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Sample records for madagascar periwinkle model

  1. Candidatus Phytoplasma malaysianum, a novel taxon associated with virescence and phyllody of Madagascar periwinkle (Catharanthus roseus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study addressed the taxonomic position and group classification of a phytoplasma responsible for virescence and phyllody symptoms in naturally diseased Madagascar periwinkle plants in western Malaysia. Unique regions in the 16S rRNA gene from the Malaysian periwinkle virescence (MaPV) phytopla...

  2. 'Candidatus Phytoplasma malaysianum', a novel taxon associated with virescence and phyllody of Madagascar periwinkle (Catharanthus roseus).

    PubMed

    Nejat, Naghmeh; Vadamalai, Ganesan; Davis, Robert E; Harrison, Nigel A; Sijam, Kamaruzaman; Dickinson, Matthew; Abdullah, Siti Nor Akmar; Zhao, Yan

    2013-02-01

    This study addressed the taxonomic position and group classification of a phytoplasma responsible for virescence and phyllody symptoms in naturally diseased Madagascar periwinkle plants in western Malaysia. Unique regions in the 16S rRNA gene from the Malaysian periwinkle virescence (MaPV) phytoplasma distinguished the phytoplasma from all previously described 'Candidatus Phytoplasma' species. Pairwise sequence similarity scores, calculated through alignment of full-length 16S rRNA gene sequences, revealed that the MaPV phytoplasma 16S rRNA gene shared 96.5 % or less sequence similarity with that of previously described 'Ca. Phytoplasma' species, justifying the recognition of the MaPV phytoplasma as a reference strain of a novel taxon, 'Candidatus Phytoplasma malaysianum'. The 16S rRNA gene F2nR2 fragment from the MaPV phytoplasma exhibited a distinct restriction fragment length polymorphism (RFLP) profile and the pattern similarity coefficient values were lower than 0.85 with representative phytoplasmas classified in any of the 31 previously delineated 16Sr groups; therefore, the MaPV phytoplasma was designated a member of a new 16Sr group, 16SrXXXII. Phytoplasmas affiliated with this novel taxon and the new group included diverse strains infecting periwinkle, coconut palm and oil palm in Malaysia. Three phytoplasmas were characterized as representatives of three distinct subgroups, 16SrXXXII-A, 16SrXXXII-B and 16SrXXXII-C, respectively. PMID:22523165

  3. Expression Patterns of Genes Involved in the Defense and Stress Response of Spiroplasma citri Infected Madagascar Periwinkle Catharanthus roseus

    PubMed Central

    Nejat, Naghmeh; Vadamalai, Ganesan; Dickinson, Matthew

    2012-01-01

    Madagascar periwinkle is an ornamental and a medicinal plant, and is also an indicator plant that is highly susceptible to phytoplasma and spiroplasma infections from different crops. Periwinkle lethal yellows, caused by Spiroplasma citri, is one of the most devastating diseases of periwinkle. The response of plants to S. citri infection is very little known at the transcriptome level. In this study, quantitative real-time PCR (RT-qPCR) was used to investigate the expression levels of four selected genes involved in defense and stress responses in naturally and experimentally Spiroplasma citri infected periwinkles. Strictosidine β-glucosidase involved in terpenoid indole alkaloids (TIAs) biosynthesis pathway showed significant upregulation in experimentally and naturally infected periwinkles. The transcript level of extensin increased in leaves of periwinkles experimentally infected by S. citri in comparison to healthy ones. A similar level of heat shock protein 90 and metallothionein expression was observed in healthy, naturally and experimentally spiroplasma-diseased periwinkles. Overexpression of Strictosidine β-glucosidase demonstrates the potential utility of this gene as a host biomarker to increase the fidelity of S. citri detection and can also be used in breeding programs to develop stable disease-resistance varieties. PMID:22408455

  4. Ornamental exterior versus therapeutic interior of Madagascar periwinkle (Catharanthus roseus): the two faces of a versatile herb.

    PubMed

    Nejat, Naghmeh; Valdiani, Alireza; Cahill, David; Tan, Yee-How; Maziah, Mahmood; Abiri, Rambod

    2015-01-01

    Catharanthus roseus (L.) known as Madagascar periwinkle (MP) is a legendary medicinal plant mostly because of possessing two invaluable antitumor terpenoid indole alkaloids (TIAs), vincristine and vinblastine. The plant has also high aesthetic value as an evergreen ornamental that yields prolific blooms of splendid colors. The plant possesses yet another unique characteristic as an amiable experimental host for the maintenance of the smallest bacteria found on earth, the phytoplasmas and spiroplasmas, and serves as a model for their study. Botanical information with respect to synonyms, vernacular names, cultivars, floral morphology, and reproduction adds to understanding of the plant while the geography and ecology of periwinkle illustrate the organism's ubiquity. Good agronomic practices ensure generous propagation of healthy plants that serve as a source of bioactive compounds and multitudinous horticultural applications. The correlation between genetic diversity, variants, and TIA production exists. MP is afflicted with a whole range of diseases that have to be properly managed. The ethnobotanical significance of MP is exemplified by its international usage as a traditional remedy for abundant ailments and not only for cancer. TIAs are present only in micro quantities in the plant and are highly poisonous per se rendering a challenge for researchers to increase yield and reduce toxicity. PMID:25667940

  5. Ornamental Exterior versus Therapeutic Interior of Madagascar Periwinkle (Catharanthus roseus): The Two Faces of a Versatile Herb

    PubMed Central

    Valdiani, Alireza; Cahill, David; Tan, Yee-How; Maziah, Mahmood; Abiri, Rambod

    2015-01-01

    Catharanthus roseus (L.) known as Madagascar periwinkle (MP) is a legendary medicinal plant mostly because of possessing two invaluable antitumor terpenoid indole alkaloids (TIAs), vincristine and vinblastine. The plant has also high aesthetic value as an evergreen ornamental that yields prolific blooms of splendid colors. The plant possesses yet another unique characteristic as an amiable experimental host for the maintenance of the smallest bacteria found on earth, the phytoplasmas and spiroplasmas, and serves as a model for their study. Botanical information with respect to synonyms, vernacular names, cultivars, floral morphology, and reproduction adds to understanding of the plant while the geography and ecology of periwinkle illustrate the organism's ubiquity. Good agronomic practices ensure generous propagation of healthy plants that serve as a source of bioactive compounds and multitudinous horticultural applications. The correlation between genetic diversity, variants, and TIA production exists. MP is afflicted with a whole range of diseases that have to be properly managed. The ethnobotanical significance of MP is exemplified by its international usage as a traditional remedy for abundant ailments and not only for cancer. TIAs are present only in micro quantities in the plant and are highly poisonous per se rendering a challenge for researchers to increase yield and reduce toxicity. PMID:25667940

  6. A 7-Deoxyloganetic Acid Glucosyltransferase Contributes a Key Step in Secologanin Biosynthesis in Madagascar Periwinkle[C][W][OPEN

    PubMed Central

    Asada, Keisuke; Salim, Vonny; Masada-Atsumi, Sayaka; Edmunds, Elizabeth; Nagatoshi, Mai; Terasaka, Kazuyoshi; Mizukami, Hajime; De Luca, Vincenzo

    2013-01-01

    Iridoids form a broad and versatile class of biologically active molecules found in thousands of plant species. In addition to the many hundreds of iridoids occurring in plants, some iridoids, such as secologanin, serve as key building blocks in the biosynthesis of thousands of monoterpene indole alkaloids (MIAs) and many quinoline alkaloids. This study describes the molecular cloning and functional characterization of three iridoid glucosyltransfeases (UDP-SUGAR GLYCOSYLTRANSFERASE6 [UGT6], UGT7, and UGT8) from Madagascar periwinkle (Catharanthus roseus) with remarkably different catalytic efficiencies. Biochemical analyses reveal that UGT8 possessed a high catalytic efficiency toward its exclusive iridoid substrate, 7-deoxyloganetic acid, making it better suited for the biosynthesis of iridoids in periwinkle than the other two iridoid glucosyltransfeases. The role of UGT8 in the fourth to last step in secologanin biosynthesis was confirmed by virus-induced gene silencing in periwinkle plants, which reduced expression of this gene and resulted in a large decline in secologanin and MIA accumulation within silenced plants. Localization studies of UGT8 using a carborundum abrasion method for RNA extraction show that its expression occurs preferentially within periwinkle leaves rather than in epidermal cells, and in situ hybridization studies confirm that UGT8 is preferentially expressed in internal phloem associated parenchyma cells of periwinkle species. PMID:24104568

  7. Phytochemical genomics of the Madagascar periwinkle: Unravelling the last twists of the alkaloid engine.

    PubMed

    Dugé de Bernonville, Thomas; Clastre, Marc; Besseau, Sébastien; Oudin, Audrey; Burlat, Vincent; Glévarec, Gaëlle; Lanoue, Arnaud; Papon, Nicolas; Giglioli-Guivarc'h, Nathalie; St-Pierre, Benoit; Courdavault, Vincent

    2015-05-01

    The Madagascar periwinkle produces a large palette of Monoterpenoid Indole Alkaloids (MIAs), a class of complex alkaloids including some of the most valuable plant natural products with precious therapeutical values. Evolutionary pressure on one of the hotspots of biodiversity has obviously turned this endemic Malagasy plant into an innovative alkaloid engine. Catharanthus is a unique taxon producing vinblastine and vincristine, heterodimeric MIAs with complex stereochemistry, and also manufactures more than 100 different MIAs, some shared with the Apocynaceae, Loganiaceae and Rubiaceae members. For over 60 years, the quest for these powerful anticancer drugs has inspired biologists, chemists, and pharmacists to unravel the chemistry, biochemistry, therapeutic activity, cell and molecular biology of Catharanthus roseus. Recently, the "omics" technologies have fuelled rapid progress in deciphering the last secret of strictosidine biosynthesis, the central precursor opening biosynthetic routes to several thousand MIA compounds. Dedicated C. roseus transcriptome, proteome and metabolome databases, comprising organ-, tissue- and cell-specific libraries, and other phytogenomic resources, were developed for instance by PhytoMetaSyn, Medicinal Plant Genomic Resources and SmartCell consortium. Tissue specific library screening, orthology comparison in species with or without MIA-biochemical engines, clustering of gene expression profiles together with various functional validation strategies, largely contributed to enrich the toolbox for plant synthetic biology and metabolic engineering of MIA biosynthesis. PMID:25146650

  8. Colonization of Madagascar periwinkle (Catharanthus roseus), by endophytes encoding gfp marker.

    PubMed

    Torres, Adalgisa Ribeiro; Araújo, Welington Luiz; Cursino, Luciana; de Barros Rossetto, Priscilla; Mondin, Mateus; Hungria, Mariangela; Azevedo, João Lúcio

    2013-07-01

    This study reports the introduction of gfp marker in two endophytic bacterial strains (Pantoea agglomerans C33.1, isolated from cocoa, and Enterobacter cloacae PR2/7, isolated from citrus) to monitor the colonization in Madagascar perinwinkle (Catharanthus roseus). Stability of the plasmid encoding gfp was confirmed in vitro for at least 72 h of bacterial growth and after the colonization of tissues, under non-selective conditions. The colonization was observed using fluorescence microscopy and enumeration of culturable endophytes in inoculated perinwinkle plants that grew for 10 and 20 days. Gfp-expressing strains were re-isolated from the inner tissues of surface-sterilized roots and stems of inoculated plants, and the survival of the P. agglomerans C33:1gfp in plants 20 days after inoculation, even in the absence of selective pressure, suggests that is good colonizer. These results indicated that both gfp-tagged strains, especially P. agglomerans C33.1, may be useful tools to deliver enzymes or other proteins in plant. PMID:23695435

  9. The Complete Plastid Genome Sequence of Madagascar Periwinkle Catharanthus roseus (L.) G. Don: Plastid Genome Evolution, Molecular Marker Identification, and Phylogenetic Implications in Asterids

    PubMed Central

    Ku, Chuan; Chung, Wan-Chia; Chen, Ling-Ling; Kuo, Chih-Horng

    2013-01-01

    The Madagascar periwinkle (Catharanthusroseus in the family Apocynaceae) is an important medicinal plant and is the source of several widely marketed chemotherapeutic drugs. It is also commonly grown for its ornamental values and, due to ease of infection and distinctiveness of symptoms, is often used as the host for studies on phytoplasmas, an important group of uncultivated plant pathogens. To gain insights into the characteristics of apocynaceous plastid genomes (plastomes), we used a reference-assisted approach to assemble the complete plastome of C. roseus, which could be applied to other C. roseus-related studies. The C. roseus plastome is the second completely sequenced plastome in the asterid order Gentianales. We performed comparative analyses with two other representative sequences in the same order, including the complete plastome of Coffeaarabica (from the basal Gentianales family Rubiaceae) and the nearly complete plastome of Asclepiassyriaca (Apocynaceae). The results demonstrated considerable variations in gene content and plastome organization within Apocynaceae, including the presence/absence of three essential genes (i.e., accD, clpP, and ycf1) and large size changes in non-coding regions (e.g., rps2-rpoC2 and IRb-ndhF). To find plastome markers of potential utility for Catharanthus breeding and phylogenetic analyses, we identified 41 C. roseus-specific simple sequence repeats. Furthermore, five intergenic regions with high divergence between C. roseus and three other euasterids I taxa were identified as candidate markers. To resolve the euasterids I interordinal relationships, 82 plastome genes were used for phylogenetic inference. With the addition of representatives from Apocynaceae and sampling of most other asterid orders, a sister relationship between Gentianales and Solanales is supported. PMID:23825699

  10. Madagascar.

    PubMed

    1987-08-01

    Madagascar, in the Indian Ocean near Mozambique, is officially known as the Democratic Republic of Madagascar. This republic has 3 branches of government and includes 6 provinces or subdivisions. Since 1981, it has received more than $62 million in grants and concessional sales from the US. There have been other types of assistance as well, including a development assistance program begun in 1985. Its population is largely of mixed Asian and African origin. There exists an historic rivalry between the Catholic coastal people, Cotiers, and the Protestant Merina, who predominate in civil service, business, and the professions. To combat this, the government has set one of its goals to be the highlighting of nationalism. The beginning of Madagascar's written history can be traced to when the Arabs established trading posts along the coastal areas. Eventually, Madagascar moved toward independence from the French and became an autonomous state in 1958. The president is elected for a 7-year term and is the head, during that time, of the Supreme Revolutionary Council. There is a 3-tiered court system, including a lower court for civil and criminal cases, a criminal court for more serious crimes, and a supreme court. The government represents a strong socialist philosophy and outright criticism of the President and his government is not tolerated. The economy of Malagasy is dominated by agriculture, which employs about 85% of the population. Although it faces some serious problems in the areas of foreign exchange and imports/exports, Madagascar is a potentially prosperous country. It boasts diversified agricultural production, it is rich in minerals, and it maintains strong commercial ties to the West. Madagascar's major trading partners are France, the US, the Federal Republic of Germany, the Soviet Union, Qatar, and Japan. Madagascar maintains the Popular Armed Forces for its defense; however, there is a heavy reliance on the Soviet Union for military equipment and training. US-Malagasy relations have been warm for most of its history until 1971 when the US ambassador and 5 members of his staff were expelled. In 1980, a new ambassador arrived and in 1981, 2 Food for Peace rice agreements were concluded. In 1986, Madagascar became the 1st African country to be the recipient of assistance under the program Food for Progress, given to nations which have undertaken successful economic reform. PMID:12177963

  11. Does Diversity Matter In Modeling? Testing A New Version Of The FORMIX3 Growth Model For Madagascar Rainforests

    NASA Astrophysics Data System (ADS)

    Armstrong, A. H.; Fischer, R.; Shugart, H. H.; Huth, A.

    2012-12-01

    Ecological forecasting has become an essential tool used by ecologists to understand the dynamics of growth and disturbance response in threatened ecosystems such as the rainforests of Madagascar. In the species rich tropics, forest conservation is often eclipsed by anthropogenic factors, resulting in a heightened need for accurate assessment of biomass before these ecosystems disappear. The objective of this study was to test a new Madagascar rainforest specific version of the FORMIX3 growth model (Huth and Ditzer, 2000; Huth et al 1998) to assess how accurately biomass can be simulated in high biodiversity forests using a method of functional type aggregation in an individual-based model framework. Rainforest survey data collected over three growing seasons, including 265 tree species, was aggregated into 12 plant functional types based on size and light requirements. Findings indicated that the forest study site compared best when the simulated forest reached mature successional status. Multiple level comparisons between model simulation data and survey plot data found that though some features, such as the dominance of canopy emergent species and relative absence of small woody treelets are captured by the model, other forest attributes were not well reflected. Overall, the ability to accurately simulate the Madagascar rainforest was slightly diminished by the aggregation of tree species into size and light requirement functional type groupings.

  12. Deforestation and Rice: Using Methods in Modeling and Remote Sensing to Project Patterns of Forest Change in Eastern Madagascar

    NASA Astrophysics Data System (ADS)

    Armstrong, A. H.; Fatoyinbo, T. E.; Fischer, R.; Huth, A.; Shugart, H. H.

    2013-12-01

    In the species rich tropics, forest conservation is often eclipsed by anthropogenic disturbance, resulting in a heightened need for an accurate assessment of biomass and the gaining of predictive capability before these ecosystems disappear. The combination of multi-temporal remote sensing data, field data and forest growth modeling to quantify carbon stocks and flux is therefore of great importance. In this study, we utilize these methods to (1) improve forest biomass and carbon flux estimates for the study region in Eastern Madagascar, and (2) initialize an individual-based growth model that incorporates the anthropogenic factors causing deforestation to project ecosystem response to future environmental change. Recent studies have shown that there is a direct correlation between the international rice market and rates of deforestation in tropical countries such as Madagascar (see Minten et al., 2006). Further, although law protects the remaining forest areas, dictatorships and recent political unrest have lead to poor or non-existent enforcement of precious wood and forest protection over the past 35 years. Our approach combined multi-temporal remote sensing analysis and ecological modeling using a theoretical and mathematical approach to assess biomass change and to understand how tree growth and life history (growth response patterns) relate to past and present economic variability in Madagascar forests of the eastern Toamasina region. We measured rates of change of deforestation with respect to politics and the price of rice by classifying and comparing biomass using 30m Landsat during 5 political regime time periods (1985-1992, 1993-1996, 1997-2001, 2002-2008, 2009 to present). Forest biomass estimations were calibrated using forest inventory data collected over 3 growing seasons over the study region (130 small circular plots in primary forest). This information was then built into the previously parameterized (Armstrong et al., in prep and Fischer et al in review) Madagascar FORMIX3 Model (see Huth and Ditzer, 2000) by incorporating rice economy, selective logging and political stability modules into the model to control certain species groups (i.e. selective harvest) and fire frequency (encroachment). The improved FORMIX3 model was then used to investigate and project forest growth response to a variety of impact scenarios ranging from an increase in overall deforestation to a decrease in deforestation and increase in protection enforcement. Our findings showed a significant positive correlation between increasing deforestation rates and higher local rice prices due to political regime and international market factors. This research resulted in the first quantitative analysis of the relationship between the international rice market and local land-use in terms of slash and burn agriculture, illegal logging of precious hardwood in Madagascar.

  13. Deforestation, Madagascar

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This high oblique view shows the majority of the island of Madagascar (19.0S, 47.5E). This Texas sized island is now largely deforested and is suffering from severe soil erosion as well as a declining biological species diversity and productivity. At the turn of the century, the island was almost totally forested but now, forests cover only about 10 percent of the surface. Evidence of soil erosion can be seen in the offshore sediment plumes.

  14. Deforestation, Madagascar

    NASA Technical Reports Server (NTRS)

    1989-01-01

    This high oblique view shows the majority of the island of Madagascar (22.0S, 45.5E). This Texas sized island is now largely deforested and is suffering from severe soil erosion as well as a declining biological species diversity and productivity. At the turn of the century, the island was almost totally forested but now, forests cover only about 10 percent of the surface. Evidence of soil erosion can be seen in the offshore sediment plumes.

