53161 research outputs found
Sort by
Modeling Culicoides abundance in mainland France: implications for surveillance
No full textBackground Biting midges of the genus Culicoides Latreille (Diptera: Ceratopogonidae) are involved in the transmission of several viruses affecting humans and livestock, particularly bluetongue (BTV). Over the last decade, Culicoides surveillance has been conducted discontinuously and at various temporal and spatial scales in mainland France following the BTV epizootics in 2008-2009 and its reemergence and continuous circulation since 2015. The ability to predict seasonal dynamics and spatial abundance of Culicoides spp. is a key element in identifying periods and areas at high risk of transmission in order to strengthen surveillance for early detection and to establish seasonally disease-free zones. The objective of this study was to model the abundance of Culicoides spp. using surveillance data. Methods A mixed-effect Poisson model, adjusted for overdispersion and taking into account temperature data at each trap location, was used to model the weekly relative abundance of Culicoides spp. over a year in 24 vector zones, based on surveillance data collected during 2009-2012. Vector zones are the spatial units used for Culicoides surveillance since 2016 in mainland France. Results The curves of the predicted annual abundance of Culicoides spp. in vector zones showed three different shapes: unimodal, bimodal or plateau, reflecting the temporal variability of the observed counts between zones. For each vector zone, the model enabled to identify periods of vector activity ranging from 25 to 51 weeks. Conclusions Although the data were collected for surveillance purposes, our modeling approach integrating vector data with daily temperatures, which are known to be major drivers of Culicoides spp. activity, provided areas-specific predictions of Culicoides spp. abundance. Our findings provide decisions makers with essential information to identify risk periods in each vector zone and guide the allocation of resources for surveillance and control. Knowledge of Culicoides spp. dynamics is also of primary importance for modeling the risk of establishment and spread of midge-borne diseases in mainland France
Stratégies permettant de compenser les pertes organoleptiques associées à la reformulation des aliments dans un objectif nutritionnel
No full textLa nécessité de disposer d’une offre alimentaire qui permette aux consommateurs de suivre les recommandations nutritionnelles des organisations de santé publique est toujours aussi pressante. Pour cela il est nécessaire de développer des stratégies permettant de compenser les pertes organoleptiques associées à la réduction des teneurs en matières grasses et en sel et/ou sucre. Plusieurs stratégies sont déjà mises en oeuvre et/ou encore à l’étude. Notre laboratoire concentre ses travaux sur les stratégies s’appuyant sur les interactions multimodales, notamment entre les saveurs et les arômes. Dans cet article, nous présentons des études récentes qui nous ont permis de démontrer que certains arômes ont la capacité de renforcer la perception des saveurs salée et sucrée, mais aussi la perception de la matière grasse. Nous avons développé des méthodologies permettant de sélectionner, parmi les arômes naturellement présents dans un aliment, ceux qui sont associés à ces saveurs ; puis de tester ceux qui ont la capacité de compenser des réductions en gras, sel ou sucre pouvant aller jusqu’à 30%. Des réductions plus importantes peuvent être compensées sensoriellement en combinant cette stratégie avec d’autres stratégies comme la substitution partielle ou la distribution optimisée des composés gustatifs.The need for food supply that helps consumers to follow nutritional recommendations of public health organizations is still pressing. Therefore, it is required to develop strategies to compensate sensory losses associated with the decrease in the levels of fat and salt and/or sugar. Several strategies are already implemented and/or are still under study within research projects. Our laboratory focuses on strategies that aim leveraging multisensory interactions such as aroma-taste interactions. In this paper, we present recent studies that have allowed us to show that certain aromas can enhance the perception of salty and sweet taste, and the perception of fat content. We have developed methodologies which help selecting the aromas, naturally present in a food, that are associated to these tastes; then to test those aromas that have the ability to compensate for reductions in fat, salt or sugar up to 30%. Higher reductions can be targeted by combining this aroma-based strategy with others such as the partial substitution or the distribution optimisation of flavor-active compounds
The impact of the French soda tax on prices and purchases: an ex post evaluation
No full textWe estimate the price and consumption effects of the 2012 French tax on sweetened non-alcoholic drinks using a difference-in-difference approach. Our identification strategy exploits Italian data as a natural control group. We use French and Italian Consumer Price Indices, purchase prices and quantities from the 2011 and 2012 Kantar and GfK home-scan surveys for two French regions and two neighbouring Italian regions, and expenditure data from the 2011 and 2012 Italian Expenditure Survey. We check for the robustness of our results by applying the difference-in-difference models using only French data and considering water as the benchmark (control) good. We find that the tax is transmitted to the prices of taxed drinks, with full transmission for soft drinks and partial transmission for fruit juices. The evidence on purchase responses is mixed and less robust, indicating at most a very small reduction in soft drink purchases (about half a litre per capita per year), an impact which would be consistent with the low tax rate. We find suggestive evidence of a larger response by the sub-sample of heavy purchasers. Fruit juices and water do not seem to have been affected by the tax
