Search results for " life science"
showing 10 items of 12151 documents
Elaboration of a list of substances of interest as regards to a potential endocrine activity and prioritisation strategy for assessment
2021
Endocrine Disruptor Chemicals (EDCs) are substances that alter function(s) of the endocrine system and consequently cause adverse health effects. The endocrine system consists of many cells and tissues that interact with each other and the rest of the body by means ofhormones. This system is responsible for controlling a large number of processes in the body from gamete formation, to conception and early developmental processes such as organogenesis, and to most tissue and organ functions throughout life. EDCs interfere withendocrine function by many ways and, in doing so, lead to adverse effects on the health of humans and/or wildlife. Some of the observed health effects associated with ED…
Processus attentionnels et apprentissage moteur
2012
International audience; Le but de cet article est de synthétiser les travaux portant sur les effets de l’attention volontaire sur l’apprentissage d’une habileté motrice. Les premiers modèles d’apprentissage considèrent que l’apprenant franchit plusieurs étapes au cours desquelles la sollicitation des processus attentionnels diminue (Fitts & Posner, 1967). Ainsi, la réalisation d’un mouvement nécessiterait d’engager de l’attention en début d’apprentissage alors qu’elle serait automatique en fin d’apprentissage. Cet article propose de vérifier cette affirmation au regard des recherches récentes qui révèlent que l’apprenant débutant module volontairement son attention a fin d’optimiser la réal…
Peut-on concilier un faible usage de pesticides, une bonne performance économique et environnementale ? Analyse d’un réseau national de fermes de dém…
2017
Feeding an increasing world population with a sustainable agriculture is one of the greatest challenges of this century. The reduction of the reliance on pesticides is a critical aspect in this quest for sustainability. Whether cropping systems with reduced reliance on pesticides would be able to reconcile the various components of sustainability remains however a matter of debate. Are they as productive and profitable than current mainstream cropping systems? Here the objective is to study the feasibility of a reduced reliance on pesticides in France. We used a unique dataset from a national network of more than thousand arable commercial farms between 2009 and 2011. Launched in the framew…
Analysing the relationship between yields and farmers' incomes to help the design of more sustainable cropping systems
2022
Farmers often grow only the few high-yielding crops in the area, and target maximum yields through high levels of inputs. These practices are based on the assumption of a positive relationship between productivity and profitability over a wide range of cropping systems (Woo et al., 2020; Erythrina et al., 2021). Part of the correlation between productivity and profitability could be related to differences in production situation and therefore yield potential, i.e. characteristics that do not depend on farmers’ decisions. For a given production situation, the systems with the highest profitability and the best environmental sustainability could be systems with moderate yields. The objective …
Fonction de production, productivité et progrès technique à l'hôpital : une étude statistique par catégories d'établissements
1983
Notre propos et l'objet de la recherche qui le sous tend ne sont ni polémiques, ni théoriques, mais simplement statistiques, et donc se situent en deçà du débat évoqué, tout en contribuant à 1'éclairer. Quel est le rôle de la main-d1 oeuvre dans la production hospitalière ? Quelle est l'incidence de la spécialisation du travail sur l'évolution de la main-d'oeuvre ? Quel est l'impact conjugé du progrès technique et de l'humanisation des conditions de soins et d'hébergement sur la combinaison des facteurs de production à l'hôpital ? Y-a-t-il complémentarité ou substitution entre la main-d'oeuvre et le capital technique ? Peut-on apprécier l'existence de rendements d'échelle ? La réponse à ces…
Effect of an insect growth regulator (halofenozide) on the cuticular hydrocarbons of Culex pipiens larvae
2013
The cuticular hydrocarbons of the fourth-instar larvae of Culex pipiens aged one and six days were analysed by gas chromatography and gas chromatography-mass spectrometry. The effect of an insect growth regulator (halofenozide = RH-0345) on the cuticular hydrocarbons was evaluated using newly moulted fourth-instar larvae of C. pipiens, at the lethal concentrations (LC50 = 12.58 and LC90 = 28.58 mu g/l). A previous study revealed that RH-0345 is toxic to larvae of C. pipiens by induction of precocious larval moulting. Several cuticular hydrocarbons (CHCs) were identified and many of the other compounds remained unknown. Our data show that the CHC classes consisted of n-alkanes (C23-C29) and …
Does oral health affect food comfortability and bolus properties during consumption of dairy products in elderly population?
2017
The elderly population is growing increasingly. In 2030, 1/3 of the population will be over 60 years old. However this population has specific nutritional needs and often, oral impairments such as loss of tooth and/or decrease of salivary flow. Therefore it is necessary to develop foods adapted for the elderly, in terms of organoleptic properties and nutritional composition. In this context, the purpose of this work is to study the impact of oral impairments of elderly persons on food comfortability and bolus properties during the consumption of dairy products.76 elderly persons (ages 66 to 88, 42 women and 34 men), with or without oral health problems in terms of dental and/or salivary sta…
L'accumulation des protéines dans les graines de légumineuses
2017
The agroecological benefits of legumes and the renewed interest in the consumption of vegetable proteins stimulate researches on cognitive and applied aspects of seed biology aiming at optimizing protein composition of legume seeds. This article presents the state of knowledge on the genetic and environmental control of the accumulation of major proteins found in legume seeds, with a view to developing varieties with improved nutritional seed quality. It also shows how high-throughput genomics and post-genomics data, along with translational research aiming at transferring knowledge between model and crop species, can accelerate the identification of genes controlling the accumulation of st…
Isolement et caractérisation de saponosides extraits de deux plantes médicinales : Cyclamen africanum, Zygophyllum cornutum et évalution de leur acti…
2014
The appearance of several diseases, such as cancer, diabetes, high blood pressure and spread of infections mutagenic virus type can be linked to the quality and lifestyle that we lead today. Indeed, several studies on the factors triggering these so-called "morbid" long-or short-term illnesses are related to stress and quality of food consumed, whether of plant and animal origin. These diseases are becoming a common occurrence, they affect different races and all classes of society. According ethnobotanical research, naturally occurring substances, allowed civilizations to survive deadly diseases. For example, we thus find references to periods of malarial fever in China and one of the symp…
Contribution des interactions tanins - protéines salivaires dans la sensation d'astringence
2015
National audience