57 resultados para Reynard the Fox.
em Université de Lausanne, Switzerland
Resumo:
Résumé : Une épidémie de gale sarcoptique (Sarcoptes scabiei) touche le canton de Genève depuis 1996. Nous avons étudié l'impact de cette maladie sur différents caractères comportementaux du renard roux (Vulpes vulpes) : l'écologie alimentaire, les comportements spatiaux et l'activité, ainsi que les contacts sociaux. Nous avons également évalué si la gale pouvait influencer la composition et la transmission de la communauté helminthique intestinale du renard. En effet, cette espèce est l'hôte de parasites qui sont liés à des zoonoses importantes, en particulier le ténia échinocoque du renard (Echinococcus multilocularis) pour lequel Genève est considérée comme une zone de haute endémie. Durant 5 années, des carcasses de renards ont été récoltées sur l'ensemble du canton. Nous les avons disséquées et avons conservé différents échantillons pour des analyses ultérieures. Des données sur le poids, l'âge et le statut reproductif des femelles ont ainsi pu être obtenues. Les contenus stomacaux ont été analysés pour déterminer le régime alimentaire, les intestins pour collecter des helminthes, des échantillons de sang pour faire des sérologies et des échantillons de peau pour récupérer les sarcoptes. Des renards sauvages ont également été capturés et équipés de colliers émetteurs afin de déterminer leur activité et leur utilisation de l'espace. Finalement, nous avons réalisé des affûts sur des terriers et des observations nocturnes à l'aide d'un détecteur thermique afin d'étudier les contacts sociaux. Nous avons ensuite considéré tous ces aspects pour comparer les renards galeux aux individus sains. Trois catégories de gale ont été prises en compte selon l'importance de l'infection. L'épidémie a traversé le canton en 8 ans environ et elle a provoqué une forte diminution des populations de renard. Les animaux malades étaient caractérisés par un poids réduit, ils utilisaient des domaines vitaux réduits et présentaient un rythme d'activité irrégulier. En ce qui concerne le régime alimentaire, les renards galeux avaient souvent des estomacs vides ou contenant peu d'aliments d'origine animale. Cette réduction de l'alimentation ne semble pas seulement être liée à des capacités de prédation réduite, mais également à un désintérêt face à la nourriture. Tous les changements de comportement cités étaient plus marqués chez les animaux soumis à une forte infestation. Dix taxons d'helminthes ont été identifiés dans les intestins des renards analysés. Deux d'entre eux représentent un risque de santé publique: Echinococcus multilocularis et Toxocara carvis. Pour ces helminthes, nous n'avons pas identifié de différences de prévalence entre les renards galeux et les animaux sains, mais la charge parasitaire était significativement supérieure chez les individus galeux, en particulier ceux souffrant d'une infestation importante. Ceci est probablement lié à une susceptibilité accrue des individus qui présentent une condition physique amoindrie et des défenses immunitaire affaiblies. Selon nos résultats, nous pouvons conclure que la gale induit des changements comportementaux importants et que ces changements ont une influence potentielle sur la transmission de la gale elle-même, mais également sur la transmission du reste de la communauté parasitaire de l'hôte. Les individus qui souffrent d'une infestation importante sont susceptibles de provoquer une contamination de l'environnement accrue en ce qui concerne des helminthes pouvant provoquer des zoonoses. La gale apparaît être un facteur à ne pas négliger dans le cadre de la gestion de la faune sauvage, mais également en ce qui concerne des problématiques de santé publique. Summary An epidemic outbreak of sarcoptic mange (Sarcoptes scabiei) has struck the canton of Geneva since 1996. The impact of the disease on various behavioural traits of the main host, the red fox (Vulpes vulpes), was investigated: feeding ecology, spatial behaviour and activity, and social contacts. We also evaluated if mange might have an influence on the composition and transmission of the intestinal helminth community of foxes. Indeed, this species is host of parasites with potential zoonotic importance, particularly the fox tapeworm (Echinococcus multilocularis) for which Geneva is reported as endemic area. During 5 years, red fox carcasses have been collected throughout the canton. They were then dissected and various samples conserved for further analysis. Data on weight, age, and reproductive status of females were obtained. Stomach content were analysed for diet analysis, intestines to recover helminths, blood to proceed to ELISAs and skin samples to check for the presence of Sarcoptes mites. Further, wild foxes were captured and fitted with transmitters in order to determine their activity pattern and space use. Finally, we proceeded to direct observations at dens and using a thermal imaging sensor at night to gain information about social contacts. A comparison between healthy and mangy foxes was made for all these aspects. Three categories of mangy foxes were