  15. Phase equilibrium modeling of Pan-African incipient charnockite from southern Madagascar

    NASA Astrophysics Data System (ADS)

    Tsunogae, Toshiaki; Endo, Takahiro; Santosh, Mw; Thierry Rakotonandrasana, N. O.; Shaji, Erath; Rambeloson, Roger A.

    2013-04-01

    Dark brownish patches and/or veins of coarse-grained orthopyroxene-bearing felsic granulite (charnockite) within foliated amphibolite-facies gneiss/migmatite, are considered as examples of 'metamorphic' charnockite, and represent the transformation of amphibolite-facies rocks to dry granulites on a local scale. Such 'incipient' charnockites have been reported so far from many localities in southern India and Sri Lanka which corresponds to the central part of the East African - Antarctic Orogenic Belt related to the assembly of the Gondwana Supercontinent. Detailed petrological investigations of incipient charnockites therefore provide important insights into granulite-forming processes in the lower crust during Neoproterozoic to Cambrian. Here, we report the first occurrence of incipient charnockite from Ihosy area in southern Madagascar, and discuss the petrogenesis of granulite formation in an arrested stage on the basis of petrography, geothermobarometry, fluid inclusion study, and mineral equilibrium modeling. In the study area, patches of brownish charnockite (Pl+ Qtz + Kfs + Bt + Grt + Opx + Ilm + Mag) of about 20 to 50 cm in length occur within host orthopyroxene-free garnet-biotite gneiss (Pl + Qtz + Kfs + Bt + Grt + Ilm + Mag). The application of mineral equilibrium modeling on charnockite assemblage in NCKFMASHTO system to constrain the conditions of charnockitization defines a P - T range of 8-10.5 kbar and 820-880 C, which is broadly consistent with the results from the conventional geothermobarometry (820-880 C at 9 kbar) on Grt-Bt gneiss. The result of T versus mole H2O (M(H2O)) modeling demonstrated that orthopyroxene-free assemblage in Grt-Bt gneiss is stable only at M(H2O) >0.1 mol.%, while orthopyroxene in charnockite occurs as a stable mineral at very low M(H2O) condition of

  16. Stone tools and foraging in northern Madagascar challenge Holocene extinction models.

    PubMed

    Dewar, Robert E; Radimilahy, Chantal; Wright, Henry T; Jacobs, Zenobia; Kelly, Gwendolyn O; Berna, Francesco

    2013-07-30

    Past research on Madagascar indicates that village communities were established about AD 500 by people of both Indonesian and East African heritage. Evidence of earlier visits is scattered and contentious. Recent archaeological excavations in northern Madagascar provide evidence of occupational sites with microlithic stone technologies related to foraging for forest and coastal resources. A forager occupation of one site dates to earlier than 2000 B.C., doubling the length of Madagascar's known occupational history, and thus the time during which people exploited Madagascar's environments. We detail stratigraphy, chronology, and artifacts from two rock shelters. Ambohiposa near Iharana (Vohémar) on the northeast coast, yielded a stratified assemblage with small flakes, microblades, and retouched crescentic and trapezoidal tools, probably projectile elements, made on cherts and obsidian, some brought more that 200 km. (14)C dates are contemporary with the earliest villages. No food remains are preserved. Lakaton'i Anja near Antsiranana in the north yielded several stratified assemblages. The latest assemblage is well dated to A.D. 1050-1350, by (14)C and optically stimulated luminescence dating and pottery imported from the Near East and China. Below is a series of stratified assemblages similar to Ambohiposa. (14)C and optically stimulated luminescence dates indicate occupation from at least 2000 B.C. Faunal remains indicate a foraging pattern. Our evidence shows that foragers with a microlithic technology were active in Madagascar long before the arrival of farmers and herders and before many Late Holocene faunal extinctions. The differing effects of historically distinct economies must be identified and understood to reconstruct Holocene histories of human environmental impact. PMID:23858456

  17. Stone tools and foraging in northern Madagascar challenge Holocene extinction models

    PubMed Central

    Dewar, Robert E.; Radimilahy, Chantal; Wright, Henry T.; Jacobs, Zenobia; Kelly, Gwendolyn O.; Berna, Francesco

    2013-01-01

    Past research on Madagascar indicates that village communities were established about AD 500 by people of both Indonesian and East African heritage. Evidence of earlier visits is scattered and contentious. Recent archaeological excavations in northern Madagascar provide evidence of occupational sites with microlithic stone technologies related to foraging for forest and coastal resources. A forager occupation of one site dates to earlier than 2000 B.C., doubling the length of Madagascar’s known occupational history, and thus the time during which people exploited Madagascar’s environments. We detail stratigraphy, chronology, and artifacts from two rock shelters. Ambohiposa near Iharana (Vohémar) on the northeast coast, yielded a stratified assemblage with small flakes, microblades, and retouched crescentic and trapezoidal tools, probably projectile elements, made on cherts and obsidian, some brought more that 200 km. 14C dates are contemporary with the earliest villages. No food remains are preserved. Lakaton’i Anja near Antsiranana in the north yielded several stratified assemblages. The latest assemblage is well dated to A.D. 1050–1350, by 14C and optically stimulated luminescence dating and pottery imported from the Near East and China. Below is a series of stratified assemblages similar to Ambohiposa. 14C and optically stimulated luminescence dates indicate occupation from at least 2000 B.C. Faunal remains indicate a foraging pattern. Our evidence shows that foragers with a microlithic technology were active in Madagascar long before the arrival of farmers and herders and before many Late Holocene faunal extinctions. The differing effects of historically distinct economies must be identified and understood to reconstruct Holocene histories of human environmental impact. PMID:23858456

  18. Impacts of the Deepwater Horizon Oil Spill on Salt Marsh Periwinkles (Littoraria irrorata).

    PubMed

    Zengel, Scott; Montague, Clay L; Pennings, Steven C; Powers, Sean P; Steinhoff, Marla; Fricano, Gail; Schlemme, Claire; Zhang, Mengni; Oehrig, Jacob; Nixon, Zachary; Rouhani, Shahrokh; Michel, Jacqueline

    2016-01-19

    Deepwater Horizon was the largest marine oil spill in U.S. waters, oiling large expanses of coastal wetland shorelines. We compared marsh periwinkle (Littoraria irrorata) density and shell length at salt marsh sites with heavy oiling to reference conditions ∼16 months after oiling. We also compared periwinkle density and size among oiled sites with and without shoreline cleanup treatments. Densities of periwinkles were reduced by 80-90% at the oiled marsh edge and by 50% in the oiled marsh interior (∼9 m inland) compared to reference, with greatest numerical losses of periwinkles in the marsh interior, where densities were naturally higher. Shoreline cleanup further reduced adult snail density as well as snail size. Based on the size of adult periwinkles observed coupled with age and growth information, population recovery is projected to take several years once oiling and habitat conditions in affected areas are suitable to support normal periwinkle life-history functions. Where heavily oiled marshes have experienced accelerated erosion as a result of the spill, these habitat impacts would represent additional losses of periwinkles. Losses of marsh periwinkles would likely affect other ecosystem processes and attributes, including organic matter and nutrient cycling, marsh-estuarine food chains, and multiple species that prey on periwinkles. PMID:26713547

  19. Effects of barnacle epibionts on the periwinkle Littorina littorea (L.)

    NASA Astrophysics Data System (ADS)

    Buschbaum, C.; Reise, K.

    1999-08-01

    In a sandy bay with mussel beds in the Wadden Sea (Island of Sylt, eastern North Sea), periwinkles Littorina littorea (L.) were often strongly overgrown with the barnacle Balanus crenatus Bruguière in the lower intertidal zone. Consequences of this epibiosis on mobility, reproduction and mortalityof the snail were examined. B. crenatus growing on L. littorea increased snail volume up to 4-fold and weight up to 3.5-fold and crawling speed of fouled L. littorea was significantly slowed down. The epibiotic structure also caused a decrease in reproductive output. In laboratory experiments, egg production of fouled L. littorea was significantly lower than in snails free of barnacles. Presumably, copulation of the periwinkles is hampered by the voluminous and prickly cover of barnacles. Field studies demonstrated an increased mortality of overgrown L. littorea. A decrease in reproductive output and a lower survival of snails with a cover of barnacles suggest that B. crenatus epibionts may have a significant impact on the population of L. littorea.

  20. The possibility of using photogrammetric and remote sensing techniques to model lavaka (gully erosion) development in Madagascar

    NASA Astrophysics Data System (ADS)

    Raveloson, Andrea; Székely, Balázs; Molnár, Gábor; Rasztovits, Sascha

    2013-04-01

    Gully erosion is a worldwide problem for it has a number of undesirable effects and their development is hard to follow. Madagascar is one of the most affected countries for its highlands are densely covered with gullies named lavakas. Lavaka formation and development seems to be triggered by many regional and local causes but the actual reasons are still poorly understood. Furthermore lavakas differ from normal gullies due to their enormous size and special shape. Field surveys are time consuming and data from two-dimensional measurements and pictures (even aerial) might lack major information for morphologic studies. Therefore close range surveying technologies should be used to get three-dimensional information about these unusual and complex features. This contribution discusses which remote sensing and photogrammetric techniques are adequate to survey the development of lavakas, their volume change and sediment budget. Depending on the types and properties (such as volume, depth, shape, vegetation) of the lavaka different methods will be proposed showing pros and cons of each one of them. Our goal is to review techniques to model, survey and analyze lavakas development to better understand the cause of their formation, special size and shape. Different methods are evaluated and compared from field survey through data processing, analyzing cost-effectiveness, potential errors and accuracy for each one of them. For this purpose we will also consider time- and cost-effectiveness of the softwares able to render the images into 3D model as well as the resolution and accuracy of the outputs. Further studies will concentrate on using the three dimensional models of lavakas which will be later on used for geomorphological studies in order to understand their special shape and size. This is ILARG-contribution #07.

  1. Effect of periwinkles shell particle size on the wear behavior of asbestos free brake pad

    NASA Astrophysics Data System (ADS)

    Amaren, S. G.; Yawas, D. S.; Aku, S. Y.

    The effect of periwinkle shell particle size on the wear behavior of asbestos free brake pad has been investigated. The asbestos free brake pad produced by varying the periwinkle shell particles was from +125 to +710 μm with phenolic resin as the binder. The wear test was performed using pin on disk machine by varying the sliding speed, applied load, temperatures and periwinkle shell particle size. Full factorial design of four factor-two levels and analysis of variance were used in the study of the wear test. The results shown that wear rate increases with increasing the sliding speed, load, temperatures and periwinkle particle size. The co-efficient of friction obtained is within the recommended standard for automobile brake pad. The +125 μm particles of periwinkles gave the best wear resistance. Factorial design of the experiment can be successfully employed to describe the wear behavior of the samples and developed linear equation for predicting wear rate within selected experimental conditions. The results of this research indicate that periwinkle shell particles can be effectively used as a replacement for asbestos in brake pad manufacture.

  2. A Spatially Explicit Metapopulation Model and Cattle Trade Analysis Suggests Key Determinants for the Recurrent Circulation of Rift Valley Fever Virus in a Pilot Area of Madagascar Highlands

    PubMed Central

    Nicolas, Gaëlle; Chevalier, Véronique; Tantely, Luciano Michaël; Fontenille, Didier; Durand, Benoît

    2014-01-01

    Rift Valley fever (RVF) is a vector-borne zoonotic disease that causes high morbidity and mortality in ruminants. In 2008–2009, a RVF outbreak affected the whole Madagascar island, including the Anjozorobe district located in Madagascar highlands. An entomological survey showed the absence of Aedes among the potential RVF virus (RVFV) vector species identified in this area, and an overall low abundance of mosquitoes due to unfavorable climatic conditions during winter. No serological nor virological sign of infection was observed in wild terrestrial mammals of the area, suggesting an absence of wild RVF virus (RVFV) reservoir. However, a three years serological and virological follow-up in cattle showed a recurrent RVFV circulation. The objective of this study was to understand the key determinants of this unexpected recurrent transmission. To achieve this goal, a spatial deterministic discrete-time metapopulation model combined with cattle trade network was designed and parameterized to reproduce the local conditions using observational data collected in the area. Three scenarios that could explain the RVFV recurrent circulation in the area were analyzed: (i) RVFV overwintering thanks to a direct transmission between cattle when viraemic cows calve, vectors being absent during the winter, (ii) a low level vector-based circulation during winter thanks to a residual vector population, without direct transmission between cattle, (iii) combination of both above mentioned mechanisms. Multi-model inference methods resulted in a model incorporating both a low level RVFV winter vector-borne transmission and a direct transmission between animals when viraemic cows calve. Predictions satisfactorily reproduced field observations, 84% of cattle infections being attributed to vector-borne transmission, and 16% to direct transmission. These results appeared robust according to the sensitivity analysis. Interweaving between agricultural works in rice fields, seasonality of vector proliferation, and cattle exchange practices could be a key element for understanding RVFV circulation in this area of Madagascar highlands. PMID:25474116

  3. A spatially explicit metapopulation model and cattle trade analysis suggests key determinants for the recurrent circulation of rift valley Fever virus in a pilot area of madagascar highlands.

    PubMed

    Nicolas, Gaëlle; Chevalier, Véronique; Tantely, Luciano Michaël; Fontenille, Didier; Durand, Benoît

    2014-12-01

    Rift Valley fever (RVF) is a vector-borne zoonotic disease that causes high morbidity and mortality in ruminants. In 2008-2009, a RVF outbreak affected the whole Madagascar island, including the Anjozorobe district located in Madagascar highlands. An entomological survey showed the absence of Aedes among the potential RVF virus (RVFV) vector species identified in this area, and an overall low abundance of mosquitoes due to unfavorable climatic conditions during winter. No serological nor virological sign of infection was observed in wild terrestrial mammals of the area, suggesting an absence of wild RVF virus (RVFV) reservoir. However, a three years serological and virological follow-up in cattle showed a recurrent RVFV circulation. The objective of this study was to understand the key determinants of this unexpected recurrent transmission. To achieve this goal, a spatial deterministic discrete-time metapopulation model combined with cattle trade network was designed and parameterized to reproduce the local conditions using observational data collected in the area. Three scenarios that could explain the RVFV recurrent circulation in the area were analyzed: (i) RVFV overwintering thanks to a direct transmission between cattle when viraemic cows calve, vectors being absent during the winter, (ii) a low level vector-based circulation during winter thanks to a residual vector population, without direct transmission between cattle, (iii) combination of both above mentioned mechanisms. Multi-model inference methods resulted in a model incorporating both a low level RVFV winter vector-borne transmission and a direct transmission between animals when viraemic cows calve. Predictions satisfactorily reproduced field observations, 84% of cattle infections being attributed to vector-borne transmission, and 16% to direct transmission. These results appeared robust according to the sensitivity analysis. Interweaving between agricultural works in rice fields, seasonality of vector proliferation, and cattle exchange practices could be a key element for understanding RVFV circulation in this area of Madagascar highlands. PMID:25474116

  4. Ionic alkylleads in salt marsh periwinkles (Littorina irrorata)

    SciTech Connect

    Krishnan, K.; Marshall, W.D.; Hatch, W.I.

    1988-07-01

    Salt marsh periwinkles (Littorina irrorata), from six sites in Maryland and Virginia, were examined to determine ionic alkyllead concentrations and possible alkyllead sources in lower Chesapeake Bay. Different sources of ethylleads and trimethyllead to this species were demonstrated by statistical comparisons of the concentrations of individual analytes from different sites. These comparisons also indicated (1) that environmentally mediated methylation of Pb/sup 2 +/ contributes appreciably to Me/sub 3/Pb/sup +/ concentrations in snails and (2) that the relative concentrations of individual analytes were consistent with an environmental methylation of ethyllead salts. Compared to females, males were characterized by significantly higher concentrations of several of the alkyllead analytes. In addition, an unknown lead-containing compound was present in all samples.

  5. Investigating the Lithospheric Structure of Southern Madagascar

    NASA Astrophysics Data System (ADS)

    Tilmann, F. J.; Yuan, X.; Rumpker, G.; Heit, B.; Rambolamana, G.; Rindraharisaona, E.; Priestley, K. F.

    2013-12-01

    The island of Madagascar occupies a key region in both the assembly and the multi-stage breakup of Gondwanaland, itself part of the super-continent Pangaea. Madagascar consists of an amalgamation of continental material, with the oldest rocks being of Archaean age. Its ancient fabric is characterised by several shear zones, some of them running oblique to the N-S trend, in particular in the south of the island. More recently during the Neogene, moderate volcanism has occurred in the Central and Northern part of the island, and there are indications of uplift throughout Eastern Madagascar over the last 10 Ma. Although Madagascar is now located within the interior of the African plate and far away from major plate boundaries (> 1000 km from the East African rift system and even further from the Central and South-West Indian Ridges), its seismic activity indicates that some deformation is taking place, and present-day kinematic models based on geodetic data and earthquake moment tensors in the global catalogues identify a diffuse N-S-oriented minor boundary separating two microplates, which appears to pass through Madagascar. In spite of the presence of Archaean and Proterozoic rocks continent-wide scale studies indicate a thin lithosphere (<120 km) throughout Madagascar, but are based on sparse data and cannot resolve the difference between eastern and western Madagascar. We are operating a ENE-WSW oriented linear array of 25 broadband stations in southern Madagascar, extending from coast to coast and sampling the sedimentary basins in the west as well as the metamorphic rocks in the East, cutting geological boundaries seen at the surface at high angle. The array crosses the prominent Bongolava-Ranotsara shear zone which is thought to have been formed during Gondwanaland assembly. The array recorded the magnitude 5.3 earthquake of January 25, 2013 which occurred just off its western edge. In addition, in May 2013 we have deployed 25 short period sensors in the eastern part of the study area, where there is some so-far poorly characterised seismicity. We will present preliminary results on the lithospheric crust and mantle structure based on surface wave dispersion and waveform modelling, focussing on the contrast between the metamorphic areas in the east and the presumably stretched regions in the west. Station distribution Red diamonds: Temporary Broadband Light red squares: Short period Green: permanent stations Other temporary experiments: Open dark blue boxes: RHUM-RUM stations Open light blue boxes: MACOMO stations

  6. Seed transmission of Candidatus Liberibacter asiaticus in periwinkle and dodder resulted in low bacterial titer and very mild disease in periwinkle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Canadidatus Liberibacter asiaticus (Las) is the most widely-distributed of three species of Liberibacter that are associated with citrus Huanglongbing (HLB), a lethal disease of citrus worldwide. In addition to citrus, periwinkle (Catharanthus roseus) and dodder (Cuscuta pentagona) are two experime...

  7. The Madagascar Hissing Cockroach: A New Model for Learning Insect Anatomy

    ERIC Educational Resources Information Center

    Heyborne, William H.; Fast, Maggie; Goodding, Daniel D.

    2012-01-01

    Teaching and learning animal anatomy has a long history in the biology classroom. As in many fields of biology, decades of experience teaching anatomy have led to the unofficial selection of model species. However, in some cases the model may not be the best choice for our students. Our struggle to find an appropriate model for teaching and

  8. The Madagascar Hissing Cockroach: A New Model for Learning Insect Anatomy

    ERIC Educational Resources Information Center

    Heyborne, William H.; Fast, Maggie; Goodding, Daniel D.

