Chiral Perturbation Theory

An introduction to the methods and ideas of Chiral Perturbation Theory is presented in this talk. The discussion is illustrated with some phenomenological predictions that can be compared with available experimental results.Comment: 16 pages, 4 Postscript figures, uses epsf.sty. Talk presented at the International Conference on Particle Physics and Astrophysics in The Standard Model and Beyond, Bystra (Poland). Full Postscript file available at http://deneb.ugr.es/papers/ugft57.ps.g

Path-tracing Monte Carlo Library for 3D Radiative Transfer in Highly Resolved Cloudy Atmospheres

Interactions between clouds and radiation are at the root of many difficulties in numerically predicting future weather and climate and in retrieving the state of the atmosphere from remote sensing observations. The large range of issues related to these interactions, and in particular to three-dimensional interactions, motivated the development of accurate radiative tools able to compute all types of radiative metrics, from monochromatic, local and directional observables, to integrated energetic quantities. In the continuity of this community effort, we propose here an open-source library for general use in Monte Carlo algorithms. This library is devoted to the acceleration of path-tracing in complex data, typically high-resolution large-domain grounds and clouds. The main algorithmic advances embedded in the library are those related to the construction and traversal of hierarchical grids accelerating the tracing of paths through heterogeneous fields in null-collision (maximum cross-section) algorithms. We show that with these hierarchical grids, the computing time is only weakly sensitivive to the refinement of the volumetric data. The library is tested with a rendering algorithm that produces synthetic images of cloud radiances. Two other examples are given as illustrations, that are respectively used to analyse the transmission of solar radiation under a cloud together with its sensitivity to an optical parameter, and to assess a parametrization of 3D radiative effects of clouds.Comment: Submitted to JAMES, revised and submitted again (this is v2

Utilisation de la grille pour la simulation de température de brillance dans une atmosphère nuageuse composée de cirrus

Utilisation de la grille pour la simulation de température de brillance dans une atmosphère nuageuse composée de cirru

Les choix organisationnels des propriétaires de chevaux de loisir dans les espaces ruraux

La possession d’équidés de loisir a récemment connu un essor important. Pour entretenir ces animaux, leurs propriétaires peuvent soit les prendre en charge eux-mêmes, soit faire appel à des prestataires de services marchands. Les assimilant à des producteurs de leur propre loisir, nous proposons d’étudier les déterminants de leur choix organisationnel grâce aux théories traitant habituellement des frontières de la firme. Les 251 enquêtes réalisées démontrent la pertinence de l’application de ces cadres d’analyse à la production domestique. Les propriétaires d’équidés poursuivent un objectif d’efficience. Ils cherchent à maximiser leur utilité, tout en minimisant leurs coûts de production et de transaction et en s’adaptant aux ressources auxquelles ils peuvent avoir accès.The number of recreational Equidae owners has recently increased sharply. These owners can choose between stabling and caring for their animals domestically, on their own property, or using professional service suppliers. By considering them as producers of their own leisure activity, we proposed to study the parameters involved in this choice using theories usually employed to analyze firm boundaries. Results from our 251 inquiries demonstrated the relevance of transposing these theoretical tools to domestic production. Equidae owners pursue an objective of efficiency. They aim at maximizing their utility while minimizing their production and transaction costs and adapting to resources they can access

Sprouty1, a new target of the angiostatic agent 16K prolactin, negatively regulates angiogenesis

BACKGROUND:Disorganized angiogenesis is associated with several pathologies, including cancer. The identification of new genes that control tumor neovascularization can provide novel insights for future anti-cancer therapies. Sprouty1 (SPRY1), an inhibitor of the MAPK pathway, might be one of these new genes. We identified SPRY1 by comparing the transcriptomes of untreated endothelial cells with those of endothelial cells treated by the angiostatic agent 16K prolactin (16K hPRL). In the present study, we aimed to explore the potential function of SPRY1 in angiogenesis.RESULTS:We confirmed 16K hPRL induced up-regulation of SPRY1 in primary endothelial cells. In addition, we demonstrated the positive SPRY1 regulation in a chimeric mouse model of human colon carcinoma in which 16K hPRL treatment was shown to delay tumor growth. Expression profiling by qRT-PCR with species-specific primers revealed that induction of SPRY1 expression by 16K hPRL occurs only in the (murine) endothelial compartment and not in the (human) tumor compartment. The regulation of SPRY1 expression was NF-kappaB dependent. Partial SPRY1 knockdown by RNA interference protected endothelial cells from apoptosis as well as increased endothelial cell proliferation, migration, capillary network formation, and adhesion to extracellular matrix proteins. SPRY1 knockdown was also shown to affect the expression of cyclinD1 and p21 both involved in cell-cycle regulation. These findings are discussed in relation to the role of SPRY1 as an inhibitor of ERK/MAPK signaling and to a possible explanation of its effect on cell proliferation.CONCLUSIONS:Taken together, these results suggest that SPRY1 is an endogenous angiogenesis inhibitor

