Differential responses of amphibians and reptiles to land-use change in the biodiversity hotspot of north-eastern Madagascar

Large expanses of tropical rainforest have been converted into agricultural land- scapes cultivated by smallholder farmers. This is also the case in north-eastern Madagascar; a region that retains significant proportions of forest cover despite slash-and-burn shifting hill rice cultivation and vanilla agroforestry expansion. The region is also a global hotspot for herpetofauna diversity, but how amphibians and reptiles are affected by land-use change remains largely unknown. Using a space- for-time study design, we compared species diversity and community composition across seven prevalent land uses: unburned (old-growth forest, forest fragment, and forest-derived vanilla agroforest) and burned (fallow-derived vanilla agroforest, woody fallow, and herbaceous fallow) land-use types, and rice paddy. We con- ducted six comprehensive, time-standardized searches across at least 10 replicates per land-use type and applied genetic barcoding to confirm species identification. We documented an exceptional diversity of herpetofauna (119 species; 91% endemic). Observed plot-level amphibian species richness was significantly higher in old-growth forest than in all other land-use types. Plot-level reptile species rich- ness was significantly higher in unburned land-use types compared with burned land-use types. For both amphibians and reptiles, the less-disturbed land-use types showed more uneven communities and the species composition in old-growth for- est differed significantly from all other land-use types. Amphibians had higher for- est dependency (38% of species occurred exclusively in old-growth forest) than reptiles (26%). Our analyses thus revealed that the two groups respond differently to land-use change: we found less pronounced losses of reptile species richness especially in unburned agricultural habitats, suggesting that reptiles are less suscep- tible to land-use change than amphibians, possibly due to their ability to cope with hotter and drier microclimates. In conclusion, our findings emphasize existing con- servation opportunities – especially for reptiles – in extensive agricultural land- scapes while highlighting the precarious situation of amphibians in disappearing old-growth forest

Longitudinal survey of malaria morbidity over 10 years in Saharevo (Madagascar): further lessons for strengthening malaria control

<p>Abstract</p> <p>Background</p> <p>Madagascar has been known for having bio-geo-ecological diversity which is reflected by a complex malaria epidemiology ranging from hyperendemic to malaria-free areas. Malaria-related attacks and infection are frequently recorded both in children and adults living in areas of low malaria transmission. To integrate this variability in the national malaria control policy, extensive epidemiological studies are required to up-date previous records and adjust strategies.</p> <p>Methods</p> <p>A longitudinal malaria survey was conducted from July 1996 to June 2005 among an average cohort of 214 villagers in Saharevo, located at 900 m above the sea. Saharevo is a typical eastern foothill site at the junction between a costal wet tropical area (equatorial malaria pattern) and a drier high-altitude area (low malaria transmission).</p> <p>Results</p> <p>Passive and active malaria detection revealed that malaria transmission in Saharevo follows an abrupt seasonal variation. Interestingly, malaria was confirmed in 45% (1,271/2,794) of malaria-presumed fevers seen at the health centre. All four <it>Plasmodia </it>that infect humans were also found: <it>Plasmodium falciparum</it>; <it>Plasmodium vivax</it>, <it>Plasmodium malariae </it>and <it>Plasmodium ovale</it>. Half of the malaria-presumed fevers could be confirmed over the season with the highest malaria transmission level, although less than a quarter in lower transmission time, highlighting the importance of diagnosis prior to treatment intake. <it>P. falciparum </it>malaria has been predominant (98%). The high prevalence of <it>P. falciparum </it>malaria affects more particularly under 10 years old children in both symptomatic and asymptomatic contexts. Children between two and four years of age experienced an average of 2.6 malaria attacks with <it>P. falciparum </it>per annum. Moreover, estimated incidence of <it>P. falciparum </it>malaria tends to show that half of the attacks (15 attacks) risk to occur during the first 10 years of life for a 60-year-old adult who would have experienced 32 malaria attacks.</p> <p>Conclusion</p> <p>The incidence of malaria decreased slightly with age but remained important among children and adults in Saharevo. These results support that a premunition against malaria is slowly acquired until adolescence. However, this claims for a weak premunition among villagers in Saharevo and by extension in the whole eastern foothill area of Madagascar. While the Malagasy government turns towards malaria elimination plans nowadays, choices and expectations to up-date and adapt malaria control strategies in the foothill areas are discussed in this paper.</p

Assessment of the efficacy of antimalarial drugs recommended by the National Malaria Control Programme in Madagascar: Up-dated baseline data from randomized and multi-site clinical trials

<p>Abstract</p> <p>Background</p> <p>In order to improve the monitoring of the antimalarial drug resistance in Madagascar, a new national network based on eight sentinel sites was set up. In 2006/2007, a multi-site randomized clinical trial was designed to assess the therapeutic efficacy of chloroquine (CQ), sulphadoxine-pyrimethamine (SP), amodiaquine (AQ) and artesunate plus amodiaquine combination (ASAQ), the antimalarial therapies recommended by the National Malaria Control Programme (NMCP).</p> <p>Methods</p> <p>Children between six months and 15 years of age, with uncomplicated falciparum malaria, were enrolled. Primary endpoints were the day-14 and day-28 risks of parasitological failure, either unadjusted or adjusted by genotyping. Risks of clinical and parasitological treatment failure after adjustment by genotyping were estimated using Kaplan-Meier survival analysis. Secondary outcomes included fever clearance, parasite clearance, change in haemoglobin levels between Day 0 and the last day of follow-up, and the incidence of adverse events.</p> <p>Results</p> <p>A total of 1,347 of 1,434 patients (93.9%) completed treatment and follow-up to day 28. All treatment regimens, except for the chloroquine (CQ) treatment group, resulted in clinical cure rates above 97.6% by day-14 and 96.7% by day-28 (adjusted by genotyping). Parasite and fever clearance was more rapid with artesunate plus amodiaquine, but the extent of haematological recovery on day-28 did not differ significantly between the four groups. No severe side-effects were observed during the follow-up period.</p> <p>Conclusion</p> <p>These findings (i) constitute an up-dated baseline data on the efficacy of antimalarial drugs recommended by the NMCP, (ii) show that antimalarial drug resistance remains low in Madagascar, except for CQ, compared to the bordering countries in the Indian Ocean region such as the Comoros Archipelago and (iii) support the current policy of ASAQ as the first-line treatment in uncomplicated falciparum malaria.</p