    2012-01-01

    Teaching and learning animal anatomy has a long history in the biology classroom. As in many fields of biology, decades of experience teaching anatomy have led to the unofficial selection of model species. However, in some cases the model may not be the best choice for our students. Our struggle to find an appropriate model for teaching and…

  9. Bioreactor production of secondary metabolites from cell cultures of periwinkle and sandalwood.

    PubMed

    Valluri, Jagan V

    2009-01-01

    A bench-top bioreactor allowing continuous extraction of secondary metabolites is designed for Catharanthus roseus L. (G.) Don (periwinkle) and Santalum album L. (sandalwood) plant cell suspensions. Periwinkle cell cultures are exposed to biotic elicitors (Aspergillus niger, crude chitin) and abiotic elicitors (mannitol, methyl jasmonate) to induce alkaloid production. Whereas most of the biotic elicitors are effective when added on day 15 of culture, the abiotic elicitors are effective when added on day 20. The use of trans-cinnamic acid, an inhibitor of phenylalanine ammonia lyase (PAL) activity, results in significant increase in the alkaloid production of periwinkle cell cultures. Exposure of the cells to mannitol-induced osmotic stress produced marked increment in the total alkaloid production. When biotic and abiotic stress treatments are applied sequentially, an additive effect in alkaloid accumulation is observed. Although no essential oils are detected, secondary metabolites in the form of phenolics are produced by the sandalwood cell cultures in the bioreactor environment. The use of morphologic modification such as organ cultures and transformed cultures is believed to be required for both production and storage of essential oil constituents in sandalwood. The present chapter demonstrates that periwinkle and sandalwood cell suspensions could be developed and successfully cultured in a modified air-lift bioreactor. The exploitation of variant cell strains and biotransformation of added precursors can certainly improve the use of periwinkle and sandalwood cell cultures for the bioproduction of desired compounds. PMID:19521856

  10. Trigonalidae (Hymenoptera) of Madagascar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seven species of the primarily hyperparasitoid family Trigonalidae are reported from Madagascar: Orthogonalys brevis Smith and Tripotin, sp. n., Orthogonalys gigantea Benoit, 1951; O. hova Bischoff, 1933; O. maculata Bischoff, 1933; Orthogonalys parahova Smith and Tripotin, sp. n., O. seyrigi Bisch...

  11. Habitat-specific size structure variations in periwinkle populations ( Littorina littorea) caused by biotic factors

    NASA Astrophysics Data System (ADS)

    Eschweiler, Nina; Molis, Markus; Buschbaum, Christian

    2009-06-01

    Shell size distribution patterns of marine gastropod populations may vary considerably across different environments. We investigated the size and density structure of genetically continuous periwinkle populations ( Littorina littorea) on an exposed rocky and a sheltered sedimentary environment on two nearby islands in the south-eastern North Sea (German Bight). On the sedimentary shore, periwinkle density (917 ± 722 individuals m-2) was about three times higher than on the rocky shore (296 ± 168 individuals m-2). Mean (9.8 ± 3.9 mm) and maximum (22 mm) shell size of L. littorea on the sedimentary shore were smaller than on the rocky shore (21.5 ± 4.2 and 32 mm, respectively), where only few small snails were found. Additionally, periwinkle shells were thicker and stronger on the rocky than on the sedimentary shore. To ascertain mechanisms responsible for differences in population structures, we examined periwinkles in both environments for growth rate, predation pressure, infection with a shell boring polychaete ( Polydora ciliata) and parasitic infestation by trematodes. A crosswise transplantation experiment revealed better growth conditions on the sedimentary than on the rocky shore. However, crab abundance and prevalence of parasites and P. ciliata in adult snails were higher on the sedimentary shore. Previous investigations showed that crabs prefer large periwinkles infested with P. ciliata. Thus, we suggest that parasites and shell boring P. ciliata in conjunction with an increased crab predation pressure are responsible for low abundances of large periwinkles on the sedimentary shore while high wave exposure may explain low densities of juvenile L. littorea on the rocky shore. We conclude that biotic factors may strongly contribute to observed differences in size structure of the L. littorea populations studied on rocky and sedimentary shores.

  12. Fiddler crabs facilitate Spartina alterniflora growth, mitigating periwinkle overgrazing of marsh habitat.

    PubMed

    Gittman, Rachel K; Keller, Danielle A

    2013-12-01

    Ecologists have long been interested in identifying and testing factors that drive top-down or bottom-up regulation of communities. Most studies have focused on factors that directly exert top-down (e.g., grazing) or bottom-up (e.g., nutrient availability) control on primary production. For example, recent studies in salt marshes have demonstrated that fronts of Littoraria irrorata periwinkles can overgraze Spartina alterniflora and convert marsh to mudflat. The importance of indirect, bottom-up effects, particularly facilitation, in enhancing primary production has also recently been explored. Previous field studies separately revealed that fiddler crabs, which burrow to depths of more than 30 cm, can oxygenate marsh sediments and redistribute nutrients, thereby relieving the stress of anoxia and enhancing S. alterniflora growth. However, to our knowledge, no studies to date have explored how nontrophic facilitators can mediate top-down effects (i.e., grazing) on primary-producer biomass. We conducted a field study testing whether fiddler crabs can facilitate S. alterniflora growth sufficiently to mitigate overgrazing by periwinkles and thus sustain S. alterniflora marsh. As inferred from contrasts to experimental plots lacking periwinkles and fiddler crabs, periwinkles alone exerted top-down control of total aboveground biomass and net growth of S. alterniflora. When fiddler crabs were included, they counteracted the effects of periwinkles on net S. alterniflora growth. Sediment oxygen levels were greater and S. alterniflora belowground biomass was lower where fiddler crabs were present, implying that fiddler crab burrowing enhanced S. alterniflora growth. Consequently, in the stressful interior S. alterniflora marsh, where subsurface soil anoxia is widespread, fiddler crab facilitation can mitigate top-down control by periwinkles and can limit and possibly prevent loss of biogenically structured marsh habitat and its ecosystem services. PMID:24597218

  13. Barnacles, limpets and periwinkles: the effects of direct and indirect interactions on cyprid settlement and success

    NASA Astrophysics Data System (ADS)

    Holmes, Sebastian P.; Walker, Graham; van der Meer, Jaap

    2005-02-01

    Conventionally, direct interactions between species are considered to be the most important biological factors determining community composition, structure and stability. However, it has been suggested that the indirect interactions occurring between species may be as important. One area of ecology where the direct effects of one species on another have been well studied is in the rocky intertidal. Examination of the effect of the presence of P. vulgata (limpets) and L. littorea (periwinkles) on the settlement and development of S. balanoides (cyprids/barnacles), over a cyprid settlement season and some six months later, in four different treatments (limpets only, limpets and periwinkles combined, periwinkles only and control (no animals)) revealed the following: (1) that the presence of limpets increased cyprid settlement and recruitment success above treatments containing no limpets; (2) that cyprid settlement and success were greatest on the limpets-only treatment, followed by the limpets-and-periwinkles treatment, then by the control treatment and then by the periwinkles-only treatment; (3) that the initial effects observed in the treatments were reflected in the long-term community structure; (4) that the effects of the treatments were independent of variations in algal biomass between treatments, i.e. the effects were not indirectly mediated through a second species (host); (5) that cyprid mortality was greatest on the periwinkles-only treatment; (6) that the source of the effect of limpets on cyprid settlement appeared to originate indirectly through the action of their residual pedal mucus trails. It is concluded that periwinkles can affect the settlement and success of barnacles directly through biological disturbance (i.e. surface ablation). However, although limpets may have a direct negative effect on barnacle settlement and success, at low to medium densities, limpets can positively indirectly influence the cyprid settlement and success. This effect operates at a factor greater than that afforded by the direct negative effects of periwinkles in a mixed-species treatment. These results illustrate how the indirect effects of one species on another can have a more important structuring effect than those derived from direct effects alone.

  14. The promoter of the strictosidine synthase gene from periwinkle confers elicitor-inducible expression in transgenic tobacco and binds nuclear factors GT-1 and GBF.

    PubMed

    Pasquali, G; Erven, A S; Ouwerkerk, P B; Menke, F L; Memelink, J

    1999-04-01

    Strictosidine synthase (STR) is a key enzyme in the biosynthesis of terpenoid indole alkaloids. This class of secondary metabolites harbours several pharmaceutically important compounds used, among other applications, in cancer treatment. Terpenoid indole alkaloid biosynthesis and expression of biosynthetic genes including Str1 is induced by fungal elicitors. To identify elicitor-responsive regulatory promoter elements and trans-acting factors, the single-copy Str1 gene was isolated from the subtropical plant species Catharanthus roseus (Madagascar periwinkle). Str1 upstream sequences conferred elicitor-responsive expression to the beta-glucuronidase (gusA) reporter gene in transgenic tobacco plants. Main enhancer sequences within the Str1 promoter region studied were shown to be located between -339 and -145. This region and two other regions of the promoter bound the tobacco nuclear protein factor GT-1. A G-box located around position -105 bound nuclear and cloned G-box-binding factors (GBFs). A mutation that knocked out GBF binding had no measurable effect on expression, which indicates that the G-box is not essential for the elicitor responsiveness of the Str1 promoter. No obvious homologies with promoter elements identified in other elicitor-responsive genes were observed, suggesting that the Str1 gene may depend on novel regulatory mechanisms. PMID:10380815

  15. Oceanography of West Madagascar

    NASA Astrophysics Data System (ADS)

    John, Bemiasa

    2014-05-01

    During six week survey (August - October 2009) in Western and Northern coast of Madagascar, the R/V 'Dr. Fridtjof Nansen' has carried out a study of the pelagic ecosystem. In collaboration with Agulhas & Somali Current Large Marine Ecosystems project (ASCLME) and South West Indian Ocean Fisheries Project (SWIOFP), the aim of the survey was to establish the physical, chemical and biological characteristics of the Western Madagascar shelf region as a whole. Along selected hydrographical transects, a total of 182 CTD stations were conducted and ranged to a maximum of 3000 m depth. Water samples were also collected with Niskin bottles at predefined depths. A Seabird 911plus CTD was used to obtain vertical profiles of temperature, salinity and oxygen. As results, along the west and south coast of Madagascar, the shelf is narrow and widen slightly along the north-west coast. In all ten transects the isotherms showed stratified waters from the coast to offshore. A maximum salinity layer was observed at subsurface in all transects. Dissolved oxygen had a maximum at around 500 m depth in all transects. Low fluorescence values were observed in the upper 150-200 m, with maximum values in the range of 0.14-0.22 µg/l at intermediate layers. The conditions were consistent along and between the transects, with more variation observed at transect 9. No upwelling was observed along the western coast. The surface temperature (5 m depth) increased from 22°C in the south to 26°C in the north. The horizontal distribution of surface salinities showed homogenous conditions with values between 35.4psu (south) and 35.0 psu (north). Also starting from the coast to offshore, both the surface temperatures and surface salinities showed homogenous patterns.

  16. Zooplankton of West Madagascar

    NASA Astrophysics Data System (ADS)

    Bemiasa, John; Remanevy, Sitraka

    2014-05-01

    During six week survey (August - October 2009) in Western and Northern coast of Madagascar, the R/V 'Dr. Fridtjof Nansen' has carried out a study of the pelagic ecosystem. In collaboration with Agulhas & Somali Current Large Marine Ecosystems project (ASCLME) and South West Indian Ocean Fisheries Project (SWIOFP), the aim of the survey was to establish the physical, chemical and biological characteristics of the Western Madagascar shelf region as a whole. Zooplankton samples were collected with Hydrobios Multinet at all environmental stations ranging from 200 m depth to the surface. The Multinet was equipped with 5 nets for depth-stratified sampling. The nets were fitted with 180 µm mesh size and the water flow through the nets was measured. The Multinet was deployed and retrieved at a rate of ~ 1.5 m per second and was obliquely hauled. The five nets were triggered at the pre-selected depth intervals 0-25m, 25-50m, 50-80m, 80-120m and 120-200m. All samples were stored in marked bottles and preserved with buffered formaldehyde of 4% for further analysis. As results,the zooplankton abundance was influenced by physico-chemical factors. During the study period 34 Family of zooplankton were identified which are dominated by Copepoda (58,69%) followed by Radiolaria (12,06%), Appendicularia (6,47%), Sagitta (5,11%), Larvae (4,57%), Ostracoda (3,13%), pelagic Foraminifera (2,15%). Family of zooplankton with abundance <1% were also recorded, namely Salpidae (0,94%), Euphausiacea (0,44%), Tintinnidae (0,39%), Annélidae Polychètes (0,34%), Mysidacea (0,21%), Ptéropodae (0,13%). Highest number of zooplankton were found at the depth below the maximum of fluorescence during the day. Copepods distribution depends on site and depth. During this study, the number of identified species is always superior to 50 for all sampling sites. The findings of the present study will help to improve the scientific knowledge of the marine ecosystem of the west coast of Madagascar.

  17. Investigating the Lithospheric Structure of Southern Madagascar

    NASA Astrophysics Data System (ADS)

    Tilmann, Frederik; Yuan, Xiaohui; Rümpker, Georg; Gerard, Rambolamana; Elisa, Rindraharisaona; Priestley, Keith

    2014-05-01

    The island of Madagascar occupies a key region in both the assembly and the multi-stage breakup of Gondwanaland, itself part of the super-continent Pangaea. Madagascar consists of an amalgamation of continental material, with the oldest rocks being of Archaean age. Its ancient fabric is characterised by several shear zones, some of them running oblique to the N-S trend, in particular in the south of the island. More recently during the Neogene, moderate volcanism has occurred in the Central and Northern part of the island, and there are indications of uplift throughout Eastern Madagascar over the last 10 Ma. Although Madagascar is now located within the interior of the African plate and far away from major plate boundaries (> 1000 km from the East African rift system and even further from the Central and South-West Indian Ridges), its seismic activity indicates that some deformation is taking place, and present-day kinematic models based on geodetic data and earthquake moment tensors in the global catalogues identify a diffuse N-S-oriented minor boundary separating two microplates, which appears to pass through Madagascar. In spite of the presence of Archaean and Proterozoic rocks continent-wide scale studies indicate a thin lithosphere (<120 km) throughout Madagascar, but are based on sparse data. We are operating a ENE-WSW oriented linear array of 25 broadband stations in southern Madagascar, extending from coast to coast and sampling the sedimentary basins in the west as well as the metamorphic rocks in the East, cutting geological boundaries seen at the surface at high angle. The array crosses the prominent Bongolava-Ranotsara shear zone which is thought to have been formed during Gondwanaland assembly, although this interpretation has recently been questioned. The array recorded the magnitude 5.3 earthquake of January 25, 2013 which occurred just off its western edge. In addition, in May 2013 we have deployed 25 short period sensors in the eastern part of the study area, where there is some so-far poorly characterised seismicity. We present preliminary results on the lithospheric crust and mantle structure based on surface wave dispersion and waveform modelling, focussing on the contrast between the metamorphic areas in the east and the presumably stretched regions in the west. Interstation Green's functions have been obtained from all pairs of vertical broadband records, with coherent Rayleigh waves being identifiable for periods of 3-40 s. In addition, two-station phase dispersion measurements have allowed us to determine phase dispersion between 25 and 60 s. The ambient noise and earthquake data both indicate a slow-down of surface propagation in the western part of the array for periods < 40-45 s, but faster propagation in the western part for periods >45 s.

  18. Madagascar: Heads It's a Continent, Tails It's an Island

    NASA Astrophysics Data System (ADS)

    de Wit, Maarten J.

    Neither geologists nor biologists have a definition that is capable of classifying Madagascar unambiguously as an island or a continent; nor can they incorporate Malagasy natural history into a single model rooted in Africa or Asia. Madagascar is a microcosm of the larger continents, with a rock record that spans more than 3000 million years (Ma), during which it has been united episodically with, and divorced from, Asian and African connections. This is reflected in its Precambrian history of deep crustal tectonics and a Phanerozoic history of biodiversity that fluctuated between cosmopolitanism and parochialism. Both vicariance and dispersal events over the past 90 Ma have blended a unique endemism on Madagascar, now in decline following rapid extinctions that started about 2000 years ago.

  19. Hydrological modeling of tropical closed Lake Ihotry (SW Madagascar): Sensitivity analysis and implications for paleohydrological reconstructions over the past 4000 years

    NASA Astrophysics Data System (ADS)

    Vallet-Coulomb, Christine; Gasse, Françoise; Robison, Laurent; Ferry, Luc; Van Campo, Elise; Chalié, Françoise

    2006-11-01

    SummaryLake Ihotry is a closed saline lake extending in the semi-arid southwestern part of the Madagascar Island. Monitoring of lake level and chemistry, rainfall and pan evaporation close to the lake was conducted over more than two years, recording large seasonal variations in both lake area and salinity. In addition, diatom and pollen data from a 4000 years-sediment core showed that hydrological fluctuations of much larger magnitude have occurred in the past. The instrumental record was used to establish the present-day lake water balance and to calibrate a lake level and chloride content model at a daily time step. Sensitivity experiments showed that the present-day lake is very sensitive to rainfall variations, both through direct rainfall on the lake surface and through the local shallow groundwater availability. In the sediment core, diatom data document a wet episode with freshwater conditions from ca. 3300 to 2550-2000 cal. yr, followed by a desiccation trend punctuated by large variations of diatom-inferred salinity between ≈2250 and 1350 cal. yr, and finally the onset towards modern conditions by 700-650 cal. yr. A digital elevation model enabled to quantitatively reconstruct the morphometric parameters of an open lake. These lake area-depth-volume relationships were used in the combined water and chloride balances model to investigate conditions of the freshwater lake, and to simulate short-term oscillations of diatom-inferred salinity and the lake evolution towards its present state. We conclude that whatever the rainfall and/or evaporation changes accounting for, the regional water table evolution was an important factor controlling the long-term lake evolution, through its successive connection/disconnection to the lake.

  20. Oceanography of East Madagascar

    NASA Astrophysics Data System (ADS)

    Bemiasa, John

    2014-05-01

    During six week survey (August - September 2008) in Southern and Eastern coast of Madagascar, the R/V 'Dr. Fridtjof Nansen' has carried out a study of the pelagic ecosystem. In collaboration with Agulhas & Somali Current Large Marine Ecosystems project (ASCLME) and South West Indian Ocean Fisheries Project (SWIOFP), the aim of the survey was to establish the physical, chemical and biological characteristics of the Western Madagascar shelf region as a whole. A total of 102 CTD stations were conducted along selected hydrographical transects and ranged to a maximum of 3000 m depth. Water samples were also collected with Niskin bottles at predefined depths. A Seabird 911plus CTD was used to obtain vertical profiles of temperature, salinity and oxygen. As results, the first section between latitude 25o-26oS showed sea surface temperature values ranging between 25oC to 15oC upper 250m depth. As part of the south-west, the shelf is narrow and widen slightly along the tip south of the Island coast. In contrast of the west coast, in all transects performed along the south and the east coast, in most cases, the isotherms showed non stratified waters from the coast to offshore. The presence of the upwelling system in the south-east coast modifies drastically the patterns of all measured parameters. Fluorescence had a maximum values (0.25 µg/l) at surface near the coast in 2nd to 5th transects. Inversely, low temperature values were observed along the south and south-east with minimum values in the range of 18. 5oC-11oC at 50-250 m depth. These conditions were consistent along and between the 2nd to 5th transects, with more variation observed at transect 5. The salinity values (5 m depth) decreased from 35.7 psu in the south to 34.5 psu in the east. The horizontal distribution of oxygen showed non homogenous conditions with values between 5 ml/l (south) and 2.5 ml/l (south-east). Also starting from the coast to offshore, surface temperatures and surface salinities, surface fluorescence and dissolved oxygen showed non homogenous patterns.

  1. Evolution of Neogene Dynamic Topography in Madagascar

    NASA Astrophysics Data System (ADS)

    Paul, J. D.; Roberts, G.; White, N. J.

    2012-12-01

    Madagascar is located on the fringes of the African superswell. Its position and the existence of a +30 mGal long wavelength free-air gravity anomaly suggest that its present-day topography is maintained by convective circulation of the sub-lithospheric mantle. Residual depth anomalies of oceanic crust encompassing the island imply that Madagascar straddles a dynamic topographic gradient. In June-July 2012, we examined geologic evidence for Neogene uplift around the Malagasy coastline. Uplifted coral reef deposits, fossil beach rock, and terraces demonstrate that the northern and southern coasts are probably being uplifted at a rate of ~0.2 mm/yr. Rates of uplift clearly vary around the coastline. Inland, extensive peneplains occur at elevations of 1 - 2 km. These peneplains are underlain by 10 - 20 m thick laterite deposits, and there is abundant evidence for rapid erosion (e.g. lavaka). Basaltic volcanism also occurred during Neogene times. These field observations can be combined with an analysis of drainage networks to determine the spatial and temporal pattern of convectively driven uplift. ~100 longitudinal river profiles were extracted from a digital elevation model of Madagascar. An inverse model is then used to minimize the misfit between observed and calculated river profiles as a function of uplift rate history. During inversion, the residual misfit decreases from ~20 to ~4. Our results suggest that youthful and rapid uplift of 1-2 km occurred at rates of 0.2-0.4 mm/yr during the last ˜15 Myr. The algorithm resolves distinct phases of uplift which generate localized swells of high topography and relief (e.g. the Hauts Plateaux). Our field observations and modeling indicate that the evolution of drainage networks may contain useful information about mantle convective processes.

