7,139 research outputs found

    Avian malaria is absent in juvenile colonial herons (Ardeidae) but not Culex pipiens mosquitoes in the Camargue, Southern France

    Get PDF
    Apicomplexan blood parasites Plasmodium and Haemoproteus (together termed “Avian malaria”) and Leucocytozoon are widespread, diverse vector-transmitted blood parasites of birds, and conditions associated with colonial nesting in herons (Ardeidae) and other waterbirds appear perfect for their transmission. Despite studies in other locations reporting high prevalence of parasites in juvenile herons, juvenile Little Egrets (Egretta garzetta) previously tested in the Camargue, Southern France, had a total absence of malaria parasites. This study tested the hypotheses that this absence was due to insufficient sensitivity of the tests of infection; an absence of infective vectors; or testing birds too early in their lives. Blood was sampled from juveniles of four species shortly before fledging: Little Egret (n = 40), Cattle Egret (Bubulcus ibis; n = 40), Black-crowned Night-Heron (Nycticorax nycticorax, n = 40), and Squacco Heron (Ardeola ralloides; n = 40). Sensitive nested-Polymerase Chain Reaction was used to test for the presence of parasites in both birds and host-seeking female mosquitoes captured around the colonies. No malaria infection was found of in any of the heron species. Four different lineages of Plasmodium were detected in pooled samples of female Culex pipiens mosquitoes, including two in potentially infective mosquitoes. These results confirm that the absence of malaria parasites previously demonstrated in Little Egret is not due to methodological limitations. Although the prevalence of infection in mosquitoes was low, conditions within the colonies were suitable for transmission of Plasmodium. These colonial heron species may have evolved strategies for resisting malaria infection through physiological or behavioral mechanisms

    Impact of anthropogenic disturbances on beetle communities of French Mediterranean coastal dunes

    Get PDF
    In coastal dunes, influenced by anthropogenic activities such as tourism, it is important to determine the relative influence of environmental factors at different spatial scales to evaluate the sensitivity of local communities to disturbances. We analyzed beetle communities of 14 dunes of the French Mediterranean coast: four in the relatively preserved Camargue area, and ten in the Var department, where tourism is intensive. Beetle communities were studied three times in early spring using sand sampling. Species-environment relationships were evaluated at the regional, landscape and local scale using redundancy analysis (RDA) and variability partitioning. About 28 species were identified, of which 15 were sand-specialist species, which accounted for more than 93% of total abundance. The beetle communities of Camargue were significantly different from those of the Var department owing to the pullulation of a Tenebrionid species (Trachyscelis aphodioides Latr.) in the Var, except for one restored dune where the community was very similar to those of Camargue. Our results showed no longitudinal gradient between the two regions. Local factors (dune height, preservation and disturbance index) significantly explained most of the variation in the dominance of T. aphodioides, while some other local factors were important for other psammophilous species. This study also suggests that dune beetle communities are strongly affected on beaches intensively managed for tourism, but beetles are still abundant in much disturbed sites

    Avian malaria is absent in juvenile colonial herons (Ardeidae) but not Culex pipiens mosquitoes in the Camargue, Southern France

    Get PDF
    Apicomplexan blood parasites Plasmodium and Haemoproteus (together termed “Avian malaria”) and Leucocytozoon are widespread, diverse vector-transmitted blood parasites of birds, and conditions associated with colonial nesting in herons (Ardeidae) and other waterbirds appear perfect for their transmission. Despite studies in other locations reporting high prevalence of parasites in juvenile herons, juvenile Little Egrets (Egretta garzetta) previously tested in the Camargue, Southern France, had a total absence of malaria parasites. This study tested the hypotheses that this absence was due to insufficient sensitivity of the tests of infection; an absence of infective vectors; or testing birds too early in their lives. Blood was sampled from juveniles of four species shortly before fledging: Little Egret (n = 40), Cattle Egret (Bubulcus ibis; n = 40), Black-crowned Night-Heron (Nycticorax nycticorax, n = 40), and Squacco Heron (Ardeola ralloides; n = 40). Sensitive nested-Polymerase Chain Reaction was used to test for the presence of parasites in both birds and host-seeking female mosquitoes captured around the colonies. No malaria infection was found of in any of the heron species. Four different lineages of Plasmodium were detected in pooled samples of female Culex pipiens mosquitoes, including two in potentially infective mosquitoes. These results confirm that the absence of malaria parasites previously demonstrated in Little Egret is not due to methodological limitations. Although the prevalence of infection in mosquitoes was low, conditions within the colonies were suitable for transmission of Plasmodium. These colonial heron species may have evolved strategies for resisting malaria infection through physiological or behavioral mechanisms

