Hasard et direction en histoire évolutive

Plusieurs aspects de l’histoire évolutive sont envisagés. Les grands événements font intervenir des facteurs externes qui jouent au hasard. Les grandes séries évolutives montrent des sélections directionnelles constantes, qui orientent les changements morphologiques. Les équilibres ponctués et leur forte réintroduction de hasards sont critiqués. L’histoire des mammifères montre des évolutions répétées dans de multiples lignées de caractères nouveaux, qui suggèrent des contraintes de développement. Les progrès récents en biologie du développement expliquent comment les variations phénotypiques sont délimitées, réduisant fortement le nombre des chemins évolutifs possibles. Cette diminution de la part du hasard rend l’évolution plus compréhensible.Several aspects of evolutionary history are here taken into consideration. Great events call for external factors, which operate largely by chance. Long evolutionary series manifest directional selections that are constant, orienting morphological changes. Punctuated equilibria and their strong reintroduction of chance factors are criticized. The history of mammals evinces repeated evolutions within multiple lineages of new characters, which suggest developmental constraints. Recent advances in developmental biology explain how phenotypic variations are limited, reducing considerably the number of possible evolutionary paths. This diminution of the role of chance makes evolution more comprehensible

Learning from the Extreme Poor: Participatory Approaches to Fostering Child Health in Madagascar

Very poor people are often considered ignorant and even incapable of thinking, because they have had no opportunity to gain skill in expression through education. The experience of contempt and exclusion is deep among the poorest, whether they live in rich or poor countries, and it often prevents them from participating in social programs. This note provides a summary of a study on access to health care conducted by the International Movement ATD Fourth World in Madagascar, with the aim to outline the organization's approach to reaching the very poor and building projects in close partnership with them.Extreme Poverty, Health Care, Community Development, Madagascar

Diversity of protein-crop management in western France

ISI Document Delivery No.: HN5FPTimes Cited: 0Cited Reference Count: 42Carof, Matthieu Godinot, Olivier Ridier, AudeFrench region, Brittany; French region, Pays de la LoireThis work was funded by two French regions, Brittany and Pays de la Loire, in the project SECURIPROT.0Springer franceParis1773-0155In the European Union (EU), local production of protein crops (faba bean, field pea, lupins) is of primary interest to help farmers depend less on purchased feed, provide agronomic benefits to cropping systems, and increase the EU's protein self-sufficiency. Nonetheless, farmers rarely grow protein crops, which currently represent less than 1% of the EU's arable land. We assumed that exploration of farmers' practices will bring focus on (i) their motivations for growing protein crops, so that extension programs can be improved based on these motivations, and (ii) the diversity of their crop management so that promising ones can be disseminated. In western France, a two-step survey was conducted among farmers who grew protein crops. The first step was an online survey of 127 farmers that aimed to characterize their farming systems. The second step was a face-to-face survey (69 volunteers from the 127 farmers) that aimed to collect precise data on management of protein crops. The main motivations of surveyed farmers for growing protein crops were related to (i) replacing imported soybean with farm-grown protein crops and (ii) pre-crop values of protein crops (i.e., benefits of protein crops for subsequent crops). Based on conventional farmers' answers, we estimated a pre-crop value of 118 Euroha(-1), which notably contributes to gross profit at the crop-rotation scale. Moreover, in our study, yields of protein crops did not differ significantly between conventional and organic systems. This offers an interesting opportunity for conventional systems to integrate organic practices, such as complex intercropping, to reduce variable costs (costs of seeds, pesticides, regulators, and chemical fertilizers) and increase gross profits. This study shows for the first time that, in western France, pre-crop values of protein crops and their suitability for low-input systems are undervalued and could be emphasized more strongly to encourage their adoption

Percepcija teksture namirnica u ovisnosti o sadržaju ulja, te debljini lipidnog sloja na površini usne šupljine

