Les déboires de la démographie organisationnelle sont-ils faits pour surprendre ? Une discussion méthodologique à partir de deux cas de fusion –acquisition : Carrefour-Promodès et France Télécom-Orange.

L’objectif de cet article est de vérifier les conditions d’application du courant de la démographie organisationnelle. L’approche positiviste de la démographie organisationnelle cherche à mettre en évidence des régularités entre des variables démographiques faciles à objectiver (observables et décontextualisables) et les performances de l’organisation. Ces variables sont généralement traitées en terme de dispersion afin de mesurer l’hétérogénéité/homogénéité d’une équipe. Au delà des critiques sur la démarche méthodologique parfois qualifiée de « boîte noire » pour la sécheresse dans l’explication des mécanismes sous-jacents aux phénomènes étudiés, c’est la discussion sur l’utilisation de ces variables démographiques qui a mobilisé notre attention. On peut identifier deux grandes questions relatives à cette utilisation : – peut-on décontextualiser les variables démographiques ? – Comment fonder le jugement d’hétérogénéité ? Pour nous appuyer sur un terrain propice à la réflexion, Nous nous sommes basés sur deux études de cas de fusions (France Télécom/Orange et Carrefour/Promodès) réalisées à partir d’une trentaine d’entretiens. Les observations ainsi que les perceptions des membres des équipes révèlent de nombreuses difficultés rendant la position méthodologique de la démographie organisationnelle difficile à opérationnaliser avec rigueur. Il nous semble délicat d’arrêter une liste des dimensions pertinentes de l’hétérogénéité. Celle- ci dépend des contextes et des situations.Etude de cas; équipes; fusions-acquisitions; catégorisation; Démographie organisationnelle;

Pulse shaping with birefringent crystals: a tool for quantum metrology

A method for time differentiation based on a Babinet-Soleil-Bravais compensator is introduced. The complex transfer function of the device is measured using polarization spectral interferometry. Time differentiation of both the pulse field and pulse envelope are demonstrated over a spectral width of about 100 THz with a measured overlap with the objective mode greater than 99.8%. This pulse shaping technique is shown to be perfectly suited to time metrology at the quantum limit

Conditions for collective action: Understanding factors supporting and constraining community-based fish culture in Bangladesh, Cambodia and Vietnam

Flood-prone ecosystems in South and Southeast Asia are traditionally farmed with deepwater rice followed by post-flood rice culture during the dry season. During the flood season, the same land is inundated, creating an open-access water body subject to multiple uses by multiple users. Fish production in these areas is based on the capture of wild fish. In these seasonal flood plains, fish are trapped in rice fields, reproduce and are harvested by farmerfishers or full-time fishers. These flooded areas cover about 4.5 million hectares in Bangladesh, and 1.2-1.4 million hectares (Catling 1992) is deeply flooded in the Mekong Delta of Vietnam and Cambodia for 4 to 6 months each year. One option to improve access to protein and diversified income for local users and to improve water-use efficiency is to integrate fish culture into this system. A number of studies conducted in the 1980s tested the technical feasibility of culturing fish in seasonally flooded rice fields (Roy et al. 1990, Mukhopadhyay et al. 1992, Rothuis et al. 1998a, Rothuis et al. 1998b, Ali et al. 1998). These studies showed that fish production could be increased by more than 1 ton per hectare per year (t/ha/yr) by stocking fish in flooded rice fields in individual plots. Based on these findings, the WorldFish Center implemented between 1997 and 2000 on-farm experimental trials of community-based fish culture (CBFC) on the Ganges and Meghna floodplains of Bangladesh and the Red River and Mekong deltas in Vietnam (WorldFish 2002). Farms are cultivated individually during the dry season, but during the flood season individual landholding boundaries disappear under the water, and water bodies and flooded rice field resources become common property. The project was based on the premise that production from these water bodies could be enhanced by stocking locally important fish species, providing communities with an additional source of income and an increased supply of affordable fish for sale or consumption (e.g., Dey and Prein 2003, IIRR 2000, Sinhababu et al. 1984). The results showed that fish production can be increased, with an average of 226 kilograms (kg)/ha in Vietnam and 863 kg/ha in Bangladesh, with a significant improvement of the household income (Dey et al. 2005). CBFC was found technically and economically sound and socially acceptable. However, the project concluded that further research was needed to understand how the institutional mechanisms needed to support fish culture differ in a range of different contexts. From 2005 to 2010, the Challenge Program on Water and Food project Communitybased Fish Culture in Seasonal Floodplains developed a series of trials to test this technology under different environmental and socioeconomic conditions. The objective of the project was to test the feasibility of this approach to improve water-use efficiency and provide benefits to the various users of seasonally flooded rice fields. Technical and economic aspects were monitored, and locally appropriate group arrangements for fish culture management, benefit sharing and resource access were tested. Although the technical and environmental aspects of culture-based fisheries in various countries are well documented (De Silva 2003, Nguyen et al. 2001, De Silva etal. 2006), CBFC in seasonal floodplains is a relatively new concept, and the suitability of this approach in different contexts remains under question. The project aimed to address this issue by developing onfarm trials in seasonally flooding areas with otherwise contrasting socioeconomic and natural environments. In this report, we focus on a study designed to understand the factors and conditons that support or constrain the feasibility and uptake of community-based fish culture in seasonal floodplains. The aim of the study is to contribute to knowledge on institutions for collective action, and the feasibility of community-based approaches to resource management, based on lessons learned in this 5-year project. The study also offers useful lessons for project implementation in the field of research-for-development. The report begins with an introduction to the Community-based Fish Culture project and a description of the technical intervention. The second part of the report introduces the study to investigate the conditions for collective action in community-based fish culture, beginning with a presentation of the research approach and methodology. The third section presents the findings of the study. Finally, we present a synthesis of the factors supporing and constraining community-based fish culture, key lessons learned and recommendations

Rapports coopératifs et confrontation culturelle : le cas de la gestion post fusion Orange- France Télécom Mobiles.

