on January 6, 2006.

Optical chopper for the HIRDLS instrument

NASA Astrophysics Data System (ADS)

Opyd, Walter G.; Loewenthal, Stuart

2003-12-01

Requirements, performance and life-test results are presented for the optical chopper installed in the High-Resolution Dynamics Limb Sounder (HIRDLS) to be flown on the AURA mission of the NASA Earth Observing System (EOS). Optical chopping is essential in order to achieve the required sensitivity and accuracy in measurement of infrared emission from various chemical species in the earth's atmosphere. Chopping of the optical input as far forward in the telescope as practical minimizes calibration errors arising from variations in emission from warm optics and due to electronic drifts in the infrared detecting system. At 500 Hz, a reflective chopper blade is used to alternate the instrument view between the atmospheric limb and cold space. The HIRDLS chopper is a six-toothed, mirrored wheel driven by a brushless DC motor. Chopper design was driven by requirements of 1) continuous operation at 5000 RPM for 50,000 hours in space vacuum, 2) chopping amplitude stability of one part in 100,000, 3) lubricant loss control for both bearing reliability and prevention of optics contamination, 4) compact size to fit in the folded telescope, and 5) survival in the launch environment.

Surface Emissivity Retrieved with Satellite Ultraspectral IR Measurements for Monitoring Global Change

NASA Technical Reports Server (NTRS)

Zhou, Daniel K.; Larar, Allen M.; Liu, Xu; Smith, William L.; Schluessel, Peter

2009-01-01

Surface and atmospheric thermodynamic parameters retrieved with advanced ultraspectral remote sensors aboard Earth observing satellites are critical to general atmospheric and Earth science research, climate monitoring, and weather prediction. Ultraspectral resolution infrared radiance obtained from nadir observations provide atmospheric, surface, and cloud information. Presented here is the global surface IR emissivity retrieved from Infrared Atmospheric Sounding Interferometer (IASI) measurements under "clear-sky" conditions. Fast radiative transfer models, applied to the cloud-free (or clouded) atmosphere, are used for atmospheric profile and surface parameter (or cloud parameter) retrieval. The inversion scheme, dealing with cloudy as well as cloud-free radiances observed with ultraspectral infrared sounders, has been developed to simultaneously retrieve atmospheric thermodynamic and surface (or cloud microphysical) parameters. Rapidly produced surface emissivity is initially evaluated through quality control checks on the retrievals of other impacted atmospheric and surface parameters. Surface emissivity and surface skin temperature from the current and future operational satellites can and will reveal critical information on the Earth s ecosystem and land surface type properties, which can be utilized as part of long-term monitoring for the Earth s environment and global climate change.

Apollo 9 Mission image - Earth limb over California with S.L.A. in distance

NASA Image and Video Library

1969-03-03

Oblique Earth Observation taken by the Apollo 9 crew. View is of California including: Sanata Barbara, Los Angeles, San Diego, Santa Rosa, San Miguel, and Santa Cruz Islands, Santa Barbara Channel, Salton Sea and the Service Module (SM) Lunar Module (LM) adapter (S.L.A.) in the distance. Film magazine was A,film type was SO-368 Ektachrome with 0.460 - 0.710 micrometers film / filter transmittance response and haze filter, 80mm lens. Latitude was 32.55 N by Longitude 119.58 W, Altitude miles were 106 and cloud cover was 25%.

Modification of a Limbed Robot to Favor Climbing

NASA Technical Reports Server (NTRS)