Lipid content in food strongly influences food perception on the level of textural properties. Lipids in contact with the tongue and palate are substantially responsible for the sensory impact of a product. The aim of this study is to investigate the impact of oil content on the thickness of lipid deposition on oral surface as well as on the mouthfeel perception. The fluorescent probe method was used to study the thickness of lipid deposition on oral surface. We observed an increase in the thickness of lipid deposition depending on the increase of oil content in oil/water dispersions. Clear correlation was shown between the thickness of lipid deposition on oral surfaces and the perception of mouthfeel. A direct measure of undisrupted deposition of food components on oral surface contributes to the understanding of the behaviour of food components in the mouth and their influence on mouthfeel perception.Sadržaj lipida u hrani snažno utječe na percepciju teksture namirnica. Lipidi u kontaktu s jezikom i nepcem u najvećoj su mjeri odgovorni za senzorska svojstva hrane. Svrha je ovoga rada bila istražiti utjecaj udjela ulja u hrani na debljinu lipidnog sloja na površini usne šupljine, kao i na percepciju teksture namirnica. Za mjerenje debljine lipidnog sloja na površini usne šupljine upotrijebljena je fluorescentna proba. Uočili smo da je debljina lipidnog sloja na površini usne šupljine proporcionalna udjelu ulja u disperzijama ulja i vode. Dokazana je izrazita korelacija između debljine lipidnog sloja na površini usne šupljine i njegove percepcije u ustima. Direktno mjerenje debljine lipidnog sloja na površini usne šupljine pridonosi razumijevanju promjene sastojaka hrane u ustima i njihovog utjecaja na percepciju teksture namirnice

The work breakdown structure matrix: A tool to improve interface management

Master'sMASTER OF ENGINEERIN

Fast Timing for High-Rate Environments with Micromegas

The current state of the art in fast timing resolution for existing experiments is of the order of 100 ps on the time of arrival of both charged particles and electromagnetic showers. Current R&D on charged particle timing is approaching the level of 10 ps but is not primarily directed at sustained performance at high rates and under high radiation (as would be needed for HL-LHC pileup mitigation). We demonstrate a Micromegas based solution to reach this level of performance. The Micromegas acts as a photomultiplier coupled to a Cerenkov-radiator front window, which produces sufficient UV photons to convert the ~100 ps single-photoelectron jitter into a timing response of the order of 10-20 ps per incident charged particle. A prototype has been built in order to demonstrate this performance. The first laboratory tests with a pico-second laser have shown a time resolution of the order of 27 ps for ~50 primary photoelectrons, using a bulk Micromegas readout.Comment: MPGD2015 (4th Conference on Micro-Pattern Gaseous Detectors, Trieste, Italy, 12 - 15 October, 2015). 5 pages, 8 figure

Effects of eating rate on satiety:A role for episodic memory?

AbstractEating slowly is associated with a lower body mass index. However, the underlying mechanism is poorly understood. Here, our objective was to determine whether eating a meal at a slow rate improves episodic memory for the meal and promotes satiety. Participants (N=40) consumed a 400ml portion of tomato soup at either a fast (1.97ml/s) or a slow (0.50ml/s) rate. Appetite ratings were elicited at baseline and at the end of the meal (satiation). Satiety was assessed using; i) an ad libitum biscuit ‘taste test’ (3h after the meal) and ii) appetite ratings (collected 2h after the meal and after the ad libitum snack). Finally, to evaluate episodic memory for the meal, participants self-served the volume of soup that they believed they had consumed earlier (portion size memory) and completed a rating of memory ‘vividness’. Participants who consumed the soup slowly reported a greater increase in fullness, both at the end of the meal and during the inter-meal interval. However, we found little effect of eating rate on subsequent ad libitum snack intake. Importantly, after 3h, participants who ate the soup slowly remembered eating a larger portion. These findings show that eating slowly promotes self-reported satiation and satiety. For the first time, they also suggest that eating rate influences portion size memory. However, eating slowly did not affect ratings of memory vividness and we found little evidence for a relationship between episodic memory and satiety. Therefore, we are unable to conclude that episodic memory mediates effects of eating rate on satiety

Learning from the Extreme Poor: Participatory Approaches to Fostering Child Health in Madagascar

Very poor people are often considered ignorant and even incapable of thinking, because they have had no opportunity to gain skill in expression through education. The experience of contempt and exclusion is deep among the poorest, whether they live in rich or poor countries, and it often prevents them from participating in social programs. This note provides a summary of a study on access to health care conducted by the International Movement ATD Fourth World in Madagascar, with the aim to outline the organization's approach to reaching the very poor and building projects in close partnership with them

Learning from the Extreme Poor: Participatory Approaches to Fostering Child Health in Madagascar

Very poor people are often considered ignorant and even incapable of thinking, because they have had no opportunity to gain skill in expression through education. The experience of contempt and exclusion is deep among the poorest, whether they live in rich or poor countries, and it often prevents them from participating in social programs. This note provides a summary of a study on access to health care conducted by the International Movement ATD Fourth World in Madagascar, with the aim to outline the organization's approach to reaching the very poor and building projects in close partnership with them