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.

Monazite from mountain to ocean: a case study from Trolognaro (Fort-Dauphin), Madagascar

Abstract: We report results for 18 samples of sediments containing detrital monazite, collected along the valley of the Ifaho River, near Trolognaro (Fort Dauphin), Madagascar. This valley, approximately 50 km long, connects the Manangotry Massif, which contains monazite-rich plutonic rocks with several very large monazite occurrences, in the Anosyan mountain belt, to the Indian Ocean where sands are unusually rich in heavy minerals, including monazite. Monazite grains were extracted from the sediments using chemical, gravitational, and magnetic separation techniques. Grains were studied for morphology, chemical composition, age, and structural state. From mountain to ocean, grains become smaller and more rounded. The chemical composition (more than 400 electron probe micro-analysis, EPMA) remains constant, and always highly radioactive. All ages (55 EPMA measurements) are Pan-African. X-ray diffraction shows that the monazite grains studied are well crystallized, despite the high self-irradiation doses they have experienced. In all aspects, except shape and size, detrital monazites are identical to monazites from the source region, and are transported essentially unchanged from mountain to ocean. This study demonstrates that monazite can survive the erosion-transport-deposition sequence, and supports the proposition to use this mineral as actinide waste-form for long-term storage of nuclear materials.

Insights into the Performance of SD Bioline Malaria Ag P.f/Pan Rapid Diagnostic Test and Plasmodium falciparum Histidine-Rich Protein 2 Gene Variation in Madagascar.

Abstract: Plasmodium falciparum histidine-rich protein 2 (PfHRP2) forms the basis of many current malaria rapid diagnostic tests (RDTs). However, the parasites lacking part or all of the pfhrp2 gene do not express the PfHRP2 protein and are, therefore, not identifiable by PfHRP2-detecting RDTs. We evaluated the performance of the SD Bioline Malaria Ag P.f/Pan RDT together with pfhrp2 variation in Madagascar. Genomic DNA isolated from 260 patient blood samples were polymerase chain reaction (PCR)-amplified for the parasite 18S rRNA and pfhrp2 genes. Post-PCR ligation detection reaction-fluorescent microsphere assay (LDR-FMA) was performed for the identification of parasite species. Plasmodium falciparum histidine-rich protein 2 amplicons were sequenced. Polymerase chain reaction diagnosis of patient samples showed that 29% (75/260) were infected and P. falciparum was present in 95% (71/75) of these PCR-positive samples. Comparing RDT and P. falciparum detection by LDR-FMA, eight samples were RDT negative but P. falciparum positive (false negatives), all of which were pfhrp2 positive. The sensitivity and specificity of the RDT were 87% and 90%, respectively. Seventy-three samples were amplified for pfhrp2, from which nine randomly selected amplicons were sequenced, yielding 13 sequences. Amplification of pfhrp2, combined with RDT analysis and P. falciparum detection by LDR-FMA, showed that there was no indication of pfhrp2 deletion. Sequence analysis of pfhrp2 showed that the correlation between pfhrp2 sequence structure and RDT detection rates was unclear. Although the observed absence of pfhrp2 deletion from the samples screened here is encouraging, continued monitoring of the efficacy of the SD Bioline Malaria Ag P.f/Pan RDT for malaria diagnosis in Madagascar is warranted.

Proteolysis of shrimp by-products (Peaneus monodon) from Madagascar Proteolisis de derivados de langostino (Peaneus monodon) de Madagascar

Abstract: To generate and recover elements from shrimp heads, proteolysis was performed with commercial acidic or alkaline proteases for 22 h. The resulting phases were characterized for protein and lipid content and amino acid composition while the molecular profiles of soluble peptides were established. Whatever the protease used, more than the half of the initial dry matter was found into aqueous phase including most of the proteins while lipids were found to remain insoluble. Hydrolysates were mainly constituted by small peptides (>80% below 1000 Da) with up to 14–15 amino acids identified. Moreover, all the hydrolyses have led to an increase of the amount of essential amino acids into the hydrolysates, including lysine. Thus, such proteolysis of shrimp heads can increase their potential nutritional value (small peptides with high content in essential amino acids) while allowing the concentration of lipids into insoluble phase and a partial demineralisation of the exoskeleton. Para crear y recuperar elementos d...