Crop-model assisted phenomics and genome-wide association study for climate adaptation of indica rice. 2. Thermal stress and spikelet sterility

Low night and high day temperatures during sensitive reproductive stages cause spikelet sterility in rice. Phenotyping of tolerance traits in the field is difficult because of temporal interactions with phenology and organ temperature differing from ambient. Physiological models can be used to separate these effects. A 203-accession indica rice diversity panel was phenotyped for sterility in ten environments in Senegal and Madagascar and climate data were recorded. Here we report on sterility responses while a companion study reported on phenology. The objectives were to improve the RIDEV model of rice thermal sterility, to estimate response traits by fitting model parameters, and to link the response traits to genomic regions through genome-wide association studies (GWAS). RIDEV captured 64% of variation of sterility when cold acclimation during vegetative stage was simulated, but only 38% when it was not. The RIDEV parameters gave more and stronger quantitative trait loci (QTLs) than index variables derived more directly from observation. The 15 QTLs identified at P<1 × 10−5 (33 at P<1 × 10−4) were related to sterility effects of heat, cold, cold acclimation, or unexplained causes (baseline sterility). Nine annotated genes were found on average within the 50% linkage disequilibrium (LD) region. Among them, one to five plausible candidate genes per QTL were identified based on known expression profiles (organ, stage, stress factors) and function. Meiosis-, development- and flowering-related genes were frequent, as well a stress signaling kinases and transcription factors. Putative epigenetic factors such as DNA methylases or histone-related genes were frequent in cold-acclimation QTLs, and positive-effect alleles were frequent in cold-tolerant highland rice from Madagascar. The results indicate that epigenetic control of acclimation may be important in indica rice genotypes adapted to cool environments. (Résumé d'auteur

Expression and implication of clusterin in left ventricular remodeling after myocardial infarction

International audienceBACKGROUND: Left ventricular remodeling (LVR) after myocardial infarction is associated with an increased risk of heart failure and death. In spite of a modern therapeutic approach, LVR remains relatively frequent and difficult to predict in clinical practice. Our aim was to identify new biomarkers of LVR and understand their involvement in its development.METHODS AND RESULTS:Proteomic analysis of plasma from the REVE-2 study (Remodelage Ventriculaire)-a study dedicated to the analysis of LVR which included 246 patients after a first anterior myocardial infarction-identified increased plasma levels of CLU (clusterin) in patients with high LVR. We used a rat model of myocardial infarction to analyze CLU expression in the LV and found a significant increase that was correlated with LVR parameters. We found increased CLU expression and secretion in primary cultures of rat neonate cardiomyocytes hypertrophied by isoproterenol. Silencing of CLU in hypertrophied neonate cardiomyocytes induced a significant decrease in cell size, ANP (atrial natriuretic peptide), and BNP (B-type natriuretic peptide) expression, associated with a decreased ERK (extracellular signal-regulated kinase) 1/2 activity, suggesting a prohypertrophic role of CLU. We then confirmed a significant increase of both intracellular p-CLU (precursor form of CLU) and m-CLU (mature form of CLU) in failing human hearts. Finally, the circulating levels of CLU (secreted form) were increased in patients with chronic heart failure who died from cardiovascular cause during a 3-year follow-up (n=99) compared with survivors (n=99).CONCLUSIONS: Our results show for the first time that plasma CLU levels are associated with LVR post-myocardial infarction, have in part a cardiac origin, and are a predictor of early death in heart failure patients

