Showing papers by "University of Antananarivo published in 2000"
TL;DR: Seven species of Microcebus from western Madagascar are recognized, including a previously synonymized species, and 3 spp.
Abstract: The genus Microcebus (mouse lemurs) are the smallest extant primates. Until recently, they were considered to comprise two different species: Microcebus murinus, confined largely to dry forests on the western portion of Madagascar, and M. rufus, occurring in humid forest formations of eastern Madagascar. Specimens and recent field observations document rufous individuals in the west. However, the current taxonomy is entangled due to a lack of comparative material to quantify intrapopulation and intraspecific morphological variation. On the basis of recently collected specimens of Microcebus from 12 localities in portions of western Madagascar, from Ankarana in the north to Beza Mahafaly in the south, we present a revision using external, cranial, and dental characters. We recognize seven species of Microcebus from western Madagascar. We name and describe 3 spp., resurrect a previously synonymized species, and amend diagnoses for Microcebus murinus (J. F. Miller, 1777), M. myoxinus Peters, 1852, and M. ravelobensis Zimmermann et al., 1998.
195 citations
TL;DR: The results suggest that energy acquisition and storage are critically important in the life history strategies of female sifaka, and that "capital breeding" may be a feature of s ifaka reproductive strategies.
176 citations
TL;DR: In this paper, the authors examined the thermo-mechanical evolution of the lower crust, in Precambrian times, with an example from southern Madagascar, derived from the study of satellite images complemented by field structural analysis.
137 citations
TL;DR: A male newcomer killed the infant of a female whose male partner had left her recently, and both the social-pathology and the sexual-selection hypotheses may explain infanticidal behavior in Lepilemur edwardsi.
Abstract: During a long-term field study on the behavioral ecology and communication of a population of the monogamous Milne-Edwards' sportive lemur (Lepilemur edwardsi) in NW-Madagascar, we recorded for the first time an infanticide in a nocturnal lemur. A male newcomer killed the infant of a female whose male partner had left her recently. Both the social-pathology and the sexual-selection hypotheses may explain infanticidal behavior in Lepilemur edwardsi.
71 citations
TL;DR: The species richness found in the control site, the largest remaining block within the reserve, is comparable to other much more extensive forest blocks at parallel elevations and with similar botanical communities, so it seems that the lipotyphlan community within the controlSite has not experienced notable local extinctions.
Abstract: A small mammal survey of the Lipotyphla (Tenrecidae and Soricidae) was conducted in the montane forest of the Reserve Speciale d'Ambohitantely, Central High Plateau, Madagascar. Species richness of this group was assessed using standardized pit-fall trap techniques in a control site of 1250 ha and four smaller forest fragments (136, 30, 12 and 0.64 ha). The forests of this reserve are highly fragmented, isolated for many decades and about 90 km from the nearest large forest block. On the basis of pit-fall captures, lipotyphlan diversity was highest in the control site with nine species, including eight endemic taxa. The number of species declined progressively with diminishing forest size. The species richness found in the control site, the largest remaining block within the reserve, is comparable to other much more extensive forest blocks at parallel elevations and with similar botanical communities. Thus, it seems that the lipotyphlan community within the control site has not experienced notable local extinctions. The introduced Soricidae, Suncus murinus, has colonized the Ambohitantely forests. However, there is no evidence of competition between this species and members of the family Tenrecidae, particularly Microgale, as has been postulated in the literature.
65 citations
TL;DR: This paper presents a cladistic analysis of the deposits of Carboniferous strata of Madagascar dating back to the Bronze Age through to the Middle Ages, which shows clear signs of wear and tear over thousands of years.
Abstract: (2000). New Traversodontids (Synapsida: Eucynodontia) from the Triassic of Madagascar. Journal of Vertebrate Paleontology: Vol. 20, No. 3, pp. 422-427.
63 citations
TL;DR: The authors argue that Possessive Raising is a special case of a more general syntactic/semantic relation called Raising from NP, which violates some tenets of Relational Grammar and appears to be a new type of derivational relation within generative grammar.
Abstract: We begin this paper with a detailed study of Possessor Raising in Malagasy. Possessor Raising is shown to be exceptionally productive; moreover it largely conforms to the generalizations offered by Relational Grammar for Possessor Raising in general. But the incorporation it triggers is not of the same sort as studied in Baker (1996). Then we argue that Possessive Raising is a special case of a more general syntactic/semantic relation we call Raising from NP. This more general operation violates some tenets of Relational Grammar and appears to be a new type of derivational relation within generative grammar.