  2. Ecological Effects of the Invasive Giant Madagascar Day Gecko on Endemic Mauritian Geckos: Applications of Binomial-Mixture and Species Distribution Models

    PubMed Central

    Buckland, Steeves; Cole, Nik C.; Aguirre-Gutiérrez, Jesús; Gallagher, Laura E.; Henshaw, Sion M.; Besnard, Aurélien; Tucker, Rachel M.; Bachraz, Vishnu; Ruhomaun, Kevin; Harris, Stephen

    2014-01-01

    The invasion of the giant Madagascar day gecko Phelsuma grandis has increased the threats to the four endemic Mauritian day geckos (Phelsuma spp.) that have survived on mainland Mauritius. We had two main aims: (i) to predict the spatial distribution and overlap of P. grandis and the endemic geckos at a landscape level; and (ii) to investigate the effects of P. grandis on the abundance and risks of extinction of the endemic geckos at a local scale. An ensemble forecasting approach was used to predict the spatial distribution and overlap of P. grandis and the endemic geckos. We used hierarchical binomial mixture models and repeated visual estimate surveys to calculate the abundance of the endemic geckos in sites with and without P. grandis. The predicted range of each species varied from 85 km2 to 376 km2. Sixty percent of the predicted range of P. grandis overlapped with the combined predicted ranges of the four endemic geckos; 15% of the combined predicted ranges of the four endemic geckos overlapped with P. grandis. Levin's niche breadth varied from 0.140 to 0.652 between P. grandis and the four endemic geckos. The abundance of endemic geckos was 89% lower in sites with P. grandis compared to sites without P. grandis, and the endemic geckos had been extirpated at four of ten sites we surveyed with P. grandis. Species Distribution Modelling, together with the breadth metrics, predicted that P. grandis can partly share the equivalent niche with endemic species and survive in a range of environmental conditions. We provide strong evidence that smaller endemic geckos are unlikely to survive in sympatry with P. grandis. This is a cause of concern in both Mauritius and other countries with endemic species of Phelsuma. PMID:24785293

  3. Ecological and cosmological coexistence thinking in a hypervariable environment: causal models of economic success and failure among farmers, foragers, and fishermen of southwestern Madagascar.

    PubMed

    Tucker, Bram; Tsiazonera; Tombo, Jaovola; Hajasoa, Patricia; Nagnisaha, Charlotte

    2015-01-01

    A fact of life for farmers, hunter-gatherers, and fishermen in the rural parts of the world are that crops fail, wild resources become scarce, and winds discourage fishing. In this article we approach subsistence risk from the perspective of "coexistence thinking," the simultaneous application of natural and supernatural causal models to explain subsistence success and failure. In southwestern Madagascar, the ecological world is characterized by extreme variability and unpredictability, and the cosmological world is characterized by anxiety about supernatural dangers. Ecological and cosmological causes seem to point to different risk minimizing strategies: to avoid losses from drought, flood, or heavy winds, one should diversify activities and be flexible; but to avoid losses caused by disrespected spirits one should narrow one's range of behaviors to follow the code of taboos and offerings. We address this paradox by investigating whether southwestern Malagasy understand natural and supernatural causes as occupying separate, contradictory explanatory systems (target dependence), whether they make no categorical distinction between natural and supernatural forces and combine them within a single explanatory system (synthetic thinking), or whether they have separate natural and supernatural categories of causes that are integrated into one explanatory system so that supernatural forces drive natural forces (integrative thinking). Results from three field studies suggest that (a) informants explain why crops, prey, and market activities succeed or fail with reference to natural causal forces like rainfall and pests, (b) they explain why individual persons experience success or failure primarily with supernatural factors like God and ancestors, and (c) they understand supernatural forces as driving natural forces, so that ecology and cosmology represent distinct sets of causes within a single explanatory framework. We expect that future cross-cultural analyses may find that this form of "integrative thinking" is common in unpredictable environments and is a cognitive strategy that accompanies economic diversification. PMID:26528205

  4. Ecological and cosmological coexistence thinking in a hypervariable environment: causal models of economic success and failure among farmers, foragers, and fishermen of southwestern Madagascar

    PubMed Central

    Tucker, Bram; Tsiazonera; Tombo, Jaovola; Hajasoa, Patricia; Nagnisaha, Charlotte

    2015-01-01

    A fact of life for farmers, hunter-gatherers, and fishermen in the rural parts of the world are that crops fail, wild resources become scarce, and winds discourage fishing. In this article we approach subsistence risk from the perspective of “coexistence thinking,” the simultaneous application of natural and supernatural causal models to explain subsistence success and failure. In southwestern Madagascar, the ecological world is characterized by extreme variability and unpredictability, and the cosmological world is characterized by anxiety about supernatural dangers. Ecological and cosmological causes seem to point to different risk minimizing strategies: to avoid losses from drought, flood, or heavy winds, one should diversify activities and be flexible; but to avoid losses caused by disrespected spirits one should narrow one’s range of behaviors to follow the code of taboos and offerings. We address this paradox by investigating whether southwestern Malagasy understand natural and supernatural causes as occupying separate, contradictory explanatory systems (target dependence), whether they make no categorical distinction between natural and supernatural forces and combine them within a single explanatory system (synthetic thinking), or whether they have separate natural and supernatural categories of causes that are integrated into one explanatory system so that supernatural forces drive natural forces (integrative thinking). Results from three field studies suggest that (a) informants explain why crops, prey, and market activities succeed or fail with reference to natural causal forces like rainfall and pests, (b) they explain why individual persons experience success or failure primarily with supernatural factors like God and ancestors, and (c) they understand supernatural forces as driving natural forces, so that ecology and cosmology represent distinct sets of causes within a single explanatory framework. We expect that future cross-cultural analyses may find that this form of “integrative thinking” is common in unpredictable environments and is a cognitive strategy that accompanies economic diversification. PMID:26528205

  5. Resistances et initiatives a Madagascar (Resistance and Initiatives in Madagascar).

    ERIC Educational Resources Information Center

    Georges, Claude

    1993-01-01

    Discusses the cultural, political, and institutional barriers to population education in Madagascar and the strategies and initiatives that have been adopted to overcome them, including emphasizing the national character of a project, accommodating the values and ideals of the people involved, and assuring teachers of their classroom autonomy.

  6. Atmospheric Effects of Biomass Burning in Madagascar

    NASA Technical Reports Server (NTRS)

    Aikin, Arthur C.; Hoegy, Walter R.; Ziemke, Jerry R.; Thorpe, Arthur; Einaudi, Franco (Technical Monitor)

    2000-01-01

    Simultaneous tropospheric ozone and aerosols observed using the TOMS satellite instrument are reported for Madagascar during the 1979 through 1999 time period Ozone observations made using the TOMS tropospheric ozone convective-cloud differential method show that the tropospheric ozone amount associated with Madagascar has an average monthly value of 30 DU (Dobson units). The average value is enhanced by 10 to 15 DU in October This maximum coincides with the time of maximum biomass area burning in Madagascar and parts of southern Africa. The aerosol index derived from TOMS is examined for correlation with biomass burning in Madagascar and southern Africa. There is good correlation between a satellite observation derived fire index for different parts of Madagascar, tropospheric ozone and the TOMS aerosol index in the same geographical area. Aerosols from fires were found to reach their peak in November and to persist over Madagascar until sometime in December.

  7. Periwinkle (Littorina littorea) as a sentinel species: a field study integrating chemical and biological analyses.

    PubMed

    Noventa, Seta; Pavoni, Bruno; Galloway, Tamara S

    2011-04-01

    The gastropod Littorina littorea (common periwinkle) is an abundant and widespread North Atlantic species. The characteristic development of Intersex in L. littorea has been widely applied as a biomarker for tributyltin (TBT) contamination. Here, we assess the potential of L. littorea as a novel sentinel species for evaluating the sublethal effects in wild populations of widely distributed contaminants. We collected animals from six sites across the South coast of England. Tissue concentrations of polycyclic aromatic hydrocarbons (PAHs), organotin compounds (OTCs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) were measured and compared with biomarkers of damage to DNA (Comet assay), lysosomal stability (NRR assay), and endocrine disruption (Intersex development). There was a strong correlation between DNA damage and PAH bioaccumulation (n=6, r=0.84, p<0.05), as well as that between Intersex development and OTC pollution (n=6, r=0.91, p<0.05). The relationship between PAH bioaccumulation and DNA strand breaks was nonlinear, highlighting the need to consider the role of adaptive mechanisms in the interpretation of field results. These results illustrate the potential use of periwinkles for monitoring a wide range of priority pollutants. PMID:21401085

  8. Age-dependent zonation of the periwinkle Littorina littorea (L.) in the Wadden Sea

    NASA Astrophysics Data System (ADS)

    Saier, Bettina

    2000-12-01

    On sedimentary tidal flats near the island of Sylt (German Bight, North Sea) abundance and size distribution of periwinkles, Littorina littorea L., were studied in low intertidal and in shallow and deep subtidal mussel beds ( Mytilus edulis L.). In low intertidal mussel beds, surveys revealed that high densities (1,369±571 m-2) of juvenile snails (≤13 mm) were positively correlated with strong barnacle epigrowth ( Semibalanus balanoides L. and Balanus crenatus Bruguière) on mussels. A subsequent field experiment showed that recruitment of L. littorea was restricted to the intertidal zone. Abundances of periwinkles (213±114 m-2) and barnacles abruptly decreased in the adjacent shallow subtidal zone, which served as a habitat for older snails (>13 mm). L. littorea was completely absent from disjunct deep (5 m) subtidal mussel beds. Snail abundance varied seasonally with maxima of >4,000 m-2 in low intertidal mussel beds in October and minima in July, just before the onset of new recruitment. I suggest that the presence of cracks and crevices among the dense barnacle overgrowth in intertidal mussel beds favoured recruitment and survival of juvenile snails. Larger (older) specimens are assumed to actively migrate to the less favourable adjacent subtidal. Therefore, intertidal mussel beds are considered as nurseries for the population of L. littorea in the Wadden Sea.

  9. Grazing on green algae by the periwinkle Littorina littorea in the Wadden Sea

    NASA Astrophysics Data System (ADS)

    Wilhelmsen, U.; Reise, K.

    1994-06-01

    On sedimentary tidal flats in the Wadden Sea near the Island of Sylt, the periwinkle Littorina littorea occurred preferentially on clusters and beds of mussels and on shell beds (100 to 350 m-2), achieved moderate densities on green algal patches or mats (20 to 50 m-2), and remained rare on bare sediments (<5 m-2). Green algae covering>10% of sediment surface appeared in summer on approximately one third of the tidal zone, mainly in the upper and sheltered parts and almost never on mussel and shell beds. In feeding experiments, L. littorea ingested more of the dominant alge, Enteromorpha, than of Ulva, irrespective of whether or not algae were fresh or decaying. The tough thalli of Chaetomorpha were hardly consumed. Snails feeding on Enteromorpha produced fecal pellets from which new growth of Enteromorpha started. In the absence of periwinkles, Enteromorpha developed on mussels and the attached fucoids. Experimentally increased snail densities on sediments prevented green algal development, but the snails were unable to graze down established algal mats. It is concluded that natural densities of L. littorea hardly affect the ephemeral mass development of green algae on sediments. However, where the snails occur at high densities, i.e. on mussel beds, green algal development may be prevented.

  10. [Update on plague in Madagascar].

    PubMed

    Chanteau, S; Rahalison, L; Duplantier, J M; Rasoamanana, B; Ratsitorahina, M; Dromigny, J A; Laventure, S; Duchemin, J B; Boisier, P; Rabeson, D; Roux, J

    1998-01-01

    After a thirty year period of successful control, bubonic plague showed the first signs of return in Madagascar where a fatal outbreak occurred in Antananarivo in 1978. A second outbreak was observed in Mahajanga in 1991 after more than a half century. In 1997, 459 confirmed or presumptive cases were reported, as compared to 150 to 250 cases during the last years. However the actual extent of this recrudescence must be placed in the perspective of a more efficient control program that has led to better reporting of suspected cases and availability of more accurate diagnostic techniques. Recent research has led to the development of highly effective immunological diagnostic tools (detection of antibodies and F1 antigen) allowing not only better surveillance of the disease in man and animals but also renewed study of the epidemiological cycle in the current environment. In this regard the capacity of several endemic fleas as vectors and the role of the rat Rattus norvegicus and the musk shrew Suncus murinus are currently under investigation. Genetic study of strains collected from 1936 to 1996 has demonstrated the appearance of 3 new ribotypes of Yersinia pestis since 1982 in the zones of strongest plague activity in Madagascar. A strain showing multiresistance to standard therapeutic antibiotic agents was isolated in 1995. Bubonic plaque is a priority health problem in Madagascar but remains a major concern for the rest of the world. PMID:9812306

  11. Leptospirosis after a stay in Madagascar.

    PubMed

    Pags, Frdric; Kuli, Barbara; Moiton, Marie-Pierre; Goarant, Cyrille; Jaffar-Bandjee, Marie-Christine

    2015-01-01

    We report a case of polymerase chain reaction (PCR)-confirmed leptospirosis in a patient who recently traveled to Madagascar, a country where only two cases have been reported since 1955. Although laboratory and clinical presentations were atypical and despite leptospirosis not being a documented disease in Madagascar, blood and urine tests for leptospirosis enabled retrospective confirmation of the diagnosis. PMID:25319525

  12. [Resistances and initiatives in Madagascar].

    PubMed

    Georges, C

    1993-03-01

    Despite Madagascar's recognition of the importance of population education in changing fertility attitudes and behaviors as a step toward achieving development, population education in the country faces cultural, political and institutional resistance typical of Africa. Culturally, population education is offered in the context of a traditional educational system with a populationist ideology that favors uncontrolled fertility. Taboos concerning sexuality inhibit discussion of family planning. Loss of continuity in program development due to the frequent changes of government is a political obstacle to population education. Institutionally, the schools are by nature stable and homeostatic, offering resistance to innovations. Many teachers and administrators feel that topics included in population education such as sexuality and human reproduction are inappropriate for children. The objectives and techniques of population education, involving group work, nondirective educational techniques, and other innovations designed to encourage changes in attitudes and behaviors, are contradictory to the goals of teachers and administrators who seek to impose obedience, regularity, and discipline. Teachers in Madagascar typically have large classes and little time for lesson preparation. Few resources are available to provide the preliminary training that population education instructors need. An organizational structure responsible for implementing population education was formed as a first step in gaining official support. The 3-part organization included representatives of all the major geographic regions and categories of educational personnel. A permanent, full time technical team was recruited from the staff of the Ministry of Public Education, a scientific resource group comprised of experts in fields related to population education was assembled, and a group of collaborating teachers was formed to participate in training trainers, assist in testing new educational materials, and promote population education. The Association for the Promotion of Population Education in Madagascar has attempted to establish groups in the 112 subprefectures. Respect for the sociocultural values of the diverse ethnic groups in Madagascar is a guiding principle in determination of program content. The traditional desire for a large family as a sign of respect for the ancestors is examined in the light of current economic and demographic realities. Involvement of parents, teachers, and local officials in population education seminars counters the perception of population education as externally imposed. The cooperation of teachers is sought by involving them in program development and by assuring them that their autonomy will not be threatened by the new teaching approach to population education. The population education program seeks to cooperate with other development programs to maximize impact and minimize competition for scarce resources. PMID:12286389

  13. Dipoles of the South East Madagascar Current

    NASA Astrophysics Data System (ADS)

    Ridderinkhof, W.; Le Bars, D.; Heydt, A. S.; Ruijter, W. P. M.

    2013-02-01

    Satellite altimetry data covering 18 years together with hydrographic observations around south Madagascar show that after separation from the coast, the South East Madagascar Current (SEMC) propagates southwestward and breaks up into a regular series of symmetric counter-rotating vortex pairs. Most of them split and propagate into the Agulhas retroflection system. Interannual variability of the dipole formation is related to the El Nino-Southern Oscillation. In the observation period two "early" Agulhas retroflection events appeared both related to strong Madagascar dipoles. The symmetry of the dipoles may originate from the boundary current where negative vorticity on the inshore side is adjacent to positive vorticity further offshore.

  14. Eating the dead in Madagascar.

    PubMed

    Campbell, Gwyn

    2013-12-01

    Cannibalism has been poorly understood and has seldom been studied, since it was often suppressed by missionaries and colonial administrators, and very few societies still practise it. Cannibalistic practices are more complex than was originally thought. They may be supported in societies under stress or in times of famine, to reflect aggression and antisocial behaviour (in cases where the bodies of enemies killed in battle or people who have harmed the family are eaten), or to honour a dead kinsman. It was, for example, noted in Madagascar during the imperial campaigns of Ranavalona I in the period 1829 - 1853. Two types of cannibalism have been described: exocannibalism, where enemies were consumed, and endocannibalism, where dead relatives were eaten to assist their passing to the world of the ancestors, or to prolong contact with beloved and admired family members and absorb their good qualities. This article reviews some of the beliefs and motivations that surrounded the cannibalistic practices of the people of Madagascar in the 19th century.  PMID:24300654

  15. Provenance and tectonic significance of the Palaeoproterozoic metasedimentary successions of central and nothern Madagascar

    USGS Publications Warehouse

    De Waele, B.; Thomas, Ronald J.; Macey, P.H.; Horstwood, M.S.A.; Tucker, R.D.; Pitfield, P.E.J.; Schofield, D.I.; Goodenough, K.M.; Bauer, W.; Key, R.M.; Potter, C.J.; Armstrong, R.A.; Miller, J.A.; Randriamananjara, T.; Ralison, V.; Rafahatelo, J.-M.; Rabarimanana, M.; Bejoma, M.

    2011-01-01

    New detrital zircon U–Pb age data obtained from various quartzite units of three spatially separated supracrustal packages in central and northern Madagascar, show that these units were deposited between 1.8 and 0.8 Ga and have similar aged provenances. The distribution of detrital zircon ages indicates an overwhelming contribution of sources with ages between 2.5 and 1.8 Ga. Possible source rocks with an age of 2.5 Ga are present in abundance in the crustal segments (Antananarivo, Antongil and Masora Domains) either side of a purported Neoproterozoic suture ("Betsimisaraka Suture Zone"). Recently, possible source rocks for the 1.8 Ga age peak have been recognised in southern Madagascar. All three supracrustal successions, as well as the Archaean blocks onto which they were emplaced, are intruded by mid-Neoproterozoic magmatic suites placing a minimum age on their deposition. The similarities in detrital pattern, maximum and minimum age of deposition in the three successions, lend some support to a model in which all of Madagascar's Archaean blocks form a coherent crustal entity (the Greater Dharwar Craton), rather than an amalgamate of disparate crustal blocks brought together only during Neoproterozoic convergence. However, potential source terranes exist outside Madagascar and on either side of the Neoproterozoic sutures, so that a model including a Neoproterozoic suture in Madagascar cannot be dispelled outright.