considered from moderately to severely infected. The epidemic wave crossed the canton in about 8 years and induced a significant reduction in fox densities. Mangy individuals appeared to have reduced body weights, to use more restricted home ranges and exhibited an irregular activity pattern. Regarding food, sick foxes often had empty stomachs and consumed less food items of animal origin. The reduction in food intake appeared to be linked not only to a reduced ability to hunt, but also to a reduced interest in food. The changes observed were particularly pronounced in individuals with severe infestation. Ten helminth taxa were recovered from the intestines on the analysed fox carcasses. Two of them have an importance with regard to human public health: Echinococcus multilocularis and Toxocara cams. The prevalence of these helminths did not differ between healthy and mangy foxes, however the worm burden was significantly higher in mangy foxes, particularly those with severe mange. This is probably linked to an increased susceptibility in individuals with a reduced body condition and weakened immune defences. From our observations, we can conclude that mange induces pronounced behavioural changes in the red fox, and that those changes influence the transmission risks of mange itself, but also of the rest of the parasite community of the host. Individuals with severe mange are for example likely to increase the environment contamination of free living stages of helminths with zoonotic importance. Mange appears thus to represent a factor not to be neglected for the management of wild species and for public health issues.
Resumo:
The evolution of grasses using C4 photosynthesis and their sudden rise to ecological dominance 3 to 8 million years ago is among the most dramatic examples of biome assembly in the geological record. A growing body of work suggests that the patterns and drivers of C4 grassland expansion were considerably more complex than originally assumed. Previous research has benefited substantially from dialog between geologists and ecologists, but current research must now integrate fully with phylogenetics. A synthesis of grass evolutionary biology with grassland ecosystem science will further our knowledge of the evolution of traits that promote dominance in grassland systems and will provide a new context in which to evaluate the relative importance of C4 photosynthesis in transforming ecosystems across large regions of Earth.
Resumo:
Waist-hip ratio (WHR) is a measure of body fat distribution and a predictor of metabolic consequences independent of overall adiposity. WHR is heritable, but few genetic variants influencing this trait have been identified. We conducted a meta-analysis of 32 genome-wide association studies for WHR adjusted for body mass index (comprising up to 77,167 participants), following up 16 loci in an additional 29 studies (comprising up to 113,636 subjects). We identified 13 new loci in or near RSPO3, VEGFA, TBX15-WARS2, NFE2L3, GRB14, DNM3-PIGC, ITPR2-SSPN, LY86, HOXC13, ADAMTS9, ZNRF3-KREMEN1, NISCH-STAB1 and CPEB4 (P = 1.9 × 10⁻⁹ to P = 1.8 × 10⁻⁴⁰) and the known signal at LYPLAL1. Seven of these loci exhibited marked sexual dimorphism, all with a stronger effect on WHR in women than men (P for sex difference = 1.9 × 10⁻³ to P = 1.2 × 10⁻&supl;³). These findings provide evidence for multiple loci that modulate body fat distribution independent of overall adiposity and reveal strong gene-by-sex interactions.
Resumo:
Patients with stage I-III melanoma were vaccinated with the modified HLA-A2-binding gp100(209-2M)-peptide after complete surgical resection of their primary lesion and sentinel node biopsy. Cytoplasmic interferon-gamma production by freshly thawed peripheral blood mononuclear cells (direct ex vivo analysis) or by peripheral blood mononuclear cells subjected to 1 cycle of in vitro sensitization with peptide, interleukin-2, and interleukin-15 was measured following restimulation with the modified and native gp100 peptides, and also A2gp100 melanoma cell lines. Peptide-reactive and tumor-reactive T cells were detected in 79% and 66% of selected patients, respectively. Patients could be classified into 3 groups according to their vaccine-elicited T-cell responses. One group of patients responded only to the modified peptide used for immunization, whereas another group of patients reacted to both the modified and native gp100 peptides, but not to naturally processed gp100 antigen on melanoma cells. In the third group of patients, circulating CD8 T cells recognized A2gp100 melanoma cell lines and also both the modified and native peptides. T cells with a low functional avidity, which were capable of lysing tumor cells only if tumor cells were first pulsed by the exogenous administration of native gp100(209-217) peptide were identified in most patients. These results indicate that vaccination with a modified gp100 peptide induced a heterogeneous group of gp100-specific T cells with a spectrum of functional avidities; however, high avidity, tumor-reactive T cells were detected in the majority of patients.
