Showing papers by "University of Antananarivo published in 1991"

Demography of Propithecus verreauxi at Beza Mahafaly, Madagascar : sex ratio, survival, and fertility, 1984-1988

Abstract: Eighty-five sifakas (Propithecus uerreauxi) have been cap- tured, marked, released, and monitored between September 1984 and August 1988 at the Beza Mahafaly Special Reserve in southwest Madagascar. Esti- mates are presented of the age and sex structure of this population and of age-specific fertility and survival. Using data from this and other studies, it is shown that sifaka tertiary sex ratios do not depart significantly from 5050, but that they do differ significantly from those of haplorhine primates, which have strongly female-biased tertiary sex ratios. Two demographic mechanisms that could give rise to this distinction are considered: 1) intermittently male-biased birth cohorts among sifakas and 2) different patterns of survivor- ship in haplorhines and sifakas.

Crassulacean acid metabolism in Kalanchoë species collected in various climatic zones of Madagascar : a survey by δ13C analysis

Abstract: The carbon isotope compositions of samples of Kalanchoe species collected at the natural stands in Madagascar were determined. The results suggest that all species of the genus Kalanchoe are capable of crassulacean acid metabolism. The observed δ13C values cover the whole range from −10 to −30‰. This high diversity of the δ13C values was found among the species of the genus as well as, in certain cases, within a single species. This suggest that the CAM patterns in Kalanchoe are generally very flexible. The δ13C values show a clear correlation with the climate of the habitats from where the samples derived. Values indicative of CO2 fixation taking place exclusively during the night were found in the dry regions of Madagascar, whereas δ13C values indicative of mixed CO2 fixation during night and day or of CO2 fixation entirely during the day are distributed in the humid zones.

Plasmodium falciparum malaria transmission indices in a highland village of the Ikopa River Valley near Antananarivo, Madagascar.

Abstract: Data are reported from a malaria survey carried out in June 1991 in the small village of Ankadimbazinba, near Miantso, about 45 km North-West of Antananarivo (Madagascar). The objective was to evaluate the level of transmission of P. falciparum by entomological, parasitological and serological indices. All indices were found consistent with the description of a focus of hyperendemic transmission dependent on the presence of An. funestus at high density, corresponding to more than 50 females per house collected by hand catch. The positivity rate for the circumsporozoite protein (CS) of P. falciparum in blood-fed or gravid An. funestus was 2.0% (11/562) in the house resting sample. The parasite rate in the village population was 47.9% reaching 68.4% in the 0-14 age group and the gametocyte rate in the total sample was 25.0%. The seroprevalence of P. falciparum antisporozoite antibodies was 40.0% in children under 15 years old, 84.2% in the 15-29 age group and 90.9% in the over 29 age group.

Voix et Diathèse en Malgache

Abstract: La voix designe une categorie morphologique par opposition a la diathese qui designe une categorie semantique. On a affaire, d'un cote, a la structure formelle du verbe, qui peut etre actif, passif ou relatif selon le type d'affixe en presence; de l'autre, a l'orientation semantique du proces du verbe, qui peut etre transitif, intransitif, passif, instrumental, destinataire, datif, locatif, de moyen ou circonstanciel, selon le type d'argument focalise en sujet grammatical.