  16. The odd man out in Sub-Saharan Africa: understanding the tobacco use prevalence in Madagascar

    PubMed Central

    2013-01-01

    Background The tobacco industry has globalized and tobacco use continues to increase in low- and middle-income countries. Yet, the data and research to inform policy initiatives for addressing this phenomenon is sparse. This study aims to estimate the prevalence of adult tobacco use in 17 Sub-Saharan Africa (SSA) countries, and to identify key factors associated with adult tobacco consumption choices (smoked, smokeless tobacco and dual use) in Madagascar. Methods We used Demographic Health Survey for estimating tobacco use prevalence among adults in SSA. A multinomial logistic regression model was used to identify key determinants of adult tobacco consumption choices in Madagascar. Results While differences in tobacco use exist in SSA, Madagascar has exceptionally higher prevalence rates (48.9% of males; 10.3% of females). The regression analyses showed complexity of tobacco use in Madagascar and identified age, education, wealth, employment, marriage, religion and place of residence as factors significantly associated with the choice of tobacco use among males, while age, wealth, and employment were significantly associated with that of females. The effects, however, differ across the three choices of tobacco use compared to non-use. Conclusions Tobacco use in Madagascar was higher than the other 16 SSA countries. Although the government continues to enact policies to address the problem, there is a need for effective implementation and enforcement. There is also the need for health education to modify social norms and denormalize tobacco use. PMID:24044737

  17. Cryopreservation of Alkaloid-Producing Cell Cultures of Periwinkle (Catharanthus roseus) 1

    PubMed Central

    Chen, Tony H. H.; Kartha, Kutty K.; Leung, Nicholas L.; Kurz, Wolfgang G. W.; Chatson, Kenneth B.; Constabel, Friedrich

    1984-01-01

    A procedure for cryogenic storage of alkaloid producing cell lines of periwinkle, Catharanthus roseus (L.) G. Don., has been developed. The procedure differs from established cryopreservation protocols in several aspects. Specifically, 4-day-old suspension subcultures of three cell lines were precultured in nutrient media supplemented with 1 molar sorbitol for 6 to 20 hours. The cells were then incubated in nutrient media with 1 molar sorbitol plus 5% DMSO in an ice bath for 1 hour and, thereafter, were frozen in this solution at a cooling rate of 0.5°C per minute to −40°C prior to immersion in liquid nitrogen (LN). After rapid thawing in a 40°C water bath, the regrowth of LN stored cells was achieved by transferring them without washing onto filter paper discs over nutrient media solidified with agar for a period of 4 to 5 hours. The filter paper discs with the cells were then transferred to fresh media of the same composition for regrowth. The viability immediately after thawing as evaluated by the 2,3,5-triphenyl tetrazolium chloride method was about 60% of controls. Suspension cultures established from LN stored cells retained the capability for alkaloid synthesis and accumulation. Images Fig. 8 PMID:16663695

  18. ZCT1 and ZCT2 transcription factors repress the activity of a gene promoter from the methyl erythritol phosphate pathway in Madagascar periwinkle cells.

    PubMed

    Chebbi, Mouadh; Ginis, Olivia; Courdavault, Vincent; Glévarec, Gaëlle; Lanoue, Arnaud; Clastre, Marc; Papon, Nicolas; Gaillard, Cécile; Atanassova, Rossitza; St-Pierre, Benoit; Giglioli-Guivarc'h, Nathalie; Courtois, Martine; Oudin, Audrey

    2014-10-15

    In Catharanthus roseus, accumulating data highlighted the existence of a coordinated transcriptional regulation of structural genes that takes place within the secoiridoid biosynthetic branch, including the methyl erythritol phosphate (MEP) pathway and the following steps leading to secologanin. To identify transcription factors acting in these pathways, we performed a yeast one-hybrid screening using as bait a promoter region of the hydroxymethylbutenyl 4-diphosphate synthase (HDS) gene involved in the responsiveness of C. roseus cells to hormonal signals inducing monoterpene indole alkaloid (MIA) production. We identified that ZCT2, one of the three members of the zinc finger Catharanthus protein (ZCT) family, can bind to a HDS promoter region involved in hormonal responsiveness. By trans-activation assays, we demonstrated that ZCT1 and ZCT2 but not ZCT3 repress the HDS promoter activity. Gene expression analyses in C. roseus cells exposed to methyljasmonate revealed a persistence of induction of ZCT2 gene expression suggesting the existence of feed-back regulatory events acting on HDS gene expression in correlation with the MIA production. PMID:25108262

  19. A rehabilitation training partnership in Madagascar.

    PubMed

    Andrianabela, Sonia; Hariharan, Ram; Ford, Helen L; Chamberlain, M Anne

    2015-09-01

    We describe here the development of a mid-level training programme for doctors in Madagascar to direct regional and national rehabilitation services. Eight doctors enrolled and all gained their diplomas and have gone on to form the Association of Physical and Rehabilitation Medicine of Madagascar, which is leading further training and service developments. The course was specific to Madagascar's needs, and was devised according to the vision of the senior rehabilitation specialist in the Ministry of Health in Madagascar with support from the University of Antananarivo. The syllabus was developed with a senior Rehabilitation Medicine consultant responsible for setting up a comprehensive range of services and teaching in a University teaching hospital in the UK. Major barriers to success include the economic and political situation in Madagascar, which worsened steadily over the period of the training, the lack of resources for health, rehabilitation and rehabilitation workshops, and the withdrawal of aid. The sustainability of the training and the improved services that have been initiated will be evaluated, but these will be influenced by the situation of the country. It is hoped that this description of a highly practical training using modern teaching methods will be of use in other low-resource countries. Much of the teaching input was given by clinicians from a UK teaching hospital, and this resource will continue to be needed. PMID:26271518

  20. Asystasia mosaic Madagascar virus: a novel bipartite begomovirus infecting the weed Asystasia gangetica in Madagascar.

    PubMed

    De Bruyn, Alexandre; Harimalala, Mireille; Hoareau, Murielle; Ranomenjanahary, Sahondramalala; Reynaud, Bernard; Lefeuvre, Pierre; Lett, Jean-Michel

    2015-06-01

    Here, we describe for the first time the complete genome sequence of a new bipartite begomovirus in Madagascar isolated from the weed Asystasia gangetica (Acanthaceae), for which we propose the tentative name asystasia mosaic Madagascar virus (AMMGV). DNA-A and -B nucleotide sequences of AMMGV were only distantly related to known begomovirus sequence and shared highest nucleotide sequence identity of 72.9 % (DNA-A) and 66.9 % (DNA-B) with a recently described bipartite begomovirus infecting Asystasia sp. in West Africa. Phylogenetic analysis demonstrated that this novel virus from Madagascar belongs to a new lineage of Old World bipartite begomoviruses. PMID:25900620

  1. Receiver function analysis and preliminary body wave tomography of the MACOMO network in Madagascar

    NASA Astrophysics Data System (ADS)

    Pratt, M. J.; Wysession, M. E.; Wiens, D. A.; Nyblade, A.; Aleqabi, G. I.; Shore, P.; Rambolamana, G.; Sy Tanjona Andriampenomanana ny Ony, F.; Rakotondraibe, T.

    2013-12-01

    We present results from a set of seismological studies of the continental island of Madagascar using new seismic data from the NSF-funded MACOMO (MAdagascar, COmores, and MOzambique) IRIS PASSCAL broadband seismometer array. MACOMO involved the deployment during 2011-2013 of 26 broadband seismometers in Madagascar and 6 seismometers in Mozambique, providing the first seismic imaging across the world's 4th-largest island. We present preliminary crustal structure variations from receiver function analyses and body wave tomography results. We calculate radial receiver functions for all Madagascar stations and use the weighted linear regression methodology of Herrmann and Ammon [2002] to invert for shear velocity. Upper mantle and crustal structures from the receiver function analyses are used to help determine starting models for the teleseismic travel-time tomography. The tectonic structure of Madagascar is generally divided into four crustal blocks. Initial seismic imaging shows that the Archean Antongil block that runs along the east of the island has the thickest crust (>40 km) and three Proterozoic terranes that make up the central highlands and are bounded by fault and shear zones are closer to the average crustal thickness (35 km). There has been late Cenozoic intraplate volcanism in northern and central Madagascar (as recently as 1 million years ago), and different hypotheses for its origin will be evaluated by the preliminary results from the three different seismic studies. Complete analyses will be done incorporating seismic data from simultaneous and complementary array of both land- and ocean-based seismometers from French and German deployments.

  2. Pneumonic Plague Outbreak, Northern Madagascar, 2011

    PubMed Central

    Richard, Vincent; Herindrainy, Perlinot; Soanandrasana, Rahelinirina; Ratsitoharina, Maherisoa; Rakotomanana, Fanjasoa; Andrianalimanana, Samuel; Scholz, Holger C.; Rajerison, Minoarisoa

    2015-01-01

    Yersinia pestis, the causative agent of plague, is endemic to Madagascar, particularly to the central highlands. Although plague has not been previously reported in northern Madagascar, an outbreak of pneumonic plague occurred in this remote area in 2011. Over a 27-day period, 17 suspected, 2 presumptive, and 3 confirmed human cases were identified, and all 15 untreated 20 patients died. Molecular typing of Y. pestis isolated from 2 survivors and 5 Rattus rattus rat samples identified the Madagascar-specific 1.ORI3-k single-nucleotide polymorphism genotype and 4 clustered regularly interspaced short palindromic repeat patterns. This outbreak had a case-fatality rate of 100% for nontreated patients. The Y. pestis 1.ORI3-k single-nucleotide polymorphism genotype might cause larger epidemics. Multidrug-resistant strains and persistence of the pathogen in natural foci near human settlements pose severe risks to populations in plague-endemic regions and require outbreak response strategies. PMID:25530466

  3. Pneumonic plague outbreak, Northern Madagascar, 2011.

    PubMed

    Richard, Vincent; Riehm, Julia M; Herindrainy, Perlinot; Soanandrasana, Rahelinirina; Ratsitoharina, Maherisoa; Rakotomanana, Fanjasoa; Andrianalimanana, Samuel; Scholz, Holger C; Rajerison, Minoarisoa

    2015-01-01

    Yersinia pestis, the causative agent of plague, is endemic to Madagascar, particularly to the central highlands. Although plague has not been previously reported in northern Madagascar, an outbreak of pneumonic plague occurred in this remote area in 2011. Over a 27-day period, 17 suspected, 2 presumptive, and 3 confirmed human cases were identified, and all 15 untreated 20 patients died. Molecular typing of Y. pestis isolated from 2 survivors and 5 Rattus rattus rat samples identified the Madagascar-specific 1.ORI3-k single-nucleotide polymorphism genotype and 4 clustered regularly interspaced short palindromic repeat patterns. This outbreak had a case-fatality rate of 100% for nontreated patients. The Y. pestis 1.ORI3-k single-nucleotide polymorphism genotype might cause larger epidemics. Multidrug-resistant strains and persistence of the pathogen in natural foci near human settlements pose severe risks to populations in plague-endemic regions and require outbreak response strategies. PMID:25530466

  4. Geological evolution of the Neoproterozoic Bemarivo Belt, northern Madagascar

    USGS Publications Warehouse

    Thomas, Ronald J.; De Waele, B.; Schofield, D.I.; Goodenough, K.M.; Horstwood, M.; Tucker, R.; Bauer, W.; Annells, R.; Howard, K. J.; Walsh, G.; Rabarimanana, M.; Rafahatelo, J.-M.; Ralison, A.V.; Randriamananjara, T.

    2009-01-01

    The broadly east-west trending, Late Neoproterozoic Bemarivo Belt in northern Madagascar has been re-surveyed at 1:100 000 scale as part of a large multi-disciplinary World Bank-sponsored project. The work included acquisition of 14 U-Pb zircon dates and whole-rock major and trace element geochemical data of representative rocks. The belt has previously been modelled as a juvenile Neoproterozoic arc and our findings broadly support that model. The integrated datasets indicate that the Bemarivo Belt is separated by a major ductile shear zone into northern and southern "terranes", each with different lithostratigraphy and ages. However, both formed as Neoproterozoic arc/marginal basin assemblages that were translated southwards over the north-south trending domains of "cratonic" Madagascar, during the main collisional phase of the East African Orogeny at ca. 540 Ma. The older, southern terrane consists of a sequence of high-grade paragneisses (Sahantaha Group), which were derived from a Palaeoproterozoic source and formed a marginal sequence to the Archaean cratons to the south. These rocks are intruded by an extensive suite of arc-generated metamorphosed plutonic rocks, known as the Antsirabe Nord Suite. Four samples from this suite yielded U-Pb SHRIMP ages at ca. 750 Ma. The northern terrane consists of three groups of metamorphosed supracrustal rocks, including a possible Archaean sequence (Betsiaka Group: maximum depositional age approximately 2477 Ma) and two volcano-sedimentary sequences (high-grade Milanoa Group: maximum depositional age approximately 750 Ma; low grade Daraina Group: extrusive age = 720-740 Ma). These supracrustal rocks are intruded by another suite of arc-generated metamorphosed plutonic rocks, known as the Manambato Suite, 4 samples of which gave U-Pb SHRIMP ages between 705 and 718 Ma. Whole-rock geochemical data confirm the calc-alkaline, arc-related nature of the plutonic rocks. The volcanic rocks of the Daraina and Milanoa groups also show characteristics of arc-related magmatism, but include both calc-alkaline and tholeiitic compositions. It is not certain when the two Bemarivo terranes were juxtaposed, but ages from metamorphic rims on zircon suggest that both the northern and southern terranes were accreted to the northern cratonic margin of Madagascar at about 540-530 Ma. Terrane accretion included the assembly of the Archaean Antongil and Antananarivo cratons and the high-grade Neoproterozoic Anaboriana Belt. Late- to post-tectonic granitoids of the Maevarano Suite, the youngest plutons of which gave ca. 520 Ma ages, intrude all terranes in northern Madagascar showing that terrane accretion was completed by this time. ?? 2009 Natural Environment Research Council (NERC).

  5. Earth structure and instrumental seismicity of Madagascar: Implications on the seismotectonics

    NASA Astrophysics Data System (ADS)

    Rindraharisaona, Elisa Josiane; Guidarelli, Mariangela; Aoudia, Abdlkarim; Rambolamanana, Gérard

    2013-05-01

    The aim of this study is to improve the knowledge of the seismotectonics of Madagascar. We first investigate the structure of the Earth beneath Madagascar through the joint inversion of receiver functions and Rayleigh wave group velocities. Then we use the obtained velocity models to relocate local earthquakes in order to analyse the distribution of seismicity. Finally, we use structural models and earthquake coordinates to compute focal mechanisms. Our retrieved Earth structure models confirm a thin lithosphere beneath Madagascar when compared to the nearby East African Rift. The High Plateau in the Central region coincides with the thinnest lithosphere over the slowest asthenosphere. Our results are in good agreement with the gravity anomalies and likely confirm a localised asthenospheric upwelling beneath the central part of Madagascar. The surface expression of the asthenospheric upwelling consists in a horst-graben structure. The moderate seismicity is localised along pre-existing structures reflecting an E-W extension that is mostly accommodated in the lower crust.

  6. Himasthla elongata: effect of infection on expression of the LUSTR-like receptor mRNA in common periwinkle haemocytes.

    PubMed

    Gorbushin, A M; Klimovich, A V; Iakovleva, N V

    2009-09-01

    The first mollusc mRNA coding G-protein-coupled transmembrane receptor (GPcapital ES, CyrillicR), homologous to human receptors LUSTR 1 (GPR107) and LUSTR 2 (GPR108), was isolated from haemocytes of common periwinkle Littorina littorea. The analyses showed that the full-length cDNA is 1935 bp long and is predicted to encode a 614 amino acid protein (named Lit-LUSTR) with a calculated molecular mass of 69.6 kDa and theoretical isoelectric point 7.59. Pair-wise comparisons between Lit-LUSTR and LUSTR proteins from human or mouse have approximately 38% identity and 56% similarity. Lit-LUSTR clusters with LUSTR-A sub-family proteins and is a first characterization of proteins containing Lung7TM-R domain in Mollusca. Significant differences were found between the Lit-LUSTR mRNA levels in haemocytes of healthy periwinkles and those naturally infected with the echinostome trematode Himasthla elongata. Down regulated expression of the LUSTR-like receptor caused by infection illustrates modification of the haemocyte receptor system and may be attributed to the previously demonstrated greater numbers of "immature" haemocytes in the circulation of infected snails. PMID:19460375

  7. Determination of arsenic species in edible periwinkles (Littorina littorea) by HPLC-ICPMS and XAS along a contamination gradient

    SciTech Connect

    Whaley-Martin, K. J.; Koch, I.; Reimer, K. J.

    2013-06-12

    Arsenic is naturally found in the tissues of marine animals, usually as the non-toxic arsenical arsenobetaine, but exposure to elevated arsenic concentrations in the environment may alter the arsenic species distribution within tissues of the organism. This study examined the arsenic species in the tissues of the marine periwinkle (Littorina littorea) along an arsenic concentration gradient in the sediment. The arsenicals in L. littorea were examined using the complementary analytical methods high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC–ICPMS) and X-ray absorption spectroscopy (XAS). Total arsenic concentrations in the periwinkle tissues ranged from 56 to 840 mg · kg-1 dry weight (equivalent to 13 to 190 mg · kg-1 wet weight). Inorganic arsenicals were found to be positively correlated with total arsenic concentrations (R2 = 0.993) and reached 600 mg · kg-1 dry weight, the highest reported to date in marine organisms. These high inorganic arsenic concentrations within this low trophic organism pose a potential toxicological risk to higher trophic consumers.

  8. Immunological and physiological responses of the periwinkle Littorina littorea during and after exposure to the toxic dinoflagellate Alexandrium minutum.

    PubMed

    Neves, Raquel A F; Figueiredo, Gisela M; Valentin, Jean Louis; da Silva Scardua, Patricia Mirella; Hégaret, Hélène

    2015-03-01

    Species of the dinoflagellate genus Alexandrium produce phycotoxins responsible for paralytic shellfish poisoning. Blooms of Alexandrium minutum reach very high concentrations of vegetative cells in the water column; and when these blooms occur, large numbers of toxic cysts can be produced and deposited on sediments becoming available to benthic species. The present study investigated the potential effect of exposure to toxic cysts of A. minutum on the periwinkle Littorinalittorea. Snails were exposed for nine days to pellicle cysts of toxic and non-toxic dinoflagellates, A. minutum and Heterocapsa triquetra, respectively, followed by six days of depuration while they were fed only H. triquetra. Toxin accumulation, condition index, immune and histopathological responses were analyzed. Histological alterations were also monitored in snails exposed to a harmful A. minutum bloom, which naturally occurred in the Bay of Brest. Snails exposed to toxic cysts showed abnormal behavior that seems to be toxin-induced and possibly related to muscle paralysis. Periwinkles accumulated toxins by preying on toxic cysts and accumulation appeared dependent on the time of exposure, increasing during intoxication period but tending to stabilize during depuration period. Toxic exposure also seemed to negatively affect hemocyte viability and functions, as ROS production and phagocytosis. Histological analyses revealed that toxic exposure induced damages on digestive organs of snails, both in laboratory and natural systems. This study demonstrates that an exposure to the toxic dinoflagellate A. minutum leads to sublethal effects on L. littorea, which may alter individual fitness and increase the susceptibility of snails to pathogens and diseases. PMID:25621399

  9. Determination of arsenic species in edible periwinkles (Littorina littorea) by HPLC-ICPMS and XAS along a contamination gradient.

    PubMed

    Whaley-Martin, K J; Koch, I; Reimer, K J

    2013-07-01

    Arsenic is naturally found in the tissues of marine animals, usually as the non-toxic arsenical arsenobetaine, but exposure to elevated arsenic concentrations in the environment may alter the arsenic species distribution within tissues of the organism. This study examined the arsenic species in the tissues of the marine periwinkle (Littorina littorea) along an arsenic concentration gradient in the sediment. The arsenicals in L. littorea were examined using the complementary analytical methods high performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICPMS) and X-ray absorption spectroscopy (XAS). Total arsenic concentrations in the periwinkle tissues ranged from 56 to 840 mg·kg(-1) dry weight (equivalent to 13 to 190 mg·kg(-1) wet weight). Inorganic arsenicals were found to be positively correlated with total arsenic concentrations (R(2)=0.993) and reached 600 mg·kg(-1) dry weight, the highest reported to date in marine organisms. These high inorganic arsenic concentrations within this low trophic organism pose a potential toxicological risk to higher trophic consumers. PMID:23588137

  10. Barriers to Student Success in Madagascar

    ERIC Educational Resources Information Center

    Wills, Abigail R.; Reuter, Kim E.; Gudiel, Arleen A.; Hessert, Bryan P.; Sewall, Brent J.