Win-win opportunities combining high yields with high multi-taxa biodiversity in tropical agroforestry

Resolving ecological-economic trade-offs between biodiversity and yields is a key challenge when addressing the biodiversity crisis in tropical agricultural landscapes. Here, we focused on the relation between seven different taxa (trees, herbaceous plants, birds, amphibians, reptiles, butterflies, and ants) and yields in vanilla agroforests in Madagascar. Agroforests established in forests supported overall 23% fewer species and 47% fewer endemic species than old-growth forests, and 14% fewer endemic species than forest fragments. In contrast, agroforests established on fallows had overall 12% more species and 38% more endemic species than fallows. While yields increased with vanilla vine density and length, non-yield related variables largely determined biodiversity. Nonetheless, trade-offs existed between yields and butterflies as well as reptiles. Vanilla yields were generally unrelated to richness of trees, herbaceous plants, birds, amphibians, reptiles, and ants, opening up possibilities for conservation outside of protected areas and restoring degraded land to benefit farmers and biodiversity alike

Relevance of CFD in the development of separation processes

International audienc

Use of synchronised PIV to measure a pulsed flow velocity field in a discs and doughnuts column

The study presented here deals with the pulsed flow in a discs and doughnuts column. We aim for the understanding of the hydrodynamic properties of the one-phase flow. We experimentaly investigate the pulsation intensity effects on flow structure. Velocity fields from the PIV process reveal that the use of pulsation intensity (Amplitude x Frequency) can only be limited to qualitative analysis. No obvious tendency of the flow structure and intensity could be linked to it. Moreover, an unexpected eddy stemming from the lack of centenring of the packings appeared in the measured velocity fields, highlighting the asymmetry of the flow

Study of irradiated and non-irradiated MOX fuel reprocessing

International audienceAn important RandD program on reprocessing of MOX nuclear fuels is on-going at the French Alternative Energies and Atomic Energy Commission. This program covers both experiments on real nuclear fuels with different characteristics and modelling developments. It is lead in support of Orano's industrial project of a future polyvalent dissolution unit at La Hague facility called TCP (French acronym for specific fuel treatment) workshop [1].Plutonium-rich fuels being hard to dissolve, a specific dissolution process has been designed for the TCP unit. In the UOX standard reprocessing flowsheet, the sheared nuclear fuel is dissolved in a nitric acid solution. In the case of MOx fuel, hulls and undissolved particles possibly obtained after this dissolution step still contain significant quantities of plutonium which have to be recovered. That's why a complementary oxidizing dissolution step is added by using silver ion. In the presence of silver ions, the plutonium dissolution is enhanced by the modification of its oxidation state from IV to VI. This promising process is studied in order to optimize the operating parameters, with analysis performed on both liquid and solid phases. The process gas treatment is also investigated in particular regarding the release of gaseous ruthenium. The RandD program aims to validate the efficiency of the TCP dissolution process on different kinds of MOX fuels sodium fast reactor (SFR) fuels and light water reactor fuels (LWR) of different Pu contents, burnups, claddings and manufacturing methods. All the experiments are performed at laboratory scale in the Atalante facility

Win-win opportunities combining high yields with high multi-taxa biodiversity in tropical agroforestry

This repository includes data from the synthesis "Win-win opportunities combining high yields with high multi-taxa biodiversity in tropical agroforestry" from the interdisciplinary Diversity Turn in Land Use Project (German-Malagasy research project). Data assessed: 2017 and 2018 Location: SAVA region (north-eastern Madagascar). Studied land-use types: Old growth forest, Forest fragment, Fallows (Woody fallow; Herbaceous fallow), Forest-derived vanilla agroforest, Fallow-derived vanilla agroforest. Resolving ecological-economic trade-offs between biodiversity and yields is a key challenge when addressing the biodiversity crisis in tropical agricultural landscapes. Here, we focused on the relation between seven different taxa (trees, herbaceous plants, birds, amphibians, reptiles, butterflies, and ants) and yields in vanilla agroforests in Madagascar. Agroforests established in forests supported overall 23% fewer species and 47% fewer endemic species than old-growth forests, and 14% fewer endemic species than forest fragments. In contrast, agroforests established on fallows had overall 12% more species and 38% more endemic species than fallows. While yields increased with vanilla vine density and length, non-yield related variables largely determined biodiversity. Nonetheless, trade-offs existed between yields and butterflies as well as reptiles. Vanilla yields were generally unrelated to richness of trees, herbaceous plants, birds, amphibians, reptiles, and ants, opening up possibilities for conservation outside of protected areas and restoring degraded land to benefit farmers and biodiversity alike