647 research outputs found
I021 Impact du polymorphisme génétique C(-260)T du CD14 sur la pression pulsée en fonction d’autres facteurs de risque cardiovasculaires : etude populationnelle transversale à partir du registre monica
Objectif de l’étudeLe CD14 est à l’intersection entre l’inflammation, les maladies infectieuses et le syndrome métabolique. Une corrélation positive entre la concentration plasmatique du CD14 soluble (sCD14) et la rigidité aortique a été décrite dans une étude transversale. Mais différents résultats ont été retrouvés sur l’incidence des évènements cardiovasculaires en fonction du polymorphisme C(-260)T du gène du CD14.L’objectif de cette étude est d’étudier l’influence du polymorphisme C(-260)T du CD14 sur la pression pulsée et indirectement sur le risque cardiovasculaire à partir de l’étude populationnelle transversale MONICA.Déroulement de l’étude1 155 sujets âgés entre 35 et 64 ans, en prévention primaire, ont été recrutés à partir des listes électorales de la Haute Garonne entre 1995 et 1997.MéthodesLa pression pulsée brachiale était mesurée au repos à 2 reprises puis moyennée. La concentration plasmatique du sCD14 a été mesurée par méthode immunoenzymatique. La randomisation est de type mendélienne. Les sujets ont été répartis en fonction du polymorphisme C(-260)T du CD14 après génotypage : homozygotes CC, homozygotes TT ou hétérozygotes CT.RésultatsLes sujets homozygotes TT ont une pression pulsée (PP) significativement plus basse et une concentration en sCD14 significativement plus élevée. Après ajustement avec les principaux facteurs confondants (âge, sexe, facteurs de risque cardiovasculaires traités), seul le génotype du CD14 reste corrélé à la PP. Cette corrélation n’intervient qu’en présence de facteurs de risque traités. Les diabétiques traités homozygotes TT sont ceux qui bénéficient de la plus importante baisse de PP par rapport aux homozygotes diabétiques CC (− 19,4mmHg, p=0,006).ConclusionCette étude suggère que les facteurs de risque ont un impact différent sur la pression pulsée en fonction du polymorphisme C(-260)T du CD14. Cette observation pourrait contribuer à affiner le risque cardiovasculaire absolu individuel, les sujets homozygotes TT ayant un risque cardiovasculaire moindre
Using a Crop Model to Benchmark Miscanthus and Switchgrass
Crop yields are important items in the economic performance and the environmental impacts of second-generation biofuels. Since they strongly depend on crop management and pedoclimatic conditions, it is important to compare candidate feedstocks to select the most appropriate crops in a given context. Agro-ecosystem models offer a prime route to benchmark crops, but have been little tested from this perspective thus far. Here, we tested whether an agro-ecosystem model (CERES-EGC) was specific enough to capture the differences between miscanthus and switchgrass in northern Europe. The model was compared to field observations obtained in seven long-term trials in France and the UK, involving different fertilizer input rates and harvesting dates. At the calibration site (Estrées-Mons), the mean deviations between simulated and observed crop biomass yields for miscanthus varied between −0.3 t DM ha−1 and 4.2 t DM ha−1. For switchgrass, simulated yields were within 1.0 t DM ha−1 of the experimental data. Observed miscanthus yields were higher than switchgrass yields in most sites and for all treatments, with one exception. Overall, the model captured the differences between both crops adequately, with a mean deviation of 0.46 t DM ha−1, and could be used to guide feedstock selections over larger biomass supply areas
Apatites in Gale Crater
ChemCam is an active remote sensing instrument suite that has operated successfully on MSL since landing Aug. 6th, 2012. It uses laser pulses to remove dust and to analyze rocks up to 7 m away. Laser-induced breakdown spectroscopy (LIBS) obtains emission spectra of materials ablated from the samples in electronically excited states. The intensities of the emission lines scale with the abundances of the related element. ChemCam is sensitive to most major rock-forming elements as well as to a set of minor and trace elements such as F, Cl, Li, P, Sr, Ba, and Rb. The measured chemical composition can then be used to infer the mineralogical composition of the ablated material. Here, we report a summary of inferred apatite detections along the MSL traverse at Gale Crater. We present the geologic settings of these findings and derive some interpretations about the formation conditions of apatite in time and space
A new physiological model for studying the effect of chest compression and ventilation during cardiopulmonary resuscitation: The Thiel cadaver
BACKGROUND: Studying ventilation and intrathoracic pressure (ITP) induced by chest compressions (CC) during Cardio Pulmonary Resuscitation is challenging and important aspects such as airway closure have been mostly ignored. We hypothesized that Thiel Embalmed Cadavers could constitute an appropriate model.
