35 research outputs found
Computation of Solar Radiative Fluxes by 1D and 3D Methods Using Cloudy Atmospheres Inferred from A-train Satellite Data
The main point of this study was to use realistic representations of cloudy atmospheres to assess errors in solar flux estimates associated with 1D radiative transfer models. A scene construction algorithm, developed for the EarthCARE satellite mission, was applied to CloudSat, CALIPSO, and MODIS satellite data thus producing 3D cloudy atmospheres measuring 60 km wide by 13,000 km long at 1 km grid-spacing. Broadband solar fluxes and radiances for each (1 km)2 column where then produced by a Monte Carlo photon transfer model run in both full 3D and independent column approximation mode (i.e., a 1D model)
Animal Ca2+ release-activated Ca2+ (CRAC) channels appear to be homologous to and derived from the ubiquitous cation diffusion facilitators
<p>Abstract</p> <p>Background</p> <p>Antigen stimulation of immune cells triggers Ca<sup>2+ </sup>entry through Ca<sup>2+ </sup>release-activated Ca<sup>2+ </sup>(CRAC) channels, promoting an immune response to pathogens. Defects in a CRAC (Orai) channel in humans gives rise to the hereditary Severe Combined Immune Deficiency (SCID) syndrome. We here report results that define the evolutionary relationship of the CRAC channel proteins of animals, and the ubiquitous Cation Diffusion Facilitator (CDF) carrier proteins.</p> <p>Findings</p> <p>CDF antiporters derived from a primordial 2 transmembrane spanner (TMS) hairpin structure by intragenic triplication to yield 6 TMS proteins. Four programs (IC/GAP, GGSEARCH, HMMER and SAM) were evaluated for identifying sequence similarity and establishing homology using statistical means. Overall, the order of sensitivity (similarity detection) was IC/GAP = GGSEARCH > HMMER > SAM, but the use of all four programs was superior to the use of any two or three of them. Members of the CDF family appeared to be homologous to members of the 4 TMS Orai channel proteins.</p> <p>Conclusions</p> <p>CRAC channels derived from CDF carriers by loss of the first two TMSs of the latter. Based on statistical analyses with multiple programs, TMSs 3-6 in CDF carriers are homologous to TMSs 1-4 in CRAC channels, and the former was the precursor of the latter. This is an unusual example of how a functionally and structurally more complex protein may have predated a simpler one.</p
Echocardiography practice, training and accreditation in the intensive care: document for the World Interactive Network Focused on Critical Ultrasound (WINFOCUS)
Echocardiography is increasingly used in the management of the critically ill patient as a non-invasive diagnostic and monitoring tool. Whilst in few countries specialized national training schemes for intensive care unit (ICU) echocardiography have been developed, specific guidelines for ICU physicians wishing to incorporate echocardiography into their clinical practice are lacking. Further, existing echocardiography accreditation does not reflect the requirements of the ICU practitioner. The WINFOCUS (World Interactive Network Focused On Critical UltraSound) ECHO-ICU Group drew up a document aimed at providing guidance to individual physicians, trainers and the relevant societies of the requirements for the development of skills in echocardiography in the ICU setting. The document is based on recommendations published by the Royal College of Radiologists, British Society of Echocardiography, European Association of Echocardiography and American Society of Echocardiography, together with international input from established practitioners of ICU echocardiography. The recommendations contained in this document are concerned with theoretical basis of ultrasonography, the practical aspects of building an ICU-based echocardiography service as well as the key components of standard adult TTE and TEE studies to be performed on the ICU. Specific issues regarding echocardiography in different ICU clinical scenarios are then described
Computation of Solar Radiative Fluxes by 1D and 3D Methods Using Cloudy Atmospheres Inferred from A-train Satellite Data
Solar cycle and climate predictions
The impact of solar activity on climate has been debated heatedly. Simulations with a climate model using new observations of solar variability suggest a substantial influence of the Sun on the winter climate in the Northern Hemisphere
Modeling Sustainability: Population, Inequality, Consumption, and Bidirectional Coupling of the Earth and Human Systems
Caractérisation de la capture du VIH-1 (du récepteur DC-SIGN aux extensions trans-épithéliales des cellules dendritiques)
En tant que sentinelles du système immunitaire, les CD expriment une lectine, le DC-SIGN, présentant une forte affinité pour de nombreux pathogènes, incluant le VIH-1. L objectif premier de cette étude est d utiliser cette lectine comme outil de screening d enveloppes issues d isolats primaires de primo-infection afin d identifier une enveloppe d intérêt comme immunogène bloquant l interaction avec le DC-SIGN. Nous avons ainsi pu identifier deux mutations dans la gp41 susceptibles d amplifier l interaction DC-SIGN /gp120. Enfin, nous avons étudié la capacité de prise en charge locale et spécifique d Aspergillus fumigatus par des extensions trans-épithéliales formées par les CD au niveau des villosités de l iléon terminal murin. Notre étude souligne le rôle primordial du DC-SIGN au niveau des muqueuses monostratifiées que ce soit pour la voie de contamination homosexuelle du VIH-1 ou pour l efficacité de capture de pathogènes par les dendrites trans-épithéliales des CDAs the sentinels of the immune system, DC express a lectin DC-SIGN known to bind with high affinity a wide range of pathogens, including HIV-1. The first aim of this study is to use this lectin as a screening tool for envelopes from acute HIV-1 primary isolates in order to identify an envelope of interest that could be used as an immunogen to block the interaction with DC-SIGN. We have identified two point mutations in the gp41 susceptible to increase the DC-SIGN/gp120 interaction. At last, we have studied the local and specific uptake of Aspergillus fumigatus by trans-epithelial dendrites formed by DC in villi of the murine terminal ileum. Our study highlights the crucial role of DC-SIGN in monolayered mucosa, as suggested by the predominance of HIV-1 homosexual contamination or the efficiency of DC trans-epithelial dendrites to capture pathogensLYON1-BU.Sciences (692662101) / SudocSudocFranceF
Evaluating EOF-modes against a stochastic null hypothesis
In this paper it is suggested that a stochastic isotropic diffusive process, representing a spatial first order auto regressive process (AR(1)-process), can be used as a null hypothesis for the spatial structure of climate variability. By comparing the leading empirical orthogonal functions (EOFs) of a fitted null hypothesis with EOF modes of an observed data set, inferences about the nature of the observed modes can be made. The concept and procedure of fitting the null hypothesis to the observed EOFs is in analogy to time analysis, where an AR(1)-process is fitted to the statistics of the time series in order to evaluate the nature of the time scale behavior of the time series. The formulation of a stochastic null hypothesis allows one to define teleconnection patterns as those modes that are most distinguished from the stochastic null hypothesis. The method is applied to several artificial and real data sets including the sea surface temperature of the tropical Pacific and Indian Ocean and the Northern Hemisphere wintertime and tropical sea level pressure