    An integrated study of the development of organic rice cultivation in the Camargue (France)-

    Get PDF
    In the Camargue, rice and durum wheat are associated in rotations that have an ambivalent ecological impact: on the one hand, these two crops contribute to the preservation of the surrounding ecosystem, while on the other hand, when cropped intensively, they can threaten the ecological equilibrium of this protected area. In this context, organic agriculture would seem to be an alternative adopted by a certain number of producers and processors. However, the pioneers of this practice encounter numerous problems, both agronomic and economic. The study presented here aims: to construct a pluridisciplinary approach to analyse the conditions of the development of organic cereal cultivation in the Camargue: to identify the principal factors that limit the development of this new practice: to produce knowledge useful in helping ricegrowers put into practice organic cropping systems

    Assessing the role of the research in the transition to organic farming by using the Actor Network Theory: lessons from two case studies in France and Bulgaria

    Get PDF
    This paper explores the potential of Actor Network Theory (ANT) in understanding how the process of interaction and translation between human and non-human actors contribute to the development, adoption and diffusion of science-based innovations linked to the transition to organic farming. The study relies on two case studies, the French Camargue case covering a range of technical and social innovations, and the case from Bulgaria focusing on the development of a technical and product innovation, i.e. a veterinary product for organic beekeeping. The paper shows the limitations of classical approaches in studying innovations since they underestimate the role of heterogeneous actors, their status, and how they interact with each other. We argue that focusing on actors’ interactions helps to better understand the so-called “uncertainties” and “turning points” in the innovation development, as well as to interpret them as natural elements. Moreover we argue that challenges to tackle should be problematized to increase the success of research programs. We also stress the importance of opinion leaders during the implementation and diffusion phase of the innovation

    Strategy of external growth and group managerial tools at Alais, Froges et Camargue during inter war period

    Get PDF
    This article shows the relationship between the strategy of external growth carried out from 1921 to 1939 by the French company Alais, Froges et Camargue and the introduction of new management tools intended to control subsidiaries. The establishment of financial reporting in 1921 and the development in 1927 of a financial statement whose conceptual foundations were based on group accounting, were the solutions implemented by the directors to manage the Group's increasing complexity and impenetrability.Accounting history, reporting, control, subsidiaries, group accounts, Alais, Froges et Camargue (Pechiney).

    Worst Case Scenario and Stakeholder Group Decision: A 5-6 Meter Sea Level Rise in the Rhone Delta, France

    Get PDF
    Risk policy and public attitudes appear disconnected from research predicting warmer climate partially due to human activity. To step out of this stalled situation, a worst case scenario of a 5-6m sea level rise (SLR) induced by the collapse of the WAIS and occurring during the period 2030-2130 is constructed and applied to the Rhone delta. Physical and socio-economic scenarios developed with data from the Rhone delta context are developed and submitted to stakeholders for a day-long workshop. Group process analysis shows a high level of trust and cooperation mobilized to face the 5-6m SLR issue, despite potentially diverging interests. Two sets of recommendations stem from the scenario workshop. A conservative "wait and see" option is decided when the risk of the WAIS collapse is announced in 2030. After WAIS collapse generates an effective 1m SLR rise by 2050, decisions are taken for total retreat and rendering of the Rhone delta to its hydrological function. The transposition of these results into present times policy decisions could be considered. The methodology developed here could be applied to other risk objects and situations, and serve for policy exercises and crisis prevention.Sea level rise, France, Camargue, scenario, extreme climate, stakeholder workshop

