Mise en oeuvre mutuelle du Traité International sur les Ressources Phytogénétiques pour l’Alimentation et l’Agriculture et le Protocole de Nagoya sur l’accès aux ressources génétiques et au partage des avantages découlant de leur utilisation à Madagascar

Du point de vue de la biodiversité, Madagascar est classé parmi les pays mégadivers donc à fort taux d’endémisme, c’est à dire, biologiquement très riche. La biodiversité ou diversité biologique désigne la quantité et la diversité des espèces biologiques vivant sur notre planète. La diversité biologique est une ressource très importante pour l’adaptation aux changements climatiques, la sécurité alimentaire et la réduction de la pauvreté. Cette diversité biologique est confrontée à différentes pressions d’origine anthropique mais aussi d’origine environnementale dont les changements climatiques. Cela a pour effet, la disparition de certaines espèces, la diminution des rendements agricoles, la pression sur les écosystèmes, les espèces et les ressources génétiques, l’insécurité alimentaire, la pauvreté. Pour minimiser l’ampleur des pertes de la diversité dans la plupart des pays, la communauté internationale et les pays ont mis en place des instruments juridiques tels que les suivants : La Convention sur la Diversité biologique (CDB), entrée en vigueur en décembre 1993 et ratifiée par Madagascar en 1996, est le premier texte de droit international à reconnaître que la conservation de la biodiversité est une préoccupation commune pour l’ensemble de l’humanité. Sous cette Convention a été élaboré le Traité International sur les Ressources Phytogénétiques pour l’Alimentation et l’Agriculture (TIRPAA) et le Protocole de Nagoya sur l’Accès aux ressources génétiques et au Partage des Avantages découlant de leur utilisation (PN/APA)

Pleiotropic effects of statins in distal human pulmonary artery smooth muscle cells

<p>Abstract</p> <p>Background</p> <p>Recent clinical data suggest statins have transient but significant effects in patients with pulmonary arterial hypertension. In this study we explored the molecular effects of statins on distal human pulmonary artery smooth muscle cells (PASMCs) and their relevance to proliferation and apoptosis in pulmonary arterial hypertension.</p> <p>Methods</p> <p>Primary distal human PASMCs from patients and controls were treated with lipophilic (simvastatin, atorvastatin, mevastatin and fluvastatin), lipophobic (pravastatin) and nitric-oxide releasing statins and studied in terms of their DNA synthesis, proliferation, apoptosis, matrix metalloproteinase-9 and endothelin-1 release.</p> <p>Results</p> <p>Treatment of human PASMCs with selected statins inhibited DNA synthesis, proliferation and matrix metalloproteinase-9 production in a concentration-dependent manner. Statins differed in their effectiveness, the rank order of anti-mitogenic potency being simvastatin > atorvastatin > > pravastatin. Nevertheless, a novel nitric oxide-releasing derivative of pravastatin (NCX 6550) was effective. Lipophilic statins, such as simvastatin, also enhanced the anti-proliferative effects of iloprost and sildenafil, promoted apoptosis and inhibited the release of the mitogen and survival factor endothelin-1. These effects were reversed by mevalonate and the isoprenoid intermediate geranylgeranylpyrophosphate and were mimicked by inhibitors of the Rho and Rho-kinase.</p> <p>Conclusions</p> <p>Lipophilic statins exert direct effects on distal human PASMCs and are likely to involve inhibition of Rho GTPase signalling. These findings compliment some of the recently documented effects in patients with pulmonary arterial hypertension.</p

Les bois de Tapia de Madagascar: approches phytogéographique, floristique et écologique

Ce chapitre a trois objectifs. En premier lieu, il rappelle que les formations végétales à dominance de tapia sont distribuées en quatre ensembles sur les « Hautes Terres malgaches ». En second lieu, à partir d’un examen global de la littérature et de relevés floristiques effectués dans deux des entités, à savoir Arivonimamo et Ambatofinandrahana, il dresse une liste actualisée de la diversité floristique des bois de tapia. Celle-ci est partiellement illustrée par un support photographique et des planches sur un CD-ROM qui reprend également les noms vernaculaires des taxons considérés. Enfin une approche écologique préliminaire est effectuée sur base des groupements végétaux et/ou des niches écologiques de certains taxons inventoriés.This chapter has three objectives. Firstly, it is emphasized that tapia-dominated areas are spatially distributed into four localities situated on the so-called “Highlands”. Secondly, based on a global survey of available literature on tapia vegetation as well as on floristic surveys carried out in two entities (Arivonimamo et Ambatofinandrahana), an actualized list of their floristic diversity is composed. This list is partially illustrated with photographs and plates on a CD-ROM; vernacular names of the considered taxa are quoted. Finally a preliminary ecological interpretation is given based on the vegetation units and (or) ecological niches which are schematically represented

Modification of Anopheles gambiae distribution at high altitudes in Madagascar

In Madagascar, Anopheles gambiae has been found below altitudes of 1,000 m. We sampled An. gambiae sensu lato (sl) between 2008 and 2010 in the Central Highlands of Madagascar at altitudes over 1,200 m. The study site consists of rainforest, rainforest edge, and an open savanna biotope. Anopheles gambiae and An. arabiensis, as well as molecular forms of An. gambiae, were identified molecularly. An. gambiae accounted for 26.7% at the edge of the rainforest and 2.3% in the open savanna biotope. One specimen of this species was caught in the forest. An. arabiensis accounted for 66.3% at the edge of the rainforest and 97.7 % in the open savanna biotope. All An. gambiae adults tested belonged to the S molecular form. An. gambiae is present at high altitudes in Madagascar, with a high prevalence at the rainforest edge. Several factors, including the appearance of new favorable biotopes, recolonization after a reduction of indoor vector control, and climate change, may contribute to its distribution. The changing distribution of An. gambiae may have consequences for the distribution and incidence of malaria in the Malagasy Highlands

Biology of mosquitoes that are potential vectors of rift valley fever virus in different biotopes of the central highlands of Madagascar

There were epidemic-epizootics of Rift Valley Fever (RVF) affecting humans and cattle in Madagascar in the district of Anjozorobe in 2008. Little is known about the role of Malagasy mosquitoes in the circulation of RVF virus. Therefore, we investigated the species diversity, dynamics and biology of potential RVF virus vectors in the rainforest, rainforest edge (village of Anorana), and savanna biotope (village of Antanifotsy) of this district between November 2008 and July 2010. We captured 56,605 adults of 35 different species. Anopheles squamosus (Theobald), Anopheles coustani (Laveran), Culex antennatus (Becker), Culex pipiens (L.), and Culex univittatus (Theobald) were the most abundant during the rainy season with Cx. pipiens the most abundant species in the rainforest (47%), and An. squamosus the most abundant species in the rainforest edge and in the savanna biotope (56%, 60%, respectively). Only Cx. univittatus was abundant in the dry season. The parous rate was > 60% throughout the rainy season for An. squamosus and it was > 50% from the middle to the end of the rainy season for Cx. pipiens. Two additional species have been found only at larval stage. Cattle were the most attractive bait for all species, followed by sheep and poultry. Human was the least attractive for all species. Most of the 163 bloodmeals tested were taken from cattle. Three were from poultry, one was from dog and one was a mixed bloodmeal taken from sheep and cattle. These results on vectorial capacity parameters may allow considering the involvement of mosquito transmission of the virus in the district of Anjozorobe during the recent epidemic-epizootic