Search results for " Reproduction"
showing 10 items of 282 documents
Emotions et personnalité : au cœur des décisions chez un poisson monogame
2018
During their lives animals constantly need to make decisions that influence their survival and their reproductive success. The objective of this thesis was to evaluate the role of two variability sources in decision-making — personality and emotional states — in a sexual context in a monogamous fish, the convict cichlid. Our work about personality highlights its importance on pair compatibility and reproductive success. We also observe that reactive individuals adjusted their behaviour to their partner and thus increased their reproductive fitness. This result supports the hypothesis that reactive individuals are more flexible and thus compensate for their weak competitiveness.Personality t…
Possible role of eclampsia/preeclampsia in evolution of human reproduction.
2008
10 pages
Black currant project: Multidisciplinary approach to agro-ecological measures
2022
The decline of wild pollinators leads to a drastic drop in the associated ecosystem service, resulting in significant lossesin agricultural yields. The production of blackcurrant “Noir de Bourgogne” could potentially be tripled, if populationsof wild pollinators were restored. Various agroecological measures beneficial to pollinators are discussed here, as wellas ongoing experimental tests. We discuss the practical possibilities of implementing these measures by blackcurrantgrowers as well as the technical locks that still exist. The return to an agroecological equlibrium for which pollinationbecomes again a free ecosystem service for agriculture, requires the integration of multiple agroec…
Les causes biologiques de la régression du bleuet (Centaurea cyanus L.)
2012
National audience; Dans les agroécosystèmes, un déclin de la diversité biologique causé par l’intensification des pratiques agricoles est actuellement observé. Parmi les espèces adventices, toutes ne répondent pas de la même façon à ces changements. Des traits biologiques spécifiques pourraient expliquer le déclin de certaines et la réussite d’autres. Ainsi, mieux comprendre les causes biologiques de la régression permettrait de mettre en place des stratégies de gestion dans ces systèmes agricoles intensifs. Le bleuet (Centaurea cyanus L.) est une messicole spécialiste de l’agroécosystème qui est actuellement en régression dans l’ouest de l’Europe . Cette espèce est par ailleurs considérée …
L'homosexualité et la constitution de la famille : situations française et européenne
2016
The 2013-404 law of 17 May 2013 which opened up the possibility for people of the same gender to get married shows a turning point for the family rights in France. This law, sometimes described as a real tsunami, is the outcome of taking into account the homosexuals' claim for starting a family. Before 2013 the French right did not allow a homosexual couple to be a homoparental family. It did not authorize people of the same gender to get married. Moreover Assisted Reproduction is only reserved to heterosexual couples and Gestation for Others is strictly forbidden in France. This seemingly constrained consensus on the non-legal recognition of the homosexual family is reinforced by the Europ…
Illustration et intermédialité, entre gravure et photographie
2014
International audience; Cet article envisage le rôle de l’illustrateur comme « changeur » du texte en image dans les manuels sur l’illustration parus dans les années 1890, alors que les procédés photomécaniques marquent des progrès décisifs. La transaction intermédiale particulière qui s’opère dans le livre illustré est envisagée à cette époque du point de vue des supports techniques conçus comme des écrans interposés entre l’original et sa reproduction. Les écrits de Liliane Louvel, Gérard Genette, Hans Belting, Jacques Rancière et Philippe Dubois sont convoqués pour montrer comment l’évolution de l’illustration s’inscrit alors dans le conflit médial opposant gravure et photographie et ref…
The evolutionary dynamics of adaptive virginity, sex-allocation and altruistic helping in haplodiploid animals
2018
In haplodiploids, females can produce sons from unfertilized eggs without mating. However, virgin reproduction is usually considered to be a result of a failure to mate, rather than an adaptation. Here, we build an analytical model for evolution of virgin reproduction, sex-allocation, and altruistic female helping in haplodiploid taxa. We show that when mating is costly (e.g., when mating increases predation risk), virginity can evolve as an adaptive female reproductive strategy. Furthermore, adaptive virginity results in strongly divergent sex-ratios in mated and virgin queen nests ("split sex ratios"), which promotes the evolution of altruistic helping by daughters in mated queen nests. H…
ART AND TECHNIQUE: ARTISTIC REPRODUCTION OF THE ANCIENT BRONZE IL GUERRIERO DA PETRALIA SOTTANA
2016
The reproduction of artistic objects is useful for museological, teaching, and commercial purposes. In some cases, the reproduction is carried out to replace the originals located in outdoor environments and to prevent the deterioration due to weathering or pollution. This article describes the different phases that led to the reproduction of the Il Guerriero da Petralia Sottana. The observation of stylistic characteristics and the physical-chemical investigation were carried out in order to obtain information about the composition of the alloy and the technological properties of the artifact by using Optical Microscopy and X- ray Fluorescence. The reproduction in wax was performed by using…
Differences in allozyme patterns between Diaphanosoma brachyurum and Diaphanosoma mongolianum, as revealed in Central European populations
1995
Recent taxonomic revisions in the genus Diaphanosoma have made the uncertainty in species discrimination with morphological characters obvious. Therefore species characterization on a genetic basis seems to be required. Here we examined the genetic structure of two Diaphanosoma mongolianum populations and three Diaphanosoma brachyurum populations in Central Europe by allozyme electrophoresis. A genetic differentiation between both species was evident. 5 out of 9 tested loci carried diagnostic alleles. Both species differed in their habitat choice: D. mongolianum was adapted to higher trophic levels than D. brachyurum. Co-occurrence was observed in a eutrophic lake. Populations sampled from …
Mate fidelity and coloniality in waterbirds: a comparative analysis
1998
Increased opportunities for information are one potential benefit of sociality. We apply this idea to the advantages of colonial breeding in bird species that are typically monogamous within a breeding season but often form new pair-bonds in subsequent seasons. Individuals may benefit from nesting in colonies at high density by identifying good-quality potential alternative mates among their neighbours. The opportunities for finding a better mating option are likely to increase with colony size and density. We tested this prediction with a comparative analysis of the association between mate fidelity and coloniality in waterbirds (wading birds and seabirds), where there is wide variation in…