Okon, Avi; Kennedy, Brett; Garrett, Michael; Magnone, Lee

2006-01-01

The figure shows the LEMUR IIb, which is a modified version of the LEMUR II the second generation of the Limbed Excursion Mechanical Utility Robot (LEMUR). Except as described below, the LEMUR IIb hardware is mostly the same as that of the LEMUR II. The IIb and II versions differ in their kinematic configurations and characteristics associated with their kinematic configurations. The differences are such that relative to the LEMUR II, the LEMUR IIb is simpler and is better suited to climbing on inclined surfaces. The first-generation LEMUR, now denoted the LEMUR I, was described in Six-Legged Experimental Robot (NPO-20897), NASA Tech Briefs, Vol. 25, No. 12 (December 2001), page 58. The LEMUR II was described in Second-Generation Six-Limbed Experimental Robot (NPO-35140) NASA Tech Briefs, Vol. 28, No. 11 (November 2004), page 55. To recapitulate: the LEMUR I and LEMUR II were six-legged or sixlimbed robots for demonstrating robotic capabilities for assembly, maintenance, and inspection. They were designed to be capable of walking autonomously along a truss structure toward a mechanical assembly at a prescribed location. They were equipped with stereoscopic video cameras and image-data-processing circuitry for navigation and mechanical operations. They were also equipped with wireless modems, through which they could be commanded remotely. Upon arrival at a mechanical assembly, the LEMUR I would perform simple mechanical operations by use of one or both of its front legs (or in the case of the LEMUR II, any of its limbs could be used to perform mechanical operations). Either LEMUR could also transmit images to a host computer. The differences between the LEMUR IIb and the LEMUR II are the following: Whereas the LEMUR II had six limbs, the LEMUR IIb has four limbs. This change has reduced both the complexity and mass of the legs and of the overall robot. Whereas each limb of the LEMUR II had four degrees of freedom (DOFs), each limb of the LEMUR IIb has three DOFs

Production of N2 Vegard-Kaplan and Lyman-Birge-Hopfield emissions on Pluto

NASA Astrophysics Data System (ADS)

Jain, Sonal Kumar; Bhardwaj, Anil

2015-01-01

We have developed a model to calculate the emission intensities of various vibrational transitions of N2 triplet band and Lyman-Birge-Hopfield (LBH) band emissions in the dayglow of Pluto for solar minimum, moderate, and maximum conditions. The calculated overhead intensities of Vegard-Kaplan (A3Σu+ -X1 Σg+) , First Positive (B3Πg -A3 Σu+), Second Positive (C3Πu -B3Πg) , Wu-Benesch (W3Δu -B3Πg) , Reverse First Positive, and LBH (a1Πg -X1 Σg+) bands of N2 are 17 (74), 14.8 (64), 2.4 (10.8), 2.9 (12.7), 2.9 (12.5), and 2.3 (10) R, respectively, for solar minimum (maximum) condition. We have predicted the overhead and limb intensities of VK (150-190 nm) and LBH (120-190 nm) bands of N2 on Pluto for the New Horizons (NH) flyby condition that can be observed by ALICE: the ultraviolet imaging spectrograph also know as P-ALICE. The predicted limb intensities of VK and LBH bands peak at radial distance of ∼2000 km with the value of about 5 (13) and 9.5 (22) R for solar zenith angle 60° (0°), respectively. We have also calculated overhead and limb intensities of few prominent transition of CO Fourth Positive bands for NH flyby condition.

Epidemiology of traumatic upper limb amputations.

PubMed

Pomares, G; Coudane, H; Dap, F; Dautel, G

2018-04-01

While published data on functional outcomes after upper limb amputations are plentiful, epidemiology data are relatively rare. This led us to performing an epidemiology study of traumatic upper limb amputations at our facility. This retrospective study spanned a 10-year period of cases seen at the SOS Main (Hand emergency center) of the Nancy University Hospital in France. Patients who suffered traumatic amputation of the upper limb were identified and divided into two groups: replantation and surgical amputation. All anatomical amputation levels were retained. Non-traumatic amputations were excluded. Epidemiology data (sex, age, dominant side, injured side) was collected along with the specific anatomical level of the injury, the injury mechanism and whether it was work-related. We also looked at the success rate of microsurgery and whether multi-finger amputations were partial or complete. In parallel, the annual incidence of amputations seen at the SOS Main over this period was calculated. Over the 10-year period, 1715 traumatic upper-limb amputations were identified, which was 3% of all cases seen at the SOS Main. Most of the cases involved middle-aged men. Revascularization was attempted in one-third of cases and microsurgery was successful in 70% of cases. The surgical amputation group consisted of 1132 patients with a mean age of 59 years, while the replantation group consisted of 583 patients with a mean age of 48 years. The primary mechanism of injury was a table saw. This injury, which must be addressed urgently, is not very common in everyday practice. This is contrary to lower limb amputations, which are more common and occur in the context of micro- and macroangiopathy in older patients. The success rate of microsurgery in this cohort must be placed in the context of age, amputation level and mechanism. The functional outcomes are not always as good as the vascular outcomes. This data is invaluable as it fills a gap in our knowledge about amputations