Changements climatiques et risques naturels dans les Alpes

Sous l’effet des changements climatiques, les territoires de montagne alpins enregistrent des évolutions rapides et manifestes qui suscitent l’attention croissante des populations, des scientifiques et des gestionnaires. Pour mieux faire face aux aléas et aux vulnérabilités spécifiques à ces territoires, l’adaptation de la prévention des risques naturels aux changements climatiques est aujourd’hui prescrite par les politiques publiques nationales et communautaires en vigueur dans l’arc alpin. Cet article passe en revue les progrès récents dans la connaissance des changements perçus, mesurés et projetés à l’échelle des Alpes françaises dans 1) les paramètres climatiques, 2) la cryosphère, les hydrosystèmes et la morphodynamique des versants, 3) les aléas naturels et 4) les risques induits. Cette synthèse renouvelée fournit un aperçu des résultats des projets de recherche, de coopération et de capitalisation sur ces thématiques, acquis pour la plupart au cours de la période de programmation 2007-2013, en s’appuyant sur des bases de données et plates-formes de connaissances développées par différents opérateurs scientifiques et techniques dans le cadre de l’arc alpin. Elle est illustrée par une méta-analyse d’exemples déjà publiés de chroniques d’activité d’aléas hydro-gravitaires, accompagnées des paramètres climatiques identifiés comme « prédicteurs ».Under the effects of climate change, Alpine mountainous regions are undergoing fast and well-perceptible evolutions, which are attracting the growing attention of people, scientists and managers. To cope better with the hazards and vulnerabilities specific to these territories, the current national and European public policies in the Alpine countries now prescribe adapting natural hazard prevention to climate change. This paper provides a review of recent advances in knowledge on the perceived, measured and projected changes in i) climate patterns, ii) the cryosphere, hydrosystems and geomorphological dynamics on Alpine slopes, and iii) natural hazard evolution and induced risks at the scale of the French Alps. We give a brief overview of new results achieved by research, cooperation and capitalisation projects in these thematic fields during the programme period 2007-2013, which are available on databases, thematic knowledge platforms and observatories developed by different scientific and technical operators in the larger framework of the European Alpine arc. We illustrate this renewed synthesis by published examples of hydro-gravitational hazard activity chronicles, along with climate patterns identified as “predictors”

Régime sans gluten

Tuberculosis, despite its prevention, remains an endemic affection in Morocco. Although rare, pseudo surgical forms and especially peritonitis are mainly due to delayed diagnosis. We report the case of a 30-year-old woman, admitted for peritonitis. The diagnosis of tuberculous peritonitis was established during surgery with macroscopic observation of granulations, and confirmed after biopsy specimens by identification of a giant lymph node cell granuloma with caseous necrosis. Outcome was favorable after appropriate antibiotic therapy. This observation emphasizes the fact that peritonitis, although a rare complication of peritoneal tuberculosis, poses problems of positive and differential diagnosis. Even if treatment is based on antituberculous quadritherapy, surgery is sometimes necessary and should be decided in due time

Antimalarial drug use in general populations of tropical Africa

<p>Abstract</p> <p>Background</p> <p>The burden of <it>Plasmodium falciparum </it>malaria has worsened because of the emergence of chloroquine resistance. Antimalarial drug use and drug pressure are critical factors contributing to the selection and spread of resistance. The present study explores the geographical, socio-economic and behavioural factors associated with the use of antimalarial drugs in Africa.</p> <p>Methods</p> <p>The presence of chloroquine (CQ), pyrimethamine (PYR) and other antimalarial drugs has been evaluated by immuno-capture and high-performance liquid chromatography in the urine samples of 3,052 children (2–9 y), randomly drawn in 2003 from the general populations at 30 sites in Senegal (10), Burkina-Faso (10) and Cameroon (10). Questionnaires have been administered to the parents of sampled children and to a random sample of households in each site. The presence of CQ in urine was analysed as dependent variable according to individual and site characteristics using a random – effect logistic regression model to take into account the interdependency of observations made within the same site.</p> <p>Results</p> <p>According to the sites, the prevalence rates of CQ and PYR ranged from 9% to 91% and from 0% to 21%, respectively. In multivariate analysis, the presence of CQ in urine was significantly associated with a history of fever during the three days preceding urine sampling (OR = 1.22, p = 0.043), socio-economic level of the population of the sites (OR = 2.74, p = 0.029), age (2–5 y = reference level; 6–9 y OR = 0.76, p = 0.002), prevalence of anti-circumsporozoite protein (CSP) antibodies (low prevalence: reference level; intermediate level OR = 2.47, p = 0.023), proportion of inhabitants who lived in another site one year before (OR = 2.53, p = 0.003), and duration to reach the nearest tarmacked road (duration less than one hour = reference level, duration equal to or more than one hour OR = 0.49, p = 0.019).</p> <p>Conclusion</p> <p>Antimalarial drug pressure varied considerably from one site to another. It was significantly higher in areas with intermediate malaria transmission level and in the most accessible sites. Thus, <it>P. falciparum </it>strains arriving in cross-road sites or in areas with intermediate malaria transmission are exposed to higher drug pressure, which could favour the selection and the spread of drug resistance.</p

Risques et adaptation nutritionnelle en cancérologie

This article starts with a presentation of Caycedian Sophrology. We then evaluate its impact on stress reduction through a questionnaire on a students’ population. It appears that stress level increases between the two sessions in the control group while it decreases in the experimental group