Search results for "food chain"
showing 10 items of 197 documents
European catfish (Silurus glanis) as a freshwater apex predator drives ecosystem via its diet adaptability
2017
AbstractApex predators play a key role in ecosystem stability across environments but their numbers in general are decreasing. By contrast, European catfish (Silurus glanis), the European freshwater apex predator, is on the increase. However, studies concerning apex predators in freshwaters are scarce in comparison to those in terrestrial and marine ecosystems. The present study combines stomach content and stable isotope analyses with diet preferences of catfish to reveal its impact on the ecosystem since stocking. Catfish niche width is extremely wide in comparison to the typical model predator, Northern pike (Esox lucius). Catfish and pike have different individual dietary specialization…
Antipredator strategies of pupae: how to avoid predation in an immobile life stage?
2019
Antipredator strategies of the pupal stage in insects have received little attention in comparison to larval or adult stages. This is despite the fact that predation risk can be high during the pupal stage, making it a critical stage for subsequent fitness. The immobile pupae are not, however, defenceless; a wide range of antipredator strategies have evolved against invertebrate and vertebrate predators. The most common strategy seems to be ‘avoiding encounters with predators' by actively hiding in vegetation and soil or via cryptic coloration and masquerade. Pupae have also evolved behavioural and secondary defences such as defensive toxins, physical defences or deimatic movements and soun…
Early endocrine disruptors exposure acts on 3T3-L1 differentiation and endocrine activity
2017
International audience; Introduction: Data from last years suggested that early exposure to endocrine disruptors (EDs) can predispose newborns to endocrine dysfunction of adipocytes, obesity, and associated disorders. The implication of EDs at low doses on adipocyte development has been poorly investigated. For instance, vinclozolin (V) is a dicarboximide fungicide widely used in agriculture since the 90's, alone or in mixture with genistein (G), an isoflavonoid from Leguminosae. This study aims to identify the effect of vinclozolin alone or with genistein, on adipose tissue properties using cell culture.Methods: In steroid-free conditions, 3T3-L1 pre-adipocytes were induced to differentiat…
Trematode cercariae as prey for zooplankton: effect on fitness traits of predators.
2019
AbstractRemoval of parasite free-living stages by predators has previously been suggested an important factor controlling parasite transmission in aquatic habitats. Experimental studies of zooplankton predation on macroparasite larvae are, however, scarce. We tested whether trematode cercariae, which are often numerous in shallow waters, are suitable prey for syntopic zooplankters. Feeding rates and survival of freshwater cyclopoids (Megacyclops viridis, Macrocyclops distinctus), calanoids (Arctodiaptomus paulseni), cladocerans (Sida crystallina) and rotifers Asplanchna spp., fed with cercariae of Diplostomum pseudospathaceum, a common fish trematode, were studied. In additional long-term e…
Use of reliable bioassays to detect potential hazard of food contact materials extracts to ensure quality, safety and innovation of paperboards
2015
International audience; Food contact materials (FCM) represent a major economic issue and also an important field of innovation for packaging industries. Food packaging production must currently meet manufacturing good practices, safety for human health and thus be in compliance with the article 3 of the European Regulation 1935/2004: “Material and articles in contact with food do not transfer substances in amounts which could endanger human health…”.
Principes généraux d'évaluation/gestion du risque des matériaux au contact des denrées alimentaires
2017
International audience; Les matériaux au contact des denrées alimentaires (MCDA) jouent un rôle incontournable en matière de conservation et de protection des aliments. Cependant, des substances de l'emballage (monomères, additifs) peuvent migrer dans les aliments. Ainsi, pour être aptes au contact alimentaire, les MCDA ne doivent pas libérer des substances en une quantité qui pourrait mettre en danger la santé humaine ou modifier les caractères organoleptiques et la composition des aliments : c'est le principe d'inertie du Règlement no 1935/2004 du Parlement européen et du Conseil sur les MCDA. De plus, une réglementation harmonisée au niveau européen existe pour certains matériaux (cas de…
Bacterial community response to changes in a tri-trophic cascade during a whole-lake fish manipulation
2015
Microbial communities play a key role in biogeochemical processes by degrading organic material and recycling nutrients, but can also be important food sources for upper trophic levels. Trophic cascades might modify microbial communities either directly via grazing or indirectly by inducing changes in other biotic or in abiotic factors (e.g., nutrients). We studied the effects of a tri-trophic cascade on microbial communities during a whole-lake manipulation in which European perch (Perca fluviatilis) were added to a naturally fishless lake divided experimentally into two basins. We measured environmental parameters (oxygen, temperature, and nutrients) and zooplankton biomass and studied th…
Risk analysis of main mycotoxins occurring in food for children: An overview
2015
Mycotoxins are secondary metabolites produced by fungi contaminating the food chain that are toxic to animals and humans. Children up to 12 years old are recognized as a potentially vulnerable subgroup with respect to consumption of these contaminants. Apart from having a higher exposure per kg body weight, they have a different physiology from that of adults. Therefore they may be more sensitive to neurotoxic, endocrine and immunological effects. For these reasons, a specific and up-to-date risk analysis for this category is of great interest. In this review, an accurate analysis of the main mycotoxins occurring in food intended for children (deoxynivalenol, aflatoxins, ochratoxins, patuli…
The Green Deal and the CAP: policy implications to adapt farming practices and to preserve the EU's natural resources
2020
The June 2018 CAP proposals are only marginally consistent with the ambitions of the Green Deal. This is also the case of the regulation revisions being adopted by either the Council or the European Parliament in October 2020. Making EU agriculture consistent with the Green Deal but would require a whole food chain policy that encompasses more stringent instruments on the supply side and extensive changes in eating patterns.
Critical review: Grand challenges in assessing the adverse effects of contaminants of emerging concern on aquatic food webs
2019
Much progress has been made in the past few decades in understanding the sources, transport, fate, and biological effects of contaminants of emerging concern (CECs) in aquatic ecosystems. Despite these advancements, significant obstacles still prevent comprehensive assessments of the environmental risks associated with the presence of CECs. Many of these obstacles center around the extrapolation of effects of single chemicals observed in the laboratory or effects found in individual organisms or species in the field to impacts of multiple stressors on aquatic food webs. In the present review, we identify 5 challenges that must be addressed to promote studies of CECs from singular exposure e…