Modeling rate sensitivity of exercise transient responses to limb motion.

PubMed

Yamashiro, Stanley M; Kato, Takahide

2014-10-01

Transient responses of ventilation (V̇e) to limb motion can exhibit predictive characteristics. In response to a change in limb motion, a rapid change in V̇e is commonly observed with characteristics different than during a change in workload. This rapid change has been attributed to a feed-forward or adaptive response. Rate sensitivity was explored as a specific hypothesis to explain predictive V̇e responses to limb motion. A simple model assuming an additive feed-forward summation of V̇e proportional to the rate of change of limb motion was studied. This model was able to successfully account for the adaptive phase correction observed during human sinusoidal changes in limb motion. Adaptation of rate sensitivity might also explain the reduction of the fast component of V̇e responses previously reported following sudden exercise termination. Adaptation of the fast component of V̇e response could occur by reduction of rate sensitivity. Rate sensitivity of limb motion was predicted by the model to reduce the phase delay between limb motion and V̇e response without changing the steady-state response to exercise load. In this way, V̇e can respond more quickly to an exercise change without interfering with overall feedback control. The asymmetry between responses to an incremental and decremental ramp change in exercise can also be accounted for by the proposed model. Rate sensitivity leads to predicted behavior, which resembles responses observed in exercise tied to expiratory reserve volume. Copyright © 2014 the American Physiological Society.

Vascular anomalies and the growth of limbs: a review.

PubMed

Enjolras, Odile; Chapot, René; Merland, Jean Jacques

2004-11-01

Growth of the limb in a child can be impaired, with the coexistence of a vascular malformation. In these vascular bone syndromes, altered growth is manifest as overgrowth or hypotrophy. The vascular malformation is usually complex and gets progressively worse with time. The two types of vascular anomalies in limbs, fast-flow and slow-flow, can be associated with limb length discrepancies. The fast-flow vascular malformations together with arteriovenous fistulae are part of Parkes Weber syndrome, characterized by congenital red cutaneous staining, hypertrophy in girth and increasing of limb length, lymphedema, increasing skin alterations due to a distal vascular steal, and pain, all of which develop during childhood. Treatment is generally conservative. An affected lower extremity can be complicated by pelvic tilting and scoliosis because leg length discrepancy may reach 10 cm. To avoid such a course, stapling epiphysiodesis of the knee cartilages is often performed, but this orthopedic procedure may augment the worsening of the arterial venous malformation in the limb. Therefore, less aggressive orthopedic management is preferable. Slow-flow vascular anomalies associated with limb growth alteration include (1) a diffuse capillary malformation (port-wine stain) with congenital hypertrophy of the involved extremity which is non-progressive; (2) purely venous malformations invading skin, muscles and joints, with pain, functional impairment, a chronic localized intravascular coagulopathy requiring distinctive management, and usually a slight undergrowth of the affected extremity and progressing amyotrophy; (3) the triad of a port-wine stain, anomalous veins and overgrowth of the limb, often known as Klippel-Trenaunay syndrome, which requires orthopedic management to decide the optimal timing for epiphysiodesis (i.e. when leg length discrepancy is >2.5 cm). Varicose veins are sometimes surgically removed after ultrasonographic and Doppler evaluation has confirmed a