METHODS: We assessed respiratory mechanics and ITP during CC in 11 cadavers, and we compared it to measurements obtained in 9 out-of-hospital cardiac arrest patients and to predicted values from a bench model. An oesophageal catheter was inserted to assess chest wall compliance, and ITP variation (ΔITP). Airway pressure variation (ΔPaw) at airway opening and ΔITP generated by CC were measured at decremental positive end expiratory pressure (PEEP) to test its impact on flow and ΔPaw. The patient\u27s data were derived from flow and airway pressure captured via the ventilator during resuscitation.
RESULTS: Resistance and Compliance of the respiratory system were comparable to those of the out-of-hospital cardiac arrest patients (C 42 ± 12 vs C 37.3 ± 10.9 mL/cmHO and Res 17.5 ± 7.5 vs Res 20.2 ± 5.3 cmHO/L/sec), and remained stable over time. During CC, ΔITP varied from 32 ± 12 cmHO to 69 ± 14 cmHO with manual and automatic CC respectively. Transmission of ΔITP at the airway opening was significantly affected by PEEP, suggesting dynamic small airway closure at low lung volumes. This phenomenon was similarly observed in patients.
CONCLUSION: Respiratory mechanics and dynamic pressures during CC of cadavers behave as predicted by a theoretical model and similarly to patients. The Thiel model is a suitable to assess ITP variations induced by ventilation during CC
Overcoming the Challenges Associated with Image-based Mapping of Small Bodies in Preparation for the OSIRIS-REx Mission to (101955) Bennu
The OSIRIS-REx Asteroid Sample Return Mission is the third mission in NASA's
New Frontiers Program and is the first U.S. mission to return samples from an
asteroid to Earth. The most important decision ahead of the OSIRIS-REx team is
the selection of a prime sample-site on the surface of asteroid (101955) Bennu.
Mission success hinges on identifying a site that is safe and has regolith that
can readily be ingested by the spacecraft's sampling mechanism. To inform this
mission-critical decision, the surface of Bennu is mapped using the OSIRIS-REx
Camera Suite and the images are used to develop several foundational data
products. Acquiring the necessary inputs to these data products requires
observational strategies that are defined specifically to overcome the
challenges associated with mapping a small irregular body. We present these
strategies in the context of assessing candidate sample-sites at Bennu
according to a framework of decisions regarding the relative safety,
sampleability, and scientific value across the asteroid's surface. To create
data products that aid these assessments, we describe the best practices
developed by the OSIRIS-REx team for image-based mapping of irregular small
bodies. We emphasize the importance of using 3D shape models and the ability to
work in body-fixed rectangular coordinates when dealing with planetary surfaces
that cannot be uniquely addressed by body-fixed latitude and longitude.Comment: 31 pages, 10 figures, 2 table
Sensitivity of projected long-term CO 2 emissions across the Shared Socioeconomic Pathways
Scenarios showing future greenhouse gas emissions are needed to estimate climate impacts and the mitigation efforts required for climate stabilization. Recently, the Shared Socioeconomic Pathways (SSPs) have been introduced to describe alternative social, economic and technical narratives, spanning a wide range of plausible futures in terms of challenges to mitigation and adaptation. Thus far the key drivers of the uncertainty in emissions projections have not been robustly disentangled. Here we assess the sensitivities of future CO 2 emissions to key drivers characterizing the SSPs. We use six state-of-the-art integrated assessment models with different structural characteristics, and study the impact of five families of parameters, related to population, income, energy efficiency, fossil fuel availability, and low-carbon energy technology development. A recently developed sensitivity analysis algorithm allows us to parsimoniously compute both the direct and interaction effects of each of these drivers on cumulative emissions. The study reveals that the SSP assumptions about energy intensity and economic growth are the most important determinants of future CO 2 emissions from energy combustion, both with and without a climate policy. Interaction terms between parameters are shown to be important determinants of the total sensitivities