23 citations
TL;DR: Northern and south-western parts of the island are richer in genera, whereas eastern and especially northern part of the rainforest show higher species richness, due to extensive radiations within the genera Pogonostoma and Physodeutera.
Abstract: Distributional ranges of 17 genera and 172 species of Malagasy tiger beetles (Coleoptera, Cicindelidae) have been compiled to determine patterns of species richness and endemism. These patterns reveal large sampling gaps, and potential priority areas for conservation action. Northern and south-western parts of the island are richer in genera, whereas eastern and especially northern parts of the rainforest show higher species richness, due to extensive radiations within the genera Pogonostoma and Physodeutera. A set of 23 areas are identified in this study as priority foci for tiger beetle conservation, and six general regions are bioinventory priorities.
23 citations
TL;DR: Results indicate that taxonomic revision is not warranted under the expectations of the phylogenetic, coalescent, or biological species concepts, and the genetic patterns observed among the Andringitra and lowland mitochondrial haplotypes are consistent with those expected for a single species.
Abstract: A recent survey of the high-mountain zone of the Madagascar Parc National (PN) d'Andringitra revealed the presence of an apparently isolated troop of the ring-tailed lemur Lemur catta. These animals display phenotypic and ecological characteristics that are unusual for the monotypic genus Lemur, thus raising the possibility that they are members of a different undescribed species. We present analyses of two mitochondrial genes to test the hypothesis that L. catta from Andringitra should be considered a distinct species. The results indicate that taxonomic revision is not warranted under the expectations of the phylogenetic, coalescent, or biological species concepts. Rather, the genetic patterns observed among the Andringitra and lowland mitochondrial haplotypes are consistent with those expected for a single species.
15 citations
TL;DR: The stem bark of Astrotrichilia Voamatata (Meliaceae) has yielded the novel limonoids voamatins C and D, which represent a new type of pentanortriterpenoid and are unique in containing a ring A cyclic ether.
14 citations
TL;DR: In this paper, the essential oils of the leaves and fruit of P. viridiflorum growing in Madagascar were analyzed by GC and GC/MS. And the antimicrobial activity of the oils was also determined.
Abstract: Essential oils of leaf and fruit of Pittosporum viridiflorum var. viridiflorum growing in Madagascar were analyzed by GC and GC/MS. The leaf oil, which was sesquiterpene-rich, contained δ-cadinene (10.6%) and α-cadinol (18.3%) as major components. The fruit oil contained aliphatic as well as mono- and sesquiterpenoid compounds with sabinene (13.2%), decanal (10.3%) and β-elemene (9.5%) as major components. The antimicrobial activity of the oils was also determined.
TL;DR: A new species of Phelsuma malamakibo is described, which is a medium-sized, rock-dwelling species which occurs in primary rain forest at elevations between 810 m and 1940 m and is saxicolous in rain forest.
Abstract: Andohahela Reserve Naturelle Integrale is located in southeastern Madagascar. It consists of three parcels, the largest of which (Parcel 1, 63,100 ha), lying on the eastern flank of the Anosyenne Mountains between 90 and 1972 m elevation, is dominated by rain forest. We surveyed the herpetofauna of Parcel 1 at the beginning of the warm, rainy season between 20 October and 5 December 1995. We recorded 45 amphibian and 32 reptile species in Parcel 1, including a new species of Phelsuma, which we describe in this paper. This new species, Phelsuma malamakibo, is a medium-sized, rock-dwelling species which occurs in primary rain forest at elevations between 810 m and 1940 m. It is identified by the presence of a distinct dark lateral stripe on the neck and body with a white lateral stripe beneath it and a second, thin dark lateral stripe below the white stripe; greenish dorsal ground color with reddish brown spots arranged into three longitudinal rows or lines on the neck and back; no sexual dichromat...
TL;DR: The comparison of partial sequence of the mitochondrial cytochrome b gene nucleotides for different Indriidae allowed us to confirm the species status of Avahi laniger, A. occidentalis, and Propithecus tattersalli and propose a phylogenetic tree which is discussed taking into account morphological, cytogenetic and former molecular biology data.
Abstract: The comparison of partial sequence of the mitochondrial cytochrome b gene nucleotides for different Indriidae allowed us to confirm the species status ofAvahi laniger, A. occidentalis, and Propithecus tattersalli. The nucleotide sequence allowed also to propose a phylogenetic tree which is discussed taking into account morphological, cytogenetic and former molecular biology data.
