188 resultados para Biased Innovations
Resumo:
Insect societies are paramount examples of cooperation, yet they also harbor internal conflicts whose resolution depends on the power of the opponents. The male-haploid, female-diploid sex-determining system of ants causes workers to be more related to sisters than to brothers, whereas queens are equally related to daughters and sons. Workers should thus allocate more resources to females than to males, while queens should favor an equal investment in each sex. Female-biased sex allocation and manipulation of the sex ratio during brood development suggest that workers prevail in many ant species. Here, we show that queens of Formica selysi strongly influenced colony sex allocation by biasing the sex ratio of their eggs. Most colonies specialized in the production of a single sex. Queens in female-specialist colonies laid a high proportion of diploid eggs, whereas queens in male-specialist colonies laid almost exclusively haploid eggs, which constrains worker manipulation. However, the change in sex ratio between the egg and pupae stages suggests that workers eliminated some male brood, and the population sex-investment ratio was between the queens' and workers' equilibria. Altogether, these data provide evidence for an ongoing conflict between queens and workers, with a prominent influence of queens as a result of their control of egg sex ratio.
Resumo:
[Table des matières] Technology assessment in health care in the United States: an historical review / S. Perry. - The aims and methods of technology assessment / JH Glasser. - Evaluation des technologies de la santé / A. Griffiths. - Les données nécessaires pour l'évaluation des technologies médicales / R. Chrzanowski, F. Gutzwiller, F. Paccaud. - Economic issues in technology assessment/DR Lairson, JM Swint. - Two decades of experience in technology assessment: evaluating the safety, performance, and cost effectiveness of medical equipment / JJ Nobel. - Demography and technology assessment / H. Hansluwka. - Méthodes expérimentale et non expérimentale pour l'évaluation des innovations technologiques / R. Chrzanowski, F. Paccaud. - Skull radiography in head trauma: a successful case of technology assessment / NT Racoveanu. - Complications associées à l'anesthésie: une étude prospective en France / L. Tiret et al. - Impact de l'information publique sur les taux opératoires: le cas de l'hystérectomie / G. Domenighetti, P. Luraschi, A. Casabianca. - The clinical effectiveness of acupuncture for the relief of chronic pain / MS Patel, F. Gutzwiller, F. Paccaud, A. Marazzi. - Soins à domicile et hébergement à long terme: à la recherche d'un développement optimum / G. Tinturier. - Economic evaluation of six scenarios for the treatment of stones in the kidney and ureter by surgery or ESWL / MS Patel et al. - Technology assessment and medical practice / F. Gutzwiller. - Technology assessment and health policy / SJ Reiser. - Global programme on appropriate technology for health, its role and place within WHO / K. Staehr Johansen.
Resumo:
Using a game-theoretical approach, we investigate the dispersal patterns expected if inbreeding avoidance were the only reason for dispersal. The evolutionary outcome is always complete philopatry by one sex. The rate of dispersal by the other sex depends on patch size and mating system, as well as inbreeding and dispersal costs. If such costs are sex independent, then two stable equilibria coexist (male or female philopatry), with symmetric domains of attraction. Which sex disperses is determined entirely by history, genetic drift, and gene flow. An asymmetry in costs makes one domain of attraction extend at the expense of the other. In such a case, the dispersing sex might also be, paradoxically, the one that incurs the higher dispersal costs. As asymmetry increases, one equilibrium eventually disappears, which may result in a sudden evolutionary shift in the identity of the dispersing sex. Our results underline the necessity to control for phylogenetic relationships (e.g., through the use of independent-comparisons methods) when investigating empirical trends in dispersal. Our model also makes quantitative predictions on the rate of dispersal by the dispersing sex and suggests that inbreeding avoidance may only rarely be the sole reason for dispersal.