Cet article analyse l’impact de la diversité culturelle sur les relations de coopération. Deux modes coopératifs sont définis, l’un fondé sur le calcul, l’autre sur l’identification sociale. Le cas de l’équipe chargée de l’intégration des organisations France Télécom Mobile et Orange est analysé suivant cette grille de lecture. La diversité culturelle s’avère toujours vécue comme une difficulté à dépas-ser, jamais comme une opportunité ; elle affecte essentiellement l’exercice des intérêts individuels. Ces résultats conduisent à mettre en cause la définition de la culture comme un système stable de valeurs et de normes de comportement, pour privilégier sa représentation comme construit social.This paper aims at understanding the impact of cultural diversity on co-operative relationships. Co-operation is considered through two different modes : of co-operation. The case of the team in charge of the integration process between France Telecom Mobiles and Orange UK is analysed according to a framework combining the two modes. The results suggest that cultural diversity has little influ-ence on identity issues of co-operation, whereas it is mostly linked to strategic behaviours. These find-ings imply that cultural diversity must not be seen as a difference between stable sets of values and norms, but more as an easy way to explain inter-individual difficulties.Fusions-acquisitions; Coopération; Télécommunications; Management interculturel; Mergers;

UNDERSTANDING ADOPTION AND DISCONTINUANCE FOR GREATER IMPACT

International audienceFloodplains are characterized by a period of several months when the land is not available for agriculture and large, open areas are used for fisheries. The enclosed part of these flooded areas can be utilized for fish production aside from naturally occurring self recruited species through a community-based management system. Experiences in the Vietnamese and Cambodian Mekong Delta and Ganges Delta in Bangladesh between 2006 and 2009 highlighted the potential of this model and its limitations. Comparative analysis between countries at community and household levels provide indications about enabling and constraining factors affecting the success of this model in a range of factors (governance, economic, social and, environmental/technical) using both qualitative and quantitative data. The analysis shows that the Bangladesh context is more suitable than that of Vietnam and Cambodia to develop such collective action, with a more adapted socio-economic and natural environment. Absence of trust between participants and low capacity to develop collective action were found as important constraints in Vietnam, where individual economic benefit was the main driving factor and possibly the cement of community based action. The study of so called “failures” of technical interventions helped us to understand the different requirements needed to develop Community Based Fish Culture and how such technology can be integrated in other agro-ecosystems and socio-economic environments

Crosspresentation by dendritic cells,”

MHC class I-loading complex A series of endoplasmic reticulum chaperone proteins that stabilize empty MHC class I molecules and control the loading of high-affinity peptides onto MHC class I molecules. Cross-presentation by dendritic cells Abstract | The presentation of exogenous antigens on MHC class I molecules, known as cross-presentation, is essential for the initiation of CD8 + T cell responses. In vivo, cross-presentation is mainly carried out by specific dendritic cell (DC) subsets through an adaptation of their endocytic and phagocytic pathways. Here, we summarize recent advances in our understanding of the intracellular mechanisms of cross-presentation and discuss its role in immunity and tolerance in the context of specialization between DC subsets. Finally, we review current strategies to use cross-presentation for immunotherapy

Dendritic cell quiescence during systemic inflammation driven by LPS stimulation of radioresistant cells in vivo

Dendritic cell (DC) activation is a prerequisite for T cell priming. During infection, activation can ensue from signaling via pattern-recognition receptors after contact with pathogens or infected cells. Alternatively, it has been proposed that DCs can be activated indirectly by signals produced by infected tissues. To address the contribution of tissue-derived signals, we measured DC activation in a model in which radioresistant cells can or cannot respond to lipopolysaccharide (LPS). We report that recognition of LPS by the radioresistant compartment is sufficient to induce local and systemic inflammation characterized by high circulating levels of tumor necrosis factor (TNF) α, interleukin (IL) 1β, IL-6, and CC chemokine ligand 2. However, this is not sufficient to activate DCs, whether measured by migration, gene expression, phenotypic, or functional criteria, or to render DC refractory to subsequent stimulation with CpG-containing DNA. Similarly, acute or chronic exposure to proinflammatory cytokines such as TNF-α ± interferon α/β has marginal effects on DC phenotype in vivo when compared with LPS. In addition, DC activation and migration induced by LPS is unimpaired when radioresistant cells cannot respond to the stimulus. Thus, inflammatory mediators originating from nonhematopoietic tissues and from radioresistant hematopoietic cells are neither sufficient nor required for DC activation in vivo

Dispersion-based pulse shaping for multiplexed two-photon fluorescence microscopy

International audienceWe demonstrate selective two-photon excited fluorescence microscopy with shaped pulses produced with a simple yet efficient scheme based on dispersive optical components. The pulse train from a broadband oscillator is split into two subtrains that are sent through different amounts of glass. Beam recombination results in pulse-shape switching at a rate of 150 MHz. Time-resolved photon counting detection then provides two simultaneous images resulting from selective two-photon excitation, as demonstrated in a live embryo. Although less versatile than programmable pulse-shaping devices, this novel arrangement significantly improves the performance of selective microscopy using broadband shaped pulses while simplifying the experimental setup. Cop. 2010 Optical Society of America