302 research outputs found

    Diversity of the Insect Visitors on Calluna vulgaris (Ericaceae) in Southern France Heathlands

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    As part of an ongoing research project on the pollination networks in European heathlands, the objective of this study was to assess the insect visitor guild on Calluna vulgaris (L.) Hull (Ericaceae). We focused the study on a region renowned for its largely well-preserved heathlands, the Cévennes National Park, Southern France. In 2013, flower visitors were observed over 3 d per site, in four heathland sites at mont Lozère. Honeybees (Apis mellifera L.) were the main visitors (62–88% of total visitors). Besides honeybees, a high diversity of visitors was detected with 57 different species identified (42 Diptera and 15 Hymenoptera). Hoverflies (Syrphidae, Diptera) visitors were abundant and diverse, especially individuals belonging to the genera Eristalis and Episyrphus. The reported diversity of visitors was probably due to the preservation of large heathland areas at mont Lozère and to the generalist pollination system of C. vulgaris

    Le plafond de verre dans les ministères : une analyse de la fabrication organisationnelle des dirigeant.e.s.

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    Ce rapport présente les conclusions d'une recherche financée par la DGAFP dans le cadre de l'appel d'offre sur « Les carrières des dirigeants dans la fonction publique de l'État. Approche qualitative des inégalités entre hommes et femmes ». Il est le résultat d'une enquête sociologique auprès d'une centaine (deux tiers de femmes, un tiers d'hommes) de cadres dirigeant.e.s et supérieur.e.s de deux administrations générales de Bercy et deux administrations générales des ministères sociaux. Ce travail permet de comprendre et d'expliquer les raisons de la persistance d'inégalités femmes-hommes dans la haute fonction publique (plus précisément dans quatre directions ministérielles ici), particulière- ment dans les postes les plus valorisés. Pour ce faire, l'étude prend en compte les normes organisationnelles de construction de carrières de dirigeants et leurs effets genrés, mais questionne éga- lement les incidences des évolutions récentes de l'administration, dans un contexte de transformations et de réformes de la fonction publique, accentuées depuis 2007 par la mise en place de la Réforme générale des politiques publiques (RGPP)

    Accompagner les étudiants bacheliers bioingénieurs dans le développement de leurs compétences transversales

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    Cet article propose de dĂ©crire la conception, le dĂ©roulĂ© et l’évaluation de quatre modules de formation aux compĂ©tences transversales instaurĂ©s dans le cadre d’une rĂ©forme du programme de bachelier dans la FacultĂ© des bioingĂ©nieurs de l’UCLouvain en rĂ©ponse Ă  deux enjeux facultaires : 1) intĂ©grer les disciplines dans un contexte plus appliquĂ© et 2) dĂ©velopper les compĂ©tences transversales des futurs bioingĂ©nieurs. Le scĂ©nario des modules prenait pour point d’ancrage la connaissance de soi et la conscience des diffĂ©rences interpersonnelles et visait un dĂ©veloppement progressif des compĂ©tences de collaboration, d’organisation et de communication, en articulation directe Ă  la rĂ©alisation d’un projet. Quarante-quatre Ă©quipes d’étudiants ont pris part au dispositif. Celui-ci a fait l’objet d’une Ă©valuation quantitative (enquĂŞte) et qualitative (focus group). Les rĂ©sultats intègrent des mesures de l’efficacitĂ© du groupe et des Ă©motions vĂ©cues

    Multiple introductions boosted genetic diversity in the invasive range of black cherry (Prunus serotina; Rosaceae)

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    Background and Aims Black cherry (Prunus serotina) is a North American tree that is rapidly invading European forests. This species was introduced first as an ornamental plant then it was massively planted by foresters in many countries but its origins and the process of invasion remain poorly documented. Based on a genetic survey of both native and invasive ranges, the invasion history of black cherry was investigated by identifying putative source populations and then assessing the importance of multiple introductions on the maintenance of gene diversity. Methods Genetic variability and structure of 23 populations from the invasive range and 22 populations from the native range were analysed using eight nuclear microsatellite loci and five chloroplast DNA regions. Key Results Chloroplast DNA diversity suggests there were multiple introductions from a single geographic region (the north-eastern United States). A low reduction of genetic diversity was observed in the invasive range for both nuclear and plastid genomes. High propagule pressure including both the size and number of introductions shaped the genetic structure in Europe and boosted genetic diversity. Populations from Denmark, The Netherlands, Belgium and Germany showed high genetic diversity and low differentiation among populations, supporting the hypothesis that numerous introduction events, including multiple individuals and exchanges between sites, have taken place during two centuries of plantation. Conclusions This study postulates that the invasive black cherry has originated from east of the Appalachian Mountains (mainly the Allegheny plateau) and its invasiveness in north-western Europe is mainly due to multiple introductions containing high numbers of individual

    Le genre des administrations:La fabrication des inégalités de carrière entre hommes et femmes dans la haute fonction publique

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    L’article s’intéresse aux inégalités sexuées de carrière de l’encadrement dans quatre directions générales de deux ministères – économiques et financiers d’une part, sociaux de l’autre – contrastées du point de vue de leur féminisation et des types de carrière. L’enquête s’appuie sur une centaine de récits de vie de femmes et d’hommes. Au‑delà de l’éducation familiale et d’un inégal accès à la voie royale de l’ÉNA, les blocages de carrières des femmes sont décelés au coeur des administrations, à travers des règles de disponibilité, de mobilité géographique, de cooptation homophile qu’elles s’imposent. Les politiques d’égalité professionnelle peinent à les modifier mais font émerger une plus grande conscience des inégalités.This article’s focuses on sexual inequalities of career in the management of four general directions of two ministries, economic and financial, social, contrasted from the point of view of their feminisation and the types of career. The inquiry is based on a hundred or so life stories of both men and women. Above their family education and the unequal access to senior civil service through the royal route of the ÉNA, the obstacles in the careers of women are detected at the heart of the administration, through the rules of availability, geographical mobility and the homophilic cooptation they imply. Policies of professional equality struggle to modify them but, nonetheless, succeed in creating a greater awareness of the problem

    L’aconit empoisonne-t-il ses pollinisateurs ?

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    Comment la toxicité de la plante empêche que son pollen ne serve à autre chose qu’à sa pollinisatio

    Préliminaires sur la production de nectar chez trois espèces de Vaccinium

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    In order to determine if the characteristics of the Vaccinium nectars are responsible for the visits of pollinators (bumblebees, honeybees, hoverflies) (table I), the secretions of V myrtillus, V vitis-idaea and V uliginosum have been analysed for quantity, total sugar concentration and relative ratios of sugars. The quantities of extracted nectar differed among dates, flower ages and species (fig 1), as did total sugar concentration (mean: 18.79% for V myrtillus and 16.40% for V uliginosum) (table II). Great differences are shown between species in chromatographic analysis of their relative sugar ratios. V myrtillus nectar showed sucrose dominance (93.33%), V vitis-idaea had a more balanced nectar composition (28.52% sucrose, 53.24% fructose and 18.30% glucose), and V uliginosum nectar was sucrose poor (0.33% sucrose, 62.98% fructose and 35.93% glucose) (table III). An attempt was made to establish relations between these patterns of variation and foraging behaviour of insects. Actually pollinators are quite similar and it is doubtful that nectar characteristics alone determine visits. Further experiments are required
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