Resumo:
The outcome for patients after an out-of-hospital cardiac arrest (OHCA) has been poor over many decades and single interventions have mostly resulted in disappointing results. More recently, some regions have observed better outcomes after redesigning their cardiac arrest pathways. Optimised resuscitation and prehospital care is absolutely key, but in-hospital care appears to be at least as important. OHCA treatment requires a multidisciplinary approach, comparable to trauma care; the development of cardiac arrest pathways and cardiac arrest centres may dramatically improve patient care and outcomes. Besides emergency medicine physicians, intensivists and neurologists, cardiologists are playing an increasingly crucial role in the post-resuscitation management, especially by optimising cardiac output and undertaking urgent coronary angiography/intervention.
Resumo:
Dans le contexte climatique actuel, les régions méditerranéennes connaissent une intensification des phénomènes hydrométéorologiques extrêmes. Au Maroc, le risque lié aux inondations est devenu problématique, les communautés étant vulnérables aux événements extrêmes. En effet, le développement économique et urbain rapide et mal maîtrisé augmente l'exposition aux phénomènes extrêmes. La Direction du Développement et de la Coopération suisse (DDC) s'implique activement dans la réduction des risques naturels au Maroc. La cartographie des dangers et son intégration dans l'aménagement du territoire représentent une méthode efficace afin de réduire la vulnérabilité spatiale. Ainsi, la DDC a mandaté ce projet d'adaptation de la méthode suisse de cartographie des dangers à un cas d'étude marocain (la ville de Beni Mellal, région de Tadla-Azilal, Maroc). La méthode suisse a été adaptée aux contraintes spécifiques du terrain (environnement semi-aride, morphologie de piémont) et au contexte de transfert de connaissances (caractéristiques socio-économiques et pratiques). Une carte des phénomènes d'inondations a été produite. Elle contient les témoins morphologiques et les éléments anthropiques pertinents pour le développement et l'aggravation des inondations. La modélisation de la relation pluie-débit pour des événements de référence, et le routage des hydrogrammes de crue ainsi obtenus ont permis d'estimer quantitativement l'aléa inondation. Des données obtenues sur le terrain (estimations de débit, extension de crues connues) ont permis de vérifier les résultats des modèles. Des cartes d'intensité et de probabilité ont été obtenues. Enfin, une carte indicative du danger d'inondation a été produite sur la base de la matrice suisse du danger qui croise l'intensité et la probabilité d'occurrence d'un événement pour obtenir des degrés de danger assignables au territoire étudié. En vue de l'implémentation des cartes de danger dans les documents de l'aménagement du territoire, nous nous intéressons au fonctionnement actuel de la gestion institutionnelle du risque à Beni Mellal, en étudiant le degré d'intégration de la gestion et la manière dont les connaissances sur les risques influencent le processus de gestion. L'analyse montre que la gestion est marquée par une logique de gestion hiérarchique et la priorité des mesures de protection par rapport aux mesures passives d'aménagement du territoire. Les connaissances sur le risque restent sectorielles, souvent déconnectées. L'innovation dans le domaine de la gestion du risque résulte de collaborations horizontales entre les acteurs ou avec des sources de connaissances externes (par exemple les universités). Des recommandations méthodologiques et institutionnelles issues de cette étude ont été adressées aux gestionnaires en vue de l'implémentation des cartes de danger. Plus que des outils de réduction du risque, les cartes de danger aident à transmettre des connaissances vers le public et contribuent ainsi à établir une culture du risque. - Severe rainfall events are thought to be occurring more frequently in semi-arid areas. In Morocco, flood hazard has become an important topic, notably as rapid economic development and high urbanization rates have increased the exposure of people and assets in hazard-prone areas. The Swiss Agency for Development and Cooperation (SADC) is active in natural hazard mitigation in Morocco. As hazard mapping for urban planning is thought to be a sound tool for vulnerability reduction, the SADC has financed a project aimed at adapting the Swiss approach for hazard assessment and mapping to the case of Morocco. In a knowledge transfer context, the Swiss method was adapted to the semi-arid environment, the specific piedmont morphology and to socio-economic constraints particular to the study site. Following the Swiss guidelines, a hydro-geomorphological map was established, containing all geomorphic elements related to known past floods. Next, rainfall / runoff modeling for