eKhSACIR інституційному репозитарії Харківської державної академії культури
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Some remarks on computational approaches towards sustainable complex agri-food systems
No full textInternational audienceAbstract Background Agri-food is one of the most important sectors of the industry in Europe and potentially a major contributor to the global warming. Sustainability issues in this context pose a huge challenge for several reasons: the variety of considered scales, the number of disciplines involved, the uncertainties, the out-of-equilibrium states, the complex quantitative and qualitative factors, the normative issues and the availability of data. Although important insight and breakthroughs have been attained in different scientific domains, an overarching and integrated analysis of these complex problems have yet to be realized. Scope and Approach This context creates huge opportunities for research in interaction with mathematical programming, integrative models and decision-support tools. The paper propose a computational viewpoint including questions of holistic approach, multiscale reconstruction and optimization. Some directions are discussed. Key Findings and Conclusions Several research questions based on a mathematical programming framework are emerging: how can such a framework manage uncertainty, cope with complex qualitative and quantitative information essential for social and environmental considerations, encompass diverse scales in space and time, cope with a multivariable dynamic environment and with scarcity of data. Moreover, how can it deal with different perspectives, types of models, research goals and data produced by conceptually disjoint scientific disciplines, ranging from physics and physiology to sociology and ethics? Building models is essential, but highly difficult; it will need a strong iterative interaction combining computational intensive methods, formal reasoning and the experts of the different fields. Some future research directions are proposed, involving all those dimensions: mathematical resilience, human-machine interactive learning and optimization techniques
Display of recombinant proteins at the surface of lactic acid bacteria : strategies and applications
No full textInternational audienceLactic acid bacteria (LAB) are promising vectors of choice to deliver active molecules to mucosal tissues. They are recognized as safe by the World Health Organization and some strains have probiotic properties. The wide range of potential applications of LAB-driven mucosal delivery includes control of inflammatory bowel disease, vaccine delivery, and management of auto-immune diseases. Because of this potential, strategies for the display of proteins at the surface of Lare gaining interest. To display a protein at the surface of LAB, a signal peptide and an anchor domain are necessary. The recombinant protein can be attached to the membrane layer, using a transmembrane anchor or a lipoprotein-anchor, or to the cell wall, by a covalent link using sortase mediated anchoring via the LPXTG motif, or by non-covalent liaisons employing binding domains such as LysM or WxL. Both the stability and functionality of the displayed proteins will be affected by the kind of anchor used. The most commonly surfaced exposed recombinant proteins produced in Lare antigens and antibodies and the most commonly used Lare lactococci and lactobacilli. Although it is not necessarily so that surface-display is the preferred localization in all cases, it has been shown that for certain applications, such as delivery of the human papillomavirus E7 antigen, surface-display elicits better biological responses, compared to cytosolic expression or secretion. Recent developments include the display of peptides and proteins targeting host cell receptors, for the purpose of enhancing the interactions between Land host. Surface-display technologies have other potential applications, such as degradation of biomass, which is of importance for some potential industrial applications of LAB
Recombination Rate Heterogeneity within Arabidopsis Disease Resistance Genes
No full textInternational audienceMeiotic crossover frequency varies extensively along chromosomes and is typically concentrated in hotspots. As recombination increases genetic diversity, hotspots are predicted to occur at immunity genes, where variation may be beneficial. A major component of plant immunity is recognition of pathogen Avirulence (Avr) effectors by resistance (R) genes that encode NBS-LRR domain proteins. Therefore, we sought to test whether NBS-LRR genes would overlap with meiotic crossover hotspots using experimental genetics in Arabidopsis thaliana. NBS-LRR genes tend to physically cluster in plant genomes; for example, in Arabidopsis most are located in large clusters on the south arms of chromosomes 1 and 5. We experimentally mapped 1,439 crossovers within these clusters and observed NBS-LRR gene associated hotspots, which were also detected as historical hotspots via analysis of linkage disequilibrium. However, we also observed NBS-LRR gene coldspots, which in some cases correlate with structural heterozygosity. To study recombination at the fine-scale we used high-throughput sequencing to analyze similar to 1,000 crossovers within the RESISTANCE TO ALBUGO CANDIDA1 (RAC1) R gene hotspot. This revealed elevated intragenic crossovers, overlapping nucleosome-occupied exons that encode the TIR, NBS and LRR domains. The highest RAC1 recombination frequency was promoter-proximal and overlapped CTT-repeat DNA sequence motifs, which have previously been associated with plant crossover hotspots. Additionally, we show a significant influence of natural genetic variation on NBS-LRR cluster recombination rates, using crosses between Arabidopsis ecotypes. In conclusion, we show that a subset of NBS-LRR genes are strong hotspots, whereas others are coldspots. This reveals a complex recombination landscape in Arabidopsis NBS-LRR genes, which we propose results from varying coevolutionary pressures exerted by host-pathogen relationships, and is influenced by structural heterozygosity
