Showing papers by "University of Antananarivo published in 2001"
TL;DR: IsCT is one of the shortest natural cytotoxic peptides described, and it will be a suitable model for studying peptide-lipid interactions, and the identity of IsCT is re-confirmed by comparing the chemical synthesized peptide with the natural one.
103 citations
TL;DR: The Carion granitic pluton in central Madagascar was intruded into warm continental crust following orogenic events related to the final amalgamation of Gondwana as discussed by the authors, and it has an emplacement age of 532.1±5.2 Ma followed by relatively slow cooling.
60 citations
TL;DR: The stem bark CH2Cl2 extract of Ravensara crassifolia showed antifungal activity against the phytopathogenic fungus Cladosporium cucumerinum in a bioautographic TLC assay as discussed by the authors.
Abstract: The stem bark CH2Cl2 extract of Ravensara crassifolia showed antifungal activity against the phytopathogenic fungus Cladosporium cucumerinum in a bioautographic TLC assay. Activity-guided fractionation afforded two new alpha -pyrones : (6S)-5,6-dihydro-6-[(2R)-2-hydroxy-6-phenylhexyl]-2H-pyran-2-one (1) and (6R)-6-[(4R,6R)-4,6-dihydroxy-10-phenyldec-1-enyl]-5,6-dihydro-2H-pyran-2-one (2). Their structures and absolute configurations were established by NMR spectroscopy, chemical methods, and CD spectroscopy. The antifungal activity against C. cucumerinum was determined for both compounds.
43 citations
TL;DR: A recent collection in the Mahajanga Basin of northwestern Madagascar has expanded our knowledge of Late Cretaceous elasmobranchs from the island as discussed by the authors, which are consistent with late Maastrichtian assemblages from North Africa, the Middle East, and the USA.
34 citations
TL;DR: In this paper, the authors used a continuous argon-ion laser with no direct control on temperature to analyze the cooling history of the Carion pluton in central Madagascar, showing that the pluton cooled from 850° C at 532.1 ± 5.2 Ma to 3°C/Ma between 478 and 410 Ma.
29 citations
01 Jan 2001
TL;DR: In this article, a different q-analogue of Euler numbers using q-difference operator was introduced, and it was shown that their generating functions have simple continued fraction expansions.
Abstract: The ordinary generating functions of the secant and tangent numbers have very simple continued fraction expansions. However, the classical q-secant and q-tangent numbers do not give a natural q-analogue of these continued fractions. In this paper, we introduce a different q-analogue of Euler numbers using q-difference operator and show that their generating functions have simple continued fraction expansions. Furthermore, by establishing an explicit bijection between some Motzkin paths and (k,r)-multipermutations we derive combinatorial interpretations for these q-numbers. Finally the allied q-Euler median numbers are also studied.
27 citations
TL;DR: La repartition geographique and l'ecologie des especes sont analysees en fonction of l'altitude and of the distance de the source.
Abstract: Le genre Setodes est signale pour la premiere fois a Madagascar. Cinq especes nouvelles sont decrites. Les affinites de ce petit groupe relativement homogene sont asiatiques et l'hypothese d'une colonisation probable de la Grande Ile depuis l'Inde est discutee. La repartition geographique et l'ecologie des especes sont analysees en fonction de l'altitude et de la distance de la source.
9 citations
TL;DR: Field-distilled and laboratory distilled leaf oils of Vepris leandriana (Rutaceae) were analyzed by GC and GC/MS and it was found to possess greater antimicrobial activity than chloramphenicol.
Abstract: Field-distilled and laboratory distilled leaf oils of Vepris leandriana (Rutaceae) were analyzed by GC and GC/MS. The field-distilled oil was found to contain α-terpinene (9.0%), neral (19.5%), geranial (27.0%) and citronellol (33.6%), while the laboratory-distilled oil contained α-terpinene (4.7%), neral (21.8%), geranial (33.0%) and citronellol (33.2%). The field-distilled oil was examined for antimicrobial activity. It was found to possess greater antimicrobial activity than chloramphenicol.
8 citations
TL;DR: In this paper, the acetone extract of fresh leaves of Pittosporum viridiflorum viridisplantum was used to obtain new sesquiterpene glycosides, 4-O-β-D-glucopyranosylgermacra-1(10),5-diene and its 6′ −O-acetyl and 2 −O −acetyl derivatives, the structures of which were elucidated by NMR methods.
Abstract: The acetone extract of fresh leaves of Pittosporum viridiflorum viridiflorum afforded new sesquiterpene glycosides, 4-O-β-D-glucopyranosylgermacra-1(10),5-diene and its 6′-O-acetyl and 2′-O-acetyl derivatives, the structures of which were elucidated by NMR methods. Copyright © 2001 John Wiley & Sons, Ltd.
8 citations
TL;DR: Another blackleg agent, Clostridium septicum, was isolated, and its presence was reported in the country for the first time, and an experimental vaccine was developed from that strain in order to fill the lacking valence in the conventional product.
Abstract: Blackleg outbreaks have been reported at various locations in Vakinankaratra area (Madagascar) in 1996 and 1997, and caused the death of 588 head of cattle within seven months. Even animals that had been vaccinated between April and August 1996 were not spared from the disease. After performing bacteriological investigations on samples in March 1997, another blackleg agent, Clostridium septicum , was isolated, and its presence was reported in the country for the first time. The Institute for Applied Biotechnology in the Tropics of Goettingen (Germany) confirmed the diagnosis by the gas chromatography technique in May. An experimental vaccine was developed from that strain in order to fill the lacking valence in the conventional product. The isolation of C. septicum occurred 28 years after the first outbreaks of blackleg caused by Clostridium chauvoei . Its origin is briefly discussed.
4 citations