    2014-01-01

    Various indicators suggest that math and science students in many developing countries are lagging behind their counterparts in other nations. Using Madagascar as a case study, we aimed to: (1) evaluate the effectiveness of education among those enrolled in science and math programs at primary, secondary, and university institutions; and, (2)…

  11. Low-temperature evolution of the Morondava rift shoulder in western Madagascar

    NASA Astrophysics Data System (ADS)

    Giese, Jörg; Seward, Diane; Schreurs, Guido

    2010-05-01

    Separation of Madagascar from eastern Africa resulted in the development of sedimentary basins covering the west coast of Madagascar. The largest and oldest of these basins, the Morondava basin, is bound to the east by crystalline basement of Precambrian age and stretches into the Mozambique Channel to the west. The evolution of the sedimentary sequence is mainly influenced by (I) a Permo-Triassic continental failed rift (e.g. Clark, 1998), also referred to as the Karroo rift (e.g., Montenat et al., 1996) and (II) the early Jurassic separation of Madagascar from eastern Africa (Geiger et al., 2004). Deposits related to the Karroo rift are restricted to a narrow corridor along the basement-basin contact. The rift locus shifted to the west before final separation and relative southward displacement of Madagascar commenced in early Jurassic times (Geiger et al., 2004). In the central part of the basin, the basement-basin contact features a steep escarpment with an altitude difference of greater than 1000 m from the sedimentary plains to the crystalline basement. Here, apatite fission-track analysis of a series of both basement and sediment samples across the escarpment provides the possibility to study the low temperature evolution of the exhuming Precambrian basement in the rift basin shoulder and the associated thermal evolution of the sedimentary succession. The timing of basement surface exposure is constrained by the stratigraphic ages of the overlying sediments and modelling of the thermal evolution indicates post-depositional thermal overprinting of basement and Karroo age sediments with partial annealing of fission tracks related to burial by Mesozoic sediments. The temperatures of this heating / reheating of the basin shoulder increase towards the west in the presently exposed sequences. The westernmost sample experienced almost complete resetting of the detrital apatite grains. The general younging of the apparent apatite fission-track ages towards the west indicates activity of faults, re-activating inherited Precambrian structures along the present basin-basement contact during Karroo sedimentation. Furthermore, our data show that onset of final exhumation can be correlated with (I) the end of Madagascar's drift southward relative to Africa along the Davie Ridge in the Mozambique Channel during the Early Cretaceous (Coffin and Rabinowitz, 1988), (II) activity of the Marion hot spot beneath southern Madagascar and associated Late Cretaceous break-up between Madagascar and India (Storey et al., 1995), and (III) the collision of India with Eurasia and subsequent re-organization of transform faults and spreading ridges. References Clark, D.N. (1998): Review of the exploration potential of Madagascar. Houston Geological Society Bulletin, p. 23-29. Coffin, M.F. and Rabinowitz, P.D. (1988): Evolution of the conjugate east African-Madagascan Margins and the western Somali basins. GSA Special Paper 226, pp. 78. Geiger, M., Clark, D.N. and Mette, W. (2004): Reappraisal of the timing of the breakup of Gondwana based on sedimentological and seismic evidence from the Morondava Basin, Madagascar. Journal of African Earth Sciences, v. 38, p. 363-381. Montenat, C., Ramahavory, L. and Croisile, M. (1996): Tectonic and sedimentary evolution of the Western Madagascan margin during the Jurassic in the Morondava basin, Madagascar. Bulletin des centres de recherches Exploration-Production Elf Aquitaine, v. 20, p. 323-340. Storey, M., Mahoney, J.J., Saunders, A.D., Duncan, R.A., Kelley, S.P. and Coffin, M.F. (1995): Timing of hot spot-related volcanism and the break-up of Madagascar and India. Science, v. 267, p. 852-855.

  12. Could the Madagascar bloom be fertilized by Madagascan iron?

    NASA Astrophysics Data System (ADS)

    Srokosz, M. A.; Robinson, J.; McGrain, H.; Popova, E. E.; Yool, A.

    2015-08-01

    In the oligotrophic waters to the east of Madagascar, a large phytoplankton bloom is found to occur in late austral summer. This bloom is composed of nitrogen fixers and can cover up to ˜1% of the world's ocean surface area. Satellite observations show that its spatial structure is closely tied to the underlying mesoscale eddy field in the region. The causes of the bloom and its temporal behavior (timing of its initiation and termination) and spatial variability are poorly understood, in part due to a lack of in situ observations. Here an eddy resolving 1/12° resolution ocean general circulation model and Lagrangian particle tracking are used to examine the hypothesis that iron from sediments around Madagascar could be advected east by the mesoscale eddy field to fertilize the bloom, and that variability in advection could explain the significant interannual variability in the spatial extent of the bloom. The model results suggest that this is indeed possible and furthermore imply that the bloom could be triggered by warming of the mixed layer, leading to optimal conditions for nitrogen fixers to grow, while its termination could be due to iron exhaustion. It is found that advection of Madagascan iron could resupply the bloom region with this micronutrient in the period between the termination of one bloom and the initiation of the next in the following year.

  13. AMS 14C Dates for Extinct Lemurs from Caves in the Ankarana Massif, Northern Madagascar

    NASA Astrophysics Data System (ADS)

    Simons, Elwyn L.; Burney, David A.; Chatrath, Prithijit S.; Godfrey, Laurie R.; Jungers, William L.; Rakotosamimanana, Berthe

    1995-03-01

    An extensive late Quaternary fauna, including many extinct giant lemurs, has been collected recently in a 110+-km system of caves in the Ankarana Massif of northern Madagascar. AMS 14C dates for the acid-insoluble (collagen/gelatin) fraction of bones of the giant lemur Megaladapis (26,150 400 and 12,760 70 yr B.P.) confirm its presence in the area during the late Pleistocene and provide the first Pleistocene 14 C ages from bones of the extinct megafauna of the island. The first date from bones of the recently described extinct Babakotia radofilai (4400 60 yr B.P.) shows that it was present in northern Madagascar in mid-Holocene times. A comparatively recent age of 1020 50 yr B.P. for the extinct Archaeolemur indicates survival of this genus for at least a millennium after the first direct evidence for humans in Madagascar. This suggests that the island's "extinction window" may have represented a longer time span than would have been expected under the Blitzkrieg model of late Quaternary extinctions. A mid-Holocene age (4560 70 yr B.P.) for a bone sample of the small extant lemur Hapalemur simus indicates that the disappearance of this now-restricted species from the Ankarana occurred after this date. New data from the Ankarana and other sites on the island add to the consensus that major biotic changes occurred on Madagascar in the late Holocene.

  14. Introduction of rubella-containing-vaccine to Madagascar: implications for roll-out and local elimination

    PubMed Central

    Wesolowski, Amy; Mensah, Keitly; Brook, Cara E.; Andrianjafimasy, Miora; Winter, Amy; Buckee, Caroline O.; Razafindratsimandresy, Richter; Tatem, Andrew J.; Heraud, Jean-Michel; Metcalf, C. Jessica E.

    2016-01-01

    Few countries in Africa currently include rubella-containing vaccination (RCV) in their immunization schedule. The Global Alliance for Vaccines Initiative (GAVI) recently opened a funding window that has motivated more widespread roll-out of RCV. As countries plan RCV introductions, an understanding of the existing burden, spatial patterns of vaccine coverage, and the impact of patterns of local extinction and reintroduction for rubella will be critical to developing effective programmes. As one of the first countries proposing RCV introduction in part with GAVI funding, Madagascar provides a powerful and timely case study. We analyse serological data from measles surveillance systems to characterize the epidemiology of rubella in Madagascar. Combining these results with data on measles vaccination delivery, we develop an age-structured model to simulate rubella vaccination scenarios and evaluate the dynamics of rubella and the burden of congenital rubella syndrome (CRS) across Madagascar. We additionally evaluate the drivers of spatial heterogeneity in age of infection to identify focal locations where vaccine surveillance should be strengthened and where challenges to successful vaccination introduction are expected. Our analyses indicate that characteristics of rubella in Madagascar are in line with global observations, with an average age of infection near 7 years, and an impact of frequent local extinction with reintroductions causing localized epidemics. Modelling results indicate that introduction of RCV into the routine programme alone may initially decrease rubella incidence but then result in cumulative increases in the burden of CRS in some regions (and transient increases in this burden in many regions). Deployment of RCV with regular supplementary campaigns will mitigate these outcomes. Results suggest that introduction of RCV offers a potential for elimination of rubella in Madagascar, but also emphasize both that targeted vaccination is likely to be a lynchpin of this success, and the public health vigilance that this introduction will require. PMID:27122178

  15. Introduction of rubella-containing-vaccine to Madagascar: implications for roll-out and local elimination.

    PubMed

    Wesolowski, Amy; Mensah, Keitly; Brook, Cara E; Andrianjafimasy, Miora; Winter, Amy; Buckee, Caroline O; Razafindratsimandresy, Richter; Tatem, Andrew J; Heraud, Jean-Michel; Metcalf, C Jessica E

    2016-04-01

    Few countries in Africa currently include rubella-containing vaccination (RCV) in their immunization schedule. The Global Alliance for Vaccines Initiative (GAVI) recently opened a funding window that has motivated more widespread roll-out of RCV. As countries plan RCV introductions, an understanding of the existing burden, spatial patterns of vaccine coverage, and the impact of patterns of local extinction and reintroduction for rubella will be critical to developing effective programmes. As one of the first countries proposing RCV introduction in part with GAVI funding, Madagascar provides a powerful and timely case study. We analyse serological data from measles surveillance systems to characterize the epidemiology of rubella in Madagascar. Combining these results with data on measles vaccination delivery, we develop an age-structured model to simulate rubella vaccination scenarios and evaluate the dynamics of rubella and the burden of congenital rubella syndrome (CRS) across Madagascar. We additionally evaluate the drivers of spatial heterogeneity in age of infection to identify focal locations where vaccine surveillance should be strengthened and where challenges to successful vaccination introduction are expected. Our analyses indicate that characteristics of rubella in Madagascar are in line with global observations, with an average age of infection near 7 years, and an impact of frequent local extinction with reintroductions causing localized epidemics. Modelling results indicate that introduction of RCV into the routine programme alone may initially decrease rubella incidence but then result in cumulative increases in the burden of CRS in some regions (and transient increases in this burden in many regions). Deployment of RCV with regular supplementary campaigns will mitigate these outcomes. Results suggest that introduction of RCV offers a potential for elimination of rubella in Madagascar, but also emphasize both that targeted vaccination is likely to be a lynchpin of this success, and the public health vigilance that this introduction will require. PMID:27122178

  16. The origins of the giant pill-millipedes from Madagascar (Diplopoda: Sphaerotheriida: Arthrosphaeridae).

    PubMed

    Wesener, Thomas; Raupach, Michael J; Sierwald, Petra

    2010-12-01

    Giant pill-millipedes (order Sphaerotheriida) are large-bodied millipedes without poison glands which can roll-up into a complete ball. Their disconnected area of distribution spanning South Africa, Madagascar, India, SE Asia, Australia and New Zealand makes them interesting model organisms for biogeographic studies. The here presented phylogeny is based on a molecular dataset covering all areas of distribution with a special focus on Madagascar, where some species of giant pill-millipedes show island gigantism, reaching the size of a baseball. For our study, two mitochondrial genes (partial 16S rRNA and COI) as well as the complete nuclear 18S rDNA were sequenced. While many recent vertebrate studies hint that the ancestors of the recent Malagasy fauna crossed the >350 km wide Mozambique Channel several times, no such crossing was discovered in the Sphaerotheriida. For the first time in a molecular phylogenetic study of soil arthropods, a Madagascar-India group, the family Arthrosphaeridae, is recovered, hinting to a Gondwanan origin of the Sphaerotheriida. The Malagasy-Indian family Arthrosphaeridae forms a monophyletic, statistically well-supported group in all obtained trees. The giant pill-millipedes from Madagascar are paraphyletic because the Malagasy genus Sphaeromimus is the sister-taxon of the Indian Arthrosphaera. In Sphaeromimus, an ecotone shift occurred only once: the spiny forest species Sphaeromimus musicus forms the sister-clade to the species collected in rainforests and littoral rainforests. The two species of the Malagasy genus Zoosphaerium which express island gigantism form a monophyletic group in some trees, but these trees lack good statistical support. Deeper nodes inside the Sphaerotheriida, like the position of the Australian genera Procyliosoma and Epicyliosoma, the Southeast Asian family Zephroniidae and the South African genus Sphaerotherium could not be resolved. This study is the first genetic study inside the order Sphaerotheriida and provides a proper basis for future molecular biogeographic studies in millipedes and soil organisms from Madagascar. PMID:20813191

  17. Agro-Environmental Determinants of Avian Influenza Circulation: A Multisite Study in Thailand, Vietnam and Madagascar

    PubMed Central

    Paul, Mathilde C.; Gilbert, Marius; Desvaux, Stéphanie; Rasamoelina Andriamanivo, Harena; Peyre, Marisa; Khong, Nguyen Viet; Thanapongtharm, Weerapong; Chevalier, Véronique

    2014-01-01

    Outbreaks of highly pathogenic avian influenza have occurred and have been studied in a variety of ecological systems. However, differences in the spatial resolution, geographical extent, units of analysis and risk factors examined in these studies prevent their quantitative comparison. This study aimed to develop a high-resolution, comparative study of a common set of agro-environmental determinants of avian influenza viruses (AIV) in domestic poultry in four different environments: (1) lower-Northern Thailand, where H5N1 circulated in 2004–2005, (2) the Red River Delta in Vietnam, where H5N1 is circulating widely, (3) the Vietnam highlands, where sporadic H5N1 outbreaks have occurred, and (4) the Lake Alaotra region in Madagascar, which features remarkable similarities with Asian agro-ecosystems and where low pathogenic avian influenza viruses have been found. We analyzed H5N1 outbreak data in Thailand in parallel with serological data collected on the H5 subtype in Vietnam and on low pathogenic AIV in Madagascar. Several agro-environmental covariates were examined: poultry densities, landscape dominated by rice cultivation, proximity to a water body or major road, and human population density. Relationships between covariates and AIV circulation were explored using spatial generalized linear models. We found that AIV prevalence was negatively associated with distance to the closest water body in the Red River Delta, Vietnam highlands and Madagascar. We also found a positive association between AIV and duck density in the Vietnam highlands and Thailand, and with rice landscapes in Thailand and Madagascar. Our findings confirm the important role of wetlands-rice-ducks ecosystems in the epidemiology of AI in diverse settings. Variables influencing circulation of the H5 subtype in Southeast Asia played a similar role for low pathogenic AIV in Madagascar, indicating that this area may be at risk if a highly virulent strain is introduced. PMID:25029441

  18. A Way Forward for Healthcare in Madagascar?

    PubMed

    Marks, Florian; Rabehanta, Nathalie; Baker, Stephen; Panzner, Ursula; Park, Se Eun; Fobil, Julius N; Meyer, Christian G; Rakotozandrindrainy, Raphaël

    2016-03-15

    A healthcare utilization survey was conducted as a component of the Typhoid Fever Surveillance in Africa Program (TSAP). The findings of this survey in Madagascar contrasted with those in other sites of the program; namely, only 30% of the population sought healthcare at the government-provided healthcare facilities for fever. These findings promoted us to determine the drivers and barriers in accessing and utilizing healthcare in Madagascar. Here we review the results of the TSAP healthcare utilization initiative and place them in the context of the current organization of the Madagascan healthcare system. Our work highlights the demands of the population for access to appropriate healthcare and the need for novel solutions that can quickly provide an affordable and sustainable basic healthcare infrastructure until a government-funded scheme is in place. PMID:26933025

  19. New species of Polysphondylium from Madagascar.

    PubMed

    Cavender, James C; Landolt, John C; Romeralo, Maria; Perrigo, Allison; Vadell, Eduardo M; Stephenson, Steven L

    2016-01-01

    Two series of samples collected for isolation of dictyostelid cellular slime molds (dictyostelids) in Madagascar yielded a relatively large number of isolates of Polysphondylium. Most of these turned out to be species new to science that show varying degrees of clustering from unclustered to coremiform as well as an ability to migrate. Migratory ability (phototaxis) is a common feature of species assigned to Group 2 of the Polysphondylia and is common in the new species from Madagascar. Another common feature, clustering, appears to be a strategy for keeping fruiting bodies erect for a longer time in a climate that is relatively dry, whereas migratory ability may function seasonally when there is more rainfall. Thirteen species are described herein. Each of these is characterized by a particular set of distinguishing features, and collectively they expand our concept of the genus Polysphondylium. PMID:26490703

  20. Madagascar's grasses and grasslands: anthropogenic or natural?

    PubMed

    Vorontsova, Maria S; Besnard, Guillaume; Forest, Félix; Malakasi, Panagiota; Moat, Justin; Clayton, W Derek; Ficinski, Paweł; Savva, George M; Nanjarisoa, Olinirina P; Razanatsoa, Jacqueline; Randriatsara, Fetra O; Kimeu, John M; Luke, W R Quentin; Kayombo, Canisius; Linder, H Peter

    2016-01-27

    Grasses, by their high productivity even under very low pCO2, their ability to survive repeated burning and to tolerate long dry seasons, have transformed the terrestrial biomes in the Neogene and Quaternary. The expansion of grasslands at the cost of biodiverse forest biomes in Madagascar is often postulated as a consequence of the Holocene settlement of the island by humans. However, we show that the Malagasy grass flora has many indications of being ancient with a long local evolutionary history, much predating the Holocene arrival of humans. First, the level of endemism in the Madagascar grass flora is well above the global average for large islands. Second, a survey of many of the more diverse areas indicates that there is a very high spatial and ecological turnover in the grass flora, indicating a high degree of niche specialization. We also find some evidence that there are both recently disturbed and natural stable grasslands: phylogenetic community assembly indicates that recently severely disturbed grasslands are phylogenetically clustered, whereas more undisturbed grasslands tend to be phylogenetically more evenly distributed. From this evidence, it is likely that grass communities existed in Madagascar long before human arrival and so were determined by climate, natural grazing and other natural factors. Humans introduced zebu cattle farming and increased fire frequency, and may have triggered an expansion of the grasslands. Grasses probably played the same role in the modification of the Malagasy environments as elsewhere in the tropics. PMID:26791612

  1. Madagascar's grasses and grasslands: anthropogenic or natural?

    PubMed Central

    Besnard, Guillaume; Forest, Félix; Malakasi, Panagiota; Moat, Justin; Clayton, W. Derek; Ficinski, Paweł; Savva, George M.; Nanjarisoa, Olinirina P.; Razanatsoa, Jacqueline; Randriatsara, Fetra O.; Kimeu, John M.; Luke, W. R. Quentin; Kayombo, Canisius; Linder, H. Peter

    2016-01-01

    Grasses, by their high productivity even under very low pCO2, their ability to survive repeated burning and to tolerate long dry seasons, have transformed the terrestrial biomes in the Neogene and Quaternary. The expansion of grasslands at the cost of biodiverse forest biomes in Madagascar is often postulated as a consequence of the Holocene settlement of the island by humans. However, we show that the Malagasy grass flora has many indications of being ancient with a long local evolutionary history, much predating the Holocene arrival of humans. First, the level of endemism in the Madagascar grass flora is well above the global average for large islands. Second, a survey of many of the more diverse areas indicates that there is a very high spatial and ecological turnover in the grass flora, indicating a high degree of niche specialization. We also find some evidence that there are both recently disturbed and natural stable grasslands: phylogenetic community assembly indicates that recently severely disturbed grasslands are phylogenetically clustered, whereas more undisturbed grasslands tend to be phylogenetically more evenly distributed. From this evidence, it is likely that grass communities existed in Madagascar long before human arrival and so were determined by climate, natural grazing and other natural factors. Humans introduced zebu cattle farming and increased fire frequency, and may have triggered an expansion of the grasslands. Grasses probably played the same role in the modification of the Malagasy environments as elsewhere in the tropics. PMID:26791612

  2. Development of Environmental Education Programs for Protected Areas in Madagascar

    ERIC Educational Resources Information Center

    Ormsby, Alison

    2007-01-01

    Environmental education programs for schools in the peripheral zone of protected areas in Madagascar are still needed in numerous locations. My research investigated the status of environmental education and communication (EE&C) programs at Masoala National Park, Madagascar, as well as the attitudes of local residents toward the park and park…

  3. Development of Environmental Education Programs for Protected Areas in Madagascar

    ERIC Educational Resources Information Center

    Ormsby, Alison

    2007-01-01

    Environmental education programs for schools in the peripheral zone of protected areas in Madagascar are still needed in numerous locations. My research investigated the status of environmental education and communication (EE&C) programs at Masoala National Park, Madagascar, as well as the attitudes of local residents toward the park and park

  4. Why so scarce? Dictyopharidae from Madagascar (Hemiptera: Fulgoromorpha).

    PubMed

    Stroi?ski, Adam; Szwedo, Jacek

    2015-01-01

    A new genus and species of Dictyopharidae from Madagascar-Tupala occulta gen. et sp. nov. is described and illustrated. It is the third known dictyopharid and the second representing tribe Dictyopharini. Two other taxa with taxonomic problems ascribed to Dictyopharidae are discussed. The question of paucity of Dictyopharidae of Madagascar is raised and several possible explanations are presented. PMID:26624411

  5. Zonal jets in the Madagascar plankton bloom

    NASA Astrophysics Data System (ADS)

    Huhn, F.; von Kameke, A.; Prez-Muuzuri, V.; Olascoaga, M. J.; Beronavera, F. B.

