University of Antananarivo

About: University of Antananarivo is a education organization based out in Antananarivo, Madagascar. It is known for research contribution in the topics: Population & Lemur. The organization has 1561 authors who have published 1703 publications receiving 30922 citations. The organization is also known as: Tananarive University & Antananarivo University.

A multidisciplinary approach to assessing the sustainability of freshwater crayfish harvesting in Madagascar.

Abstract: : There is growing interest among conservation decision makers in promoting harvesting of forest products as an incentive for communities to retain forest cover. Assessments of the sustainability of existing harvests are essential for implementing such policies. Madagascar's endemic freshwater crayfish, Astacoides spp., are harvested throughout their range. Despite their importance to human communities, Madagascar's crayfish, like much of the island's freshwater biodiversity, are poorly known, and there is concern that the harvest may be unsustainable. We investigated sustainability of the crayfish harvest in and around Ranomafana National Park in eastern Madagascar, focusing on the heavily harvested A. granulimanus. Several villages around the park have traditional taboos against selling crayfish, resulting in widely varying levels of crayfish exploitation. We used two approaches to assess sustainability of the harvest. First we used participatory mapping combined with a geographic information system analysis to produce a spatially accurate map of harvesting intensity. We then carried out mark-and-recapture sampling at 74 sites across a range of harvest intensities to test whether the level of harvesting was a significant predictor of crayfish density and structure. Second, we used size-structured matrix population models to estimate the forest area necessary to provide the observed annual harvest from one harvesting village and compared this estimate with the area available to the harvesters. Our findings show that the crayfish harvest in Ranomafana may be sustainable under current socioeconomic conditions, suggesting that A. granulimanus is less vulnerable to overexploitation than previously thought. We emphasize the importance of a multidisciplinary approach to assessing sustainability involving both ecological information about the harvested species and socioeconomic data about the level and spatial pattern of the harvest. Resumen: Entre los tomadores de decisiones de conservacion hay un creciente interes por promover la cosecha de productos forestales como un incentivo para que las comunidades mantengan la cobertura forestal. La realizacion de evaluaciones de la sustentabilidad de las cosechas es esencial para la implementacion de tales politicas. Los cangrejos de rio endemicos de Madagascar, Astacoides spp., son cosechados en toda su area de distribucion. A pesar de su importancia para las comunidades humanas, los cangrejos de rio de Madagascar, como mucha de la biodiversidad dulceacuicola de la isla, son poco conocidos, y existe la preocupacion de que su captura puede ser no sustentable. Investigamos la sustentabilidad de la captura de cangrejos de rio en y alrededor del Parque Nacional Ranomafana en el este de Madagascar, con mayor atencion en A. granulimanus que es capturada intensamente. Varias aldeas alrededor del parque tienen tabues tradicionales contra la venta de cangrejos de rio, lo que resulta en niveles muy variados de explotacion de cangrejos de rio. Utilizamos dos metodos para evaluar la sustentabilidad de la captura. Primero utilizamos mapeo participativo combinado con un analisis de sistema de informacion geografica para producir un mapa espacialmente preciso de la intensidad de captura. Luego realizamos muestreos de marcaje y recaptura en 74 sitios a lo largo de un gradiente de intensidades de captura para probar si el nivel de captura era un pronosticador significativo de la densidad y estructura de los cangrejos de rio. El segundo metodo fue la utilizacion de modelos poblacionales con una matriz estructurada por tamanos para estimar la superficie forestal necesaria para proporcionar la captura anual observada en una aldea y comparamos esta estimacion con el area disponible para los cosechadores. Nuestros hallazgos muestran que la captura de cangrejos de rio en Ranomafana puede ser sustentable bajo las condiciones socioeconomicas actuales, y sugieren que A. granulimanus es menos vulnerable a la sobreexplotacion que lo que se pensaba anteriormente. Enfatizamos la importancia de un metodo multidisciplinario para evaluar la sustentabilidad que involucre tanto informacion ecologica de la especie capturada como datos socioeconomicos sobre el nivel y patron espacial de la captura.

