Utilisation de nanomembranes pour le dessalement de l'eau et comparaison avec l'osmose inverse et la distillation

De nouvelles technologies innovatrices sont continuellement à l’étude dans le domaine du traitement de l’eau afin de pourvoir aux besoins grandissant de la population mondiale. Le domaine des nanotechnologies offre de plus en plus d’alternatives et une membrane à base de nanotubes de carbone a démontré lors d’essais en laboratoire des capacités plus intéressantes que les technologies utilisées à l’heure actuelle pour le dessalement de l’eau. La comparaison de celle-ci avec les technologies actuelle permet d’établir des avantages en faveur d’une membrane plus performante. Cependant, des études approfondies seront nécessaires dans les années futures afin de réduire l’incertitude concernant les risques et les impacts de l’utilisation de nanotubes de carbone pour le traitement de l’eau. Avec l’engouement suscité par les nanotechnologies, il y a lieu de se demander si les connaissances actuelles permettent d’évaluer adéquatement les impacts et risques potentiels pour l’humain et l’environnement et le cas échéant si le principe de précaution est appliqué

Effet du niveau de compétition alimentaire sur l'expression des rapports sociaux entre femelles chez le macaque crabier (Macaca fascicularis)

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal

Mating skew in Barbary macaque males: the role of female mating synchrony, female behavior, and male-male coalitions

A fundamental question of sexual selection theory concerns the causes and consequences of reproductive skew among males. The priority of access (PoA) model (Altmann, Ann NY Acad Sci 102:338-435, 1962) has been the most influential framework in primates living in permanent, mixed-sex groups, but to date it has only been tested with the appropriate data on female synchrony in a handful of species. In this paper, we used mating data from one large semi-free ranging group of Barbary macaques: (1) to provide the first test of the priority-of-access model in this species, using mating data from 11 sexually active females (including six females that were implanted with a hormonal contraceptive but who showed levels of sexual activity comparable to those of naturally cycling females) and (2) to determine the proximate mechanism(s) underlying male mating skew. Our results show that the fit of the observed distribution of matings with sexually attractive females to predictions of the PoA model was poor, with lower-ranking males mating more than expected. While our work confirms that female mating synchrony sets an upper limit to monopolization by high-ranking individuals, other factors are also important. Coalitionary activity was the main tactic used by males to lower mating skew in the study group. Coalitions were expressed in a strongly age-related fashion and allowed subordinate, post-prime males to increase their mating success by targeting more dominant, prime males. Conversely, females, while mating promiscuously with several males during a given mating cycle, were more likely to initiate their consortships with prime males, thus reducing the overall effectiveness of coalitions. We conclude that high-ranking Barbary macaque males have a limited ability to monopolize mating access, leading to a modest mating skew among the

Coalitions in theory and reality: a review of pertinent variables and processes

Coalitions and alliances are ubiquitous in humans and many other mammals, being part of the fabric of complex social systems. Field biologists and ethologists have accumulated a vast amount of data on coalition and alliance formation, while theoretical biologists have developed modelling approaches. With the accumulation of empirical data and sophisticated theory, we are now potentially able to answer a host of questions about how coalitions emerge and are maintained in a population over time, and how the psychology of this type of cooperation evolved. Progress can only be achieved, however, by effectively bridging the communication gap that currently exists between empiricists and theoreticians. In this paper, we aim to do so by asking three questions: (1) What are the primary questions addressed by theoreticians interested in coalition formation, and what ar

Vers une nouvelle érudition : numérisation et recherche en histoire du livre

En décembre 1999, à l\u27Enssib, s’est déroulé le colloque "Vers une nouvelle érudition : numérisation et recherche en histoire du livre", organisé dans le cadre des 12e Entretiens du Centre Jacques Cartier sous la responsabilité de Dominique Varry (enssib), Annie Charon (école nationale des chartes) et Guylaine Baudry (Université de Montréal)

Mating skew in Barbary macaque males: the role of female mating synchrony, female behavior, and male–male coalitions