    2012-04-01

    We study the relation between advection by mesoscale eddies and jets and the remarkable eastward propagation of the Madagascar plankton bloom. Analyzing geostrophic velocity fields from altimetry with state-of-the-art Lagrangian techniques, we find fast coherent zonal jets in the recently discovered South Indian Ocean Countercurrent (SICC) at the exact position of the bloom. The coherent jets have a length of up to 1500km and provide a fast transport to the east. We use a new simple Lagrangian metric, the Finite-Time Zonal Drift (FTZD) to quantify the zonal transport and find that the jets can partly explain the explosive eastward propagation seen in the evolution of the Madagascar plankton bloom. Numerical experiments with a passive tracer concentration released at a known upwelling region south of Madagascar also supports the hypothesis that an important nutrient source of the plankton bloom could be located in that area. Until now, the reasons for the eastward propagation of the bloom's front remained totally unclear and even a propagation against the mean flow had been suggested. Moreover, we extract zonal jet-like Lagrangian Coherent Structures (LCS) from fields of the well-established Finite-Time Lyapunov Exponents (FTLE) that can be identified with barriers to meridional transport. Comparing these LCS with fields of chlorophyll concentration of the Madagascar plankton bloom measured by the Sea-viewing Wide Field-of view Sensor (SeaWiFS), we show that the location of jet-like LCS coincide with the boundaries of the plankton bloom, e.g. an LCS prevents cross-transport and confines the bloom to one side of the LCS. Phytoplankton is one of the few natural tracers that can be used to verify if the ubiquitous zonal mesoscale jets act as transport barriers. In the case of the Madagascar plankton bloom, we find clear evidence that the zonal jets in the SICC indeed represent transport barriers to the ambient flow and shape the northern boundary of the chlorophyll distribution. In other countercurrents, the Atlantic North Equatorial Countercurrent off Brazil and the Pacific North Equatorial Countercurrent off Indonesia, similar plankton patterns with sharp meandering boundaries appear which suggests that the results presented here might be valid more generally.

  6. Modulation of mitogen-activated protein kinases (MAPK) activity in response to different immune stimuli in haemocytes of the common periwinkle Littorina littorea.

    PubMed

    Iakovleva, Nadya V; Gorbushin, Alexander M; Storey, Kenneth B

    2006-09-01

    The modulation of mitogen-activated protein kinase (MAPK) activity in haemocytes of the common periwinkle (Littorina littorea) in response to immune challenges by lipopolysaccharide from Echerichia coli (LPS), mannan from baker's yeast Saccharomyces cerevisiae and secretory-excretory products (SEP) of trematodes Himasthla elongata (Echinostomatidae) or after the treatment with phorbol ester (PMA) has been studied by Western blotting using affinity purified rabbit polyclonal antibodies. Exposure of the cells in suspension to PMA, LPS and mannan triggered an activation of p38 and ERK2. The JNK-mediated cascade was modulated differently by the elicitors examined. PMA treatment caused a transient activation of the JNK54 isoform, LPS exposure resulted in a decrease in activity of JNK46, and mannan had no effect on JNK phosphorylation status. Incubation of periwinkle haemocytes in culture medium containing trematode SEP did not affect the activity of any MAPK. PMID:16533608

  7. An Abelisauroid Theropod Dinosaur from the Turonian of Madagascar

    PubMed Central

    Farke, Andrew A.; Sertich, Joseph J. W.

    2013-01-01

    Geophysical evidence strongly supports the complete isolation of India and Madagascar (Indo-Madagascar) by ∼100 million years ago, though sparse terrestrial fossil records from these regions prior to ∼70 million years ago have limited insights into their biogeographic history during the Cretaceous. A new theropod dinosaur, Dahalokely tokana, from Turonian-aged (∼90 million years old) strata of northernmost Madagascar is represented by a partial axial column. Autapomorphies include a prominently convex prezygoepipophyseal lamina on cervical vertebrae and a divided infraprezygapophyseal fossa through the mid-dorsal region, among others. Phylogenetic analysis definitively recovers the species as an abelisauroid theropod and weakly as a noasaurid. Dahalokely is the only known dinosaur from the interval during which Indo-Madagascar likely existed as a distinct landmass, but more complete material is needed to evaluate whether or not it is more closely related to later abelisauroids of Indo-Madagascar or those known elsewhere in Gondwana. PMID:23637961

  8. Economie et enseignement a Madagascar. (Economy and Education in Madagascar.) Financement des systemes educatifs: etudes de cas Nationales 8.

    ERIC Educational Resources Information Center

    Hugon, Philippe

    The purpose of this volume is to analyze the problems of school finance in Madagascar, including those that have arisen in the past decade and those anticipated in the present decade (through 1980). More generally, this book examines past and future connections between the economic and educational systems in Madagascar. The author examines the

  9. Occurrence of 210Po in periwinkle (Littorina undulata, Gray, 1839) collected from Kudankulam (Gulf of Mannar (GOM), Southeast coast of India).

    PubMed

    Sunith Shine, S R; Feroz Khan, M; Godwin Wesley, S

    2013-10-15

    Polonium-210 activity concentration was analysed in the whole body tissue of periwinkle Littorina undulata collected from intertidal rocky shore along Kudankulam coast. We carried out the study for a period of 12 months (2011-2012) focusing on three seasons. (210)Po was found non-uniformly distributed among the periwinkles depending on the allometry. The (210)Po accumulation showed a significant difference between seasons (p<0.05). Smaller sized winkles registered higher activity of (210)Po compared to larger ones (p<0.05). The overall activity range of (210)Po varied from 13.5 to 58.9 Bq/kg (wet). The activity of (210)Po was also quantified in seawater and intertidal sediments to calculate the biological concentration factor (BCF) and radiation dose rate. The dose rate to the winkles was performed using ERICA Assessment Tool and it was within the prescribed limit. The intake of (210)Po through periwinkles delivered an effective dose in the range of 2.2-9.6 μSv/y to human beings. PMID:23871576

  10. Detecting cryptic speciation in the widespread and morphologically conservative carpet chameleon (Furcifer lateralis) of Madagascar.

    PubMed

    Florio, A M; Ingram, C M; Rakotondravony, H A; Louis, E E; Raxworthy, C J

    2012-07-01

    Species delimitation within recently evolved groups can be challenging because species may be difficult to distinguish morphologically. Following the General Lineage Concept, we apply a multiple evidence approach to assess species limits within the carpet chameleon Furcifer lateralis, which is endemic to Madagascar and exported in large numbers for the pet trade. Cryptic speciation within F. lateralis was considered likely because this species (1) has a vast distribution, (2) occupies exceptionally diverse habitats and (3) exhibits subtle regional differences in morphology. Phylogenetic trees reconstructed using nuclear and mitochondrial genes recovered three well-supported clades corresponding with geography. Morphological results based on canonical variates analysis show that these clades exhibit subtle differences in head casque morphology. Ecological niche modelling results found that these phylogenetic groups also occupy unique environmental space and exhibit patterns of regional endemism typical of other endemic reptiles. Combined, our findings provide diverse yet consistent evidence for the existence of three species. Consequently, we elevate the subspecies F. lateralis major to species rank and name a new species distributed in northern and western Madagascar. Initial ecological divergence, associated with speciation of F. lateralis in humid eastern habitat, fits the Ecographic Constraint model for species diversification in Madagascar. By contrast, the second speciation event provides some support for the Riverine Barrier model, with the Mangoky River possibly causing initial isolation between species. These findings thus support two contrasting models of speciation within closely related species and demonstrate the utility of applying a combined-evidence approach for detecting cryptic speciation. PMID:22686488

  11. Seismic anisotropy of the lithosphere-asthenosphere system beneath southern Madagascar

    NASA Astrophysics Data System (ADS)

    Reiss, Miriam Christina; Rümpker, Georg; Tilmann, Frederik; Yuan, Xiaohui; Josiane Rindraharisaona, Elisa

    2015-04-01

    Madagascar is considered as a key region with respect to the assembly and break-up of the supercontinent Gondwana. Following the collision between East- and West-Gondwana (~700-650 Ma), its position was central to the Panafrican orogenesis. Madagascar then separated from East Africa and later from the Indian and Antarctic plates until these processes came to a halt about 69 Ma ago. Today, Madagascar consists of different tectonic units; the eastern parts (two thirds of the island) are composed mainly of Precambian rocks, whereas the western part is dominated by sedimentary deposits. Furthermore, southern Madagascar is characterized by several NS to NW-SE trending shear zones. Madagascar has been the target of a number of geological studies, but seismological investigations of the presumed complex lithosphere-asthenosphere system and of deeper upper-mantle structures are sparse. To increase our understanding of these structures and related tectonic processes, we installed a dense temporary seismic network in southern Madagascar. It consisted of 25 broadband and 25 short-period stations, which were in operation for up to 2 years between 2012 and 2014. The broadband stations crossed the island along an east-west profile; the eastern section was supplemented by a network of short-period stations. Here we present results from shear-wave splitting analyses to infer the seismic anisotropy of the lithosphere-asthenosphere system in response to deformational processes. The polarization of the fast shear wave and the delay time between the fast and slow waves provide constraints on the anisotropic fabric. For our study, we use SKS-phases from up to 12 events recorded at the temporary stations and from 10 events at the permanent GEOFON station VOI. We first apply a single-event splitting analysis by minimizing the transverse component. For stations that do not show a significant azimuthal dependence of the splitting parameters, we also apply a joint inversion involving all recorded SKS waveforms. Our preliminary results exhibit delay times between 0.4 and 1.5 s. In the center of the E-W profile, fast axes are mainly oriented NNW-SSE, whereas east of the Ranotsara shear zone, fast axes are oriented NE-SW. Additionally, we will apply splitting analysis of Ps phases as well as waveform modelling to resolve the possible influence of the crust on the anisotropy inferred from the SKS phases.

  12. [Epidemiological data on the plague in Madagascar].

    PubMed

    Ratsitorahina, M; Chanteau, S; Rosso, M L; Randriambelosoa, J; Ratsifasoamanana, L; Rabarijaona, L P; Mauclère, P; Migliani, R

    2002-01-01

    The first case of plague was introduced in Madagascar in 1898 in the east coast by way of boat from India. In 1921, plague reach the highlands and a large epidemic over the next twenty years. Until the beginning of the 80's, only of few case were identified, notified mostly in rural setting. However gradually it has re-emerged as a public health problem. Urban plague is located in the city of Antananarivo (resurgence in 1978 after 28 years of apparent silence) and in Mahajanga port (resurgence in 1991 after 63 years of silence). The reactivation of the Plague National Control Program from 1994 will allow better surveillance. The aim of this analysis is to update the epidemiological data on human plague in Madagascar based on reported cases obtained from the Central Lab of the Pasteur Institute of Madagascar from 1980 to 2001 (16,928 suspected cases of which 3,500 are likely positives or confirmed positives). The Plague season runs from October to March on the central highlands and July to November on the north-western coast. Sex-ratio male/female is 1.3/1, and the age-group of 5 to 25 years is more affected. The case fatality rate was 40% in the beginning of the 1980's, and decreased to 20% by the end of the 1990's. The percentage of case with pulmonary plague decrease from 15% to less than 5%. However, geographical extension is demonstrated: 4 districts in 1980, 30 districts in 1999 and 21 districts in 2001. In 2002, the diffusion of a new rapid test (reagent strip) in the primary health centres (CSB) in 42 endemic districts may help to decrease the morbidity and the letality due to plague and improve its control at the national level. PMID:12643093

  13. Plague, a reemerging disease in Madagascar.

    PubMed

    Chanteau, S; Ratsifasoamanana, L; Rasoamanana, B; Rahalison, L; Randriambelosoa, J; Roux, J; Rabeson, D

    1998-01-01

    Human cases of plague, which had virtually disappeared in Madagascar after the 1930s, reappeared in 1990 with more than 200 confirmed or presumptive cases reported each year since. In the port of Mahajanga, plague has been reintroduced, and epidemics occur every year. In Antananarivo, the capital, the number of new cases has increased, and many rodents are infected with Yersinia pestis. Despite surveillance for the sensitivity of Y. pestis and fleas to drugs and insecticides and control measures to prevent the spread of sporadic cases, the elimination of plague has been difficult because the host and reservoir of the bacillus, Rattus rattus, is both a domestic and a sylvatic rat. PMID:9452403

  14. Tungiasis Outbreak in Travelers From Madagascar.

    PubMed

    Belaz, Sorya; Gay, Eugénie; Robert-Gangneux, Florence; Beaucournu, Jean-Claude; Guiguen, Claude

    2015-01-01

    Seven patients from a group of 16 travelers were diagnosed at our institution with one or more sand fleas on their toes, 1 day to 3 weeks after returning from Madagascar. A questionnaire was sent to the whole group to collect clinical and epidemiological information, which showed that 9 of 13 (69%) had received pre-travel medical advice, but none were aware of sand flea; thus prevention measures were rarely applied. Five of seven (71%) patients wore open sandals throughout the trip. Overall, 10 sand fleas were extracted. PMID:26031478

  15. The Effect of Recent Volcanic Activity on the Seismic Structure of Madagascar

    NASA Astrophysics Data System (ADS)

    Wysession, M. E.; Aleqabi, G. I.; Pratt, M. J.; Shore, P.; Wiens, D. A.; Nyblade, A.; Rambolamanana, G.; Andriampenomanana Ny Ony, F. S. T.; Tsiriandrimanana, R.

    2014-12-01

    The seismic structure of Madagascar is determined using ambient-noise and two-plane-wave earthquake surface waves analyses. A deep low-velocity anomaly is seen in regions of recent volcanic activity in the central and northern regions of the island. The primary data used are from the 2011-2013 MACOMO (Madagascar, the Comoros, and Mozambique) broadband seismic array from the PASSCAL program of IRIS (Incorporated Research Institutions for Seismology), funded by the NSF. Additional data came from the RHUM-RUM project (led by G. Barruol and K. Sigloch), the Madagascar Seismic Profile (led by F. Tilmann), and the GSN. For the ambient-noise study, Rayleigh wave green's functions for all interstation paths are extracted from the broadband seismic data recorded from August 2011 until October 2013. Rayleigh wave group and phase velocity dispersion curves are extracted in the 8 - 50 s period range, identifying shallow crustal structure. For deeper structure, the two-plane-wave method is used on teleseismic earthquake data to obtain surface wave phase velocities in the 20 - 182 s period range. In the inversion, a finite-frequency kernel is used for each period, and a 1-D shear velocity structure is determined at each location. A three-dimensional S-wave velocity model of the crust and upper mantle is obtained from assembling the 1-D models. Preliminary results show a good correlation between the Rayleigh wave velocities and the geology of Madagascar, which includes areas of ancient Archaean craton. The slowest seismic velocities are associated with known volcanic regions in both the central and northern regions, which have experienced volcanic activity within the past million years.

  16. Temporal and spatial evolution of dynamic support from river profiles: A framework for Madagascar

    NASA Astrophysics Data System (ADS)

    Roberts, Gareth G.; Paul, Jonathan D.; White, Nicky; Winterbourne, Jeffrey

    2012-04-01

    We present a strategy for calculating uplift rates as a function of space and time from large sets of longitudinal river profiles. This strategy assumes that the shape of a river profile is controlled by the history of uplift rate and moderated by the erosional process. We assume that upstream drainage area is invariant. The algorithm was tested on a set of 100 river profiles which were extracted from a digital elevation model of Madagascar. This set of profiles was simultaneously inverted to obtain uplift rate as a smooth function of space and time. The fit between observed and calculated profiles is excellent and suggests that Madagascar was uplifted by 1-2 km at rates of 0.2-0.4 mm/yr during the last 15 Myrs. The location of Madagascar suggests that its topographic elevation is maintained by convective circulation of the sub-lithospheric mantle. Residual depth anomalies of oceanic fragments encompassing the island show that the island straddles a dynamic topographic gradient which generates asymmetric Neogene uplift. Volcanism, warped peneplains and uplifted marine terraces corroborate the existence of youthful uplift. We suggest that sets of longitudinal river profiles contain useful information about the history of regional uplift which can be extracted by inverse modeling and calibrated by independent geologic observations.

  17. The Madagascar Bloom - a serendipitous study

    NASA Astrophysics Data System (ADS)

    Srokosz, M. A.; Quartly, G.

    2012-12-01

    The late austral summer (February-April) phytoplankton bloom that occurs east of Madagascar, exhibits significant interannual variability and at its largest extent covers ~1% of the world's ocean surface area. The bloom raises many intriguing questions about how it begins, is sustained, propagates to the east, exports carbon and ends. It has been observed and studied using satellite ocean colour observations, but the lack of in situ data makes it difficult to address these questions. Here we describe observations that were made on a cruise in February 2005 serendipitously. These show clearly for the first time the existence of both a deep chlorophyll maximum at ~70-110m depths (seen in SeaSoar fluorimeter data) and a surface chlorophyll signature (seen in SeaWiFS satellite ocean colour data). The observations also show the modulation of biological signature at the surface by the eddy field, but not apparently of the deep chlorophyll maximum. In situ observations indicate that Trichodesmium dominates the bloom nearer to Madagascar, while the diatom Rhizosolenia clevei (and its symbiont Richelia intracellularis) dominates further from the island. In addition, SeaSoar Optical Plankton Counter (OPC), temperature and salinity data suggest that the surface bloom seen in the SeaWiFS data is confined to the shallow (~30m) mixed layer. It is hypothesised that the interannual variability in bloom intensity may be due to variations in coastal upwelling and thus the supply of iron, which is a micronutrient that can limit diazotroph growth.

  18. Satellite Altimetry over rivers of Madagascar

    NASA Astrophysics Data System (ADS)

    Andriambeloson, Johary; Paris, Adrien; Rakotondraompiana, Solofo; calmant, stephane

    2015-04-01

    In Madagascar, many in-situ stations aren't any longer working and the few lasting are too sparse to provide sufficient spatial coverage of the big island. Establishing additional way for observing surface waters is an important key for better understanding and management of the water ressource of the country. Also, data from the remaining stations are lately updated. Hence, spatial altimetry have been tested to estimate variation of heights of surface waters for the first time in Madagascar over the rivers, generally narrow and shallow. Results reported here have been obtained by processing Envisat, Jason 2 and Saral data. Some virtual stations (ground tracks crossing rivers) were found and associated time series have been produced. The Envisat series have been validated by comparison with with gauge measurements over the Sofia river. Also, some internal validation were possible at some crossovers. Good correlations were obtained as well as relatively low root mean squared error, comparable with previous studies. These esults indicate that satellite altimetry is exploitable and has potential applications for the malagasy rivers.