Intérêt des ressources agricoles et forestières pour la bioénergie
No full textCe numéro comprend les articles correspondant aux présentations du Colloque Bioénergies durables : innovations dans les territoires et les filières, qui s’est tenu à Reims le 22 novembre 2016.Article daté de 2016 sur le site de l'éditeur, mais volume publié en 2017Lignocellulosic feedstocks for renewable energy need to reconcile high yield, a limited environmentalfootprint and a composition adapted to the industrial procedures for the production of heat andelectricity, methane or second-generation transport fuels. This article will review the performance ofseveral dedicated feedstocks for sustainable biomass production. At the agronomic level, feedstocksare compared for their biomass yield, nitrogen export and nitrogen/carbon ratios as well as the reductionof greenhouse gas emissions and corresponding costs. In addition, the productivity of ethanol per ha isillustrated and perspectives for genetic improvement are discussed. Concerning forestry crops, shortand very short rotation coppice and “stored coppice” systems are presented including the considerablescope for further genetic improvement and the development of semi-dedicated feedstock strategies. Inconclusion, perennial C4 grasses (miscanthus, switchgrass) and trees under a short rotation coppiceregime are complementary bioenergy feedstocks and are the object of genetic improvement programsin INRA laboratories.L’utilisation des ressources lignocellulosiques comme source d’énergie renouvelable devra concilierrendement important, faible empreinte environnementale et composition adaptée à l’utilisationénergétique (combustion, méthanisation, carburants « deuxième génération »). Cet article présente unerevue des performances de plusieurs cultures agricoles et forestières pour la production durable debiomasse. Au niveau agronomique, différentes cultures sont comparées pour la production debiomasse, l’exportation d’azote et le ratio azote/carbone, mais aussi pour les réductions de gaz à effetde serre engendrées et le « coût » que cela représente. Enfin, la production d’éthanol par hectare estillustrée et des perspectives d’amélioration génétique pour la bioénergie sont évoquées. Au niveauforestier, la production de biomasse nécessite des plantations à fortes densité, telles que les cultures detaillis à courte rotation (TCR) ou à très coute rotation (TTCR) et la futaie à courte révolution (FCR). Lagénétique offre d’importantes marges de progrès pour l’optimisation des rendements en TCR.Concernant les FCR, les scénarios dits « semi-dédiés biomasse » sont les plus prometteurs. Ainsi, lesgraminées C4 pérennes (miscanthus, switchgrass) et les cultures forestières en TCR ou FCR, sont desressources très complémentaires pour la production durable de biomasse à vocation énergétique et fontl’objet, pour plusieurs d’entre elles, d’amélioration génétique à l’INRA
Effect of pretreatment parameters on the size and morphology of the lignocellulosic biomass particles: Production of the cellulosic bioethanol
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Adaptation des types variétaux de pois dans différentes régions françaises : réponse du modèle AZODYN-pois
No full textGEAPSI AGROSUP INRANational audienceLe pois (Pisum sativum L.) est une culture particulièrement sensible aux stress abiotiques tout au long de son cycle, de l’implantation à la phase d’élaboration du rendement (Schneider and Huyghe 2015). Le contexte actuel de changement climatique augmente les incertitudes concernant ces stress (Stocker et al. 2013). Or le climat est une cause importante de baisse de rendement en pois de printemps. On a par ailleurs observé depuis quelques années une évolution de l’aire géographique de production de la culture : le pois a quitté des zones à potentiel de rendement élevé pour s’implanter dans des zones moins favorables. Pour échapper en partie à ces stress abiotiques, les sélectionneurs ont développé, depuis une quinzaine d’années, des variétés de pois d’hiver, à semer à l’automne, plus résistantes au gel et à floraison plus précoce ainsi que des variétés dites « Hr » réactives à la photopériode permettant d’être implanté de manière plus précoce encore. Pourtant, le pois d’hiver peine à s’implanter et les surfaces stagnent à 25 000 ha depuis le début des années 2000. Notre objectif est d’étudier, pour chaque type de pois, les performances des différents types variétaux dans des climats de différentes régions contrastées françaises, afin de fournir des informations pour adapter le choix du type variétal à la fréquence et à l’intensité des stress rencontrés. Dans ce but, nous avons adapté le modèle de culture AZODYN-Pois (Jeuffroy et al. 2012) aux différents types variétaux et à la prise en compte des différents stress abiotiques. Le modèle a ensuite été utilisé afin d’évaluer les trois types variétaux sur les dix années climatiques écoulées dans différents départements français dans le but d’identifier les types de pois les mieux adaptés à chaque environnement (région x climat). Nous montrons ici le potentiel du pois d’hiver pour différents climats français. L’utilisation d’AZODYN-Pois permettra également, dans un deuxième temps, d’explorer des combinaisons inédites de caractères afin de concevoir des idéotypes de pois et de faire émerger de nouvelles variétés au sein de chaque type