Pollination ecology of the dioecious tree Commiphora guillauminii in Madagascar

Abstract: In dioecious plant species differences in morphology and resources between female and male flowers can have consequences for flower visitation rates. Female flowers sometimes lack pollen and can be less attractive to pollinators than male flowers. We studied the pollination ecology of the dioecious tree Commiphora guillauminii in a dry deciduous forest in western Madagascar. We recorded floral display, visiting insect species and visitation rates for female and male trees. The results showed that female trees produce significantly larger but fewer flowers per inflorescence than male ones. Number of flowers per tree did not differ between the sexes. During 270 observation-hours we observed 17 insect and two bird species visiting the flowers. Mean visitation rates of male flowers were 6.1 times higher than those of female flowers (1.07 vs. 0.18 visitors per flower h -1 ). Visitation rates to female and male trees showed similar daily and seasonal patterns. Fruit set (2.9%) was low. which could have been caused by pollinator or pollen limitation. This study suggests that dioecy may pose a risk for fruit set and, potentially, reproductive success for plant species with depauperate pollinator faunas on islands such as Madagascar.

Defining the next generation of Plasmodium vivax diagnostic tests for control and elimination: Target product profiles

Abstract: The global prevalence of malaria has decreased over the past fifteen years, but similar gains have not been realized against Plasmodium vivax because this species is less responsive to conventional malaria control interventions aimed principally at P. falciparum. Approximately half of all malaria cases outside of Africa are caused by P. vivax. This species places dormant forms in human liver that cause repeated clinical attacks without involving another mosquito bite. The diagnosis of acute patent P. vivax malaria relies primarily on light microscopy. Specific rapid diagnostic tests exist but typically perform relatively poorly compared to those for P. falciparum. Better diagnostic tests are needed for P. vivax. To guide their development, FIND, in collaboration with P. vivax experts, identified the specific diagnostic needs associated with this species and defined a series of three distinct target product profiles, each aimed at a particular diagnostic application: (i) point-of-care of acutely ill patients for clinical care purposes; (ii) point-of-care asymptomatic and otherwise sub-patent residents for public health purposes, e.g., mass screen and treat campaigns; and (iii) ultra-sensitive not point-of-care diagnosis for epidemiological research/surveillance purposes. This report presents and discusses the rationale for these P. vivax-specific diagnostic target product profiles. These contribute to the rational development of fit-for-purpose diagnostic tests suitable for the clinical management, control and elimination of P. vivax malaria.

Geographic and Phylogeographic Variation in Chaerephon leucogaster (Chiroptera: Molossidae) of Madagascar and the Western Indian Ocean Islands of Mayotte and Pemba

Abstract: We examine patterns of morphological and genetic variation in Chaerephon leucogaster (family Molossidae) on Madagascar, Mayotte in the Comoros Archipelago, and the offshore Tanzanian island of Pemba. Five external, 10 cranial, and eight dental measurements of animals from different Malagasy populations (grouped according to bioclimatic regions) show differences in the degree of sexual dimorphism and size variation. Further, the population on Mayotte is largely identical in size to those from western Madagascar, and animals from Pemba are notably larger than those from Madagascar and Mayotte. Cytochrome b genetic distances across samples from these islands were low (maximum 0.0035) and animals from Pemba and Mayotte shared cytochrome b haplotypes with Malagasy bats. D-loop data showed some concordance between haplotype distribution, geographical position (latitude and island), and the bioclimatic zones. Animals from Pemba and Mayotte formed a unique D-loop haplotype, which was a minimum of six mutational steps different from Malagasy haplotypes. Within Madagascar, certain haplotypes were exclusive to the north (13°S latitude band) and arid southwest (22° and 23°S latitudes) regions. In general, there was no clear concordance between variation in haplotype distribution, latitude, altitude or gender. Where concordance occurred, the genetic distances involved were not sufficiently high to warrant the definition of new taxonomic units. Hence, based on current genetic information, patterns of morphological variation of the Madagascar populations and differences between Pemba and Mayotte/Madagascar are best explained as inter-population variation and may be adaptive, associated with different climatic regimes and associated ecological variables.