Resumo:
In some fishes, water chemistry or temperature affects sex determination or creates sex-specific selection pressures. The resulting population sex ratios are hard to predict from laboratory studies if the environmental triggers interact with other factors, whereas in field studies, singular observations of unusual sex ratios may be particularly prone to selective reporting. Long-term monitoring largely avoids these problems. We studied a population of grayling (Thymallus thymallus) in Lake Thun, Switzerland, that has been monitored since 1948. Samples of spawning fish have been caught about 3 times/week around spawning season, and water temperature at the spawning site has been continuously recorded since 1970. We used scale samples collected in different years to determine the average age of spawners (for life-stage specific analyses) and to identify the cohort born in 2003 (an extraordinarily warm year). Recent tissue samples were genotyped on microsatellite markers to test for genetic bottlenecks in the past and to estimate the genetically effective population size (N(e) ). Operational sex ratios changed from approximately 65% males before 1993 to approximately 85% males from 1993 to 2011. Sex ratios correlated with the water temperatures the fish experienced in their first year of life. Sex ratios were best explained by the average temperature juvenile fish experienced during their first summer. Grayling abundance is declining, but we found no evidence of a strong genetic bottleneck that would explain the apparent lack of evolutionary response to the unequal sex ratio. Results of other studies show no evidence of endocrine disruptors in the study area. Our findings suggest temperature affects population sex ratio and thereby contributes to population decline. Persistencia de Proporción de Sexos Desigual en una Población de Tímalos (Salmonidae) y el Posible Papel del Incremento de la Temperatura.
Resumo:
A la veille de l'introduction de la réforme pénale et civile fédérale dans le canton de Vaud en 2011, la Revue historique vaudoise s'est intéressée à l'histoire de la justice et de la criminalité. Le présent numéro réunit des contributions d'historiens, historiens du droit et historiens de l'art, jeunes ou confirmés, qui livrent ici les résultats de leurs recherches en cours ou récentes, ainsi que des témoignages de magistrats sur l'exercice de la justice et sur les conséquences des changements à venir. Pour cette thématique qui est un champ dynamique de la recherche historiques en Suisse et en Europe depuis la fin des années 1970, deux axes principaux ont été privilégies pour interroger l'exercice de la justice et les interactions entre l'Etat et les justiciables. Le premier traite de la figure du criminel et de la représentation du crime par un examen des pratiques et des discours judiciaires. Le second se concentre sur les acteurs de la justice et sur leurs modes d'actions et leurs motivations. En privilégiant un traitement sur la longue durée, du Moyen Âge à nos jours, ainsi que des études de cas, ce dossier thématique propose des éclairages successifs sur la justice et la criminalité en terres vaudoises. Ils mettent en évidence des transitions, des ruptures et des innovations révélatrices des institutions, de leur fonctionnement et du rôle social de leurs agents
Resumo:
Turning biases have been associated with unbalanced hemispheric dopaminergic activity, and this activity has been correlated with cue-directed behaviors. Moreover, a sexual differentiation in hippocampal dopaminergic receptors following learning has been shown. In humans, pointing responses towards the starting point is commonly used to assess the accuracy of direction estimation after locomotion. Thus, it may be of interest for the field of spatial cognition to explore human sex differences in spontaneous turning bias when a body rotation is required. To this end, male and female blindfolded subjects were guided in a linear displacement and asked to rotate in order to point in the direction of the starting position. The main finding was a massive difference between men and women. 80% of women showed a turning bias to the right when 69% of men showed a bias to the left. Moreover, these preferences were not correlated with handedness. These results suggest basic preferences associated to sex might influence male and female performance in spatial cognition. They also suggest experimental procedures may be biased in favor of male or female strategies. Therefore, such preferences should be considered in order to gain further insight into the development of more balanced procedures.
Resumo:
Wound care made great progress during last years related to several factors. The first is an awakening of the importance of wounds. The progress made in the comprehension of the physiopathology of wounds led to innovations in all stages of this complex process which is the wound healing. Autologus platelet concentrate producing growth factors are in use to stimulate the first phase of the healing. The second phase which is the phase of proliferation and secretion is currently better managed with new categories of bandages which are true local treatments. The nutrition became one of the pillars of wound treatments especially among old patients. The reconstructive surgery took great steps since the physiology and the vascular anatomy of the skin and soft tissues are better known. Finally the bio-engineering has entered the treatment of the wound there is more than 20 years ago and methods have improved and become more reliable
Resumo:
The expansion of international standardization has reinforced enduring questions on the legitimacy of standards. In that respect, the participation of all stakeholders, including the weakest ones (unions, NGO, consumers' associations) is crucial. Given the recognized role of consumers' associations to express legitimate objectives, the question of their representation becomes central. In order to get a deeper understanding of their participation, this article explores the evolution of their representation within the Swiss national mirror committees of international standardization between 1987 and 2007. It probes the extent to which their participation is determined by the distinctiveness of issues supposedly related to consumers' concerns and by their own use of standards. The empirical findings of our study indicate an underrepresentation of consumers' associations and confirm the topical specificity of their implication in standardization processes. Finally, we found evidence that the use of standards in an association's activities supports and encourages its participation in standardization committees.