3D cloud envelope and cloud development velocity from simulated CLOUD (C3IEL) stereo images

A method to derive the 3D cloud envelope and the cloud development velocity from high spatial and temporal resolution satellite imagery is presented. The CLOUD instrument of the recently proposed C3IEL mission lends itself well to observing at high spatial and temporal resolutions the development of convective cells. Space-borne visible cameras simultaneously image, under multiple view angles, the same surface domain every 20 s over a time interval of 200 s. In this paper, we present a method for retrieving cloud development velocity from simulated multi-angular, high-resolution top of the atmosphere (TOA) radiance cloud fields. The latter are obtained via the image renderer Mitsuba for a cumulus case generated via the atmospheric research model SAM and via the radiative transfer model 3DMCPOL, coupled with the outputs of an orbit, attitude, and camera simulator for a deep convective cloud case generated via the atmospheric research model Meso-NH. Matching cloud features are found between simulations via block matching. Image coordinates of tie points are mapped to spatial coordinates via 3D stereo reconstruction of the external cloud envelope for each acquisition. The accuracy of the retrieval of cloud topography is quantified in terms of RMSE and bias that are, respectively, less than 25 and 5 m for the horizontal components and less than 40 and 25 m for the vertical components. The inter-acquisition 3D velocity is then derived for each pair of tie points separated by 20 s. An independent method based on minimising the RMSE for a continuous horizontal shift of the cloud top, issued from the atmospheric research model, allows for the obtainment of a ground estimate of the velocity from two consecutive acquisitions. The mean values of the distributions of the stereo and ground velocities exhibit small biases. The width of the distributions is significantly different, with higher a distribution width for the stereo-retrieved velocity. An alternative way to derive an average velocity over 200 s, which relies on tracking clusters of points via image feature matching over several acquisitions, was also implemented and tested. For each cluster of points, mean stereo and ground positions were derived every 20 s over 200 s. The mean stereo and ground velocities, obtained as the slope of the line of best fit to the mean positions, are in good agreement.</p

Clinical Impact of Antifungal Susceptibility, Biofilm Formation and Mannoside Expression of Candida Yeasts on the Outcome of Invasive Candidiasis in ICU: An Ancillary Study on the Prospective AmarCAND2 Cohort

Background: The link between Candida phenotypical characteristics and invasive candidiasis (IC) prognosis is still partially unknown.Methods:Candida strains isolated during the AmarCAND2 study were centrally analyzed for species identification, antifungal susceptibility, biofilm formation, and expression of surface and glycoconjugate mannosides. Correlation between these phenotypical features and patient outcome was sought using a multivariable Cox survival model.Results:Candida albicans was predominant (65.4%, n = 285), with a mortality rate significantly lower than that in patients with non-albicans strains [HR 0.67 (0.46–1.00), p = 0.048]. The rate of fluconazole-resistant strains was low (C. albicans and Candida glabrata: 3.5 and 6.2%, respectively) as well as caspofungin-resistant ones (1 and 3.1%, respectively). Early biofilm formation was less frequent among C. albicans (45.4%) than among non-albicans (81.2%). While the strains of C. albicans showed variable levels of surface mannosides expression, strains isolated from candidemia exhibited a high expression of β-man, which was correlated with an increased mortality (p = 0.02).Conclusion:Candida albicans IC were associated with lower mortality, and with strains that exhibited less frequently early biofilm formation than non-albicans strains. A high expression of β-man was associated with increased IC mortality. Further studies are warranted to confirm this data and to evaluate other virulence factors in yeasts

Alimentation du nourrisson (évolution et place des recommandations nutritionnelles dans la pratique quotidienne du médecin généraliste et application par les parents)

PARIS6-Bibl.Pitié-Salpêtrie (751132101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF