41 research outputs found

    Depauperate Avifauna in Plantations Compared to Forests and Exurban Areas

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    Native forests are shrinking worldwide, causing a loss of biological diversity. Our ability to prioritize forest conservation actions is hampered by a lack of information about the relative impacts of different types of forest loss on biodiversity. In particular, we lack rigorous comparisons of the effects of clearing forests for tree plantations and for human settlements, two leading causes of deforestation worldwide. We compared avian diversity in forests, plantations and exurban areas on the Cumberland Plateau, USA, an area of global importance for biodiversity. By combining field surveys with digital habitat databases, and then analyzing diversity at multiple scales, we found that plantations had lower diversity and fewer conservation priority species than did other habitats. Exurban areas had higher diversity than did native forests, but native forests outscored exurban areas for some measures of conservation priority. Overall therefore, pine plantations had impoverished avian communities relative to both native forests and to exurban areas. Thus, reports on the status of forests give misleading signals about biological diversity when they include plantations in their estimates of forest cover but exclude forested areas in which humans live. Likewise, forest conservation programs should downgrade incentives for plantations and should include settled areas within their purview

    Lymphatic filariasis in the Democratic Republic of Congo; micro-stratification overlap mapping (MOM) as a prerequisite for control and surveillance

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    <p>Abstract</p> <p>Background</p> <p>The Democratic Republic of Congo (DRC) has a significant burden of lymphatic filariasis (LF) caused by the parasite <it>Wuchereria bancrofti</it>. A major impediment to the expansion of the LF elimination programme is the risk of serious adverse events (SAEs) associated with the use of ivermectin in areas co-endemic for onchocerciasis and loiasis. It is important to analyse these and other factors, such as soil transmitted helminths (STH) and malaria co-endemicity, which will impact on LF elimination.</p> <p>Results</p> <p>We analysed maps of onchocerciasis community-directed treatment with ivermectin (CDTi) from the African Programme for Onchocerciasis Control (APOC); maps of predicted prevalence of <it>Loa loa</it>; planned STH control maps of albendazole (and mebendazole) from the Global Atlas of Helminth Infections (GAHI); and bed nets and insecticide treated nets (ITNs) distribution from Demographic and Health Surveys (DHS) as well as published historic data which were incorporated into overlay maps. We developed an approach we designate as micro-stratification overlap mapping (MOM) to identify areas that will assist the implementation of LF elimination in the DRC. The historic data on LF was found through an extensive review of the literature as no recently published information was available.</p> <p>Conclusions</p> <p>This paper identifies an approach that takes account of the various factors that will influence not only country strategies, but suggests that country plans will require a finer resolution mapping than usual, before implementation of LF activities can be efficiently deployed. This is because 1) distribution of ivermectin through APOC projects will already have had an impact of LF intensity and prevalence 2) DRC has been up scaling bed net distribution which will impact over time on transmission of <it>W. bancrofti </it>and 3) recently available predictive maps of <it>L. loa </it>allow higher risk areas to be identified, which allow LF implementation to be initiated with reduced risk where <it>L. loa </it>is considered non-endemic. We believe that using the proposed MOM approach is essential for planning the expanded distribution of drugs for LF programmes in countries co-endemic for filarial infections.</p

    An updated view of hypothalamic-vascular-pituitary unit function and plasticity

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    The discoveries of novel functional adaptations of the hypothalamus and anterior pituitary gland for physiological regulation have transformed our understanding of their interaction. The activity of a small proportion of hypothalamic neurons can control complex hormonal signalling, which is disconnected from a simple stimulus and the subsequent hormone secretion relationship and is dependent on physiological status. The interrelationship of the terminals of hypothalamic neurons and pituitary cells with the vasculature has an important role in determining the pattern of neurohormone exposure. Cells in the pituitary gland form networks with distinct organizational motifs that are related to the duration and pattern of output, and modifications of these networks occur in different physiological states, can persist after cessation of demand and result in enhanced function. Consequently, the hypothalamus and pituitary can no longer be considered as having a simple stratified relationship: with the vasculature they form a tripartite system, which must function in concert for appropriate hypothalamic regulation of physiological processes, such as reproduction. An improved understanding of the mechanisms underlying these regulatory features has implications for current and future therapies that correct defects in hypothalamic–pituitary axes. In addition, recapitulating proper network organization will be an important challenge for regenerative stem cell treatment

    Les conséquences de la marchandisation de l’arganier sur la vie socio-économique et culturelle à Haha

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    Arbre à usages multiples, l’arganier est aussi à multifonctions : économique, sociale et environnementale. Il était, et il est encore, un élément important du système agraire local et participe au maintien d’une biodiversité particulière. Comme il a toujours configuré et rythmé la vie des populations de l’arganeraie puisqu’il était (ou l’un de ses produits) toujours présent dans leurs activités culinaires, festives ou socioculturelles. Cependant, l’augmentation rapide du prix de l’huile d’argan a engendré de multiples conséquences sur la vie socioéconomique et culturelle de ces populations. En fait, la marchandisation de l’huile d’argan a eu à la fois des retombées positives et des effets négatifs sur tout l’écosystème. Pour comprendre et analyser ces évolutions et les nouvelles dynamiques locales qui s’y développent, nous avons réalisé une étude dans la zone de Haha, région d’Essaouira, en prenant comme cas les deux communes rurales d’Aguerd et de Tidzi. Ce qui nous a permis, en plus de l’analyse historique, de comparer les dynamiques qui sont en cours au niveau de ces deux communes rurales

    Saharan dust impacts on air quality: What are the potential health risks in West Africa?

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    Despite the proximity of the Sahara, very few studies about dust impact on air quality and human health have been conducted in West Africa. The lack of data is a major constraint on our understanding of the impacts on human health in this area. We analyzed PM10 concentrations and horizontal visibility recorded in four West African stations. The pollution levels often exceed the standards defined by many countries/regulatory authorities and have been associated with serious health risks outside Africa. Over the Sahelian stations, 45.6% of the days between November 2006 and March 2007 were likely to impact human health and the studied Sudanian population was exposed to potential health effects every 5 days
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