Ascoma genotyping and mating type analyses of mycorrhizas and soil mycelia of Tuber borchii in a truffle orchard established by mycelial inoculated plants
No full textTuber borchii (the Bianchetto truffle) is a heterothallic Ascomycete living in symbiotic association with trees and shrubs. Maternal and paternal genotype dynamics have already been studied for the black truffles Tuber melanosporum and Tuber aestivum but not yet for T. borchii. In this study, we analysed maternal and paternal genotypes in the first truffle orchard realized with plants inoculated with five different T. borchii mycelia. Our aims were to test the persistence of the inoculated mycelia, if maternal and/or paternal genotypes correspond to inoculated mycelia and to assess the hermaphroditism of T. borchii. The mating type of each isolate as well as those of mycorrhizas, ascomata and extraradical soil mycelia was determined. Moreover, simple sequence repeat (SSR) profiles of maternal and paternal genotypes were assessed in 18 fruiting bodies to investigate the sexual behaviour of this truffle. The maternal genotypes of the fruiting bodies corresponded to those of the inoculated mycelia with only two exceptions. This confirmed that the inoculated mycelia persisted 9 years after plantation. As regards paternal partner, only two had the same genotype as those of the inoculated mycelia, suggesting hermaphroditism. Most of the new paternal genotypes originated from a recombination of those of inoculated mycelia
The Chromatin Factor HNI9 and ELONGATED HYPOCOTYL5 Maintain ROS Homeostasis under High Nitrogen Provision
No full textReactive oxygen species (ROS) can accumulate in cells at excessive levels, leading to unbalanced redox states and to potential oxidative stress, which can have damaging effects on the molecular components of plant cells. Several environmental conditions have been described as causing an elevation of ROS production in plants. Consequently, activation of detoxification responses is necessary to maintain ROS homeostasis at physiological levels. Misregulation of detoxification systems during oxidative stress can ultimately cause growth retardation and developmental defects. Here, we demonstrate that Arabidopsis (Arabidopsis thaliana) plants grown in a high nitrogen environment express a set of genes involved in detoxification of ROS that maintain ROS at physiological levels. We show that the chromatin factor HIGH NITROGEN INENSITIVE 9 (HNI9) is an important mediator of this response and is required for the expression of detoxification genes. Mutation in HNI9 leads to elevated ROS levels and ROS-dependent phenotypic defects under high but not low N provision. In addition, we identify ELONGATED HYPOCOTYL 5 (HY5) as a major transcription factor required for activation of the detoxification program under high N. Our results demonstrate the requirement of a balance between N metabolism and ROS production, and establish major regulators required to control ROS homeostasis under conditions of excess N
Les collectifs producteurs de savoirs pour l’action : retour d’expériences sur la production de légumineuses en Bourgogne-Franche-Comté.
No full textParmi les questionnements que suscite l’injonction à l’écologisation de l’agriculture, nous cherchons à
comprendre comment les pratiques d’assolement évoluent, notamment ce qui conduit les agriculteurs à
insérer des légumineuses. Cet article explore la manière dont les collectifs d’agriculteurs contribuent à
l’adoption de nouvelles pratiques. Dix-sept entretiens conduits en Bourgogne Franche-Comté auprès
d’agriculteurs insérant déjà des légumineuses dans leur assolement ont exploré ce que le travail
collectif entre pairs apporte vis-à-vis de leurs pratiques d’exploration. Appartenir à de tels collectifs
permet de retrouver un sentiment d’autonomie décisionnelle, de poursuivre et atteindre des objectifs
précis, d’apprendre et développer ses savoirs, tout en se socialisant. Ce qui ressort est l’apport cognitif
des collectifs où les savoirs sont non seulement partagés, échangés, mais aussi construits. Apportant
également un soutien moral, les collectifs se présentent comme des outils facilitateurs pour le
développement de pratiques agroécologiques.Among the questions raised by the greening of agriculture injunction, we seek to understand how
cropping practices are changing, particularly what leads farmers to insert legumes. This article explores
how farmers' collectives contribute to the adoption of new practices. Seventeen interviews were
conducted in Burgundy Franche-Comté with farmers already including legumes in their rotation, and
explored what collective working, between peers, brings to their exploration practices. Belonging to such
collective allows to regain a sense of decision-making autonomy, to pursue and achieve specific
objectives, to learn and develop one’s knowledge, while also socializing. What stands out is the
cognitive contribution of collectives where knowledge is not only shared, exchanged, but also
constructed. Also providing moral support, collectives are considered as facilitating tools for the
development of agroecological practices
Rapid and dfferential evolution of the venom composition of a parasitoid wasp depending on the host strain
No full textAbstract: Parasitoid wasps rely primarily on venom to suppress the immune response and regulate
the physiology of their host. Intraspecific variability of venom protein composition has been
documented in some species, but its evolutionary potential is poorly understood. We performed an
experimental evolution initiated with the crosses of two lines of Leptopilina boulardi of different
venom composition to generate variability and create new combinations of venom factors. The
offspring were maintained for 10 generations on two strains of Drosophila melanogaster differing in