    Beginnings of financial reporting and premises of consolidation of accounts in French aluminium industry,1921-1939

    Get PDF
    The expansion of groups of companies during the inter-war years is one of the most profound transformations in the structure of French capitalism. Studies in economic history have shown the importance of the subsidiary creation phenomenon in relation to Compagnie Générale d'Electricité, Energie industrielle or Schneider . By contrast, these studies are less interested in the specific arrangements for auditing subsidiaries and managing Company Groups. This article seeks to show how and why the directors of Alais, Froges et Camargue - The largest French company in the aluminum sector- established specific audit measures from the 1920s onwards. This research is essentially based on the company's archives (annual reports, general organisation chart and memoranda from the general secretariat). Even if the results published in the annual reports should be treated with the utmost caution, in particular owing to the absence of accounting regulation in France in the inter-war years, they remain essential for assessing the important position of subsidiaries and main shareholdings in assets. The scope of the subsidiary creation phenomenon, which is behind the establishment of specific controls, is highlighted. This trend, far from being linear, is strongly influenced by the economic and political situation. The size of the Group's growth gave rise to two types of requirements for the directors of Alais, Froges et Camargue, namely to audit the subsidiaries and to measure the group's net cash flow. The response to the need for auditing the subsidiaries was provided by the introduction of financial reporting from 1921. Faced with the increasing number of subsidiaries and main shareholdings held by Alais, Froges et Camargue, this control mechanism was to be strengthened in 1931. Furthermore, the necessity of measuring the Group's net cash flow led the directors in 1927 to draw up a financial statement whose conceptual foundations were based on those of the consolidation of accountsfinancial reporting, accounting history, group accounts, French aluminium industry, shareholdings.

    Heterogeneous anchoring in dichotomous choice valuation framework

    Get PDF
    This article addresses the important issue of anchoring in contingent valuation surveys that use the double-bounded elicitation format. Anchoring occurs when responses to the follow-up dichotomous choice valuation question are influenced by the bid presented in the initial dichotomous choice question. Specifically, we adapt a theory from psychology to characterize respondents as those who are likely to anchor and those who are not. Using a model developed by Herriges and Shogren (1996), our method appears successful in discriminating between those who anchor and those who did not. An important result is that when controlling for anchoring - and allowing the degree of anchoring to differ between respondent groups - the efficiency of the double-bounded welfare estimate is greater than for the initial dichotomous choice question. This contrasts with earlier research that finds that the potential efficiency gain from the double-bounded questions is lost when anchoring is controlled for and that we are better off not asking follow-up questions.Anchoring; Contingent Valuation; Heterogeneity; Framing effects

    Preferences, Norms and Constraints in farmers' agro-ecological choices. Case study using choice experiments survey in the Rhone River Delta, France

    Get PDF
    The aim of this paper is to elicit the sensitivity of farmers to payment for agro-environmental services in a context of strong ecological and policy constraints. We present results from a choice experiment survey performed among the whole population of agricultural decision-makers (104) in the Camargue area. Several econometric models have been estimated, the most significant being the Latent Classes one. Three classes have been identified, two of them representing farmers with strong committment to a specified technology (either very chemicals intensive or organic farming ), the main class encompassing farmers complying with the norms of the PGI « Riz de Camargue » . The estimated parameters of the utility function, together with the parameter of the monetary attribute provided the monetary value of each relevant agro-ecological attribute and the associated outcomes (average and risk yield). Outcomes of the choice experiments make a strong case for differentiating incentives for spreading environmental friendly technologies.
    • …
    corecore