3,795 research outputs found
Landsat Data Continuity Mission Expected Instrument Performance
The Landsat Data Continuity Mission (LDCM) is scheduled for a December 2012 launch date. LDCM is being managed by an interagency partnership between NASA and the U.S. Geological Survey (USGS). In order to provide the necessary spectral coverage of the visible through shortwave-infrared (SWIR) and the thermal-infrared (TIR), the satellite will carry two sensors. The Operational Land Imager (OLI) will collect data for nine visible to shortwave spectral bands with a spatial resolution of 30 m (with a 15 m panchromatic band). The Thermal Infrared Sensor (TIRS) will collect coincident image data for two TIR bands with a spatial resolution of 100 m. The OLI is fully assembled and tested and has been shipped by it's manufacturer, Ball Aerospace and Technology Corporation, to the Orbital Sciences Corporation (Orbital) facility where it is being integrated onto the LDCM spacecraft. Pre-launch testing indicates that OLI will meet all performance specification with margin. TIRS is in development at the NASA Goddard Space F!ight Center (GSFC) and is in final testing before shipping to the Orbital facility in January, 2012. The presentation will describe the LDCM satellite instrument systems, present pre-launch performance data for OLI and TIRS, and present simulated images to highlight notable features and expected imaging performance
Draft Genome Sequences of 1,183 Salmonella Strains from the 100K Pathogen Genome Project.
Salmonella is a common food-associated bacterium that has substantial impact on worldwide human health and the global economy. This is the public release of 1,183 Salmonella draft genome sequences as part of the 100K Pathogen Genome Project. These isolates represent global genomic diversity in the Salmonella genus
Landsat Data Continuity Mission Calibration and Validation
The primary payload for the Landsat Data Continuity Mission (LDCM) is the Operational Land Imager (OLI), being built by Ball Aerospace and Technologies, under contract to NASA. The OLI has spectral bands similar to the Landsat-7 ETM+, minus the thermal band and with two new bands, a 443 nm band and 1375 nm cirrus detection band. On-board calibration systems include two solar diffusers (routine and pristine), a shutter and three sets of internal lamps (routine, backup and pristine). Being a pushbroom opposed to a whiskbroom design of ETM+, the system poses new challenges for characterization and calibration, chief among them being the large focal plane with 75000+ detectors. A comprehensive characterization and calibration plan is in place for the instrument and the data throughout the mission including Ball, NASA and the United States Geological Survey, which will take over operations of LDCM after on-orbit commissioning. Driving radiometric calibration requirements for OLI data include radiance calibration to 5% uncertainty (1 q); reflectance calibration to 3% uncertainty (1 q) and relative (detector-to-detector) calibration to 0.5% (J (r). Driving geometric calibration requirements for OLI include bandto- band registration of 4.5 meters (90% confidence), absolute geodetic accuracy of 65 meters (90% CE) and relative geodetic accuracy of 25 meters (90% CE). Key spectral, spatial and radiometric characterization of the OLI will occur in thermal vacuum at Ball Aerospace. During commissioning the OLI will be characterized and calibrated using celestial (sun, moon, stars) sources and terrestrial sources. The USGS EROS ground processing system will incorporate an image assessment system similar to Landsat-7 for characterization and calibration. This system will have the added benefit that characterization data will be extracted as part of the normal image data processing, so that the characterization data available will be significantly larger than for Landsat-7 ETM+
Distribution of endemic and imperiled fauna of the Tallapoosa River system of Georgia
Proceedings of the 2003 Georgia Water Resources Conference, held April 23-24, 2003, at the University of Georgia.A proposal for a water supply reservoir in
the Tallapoosa River system in Northwest Georgia has
called attention to the potential effects of a large
impoundment on the faunal resources of the system.
The Tallapoosa and Little Tallapoosa Rivers and their
tributaries support species assemblages found nowhere
else, including five endemic fishes, two endemic
crayfishes, and an endemic snail, in addition to a
federally threatened mussel (Lampsilis altilis). We are
analyzing survey data collected in 1990 and in 2002 to
estimate species distributions, abundances, and changes
in both of these factors relative to changes in land use.
