Search results for "RESISTANCE"
showing 10 items of 3641 documents
Parasite resistance and avoidance behaviour in preventing eye fluke infections in fish.
2004
This paper examines the efficiency of acquired resistance in protecting the fish host, rainbow trout (Oncorhynchus mykiss), against the trematode parasite Diplostomum spathaceum, and the hypothesis that fish recognize areas where infective stages are aggregated and show avoidance behaviour. We found that when fish with a low level of infection were held in restricted cages in natural conditions they became infected and developed cataracts as a result of this infection. This suggests that acquired resistance is insufficient in protecting fish against the parasite or the deleterious effects of infection in conditions where fish could not avoid the parasite. Behavioural experiments in the labo…
Introduction. Ecological immunology.
2009
12 pages; International audience; An organism's fitness is critically reliant on its immune system to provide protection against parasites and pathogens. The structure of even simple immune systems is surprisingly complex and clearly will have been moulded by the organism's ecology. The aim of this review and the theme issue is to examine the role of different ecological factors on the evolution of immunity. Here, we will provide a general framework of the field by contextualizing the main ecological factors, including interactions with parasites, other types of biotic as well as abiotic interactions, intraspecific selective constraints (life-history trade-offs, sexual selection) and popula…
Influence of cutting process mechanics on surface integrity and electrochemical behavior of OFHC copper
2014
The authors gratefully acknowledge the support received from IC ARTS and CEA Valduc; International audience; Superfinishing machining has a particular impact on cutting mechanics, surface integrity and local electrochemical behavior. In fact, material removal during this process induces geometrical, mechanical and micro-structural modifications in the machined surface and sub-surface. However, a conventional 3D cutting process is still complex to study in terms of analytical/numerical modeling and experimental process monitoring. So, researchers are wondering if a less intricate configuration such as orthogonal cutting would be able to provide information about surface integrity as close as…
Généralités sur la résistance aux Produits de Protection des Plantes (PPP)
2015
SPEPôle GEAPSICT2Communication orale invitée; Au niveau d’un individu, la résistance « biologique » correspond à une moindre sensibilité à un PPP en comparaison d’individus sensibles de référence, mesurée au laboratoire. Un individu résistant peut être caractérisé par son facteur de résistance (l’« intensité » ou la « force » de la résistance, correspondant au rapport entre la quantité de PPP requise pour avoir le même effet sur un individu résistant que sur un individu sensible), et son profil (ou spectre) de résistance (la gamme de substances auquel l’individu sera résistant). Le caractère de résistance est transmis aux générations suivantes de bio-agresseurs, car déterminé par une ou des…
Induced resistance as a strategy for vineyard protection
2012
National audience; As most grown grapevine Vitis vinifera varieties are susceptible to diseases such as downy and powdery mildews, numerous treatments are required to ensure a satisfactory yield and harvest quality. However, the use of phytochemical fungicides has serious drawbacks: some of them are potentially harmful for the environment and human health and contribute to the selection of resistant pathogen strains. Nowadays, in an objective of sustainable viticulture, there is increasing societal request, political incitation and winegrower’s awareness to reduce the use of pesticides. For these reasons, alternative strategies of protection are under research. In our laboratory, we are stu…
Non-target-site-based resistance to herbicides: what do we know, and how can we know more?
2013
Non-target-site-based resistance (NTSR) includes all types of mechanisms conferring resistance to herbicides that do not involve modifications at the herbicide target site. NTSR can be the most widespread type of resistance in a weed species, especially in grasses. NTSR can confer resistance to herbicides with different modes of action. Despite the threat it sets upon chemical weed control, NTSR is still the dark side of resistance to herbicides. In particular, NTSR genetics is poorly known. As a consequence, there are no quick, molecular-based, NTSR diagnostic tools, which hampers the development of tactics aiming at delaying NTSR selection in the field. The lack of data regarding NTSR gen…
Gestion des adventices dans un contexte de réduction des intrants de synthèse
2018
La problématique gestion des résistances aux herbicides (et fongicides) : entre tragédie des communs et tragédie des anti-communs
2019
National audience; Les résistances aux herbicides et aux fongicides sont des problèmes majeurs en agriculture. Au travers d’un projet de recherche-action transdisciplinaire, ce travail aborde la question suivante : En quoi la gestion des résistances aux herbicides et fongicides en grandes cultures nécessite-t-elle une gestion collective et quels en sont les attributs et leviers ? Les résultats révèlent que le contexte de gestion des résistances aux pesticides dans les territoires agricoles français est caractérisé par une combinaison de « tragédie des communs » et de « tragédie des anti-communs », ce qui est un cas novateur dans la littérature sur les biens communs. Nous montrons ainsi que …
Mutant ACCase alleles endowing herbicide resistance have a direct effect on seed germination
2013
Germination and emergence dynamics and herbicide resistance are adaptive traits crucial for weed persistence in arable fields. Herbicide resistance alleles can have pleiotropic effects on other traits. We investigated the pleiotropic effects of acetyl-coenzyme A carboxylase (ACCase) alleles L1781, N2041 or G2078 on seed germination and seedling emergence in the grass weed Alopecurus myosuroides (black-grass). We used black-grass populations with homogenised genetic backgrounds that segregated for L1781, N2041 or G2078 ACCase alleles. In two series of experiments, germination dynamics and seedling growth were compared among seeds containing embryos carrying no, one or two copies of a given m…
Volatile organic compounds: a role in elicitor-induced resistance of grapevine against pathogens?
2014
International audience; As Vitis vinifera varieties are susceptible to fungal diseases, numerous chemical treatments are generally required to ensure the quantity and quality of the harvest. However, in the context of sustainable viticulture, there are increasing societal request, political incitation, and winegrowers’ awareness to reduce the use of pesticides. Among possible solutions the use of elicitors that could be included in integrated pest management or biocontrol strategies might be very promising. These bioactive compounds are able to trigger plant defences, leading to induced resistance (IR) against pathogens. Despite IR can be elicited very successfully in controlled environment…