A fundamental question of sexual selection theory concerns the causes and consequences of reproductive skew among males. The priority of access (PoA) model (Altmann, Ann NY Acad Sci 102:338–435, 1962) has been the most influential framework in primates living in permanent, mixed-sex groups, but to date it has only been tested with the appropriate data on female synchrony in a handful of species. In this paper, we used mating data from one large semi-free ranging group of Barbary macaques: (1) to provide the first test of the priority-of-access model in this species, using mating data from 11 sexually active females (including six females that were implanted with a hormonal contraceptive but who showed levels of sexual activity comparable to those of naturally cycling females) and (2) to determine the proximate mechanism(s) underlying male mating skew. Our results show that the fit of the observed distribution of matings with sexually attractive females to predictions of the PoA model was poor, with lower-ranking males mating more than expected. While our work confirms that female mating synchrony sets an upper limit to monopolization by high-ranking individuals, other factors are also important. Coalitionary activity was the main tactic used by males to lower mating skew in the study group. Coalitions were expressed in a strongly age-related fashion and allowed subordinate, post-prime males to increase their mating success by targeting more dominant, prime males. Conversely, females, while mating promiscuously with several males during a given mating cycle, were more likely to initiate their consortships with prime males, thus reducing the overall effectiveness of coalitions. We conclude that high-ranking Barbary macaque males have a limited ability to monopolize mating access, leading to a modest mating skew among them

Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches

Extracellular vesicles (EVs), through their complex cargo, can reflect the state of their cell of origin and change the functions and phenotypes of other cells. These features indicate strong biomarker and therapeutic potential and have generated broad interest, as evidenced by the steady year-on-year increase in the numbers of scientific publications about EVs. Important advances have been made in EV metrology and in understanding and applying EV biology. However, hurdles remain to realising the potential of EVs in domains ranging from basic biology to clinical applications due to challenges in EV nomenclature, separation from non-vesicular extracellular particles, characterisation and functional studies. To address the challenges and opportunities in this rapidly evolving field, the International Society for Extracellular Vesicles (ISEV) updates its 'Minimal Information for Studies of Extracellular Vesicles', which was first published in 2014 and then in 2018 as MISEV2014 and MISEV2018, respectively. The goal of the current document, MISEV2023, is to provide researchers with an updated snapshot of available approaches and their advantages and limitations for production, separation and characterisation of EVs from multiple sources, including cell culture, body fluids and solid tissues. In addition to presenting the latest state of the art in basic principles of EV research, this document also covers advanced techniques and approaches that are currently expanding the boundaries of the field. MISEV2023 also includes new sections on EV release and uptake and a brief discussion of in vivo approaches to study EVs. Compiling feedback from ISEV expert task forces and more than 1000 researchers, this document conveys the current state of EV research to facilitate robust scientific discoveries and move the field forward even more rapidly

Utilisation de nanomembranes pour le dessalement de l'eau et comparaison avec l'osmose inverse et la distillation

De nouvelles technologies innovatrices sont continuellement à l’étude dans le domaine du traitement de l’eau afin de pourvoir aux besoins grandissant de la population mondiale. Le domaine des nanotechnologies offre de plus en plus d’alternatives et une membrane à base de nanotubes de carbone a démontré lors d’essais en laboratoire des capacités plus intéressantes que les technologies utilisées à l’heure actuelle pour le dessalement de l’eau. La comparaison de celle-ci avec les technologies actuelle permet d’établir des avantages en faveur d’une membrane plus performante. Cependant, des études approfondies seront nécessaires dans les années futures afin de réduire l’incertitude concernant les risques et les impacts de l’utilisation de nanotubes de carbone pour le traitement de l’eau. Avec l’engouement suscité par les nanotechnologies, il y a lieu de se demander si les connaissances actuelles permettent d’évaluer adéquatement les impacts et risques potentiels pour l’humain et l’environnement et le cas échéant si le principe de précaution est appliqué