These data will be useful to the U.S. Fish and Wildlife
Service and others for designing conservation strategies
for the unique fauna of the Tallapoosa River system
Health economic analysis of ticagrelor in patients with acute coronary syndromes intended for non-invasive therapy
Objective: To investigate the cost effectiveness of ticagrelor versus clopidogrel in patients with acute coronary syndromes (ACS) in the Platelet Inhibition and Patient Outcomes (PLATO) study who were scheduled for non-invasive management. Methods: A previously developed cost effectiveness model was used to estimate long-term costs and outcomes for patients scheduled for non-invasive management. Healthcare costs, event rates and health-related quality of life under treatment with either ticagrelor or clopidogrel over 12 months were estimated from the PLATO study. Long-term costs and health outcomes were estimated based on data from PLATO and published literature sources. To investigate the importance of different healthcare cost structures and life expectancy for the results, the analysis was carried out from the perspectives of the Swedish, UK, German and Brazilian public healthcare systems. Results: Ticagrelor was associated with lifetime quality-adjusted life-year (QALY) gains of 0.17 in Sweden, 0.16 in the UK, 0.17 in Germany and 0.13 in Brazil compared with generic clopidogrel, with increased healthcare costs of €467, €551, €739 and €574, respectively. The cost per QALY gained with ticagrelor was €2747, €3395, €4419 and €4471 from a Swedish, UK, German and Brazilian public healthcare system perspective, respectively. Probabilistic sensitivity analyses indicated that the cost per QALY gained with ticagrelor was below conventional threshold values of cost effectiveness with a high probability. Conclusions: Treatment of patients with ACS scheduled for 12 months’ non-invasive management with ticagrelor is associated with a cost per QALY gained below conventional threshold values of cost effectiveness compared with generic clopidogrel. Trial registration number NCT000391872
Les controverses sociotechniques au prisme du Parlement
Le Parlement constitue un espace privilégié pour analyser le déploiement des controverses sociotechniques : non parce qu’il aurait la faculté de les résoudre, notamment via l’OPECST, mais parce qu’il offre de multiples occasions et modalités d’expression et de traitement de ces controverses en son sein. Espace hétérogène et poreux, il participe d’une nouvelle gouvernance des risques, plus soucieuse de leur stabilisation que de leur réduction définitive.The French Parliament offers an ideal place to analyze the unfolding of sociotechnical controversies. Not that it has any capacity to actually resolve these, including its office of science and technology; but rather because it offers a plurality of opportunities for controversies to play out within its two chambers. As a heterogeneous and porous institution, it takes part in a newly formed risk governance that aims to manage rather than definitely solve risk issues
Integral field spectroscopy of nitrogen overabundant blue compact dwarf galaxies
We study the spatial distribution of the physical properties and of oxygen
and nitrogen abundances in three Blue Compact Dwarf Galaxiess (HS 0128+2832, HS
0837+4717 and Mrk 930) with a reported excess of N/O in order to investigate
the nature of this excess and, particularly, if it is associated with
Wolf-Rayet (WR) stars We have observed these BCDs by using PMAS integral field
spectroscopy in the optical spectral range (3700 - 6900 {\AA}), mapping their
physical-chemical properties, using both the direct method and appropriate
strong-line methods. We make a statistical analysis of the resulting
distributions and we compare them with the integrated properties of the
galaxies. Our results indicate that outer parts of the three galaxies are
placed on the "AGN-zone" of the [NII]/H{\alpha} vs. [OIII]/H{\beta} diagnostic
diagram most likely due to a high N/O combined with the excitation structure in
these regions. From the statistical analysis, it is assumed that a certain
property can be considered as spatially homogeneous (or uniform) if a normal
gaussian function fits its distribution in several regions of the galaxy.
Moreover, a disagreement between the integrated properties and the mean values
of the distribution usually appears when a gaussian does not fit the
corresponding distribution. We find that for Mrk 930, the uniformity is found
for all parameters, except for electron density and reddening. The rotation
curve together with the H{\alpha} map and UV images, reveal a perturbed
morphology and possible interacting processes. The N/O is found to be constant
in the three studied objects at spatial scales of the order of several kpc so
we conclude that the number of WR stars estimated from spectroscopy is not
sufficient to pollute the ISM and to produce the observed N/O excess in these
objectsComment: 17 pages, 14 figures, accepted for publication in Astronomy &
Astrophysic
P2Y12 platelet inhibition in clinical practice
Platelet adhesion, activation and aggregation play a pivotal role in atherothrombosis. Intracoronary atherothrombosis is the most common cause of the development of acute coronary syndrome (ACS), and plays a central role in complications occurring around percutaneous coronary intervention (PCI) including recurrent ACS, procedure-related myocardial infarction or stent thrombosis. Inhibition of platelet aggregation by medical treatment impairs formation and progression of thrombotic processes and is therefore of great importance in the prevention of complications after an ACS or around PCI. An essential part in the platelet activation process is the interaction of adenosine diphosphate (ADP) with the platelet P2Y12 receptor. The P2Y12 receptor is the predominant receptor involved in the ADP-stimulated activation of the glycoprotein IIb/IIIa receptor. Activation of the glycoprotein IIb/IIIa receptor results in enhanced platelet degranulation and thromboxane production, and prolonged platelet aggregation. The objectives of this review are to discuss the pharmacological limitations of the P2Y12 inhibitor clopidogrel, and describe the novel alternative P2Y12 inhibitors prasugrel and ticagrelor and the clinical implications of the introduction of these new medicines
The ionized gas at the center of IC 10: A possible localized chemical pollution by Wolf-Rayet stars
We present results from integral field spectroscopy with the Potsdam
Multi-Aperture Spectrograph at the 3.5m telescope at Calar Alto Observatory of
the intense star-forming region [HL90] 111 at the center of the starburst
galaxy IC 10. We have obtained maps with a spatial sampling of 1" x 1" = 3.9 pc
x 3.9 pc of different emission lines and analyzed the extinction, physical
conditions, nature of the ionization, and chemical abundances of the ionized
gas, as well determined locally the age of the most recent star-formation
event. By defining several apertures, we study the main integrated properties
of some regions within [HL90] 111. Two contiguous spaxels show an unambiguous
detection of the broad He II 4686 emission line, this feature seems to be
produced by a single WNL star. We also report a probable N and He enrichment in
the precise spaxels where the WR features are detected. The enrichment pattern
is roughly consistent with that expected for the pollution of the ejecta of a
single or a very small number of WR stars. Furthermore, this chemical pollution
is very localized (~2"~7.8 pc) and it should be difficult to detect in
star-forming galaxies beyond the Local Volume. We also discuss the use of the
most-common empirical calibrations to estimate the oxygen abundances of the
ionized gas in nearby galaxies from 2D spectroscopic data. The ionization
degree of the gas plays an important role when applying these empirical
methods, as they tend to give lower oxygen abundances with increasing
ionization degree.Comment: 18 pages, 13 figures, accepted for publication in MNRA
- …