01 Jan 2000
TL;DR: The two sites of the northwest of Madagascar where Ramanantsoa observed "sacred lemurs" have been revisited in order to assess the present status of Eulemur macaco and the possible impact of human beliefs and practices on conservation as mentioned in this paper.
Abstract: The two sites of the northwest of Madagascar, where Ramanantsoa (1976) observed “sacred lemurs”, have been revisited in order to assessing the present status of Eulemur macaco and the possible impact of human beliefs and practices on conservation. All the sacred relationships towards lemurs described in 1976 are still in practice, and very similar descriptions about the benefic (or malefic in case of non-respect) effect of the “sacred lemurs” have been quoted by our informants. A direct impact on lemur conservation, and utilisation of study sites for scientists, as suggested by G.-A. Ramanantsoa, do not appear as realistic options, considering the remote location of both sites. In contrast, a further study of religious practices concerning lemurs should be an important contribution for shaping sustainable development programmes involving local populations.
TL;DR: The present study was carried out in order to investigate by electrospray mass and tandem mass spectrometry and NMR spectroscopy the structure of two new metabolite isolated from rat urine and human liver microsomes and demonstrate the presence of twonew metabolites of malagashanine corresponding to a malagASHanine N-demethylated metabolite.
Abstract: Malagashanine has been isolated from indigenous madagasean Strychnos myrtoides alkaloids used traditionally to treat malaria, This alkaloid was found to enhance the action of chloroquine against chloroquine-resistant strains of Plasmodium falciparum when combined with classical antimalarial drugs (chloroquine, quinine), The present study was carried out in order to investigate by electrospray mass and tandem mass spectrometry and NMR spectroscopy the structure of two new metabolites isolated from rat urine and human liver microsomes, We were able to demonstrate the presence of two new metabolites of malagashanine corresponding to a malagashanine N-demethylated metabolite and to the oxidation of malagashanine in the alpha-position of the N-methyl group to produce a carbinolamine function. The latter metabolite may be subject to ring and open-chain tautomerism effects and dimeric species were detected in the electrospray mass spectrum. Copyright (C) 2000 John Wiley & Sons, Ltd.
TL;DR: A reversed-phase HPLC method was developed for quantitative analysis of malagashanine in rat plasma and urine and both intra- and inter-day accuracy and precision were within acceptable limits.
TL;DR: This work provides some values of average heterozygosity of wild populations of Otolemur garnettii, Eulemur macaco macaco and E. m.
Abstract: Scheffrahn et al. (1998a,b) aimed to outline the possible contributions of genetics to conservation biology: the determination of genetic variation of wild groups and its use as a guideline in breeding programs. Unfortunately, the amount of genetic variation within wild groups of nonhuman primates is rarely known. In particular, this observation holds for prosimians. Average heterozygosity is widely considered to be a good indicator of the magnitude of intraspecific variation. We provide some values of average heterozygosity of wild populations of Otolemur garnettii, Eulemur macaco macaco and E. m. flavifrons.
TL;DR: In this paper, the embedded-atom method (EAM) was used to perform molecular-dynamics simulations of iron films grown on Cu (111) where iron atoms were randomly deposited, one at a time, above the surface just within the force range of the nearest surface atom, and the growth mode was discussed by following the iron film coverage for an incident-atom energy ranged from 5eV to 15eV.
Abstract: We have used the embedded-atom method (EAM) to perform molecular-dynamics (MD) simulations of iron films grown on Cu (111) The iron atoms were randomly deposited, one at a time, above the surface just within the force range of the nearest surface atom The growth mode is discussed by following the iron film coverage for an incident-atom energy ranged from 05eV to 15eV A transition from island to layer by layer growth is observed as a function of incident energy The effect of deposition rate is also studied
TL;DR: The stem bark of Cedrelopsis grevei has yielded β-amyrin and two novel limonoid derivatives, the pentanortriterpenoid, cedmilinol, and the hexanortramer penoid, Cedmiline as mentioned in this paper.
Abstract: The stem bark of Cedrelopsis grevei has yielded β-amyrin and two novel limonoid derivatives, the pentanortriterpenoid, cedmilinol, and the hexanortriterpenoid, cedmiline. Structures were elucidated using NMR analysis and the “Logic for Structure Determination” program.