reference events and hydraulic routing of the obtained hydrographs were carried out in order to assess hazard quantitatively. Field-collected discharge estimations and flood extent for known floods were used to verify the model results. Flood hazard intensity and probability maps were obtained. Finally, an indicative danger map as defined within the Swiss hazard assessment terminology was calculated using the Swiss hazard matrix that convolves flood intensity with its recurrence probability in order to assign flood danger degrees to the concerned territory. Danger maps become effective, as risk mitigation tools, when implemented in urban planning. We focus on how local authorities are involved in the risk management process and how knowledge about risk impacts the management. An institutional vulnerability "map" was established based on individual interviews held with the main institutional actors in flood management. Results show that flood hazard management is defined by uneven actions and relationships, it is based on top-down decision-making patterns, and focus is maintained on active mitigation measures. The institutional actors embody sectorial, often disconnected risk knowledge pools, whose relationships are dictated by the institutional hierarchy. Results show that innovation in the risk management process emerges when actors collaborate despite the established hierarchy or when they open to outer knowledge pools (e.g. the academia). Several methodological and institutional recommendations were addressed to risk management stakeholders in view of potential map implementation to planning. Hazard assessment and mapping is essential to an integrated risk management approach: more than a mitigation tool, danger maps represent tools that allow communicating on hazards and establishing a risk culture.
Resumo:
Using genome-wide data from 253,288 individuals, we identified 697 variants at genome-wide significance that together explained one-fifth of the heritability for adult height. By testing different numbers of variants in independent studies, we show that the most strongly associated ∼2,000, ∼3,700 and ∼9,500 SNPs explained ∼21%, ∼24% and ∼29% of phenotypic variance. Furthermore, all common variants together captured 60% of heritability. The 697 variants clustered in 423 loci were enriched for genes, pathways and tissue types known to be involved in growth and together implicated genes and pathways not highlighted in earlier efforts, such as signaling by fibroblast growth factors, WNT/β-catenin and chondroitin sulfate-related genes. We identified several genes and pathways not previously connected with human skeletal growth, including mTOR, osteoglycin and binding of hyaluronic acid. Our results indicate a genetic architecture for human height that is characterized by a very large but finite number (thousands) of causal variants.
Resumo:
BACKGROUND: Histologic grade in breast cancer provides clinically important prognostic information. However, 30%-60% of tumors are classified as histologic grade 2. This grade is associated with an intermediate risk of recurrence and is thus not informative for clinical decision making. We examined whether histologic grade was associated with gene expression profiles of breast cancers and whether such profiles could be used to improve histologic grading. METHODS: We analyzed microarray data from 189 invasive breast carcinomas and from three published gene expression datasets from breast carcinomas. We identified differentially expressed genes in a training set of 64 estrogen receptor (ER)-positive tumor samples by comparing expression profiles between histologic grade 3 tumors and histologic grade 1 tumors and used the expression of these genes to define the gene expression grade index. Data from 597 independent tumors were used to evaluate the association between relapse-free survival and the gene expression grade index in a Kaplan-Meier analysis. All statistical tests were two-sided. RESULTS: We identified 97 genes in our training set that were associated with histologic grade; most of these genes were involved in cell cycle regulation and proliferation. In validation datasets, the gene expression grade index was strongly associated with histologic grade 1 and 3 status; however, among histologic grade 2 tumors, the index spanned the values for histologic grade 1-3 tumors. Among patients with histologic grade 2 tumors, a high gene expression grade index was associated with a higher risk of recurrence than a low gene expression grade index (hazard ratio = 3.61, 95% confidence interval = 2.25 to 5.78; P < .001, log-rank test). CONCLUSIONS: Gene expression grade index appeared to reclassify patients with histologic grade 2 tumors into two groups with high versus low risks of recurrence. This approach may improve the accuracy of tumor grading and thus its prognostic value.