Enhancing global climate policy ambition towards a 1.5 °C stabilization: a short-term multi-model assessment
The Paris Agreement is a milestone in international climate policy as it establishes a global mitigation framework towards 2030 and sets the ground for a potential 1.5 °C climate stabilization. To provide useful insights for the 2018 UNFCCC Talanoa facilitative dialogue, we use eight state-of-the-art climate-energy-economy models to assess the effectiveness of the Intended Nationally Determined Contributions (INDCs) in meeting high probability 1.5 and 2 °C stabilization goals. We estimate that the implementation of conditional INDCs in 2030 leaves an emissions gap from least cost 2 °C and 1.5 °C pathways for year 2030 equal to 15.6 (9.0–20.3) and 24.6 (18.5–29.0) GtCO2eq respectively. The immediate transition to a more efficient and low-carbon energy system is key to achieving the Paris goals. The decarbonization of the power supply sector delivers half of total CO2 emission reductions in all scenarios, primarily through high penetration of renewables and energy efficiency improvements. In combination with an increased electrification of final energy demand, low-carbon power supply is the main short-term abatement option. We find that the global macroeconomic cost of mitigation efforts does not reduce the 2020–2030 annual GDP growth rates in any model more than 0.1 percentage points in the INDC or 0.3 and 0.5 in the 2 °C and 1.5 °C scenarios respectively even without accounting for potential co-benefits and avoided climate damages. Accordingly, the median GDP reductions across all models in 2030 are 0.4%, 1.2% and 3.3% of reference GDP for each respective scenario. Costs go up with increasing mitigation efforts but a fragmented action, as implied by the INDCs, results in higher costs per unit of abated emissions. On a regional level, the cost distribution is different across scenarios while fossil fuel exporters see the highest GDP reductions in all INDC, 2 °C and 1.5 °C scenarios
Ground and In-Flight Calibration of the OSIRIS-REx Camera Suite
The OSIRIS-REx Camera Suite (OCAMS) onboard the OSIRIS-REx spacecraft is used to study the shape and surface of the mission’s target, asteroid (101955) Bennu, in support of the selection of a sampling site. We present calibration methods and results for the three OCAMS cameras—MapCam, PolyCam, and SamCam—using data from pre-flight and in-flight calibration campaigns. Pre-flight calibrations established a baseline for a variety of camera properties, including bias and dark behavior, flat fields, stray light, and radiometric calibration. In-flight activities updated these calibrations where possible, allowing us to confidently measure Bennu’s surface. Accurate calibration is critical not only for establishing a global understanding of Bennu, but also for enabling analyses of potential sampling locations and for providing scientific context for the returned sample
Plasma Magnetohydrodynamics and Energy Conversion
Contains reports on eight research projects.National Science Foundation (Grant G-24073)United States Air Force, Aeronautical Systems Division, Aeronautical Accessories Laboratory, Wright-Patterson Air Force Base (Contract AF33(616)-7624)United States Air Force, Office of Scientific Research of the Office of Aerospace Research (Research Grant No. 62-308
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