L’expérience vécue par les élèves de 7PH/8PH en éducation physique

Ce mémoire traite de l’expérience vécue par des élèves de 7PH-8PH en éducation physique et du rapport personnel qu’ils construisent au sein de la discipline. Afin d’obtenir des éléments à ce sujet, un questionnaire a été présenté à six classes de trois établissements différents du canton de Genève. Suite à l’analyse de ces questionnaires, des entretiens individuels semi-directifs ont été menés avec certains élèves. Notre analyse se base donc uniquement sur le discours des élèves. L’enseignement de l’EP étant dispensé à la fois par les enseignants généralistes et les enseignants spécialistes, nous tentons de savoir si l’expérience que vivent les élèves est la même avec les deux enseignants et s’ils prennent du plaisir au sein des leçons. Afin de comprendre l’expérience vécue par les élèves, les concepts de motivation, de confiance en soi et d’estime de soi seront abordés

A synthesis of biological invasion hypotheses associated with the introduction–naturalisation–invasion continuum

International audienceWith the advent of the Anthropocene, biological invasions have reached an unprecedented level, and the number of species introductions is still increasing in an ever-changing world. Despite major advances in invasion science, significant debate and lack of clarity remain surrounding the determinants of success of introduced species, the magnitude and dimensions of their impact, and the mechanisms sustaining successful invasions. Empirical studies show divergent impacts of alien populations on ecosystems and contrasting effects of biotic and abiotic factors on the dynamics of alien populations, which hinders the creation of a unified theory of biological invasions. Compounding these issues is the plethora of hypotheses that aim to explain invasion success, which can be unclear and contradictory. We propose a synthesis that categorizes hypotheses along a timeline of invasion. We sorted invasion hypotheses along the invasion timeline, and considered population, community and ecosystem levels. This temporal sorting of invasion concepts shows that each is relevant at a specific stage of the invasion. Although concepts and empirical findings on alien species may appear contradictory, when mapped onto an invasion timeline, they may be combined in a complementary way. An overall scheme is proposed to summarise the theoretical dynamics of ecosystems subjected to invasions. For any given case study, this framework provides a guide through the maze of theories and should help choose the appropriate concepts according to the stage of invasion

A synthesis of biological invasion hypotheses associated with the introduction–naturalisation–invasion continuum

International audienceWith the advent of the Anthropocene, biological invasions have reached an unprecedented level, and the number of species introductions is still increasing in an ever-changing world. Despite major advances in invasion science, significant debate and lack of clarity remain surrounding the determinants of success of introduced species, the magnitude and dimensions of their impact, and the mechanisms sustaining successful invasions. Empirical studies show divergent impacts of alien populations on ecosystems and contrasting effects of biotic and abiotic factors on the dynamics of alien populations, which hinders the creation of a unified theory of biological invasions. Compounding these issues is the plethora of hypotheses that aim to explain invasion success, which can be unclear and contradictory. We propose a synthesis that categorizes hypotheses along a timeline of invasion. We sorted invasion hypotheses along the invasion timeline, and considered population, community and ecosystem levels. This temporal sorting of invasion concepts shows that each is relevant at a specific stage of the invasion. Although concepts and empirical findings on alien species may appear contradictory, when mapped onto an invasion timeline, they may be combined in a complementary way. An overall scheme is proposed to summarise the theoretical dynamics of ecosystems subjected to invasions. For any given case study, this framework provides a guide through the maze of theories and should help choose the appropriate concepts according to the stage of invasion

A synthesis of biological invasion hypotheses associated with the introduction–naturalisation–invasion continuum

International audienceWith the advent of the Anthropocene, biological invasions have reached an unprecedented level, and the number of species introductions is still increasing in an ever-changing world. Despite major advances in invasion science, significant debate and lack of clarity remain surrounding the determinants of success of introduced species, the magnitude and dimensions of their impact, and the mechanisms sustaining successful invasions. Empirical studies show divergent impacts of alien populations on ecosystems and contrasting effects of biotic and abiotic factors on the dynamics of alien populations, which hinders the creation of a unified theory of biological invasions. Compounding these issues is the plethora of hypotheses that aim to explain invasion success, which can be unclear and contradictory. We propose a synthesis that categorizes hypotheses along a timeline of invasion. We sorted invasion hypotheses along the invasion timeline, and considered population, community and ecosystem levels. This temporal sorting of invasion concepts shows that each is relevant at a specific stage of the invasion. Although concepts and empirical findings on alien species may appear contradictory, when mapped onto an invasion timeline, they may be combined in a complementary way. An overall scheme is proposed to summarise the theoretical dynamics of ecosystems subjected to invasions. For any given case study, this framework provides a guide through the maze of theories and should help choose the appropriate concepts according to the stage of invasion

Biological Invasion Theories: Merging Perspectives from Population, Community and Ecosystem Scales

International audienceBiological invasions have reached an unprecedented level and the number of introduced species is still increasing worldwide. Despite major advances in invasion science, the determinants of success of introduced species, the magnitude and dimensions of their impact, and the mechanisms sustaining successful invasions are still debated. Empirical studies show divergent impacts of nonnativepopulations on ecosystems and contrasting effects of biotic and abiotic factors on the dynamics of non-native populations; this is hindering the emergence of a unified theory of biological invasions. We propose a synthesis that merges perspectives from population, community, and ecosystem levels. Along a timeline of ecosystem transformation driven by nonnative species, from historical to human-modified ecosystems, we order invasion concepts and theories to clarify their chaining and relevance during each step of the invasion process. This temporal sorting of invasion concepts shows that each concept is relevant at a specific stage of theinvasion. Concepts and empirical findings on non-native species may appear contradictory. However, we suggest that, when mapped onto an invasion timeline, they may be combined in a complementary way. An overall scheme is proposed to summarise the theoretical dynamics of ecosystems subjected to invasions. For any given case study, this framework provides a guide through the maze of theories and should help choose the appropriate concepts according to the stage of invasion

Identification of two immunogenic domains of the prion protein—PrP—which activate class II-restricted T cells and elicit antibody responses against the native molecule.

Recent reports suggest that immunity against the prion protein (PrP) retards transmissible spongiform encephalopathies progression in infected mice. A major obstacle to the development of vaccines comes from the fact that PrP is poorly immunogenic, as it is seen as self by the host immune system. Additional questions concern the immune mechanisms involved in protection and the risk of eliciting adverse reactions in the central nervous system of treated patients. Peptide-based vaccines offer an attractive strategy to overcome these difficulties. We have undertaken the identification of the immunogenic regions of PrP, which trigger helper T cells (Th) associated with antibody production. Our results identify two main regions, one between the structured and flexible portion of PrP (98–127) and a second between {alpha} 1 and {alpha} 2 helix (143–187). Peptides (30-mer) corresponding to these regions elicit class II-restricted Th cells and antibody production against native PrP and could therefore be of potential interest for a peptide-based vaccination