Les fibres alimentaires, dans le cadre d’une sur-nutrition, ralentissent la prise de poids et protègent le foie d’une utilisation et d’un captage excessif de glucose
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Individual vs collective in public policy design, a cooperation example in the Marais Poitevin region
No full textInternational audienceThe conciliation between different issues such as production activities, biodiversity conservation and water management remains unsolved in many places in the world. As a striking example, the wet grasslands of the Marais Poitevin region (France) present many obstacles against the integration of previous issues, especially in terms of public policy design. The socio-cultural situation in this region shows a high degree of political resistance and questions the relevancy of the current Agri-Environmental Schemes (AES) as an incentive for livestock farmers to adopt biodiversity friendly practices favoring the birds’ richness of the area. Yet, the current AES based on financial support has been interpreted has a production support and has still not fulfilled its goal of agro-ecology development. The reasons of the poor effect of public policy are studied using a two-fold approach based on ethnographic field and a computer-assisted role-playing game. The game combines an agent-based model and a tabletop artifact. The game is based on two sessions involving different AES to be tested. The model simulates the grass regeneration and flows of water through a canal system and a surrounding network of plots with culture (wheat, corn, sunflower, alfaalfa), pasture and mowing. The game is played by 9 players who embody their role in real life, i.e. water managers, biodiversity managers and 7 farmers. The behaviors of the players during the sessions have been observed and analyzed through a miro economic conceptualization. A comparison is proposed between the first session where the current AES were tested and the second session where collective public policy instruments were tested. Such comparison identifies individual and collective level on an economic perspective and brings new concerns for public policy design. It also highlights the topic of integrated environmental management and questions the relevancy of participatory approaches and contradiction/dilemmas resolutions in environmental development
Ultrasonography as a method to determine body composition in cattle
No full textInternational audienceEstimation of body composition in live cattle is difficult and usually performed using subjective approaches (visual and handling evaluation). Today, there is no reference methodological framework for the standardization of the determination of body fatness in cattle by ultrasonography. The objective of this study was to compare ultrasonographic measurements of fat and muscle subcutaneous tissue thickness at the buttock, lumbar, back and rib level with the conventional body condition scoring method. We performed ultrasonography on 160 cows from 5 different breeds (Normande, Holstein, Montbeliarde, Charolaise, Salers) by selecting populations of animals with the widest range of body condition scores possible (from 0.5 to 4.5 on a 0-5 scale). The study was carried out with four experimenters working with two different ultrasound devices and repeating the measurements two times. Low variation between assessors was observed at the lumbar and the rib sites. Measurements performed on dairy cows allow good correlation between body scores and ultrasound indicators at the buttock (fat, r=0.709), lumbar (fat and muscle, r=0.829) and rib (fat and muscle, r=0.707)) sites. The best result was obtained with the measurement of fat thickness + muscle at the lumbar site on the Normandy cows (R=0.856, P<0.001). A combination of these ultrasound indicators provides an accurate and objective assessment of body composition on dairy cows. However, no relationship was found between body scores and ultrasound indicators on beef cows. Ultrasonography is an easy, objective and non-invasive way to determine body composition in dairy cows. This work is offering an opportunity to standardize this technique and use it routinely on a large number of animals in the field
Reproductive effects of gestational exposure to diesel exhaust in a rabbit model
No full textNational audienceMammary development and fonction was abnormal in exposed clams. The a!veolar lumina were characterized by a marked increase in fat globules number and volume (p< 0.05) . Total fatty acid (FA) content was increased (p< 0.05) in DE-exposed rabbit milk on days 2-4 of lactation, essentially due to higher medium-chain FA concentrations. Sex-specific responses to maternai exposure were observed in offspring after weaning. In-utero exposed males hacl metabolic disorders with increased blood pressure (p=0.058) , higher glycemia (p=0.019) , lower HDL-cholesterol (p=0.025) , reduced fat-to-bocly weight ratio (p=0.011) but in creased peri-renal fat mass (p=0.026). Females had only higher triglycerides (TG) compared to contrai offspring. Testicular and ovarian structure and fonction were analyzed by histology and immunohistochemistry, demonstrating no difference between groups. In contrast , there was more DN A fragmentation (p=0.0012) in epididymal sperm in the exposed group. Adult female offspring were bred with contrai males. Although fetoplacental biometry was not affected near term, 2nd generation fetal metabolism was modifiecl by grand-dam exposure with decreased plasma cholesterol (p=0.008) and increased TG concentrations (p=0.015). In conclusion, repeated gestational exposure to DE at levels close to urban pollution can affect feto-placental clevelopment and health over 2 generations