resistance/susceptibility to the parental parasitoid lines. The venom composition of individuals was
characterized by a semi-automatic analysis of 1D SDS-PAGE electrophoresis protein profiles whose
accuracy was checked by Western blot analysis of well-characterized venom proteins. Results made
evident a rapid and differential evolution of the venom composition on both hosts and showed that
the proteins beneficial on one host can be costly on the other. Overall, we demonstrated the capacity
of rapid evolution of the venom composition in parasitoid wasps, important regulators of arthropod
populations, suggesting a potential for adaptation to new hosts. Our approach also proved relevant
in identifying, among the diversity of venom proteins, those possibly involved in parasitism success
and whose role deserves to be deepened
Cognitive restraint and history of dieting are negatively associated with organic food consumption in a large population-based sample of organic food consumers
No full textOrganic food consumption has risen in many countries during the past decades, but individual motives leading to these choices remain unclear. This study aimed to evaluate the associations between cognitive restraint (CR), history of dieting and organic food intake. This cross-sectional analysis included 20,085 organic food consumers from the NutriNet-Santé cohort. CR (range score 1-4) was evaluated by the Three-Factor-Eating-Questionnaire and practice of dieting (never vs. past/current) was assessed by an ad hoc questionnaire. Frequencies of organic food intake overall and in 16 food groups were assessed by the Organic Food Frequency Questionnaire. Linear regression and analysis of covariance (ANCOVA) were performed to investigate the association between CR score, history of dieting and contribution of organic food intake to the total food intake. A lower overall contribution of organic options in the diet was observed in women with higher levels of CR (β = -3.61%, 95% CI: -4.32; -2.91 for 1 point of CR, p < 0.001) and with a history of dieting (31.1 ± 0.4% in past/current vs. 32.6 ± 0.3% in never dieters; p = 0.001). Consistent associations were observed in men with a history of dieting (26.4 ± 0.8% in past/current vs. 28.7 ± 0.4% in never dieters; p = 0.012). Overall, individuals-in particular women-with higher CR scores or with a history of dieting selected fewer organic food options. Our findings illustrate the complexity of potentially concurrent motives to food choices, in a context of increasing interest in organic food consumption
From bud formation to flowering: transcriptomic state defines the cherry developmental phases of sweet cherry bud dormancy.
No full textBud dormancy is a crucial stage in perennial trees and allows survival over winter to ensure optimal flowering and fruit production. Recent work highlighted physiological and molecular events occurring during bud dormancy in trees. However, they usually examined bud development or bud dormancy in isolation. In this work, we aimed to further explore the global transcriptional changes happening throughout bud development and dormancy onset, progression and release.Using next-generation sequencing and modelling, we conducted an in-depth transcriptomic analysis for all stages of flower buds in several sweet cherry (Prunus avium L.) cultivars that are characterized for their contrasted dates of dormancy release. We find that buds in organogenesis, paradormancy, endodormancy and ecodormancy stages are defined by the expression of genes involved in specific pathways, and these are conserved between different sweet cherry cultivars. In particular, we found that DORMANCY ASSOCIATED MADS-box (DAM), floral identity and organogenesis genes are up-regulated during the pre-dormancy stages while endodormancy is characterized by a complex array of signalling pathways, including cold response genes, ABA and oxidation-reduction processes. After dormancy release, genes associated with global cell activity, division and differentiation are activated during ecodormancy and growth resumption. We then went a step beyond the global transcriptomic analysis and we developed a model based on the transcriptional profiles of just seven genes to accurately predict the main bud dormancy stages.Overall, this study has allowed us to better understand the transcriptional changes occurring throughout the different phases of flower bud development, from bud formation in the summer to flowering in the following spring. Our work sets the stage for the development of fast and cost effective diagnostic tools to molecularly define the dormancy stages. Such integrative approaches will therefore be extremely useful for a better comprehension of complex phenological processes in many species
La génétique animale à l‘INRA
No full textUne vingtaine d’espèces de mammifères ou d’oiseaux ont été domestiquées par l’homme à des fins d’élevage, à partir de l’époque néolithique. Les mots ‘génétique’, ‘gène’ et ‘génotype’ apparaissent dans les premières années du XXe siècle mais l’idée d’amélioration des animaux domestiques vient de beaucoup plus loin. Une forme de sélection empirique a été opérée par les premières communautés d’éleveurs, portant sur des caractères favorisant le processus de domestication lui-même, comme la docilité.After briefly recalling the steps that led to the outbreak of quantitative genetics, i.e. the main theoretical framework of animal breeding, we survey the principal landmarks of the story of animal genetics at the National Institute for Agricultural Research, since the first recruitment of scientists working in this field in 1950. This story has included organizational changes, among which the creation of the Animal Genetics Division occurred in 1963. On scientific grounds, major innovations have dealt with statistical methods for predicting breeding values and the use of an increasing amount of genomic data, these changes being allowed by the dramatic increase in computing power