  19. The Madagascar Bloom: A serendipitous study

    NASA Astrophysics Data System (ADS)

    Srokosz, M. A.; Quartly, G. D.

    2013-01-01

    The late austral summer (February-April) phytoplankton bloom that occurs east of Madagascar exhibits significant interannual variability and at its largest extent covers ~1% of the world's ocean surface area. The bloom raises many intriguing questions about how it begins, is sustained, propagates to the east, exports carbon, and ends. It has been observed and studied using satellite ocean color observations, but the lack of in situ data makes it difficult to address these questions. Here we describe observations that were made serendipitously on a cruise in February 2005. These show clearly for the first time the simultaneous existence of a deep chlorophyll maximum at ~70-110 m depths (seen in SeaSoar fluorimeter data) and a surface chlorophyll signature [seen in Sea-viewing Wide Field-of-view Sensor (SeaWiFS) satellite ocean color data]. The observations also show the modulation of the biological signature at the surface by the eddy field but not of the deep chlorophyll maximum. Trichodesmium dominates the bloom nearer to Madagascar, while the diatom Rhizosolenia clevei (and its symbiont Richelia intracellularis) dominates further from the island. The surface bloom seen in the SeaWiFS data is confined to the shallow (~30 m) mixed layer. It is hypothesized that the interannual variability in bloom intensity may be due to variations in coastal upwelling and thus the supply of iron, which is a micronutrient that can limit diazotroph growth.

  20. Origin of birefringence in andradite from Arizona, Madagascar, and Iran

    NASA Astrophysics Data System (ADS)

    Antao, Sytle M.; Klincker, Allison M.

    2013-07-01

    The crystal structure of four birefringent andradite samples (two from Arizona, one from Madagascar, and one from Iran) was refined with the Rietveld method, space group Iaoverline{3} d, and monochromatic synchrotron high-resolution powder X-ray diffraction (HRPXRD) data. Each sample contains an assemblage of three different cubic phases. From the electron-microprobe (EMPA) results, fine-scale intergrowths in the Arizona-2 and Madagascar samples appear homogeneous with nearly identical compositions of {Ca2.99Mg0.01}Σ3[{{Fe}}_{1.99}^{3 + } {{Mn}}_{0.01}^{3 + }]Σ2(Si2.95Al0.03 {{Fe}}_{0.02}^{3 + })Σ3O12, Adr98 (Arizona-2), and Adr97 (Madagascar). Both samples are near-end-member andradite, ideally {Ca3}[{{Fe}}2^{3 + }](Si3)O12, so cation ordering in the X, Y, or Z sites is not possible. Because of the large-scale intergrowths, the Arizona-1 and Iran samples contain three different compositions. Arizona-1 has compositions Adr97 (phase-1), Adr93Grs4 (phase-2), and Adr87Grs11 (phase-3). Iran sample has compositions Adr86Uv12 (phase-1), Adr69Uv30 (phase-2), and Adr76Uv22 (phase-3). The crystal structure of the three phases within each sample was modeled quite well as indicated by the Rietveld refinement statistics of reduced χ2 and overall R ( F 2) values of, respectively, 1.980 and 0.0291 (Arizona-1); 1.091 and 0.0305 (Arizona-2); 1.362 and 0.0231 (Madagascar); and 1.681 and 0.0304 (Iran). The dominant phase for each sample has the following unit-cell parameters (Å) and weight fractions (%): a = 12.06314(1), 51.93(9) (Arizona-1); 12.04889(1), 52.47(1) (Arizona-2); 12.06276(1), 52.21(8) (Madagascar); and 12.05962(2), 63.3(1) (Iran). For these dominant phases, the distances and site occupancy factors ( sofs) in terms of neutral atoms at the Ca(X), Fe(Y), and Si(Z) sites are as follows: = 2.4348, Fe-O = 2.0121(6), Si-O = 1.6508(6) Å; Ca( sof) = 0.955(2), Fe( sof) = 0.930(2), and Si( sof) = 0.917(2) (Arizona-1); = 2.4288, Fe-O = 2.0148(7), Si-O = 1.6476(7) Å; Ca( sof) = 0.953(2), Fe( sof) = 0.891(2), and Si( sof) = 0.927(2) (Arizona-2); = 2.4319, Fe-O = 2.0220(6), Si-O = 1.6460(6) Å; Ca( sof) = 0.955(2), Fe( sof) = 0.941(2), and Si( sof) = 0.939(2) (Madagascar); and = 2.4344, Fe-O = 2.0156(8), Si-O = 1.6468(8) Å; Ca( sof) = 0.928(2), Fe( sof) = 0.908(2), and Si( sof) = 0.932(3) (Iran). The sofs based on the EMPA results are similar to those obtained from the Rietveld refinement. Each phase in the HRPXRD results can be correlated with a specific chemical composition. For example, the Iran sample composition Adr63Uv30 corresponds to phase-3 that has the smallest unit-cell parameter; Adr76Uv22 corresponds to phase-1 that has the intermediate cell value; and Adr86Uv13 corresponds to phase-2 that has the largest unit-cell parameter. The bond distances compare well with those obtained from radii sum. The three different cubic phases in each sample cause strain that arises from the mismatch of the cubic unit-cell parameters and give rise to birefringence.

  1. A giant frog with South American affinities from the Late Cretaceous of Madagascar

    PubMed Central

    Evans, Susan E.; Jones, Marc E. H.; Krause, David W.

    2008-01-01

    Madagascar has a diverse but mainly endemic frog fauna, the biogeographic history of which has generated intense debate, fueled by recent molecular phylogenetic analyses and the near absence of a fossil record. Here, we describe a recently discovered Late Cretaceous anuran that differs strikingly in size and morphology from extant Malagasy taxa and is unrelated either to them or to the predicted occupants of the Madagascar–Seychelles–India landmass when it separated from Africa 160 million years ago (Mya). Instead, the previously undescribed anuran is attributed to the Ceratophryinae, a clade previously considered endemic to South America. The discovery offers a rare glimpse of the anuran assemblage that occupied Madagascar before the Tertiary radiation of mantellids and microhylids that now dominate the anuran fauna. In addition, the presence of a ceratophryine provides support for a controversial paleobiogeographical model that posits physical and biotic links among Madagascar, the Indian subcontinent, and South America that persisted well into the Late Cretaceous. It also suggests that the initial radiation of hyloid anurans began earlier than proposed by some recent estimates. PMID:18287076

  2. Worms, wells and water in western Madagascar.

    PubMed

    Howarth, S E; Wilson, J M; Ranaivoson, E; Crook, S E; Denning, A M; Hutchings, M S

    1988-10-01

    This study of schistosomiasis and intestinal parasites was carried out on 496 children in the Firaisana (District) of Ankilivalo in Western Madagascar. The prevalence of these parasites was determined and data collected on nutrition, agriculture and the use of water in order to gain an understanding of the transmission and effects of these parasites. Recommendations for their control are suggested. In two schools within the area of a major irrigation scheme the prevalence of urinary schistosomiasis was 69%, and 50% suffer from at least one intestinal worm. In a school outside the main irrigation area, the prevalence of schistosomiasis was much lower (7%). Ultimately the control of schistosomiasis will depend on improvements to the irrigation and drainage infrastructure, and in standards of sanitation. However, chemotherapy is the only method of bringing the disease under control in the short term. PMID:3141630

  3. Genetic data suggest a natural prehuman origin of open habitats in northern Madagascar and question the deforestation narrative in this region

    PubMed Central

    Quéméré, Erwan; Amelot, Xavier; Pierson, Julie; Crouau-Roy, Brigitte; Chikhi, Lounès

    2012-01-01

    The impact of climate change and anthropogenic deforestation on biodiversity is of growing concern worldwide. Disentangling how past anthropogenic and natural factors contributed to current biome distribution is thus a crucial issue to understand their complex interactions on wider time scales and to improve predictions and conservation strategies. This is particularly important in biodiversity hotspots, such as Madagascar, dominated by large open habitats whose origins are increasingly debated. Although a dominant narrative argues that Madagascar was originally entirely covered by woodlands, which were destroyed by humans, a number of recent studies have suggested that past climatic fluctuations played a major role in shaping current biome distributions well before humans arrived. Here, we address the question of the origin of open habitats in the Daraina region in northern Madagascar, using a multiproxy approach combining population genetics modeling and remote-sensing analyses. We show that (i) contrary to most regions of Madagascar, the forest cover in Daraina remained remarkably stable over the past 60 y, and (ii) the golden-crowned sifaka (Propithecus tattersalli), a forest-dwelling lemur, underwent a strong population contraction before the arrival of the first humans, hence excluding an anthropogenic cause. Prehuman Holocene droughts may have led to a significant increase of grasslands and a reduction in the species’ habitat. This contradicts the prevailing narrative that land cover changes are necessarily anthropogenic in Madagascar but does not preclude the later role played by humans in other regions in which recent lemur bottlenecks have been observed. PMID:22826244

  4. Genetic data suggest a natural prehuman origin of open habitats in northern Madagascar and question the deforestation narrative in this region.

    PubMed

    Quéméré, Erwan; Amelot, Xavier; Pierson, Julie; Crouau-Roy, Brigitte; Chikhi, Lounès

    2012-08-01

    The impact of climate change and anthropogenic deforestation on biodiversity is of growing concern worldwide. Disentangling how past anthropogenic and natural factors contributed to current biome distribution is thus a crucial issue to understand their complex interactions on wider time scales and to improve predictions and conservation strategies. This is particularly important in biodiversity hotspots, such as Madagascar, dominated by large open habitats whose origins are increasingly debated. Although a dominant narrative argues that Madagascar was originally entirely covered by woodlands, which were destroyed by humans, a number of recent studies have suggested that past climatic fluctuations played a major role in shaping current biome distributions well before humans arrived. Here, we address the question of the origin of open habitats in the Daraina region in northern Madagascar, using a multiproxy approach combining population genetics modeling and remote-sensing analyses. We show that (i) contrary to most regions of Madagascar, the forest cover in Daraina remained remarkably stable over the past 60 y, and (ii) the golden-crowned sifaka (Propithecus tattersalli), a forest-dwelling lemur, underwent a strong population contraction before the arrival of the first humans, hence excluding an anthropogenic cause. Prehuman Holocene droughts may have led to a significant increase of grasslands and a reduction in the species' habitat. This contradicts the prevailing narrative that land cover changes are necessarily anthropogenic in Madagascar but does not preclude the later role played by humans in other regions in which recent lemur bottlenecks have been observed. PMID:22826244

  5. Spatial Biodiversity Patterns of Madagascar's Amphibians and Reptiles.

    PubMed

    Brown, Jason L; Sillero, Neftali; Glaw, Frank; Bora, Parfait; Vieites, David R; Vences, Miguel

    2016-01-01

    Madagascar has become a model region for testing hypotheses of species diversification and biogeography, and many studies have focused on its diverse and highly endemic herpetofauna. Here we combine species distribution models of a near-complete set of species of reptiles and amphibians known from the island with body size data and a tabulation of herpetofaunal communities from field surveys, compiled up to 2008. Though taxonomic revisions and novel distributional records arose since compilation, we are confident that the data are appropriate for inferring and comparing biogeographic patterns among these groups of organisms. We observed species richness of both amphibians and reptiles was highest in the humid rainforest biome of eastern Madagascar, but reptiles also show areas of high richness in the dry and subarid western biomes. In several amphibian subclades, especially within the Mantellidae, species richness peaks in the central eastern geographic regions while in reptiles different subclades differ distinctly in their richness centers. A high proportion of clades and subclades of both amphibians and reptiles have a peak of local endemism in the topographically and bioclimatically diverse northern geographic regions. This northern area is roughly delimited by a diagonal spanning from 15.5°S on the east coast to ca. 15.0°S on the west coast. Amphibian diversity is highest at altitudes between 800-1200 m above sea-level whereas reptiles have their highest richness at low elevations, probably reflecting the comparatively large number of species specialized to the extended low-elevation areas in the dry and subarid biomes. We found that the range sizes of both amphibians and reptiles strongly correlated with body size, and differences between the two groups are explained by the larger body sizes of reptiles. However, snakes have larger range sizes than lizards which cannot be readily explained by their larger body sizes alone. Range filling, i.e., the amount of suitable habitat occupied by a species, is less expressed in amphibians than in reptiles, possibly reflecting their lower dispersal capacity. Taxonomic composition of communities assessed by field surveys is largely explained by bioclimatic regions, with communities from the dry and especially subarid biomes distinctly differing from humid and subhumid biomes. PMID:26735688

  6. Spatial Biodiversity Patterns of Madagascar's Amphibians and Reptiles

    PubMed Central

    Brown, Jason L.; Sillero, Neftali; Glaw, Frank; Bora, Parfait; Vieites, David R.; Vences, Miguel

    2016-01-01

    Madagascar has become a model region for testing hypotheses of species diversification and biogeography, and many studies have focused on its diverse and highly endemic herpetofauna. Here we combine species distribution models of a near-complete set of species of reptiles and amphibians known from the island with body size data and a tabulation of herpetofaunal communities from field surveys, compiled up to 2008. Though taxonomic revisions and novel distributional records arose since compilation, we are confident that the data are appropriate for inferring and comparing biogeographic patterns among these groups of organisms. We observed species richness of both amphibians and reptiles was highest in the humid rainforest biome of eastern Madagascar, but reptiles also show areas of high richness in the dry and subarid western biomes. In several amphibian subclades, especially within the Mantellidae, species richness peaks in the central eastern geographic regions while in reptiles different subclades differ distinctly in their richness centers. A high proportion of clades and subclades of both amphibians and reptiles have a peak of local endemism in the topographically and bioclimatically diverse northern geographic regions. This northern area is roughly delimited by a diagonal spanning from 15.5°S on the east coast to ca. 15.0°S on the west coast. Amphibian diversity is highest at altitudes between 800–1200 m above sea-level whereas reptiles have their highest richness at low elevations, probably reflecting the comparatively large number of species specialized to the extended low-elevation areas in the dry and subarid biomes. We found that the range sizes of both amphibians and reptiles strongly correlated with body size, and differences between the two groups are explained by the larger body sizes of reptiles. However, snakes have larger range sizes than lizards which cannot be readily explained by their larger body sizes alone. Range filling, i.e., the amount of suitable habitat occupied by a species, is less expressed in amphibians than in reptiles, possibly reflecting their lower dispersal capacity. Taxonomic composition of communities assessed by field surveys is largely explained by bioclimatic regions, with communities from the dry and especially subarid biomes distinctly differing from humid and subhumid biomes. PMID:26735688

  7. Screening molecules for control of citrus huanglongbing using an optimized regeneration system for 'Candidatus Liberibacter asiaticus'-infected periwinkle (Catharanthus roseus) cuttings.

    PubMed

    Zhang, Muqing; Duan, Yongping; Zhou, Lijuan; Turechek, William W; Stover, Ed; Powell, Charles A

    2010-03-01

    Citrus huanglongbing is one of the most destructive diseases of citrus worldwide. The disease is associated with three different species of 'Candidatus Liberibacter', of which 'Ca. L. asiaticus' is the most widely distributed. An optimized system using 'Ca. L. asiaticus'-infected periwinkle cuttings was developed to screen chemical compounds effective for controlling the bacterial population while simultaneously assessing their phytotoxicity. The optimal regeneration conditions were determined to be the use of vermiculite as a growth medium for the cuttings, and a fertilization routine using half-strength Murashige and Tucker medium supplemented with both naphthalene acetic acid (4 microg/ml) and indole-3-butyric acid (4 microg/ml). This system allowed a plant regeneration rate of 60.6% for 'Ca. L. asiaticus'-infected cuttings in contrast to the <1% regeneration rate with water alone. Two chemical agents, penicillin G sodium and 2,2-dibromo-3-nitrilopropionamide (DBNPA), were found to be effective at eliminating or suppressing the 'Ca. L. asiaticus' bacterium in this periwinkle regeneration system. When treated with penicillin G sodium at 50 microg/ml, all plants regenerated from 'Ca. L. asiaticus'-infected cuttings were 'Ca. L. asiaticus' negative as determined by both nested polymerase chain reaction (PCR) and quantitative real-time PCR. In addition, DBNPA was also able to significantly reduce the percentage of 'Ca. L. asiaticus'-positive plants and the titer of the 'Ca. L. asiaticus' bacterium at 200 microl/liter. PMID:20128697

  8. Influenza seasonality in Madagascar: the mysterious African free-runner

    PubMed Central

    Alonso, Wladimir Jimenez; Guillebaud, Julia; Viboud, Cecile; Razanajatovo, Norosoa Harline; Orelle, Arnaud; Zhou, Steven Zhixiang; Randrianasolo, Laurence; Heraud, Jean-Michel

    2015-01-01

    Background The seasonal drivers of influenza activity remain debated in tropical settings where epidemics are not clearly phased. Antananarivo is a particularly interesting case study because it is in Madagascar, an island situated in the tropics and with quantifiable connectivity levels to other countries. Objectives We aimed at disentangling the role of environmental forcing and population fluxes on influenza seasonality in Madagascar. Methods We compiled weekly counts of laboratory-confirmed influenza-positive specimens for the period 2002 to 2012 collected in Antananarivo, with data available from sub-Saharan countries and countries contributing most foreign travelers to Madagascar. Daily climate indicators were compiled for the study period. Results Overall, influenza activity detected in Antananarivo predated that identified in temperate Northern Hemisphere locations. This activity presented poor temporal matching with viral activity in other countries from the African continent or countries highly connected to Madagascar excepted for A(H1N1)pdm09. Influenza detection in Antananarivo was not associated with travel activity and, although it was positively correlated with all climatic variables studied, such association was weak. Conclusions The timing of influenza activity in Antananarivo is irregular, is not driven by climate, and does not align with that of countries in geographic proximity or highly connected to Madagascar. This work opens fresh questions regarding the drivers of influenza seasonality globally particularly in mid-latitude and less-connected regions to tailor vaccine strategies locally. PMID:25711873

  9. Insatiable demands: Income, energy and environmental policy in Madagascar

    SciTech Connect

    Shaw, C.L.

    1993-01-01

    The island nation of Madagascar is suffering the collision of three distinct trends: economic stagnation, a rapidly expanding population and a severely threatened natural resource base. Demands for growth, new energy reserves and environmental conservation, especially of forest resources, are creating a policy dilemma for both government officials and donors. This study seeks to bring new evidence to bear on this policy dilemma. Primary data on urban household income, family size and consumption of various energy types are used to test two main hypothesis (1) that charcoal, which constitutes the fuel of choice for a vast majority of the sample, is a normal rather than an inferior good, and (2) that demand for wood-fuels constitutes a genuine threat to the viability of the forest resource. The data indicate that income elasticities of demand for charcoal are positive over a broad range of per capita income levels, revealing that charcoal is, indeed a normal good for a large portion of the population represented by the sample. A model of forest degradation is built which establishes a clear link between wood-fuel demand and forest degradation. Together, these findings make clear that under current income patterns, and for the forseeable future, charcoal is a normal good and its consumption by urban residents constitutes a serious threat to the natural forest resource. The study concludes with a policy analysis which identifies existing market failures due to government policies and recommends changes based on tested policy prescriptions in other parts of the developing world.

  10. Phylogeography in Response to Reproductive Strategies and Ecogeographic Isolation in Ant Species on Madagascar: Genus Mystrium (Formicidae: Amblyoponinae)

    PubMed Central

    Graham, Natalie R.; Fisher, Brian L.; Girman, Derek J.

    2016-01-01

    The bulk of models used to understand the species diversification on Madagascar have been constructed using vertebrate taxa. It is not clear how these models affect less vagile species that may interact at a variety of spatial scales. Several studies on vertebrates have divided Madagascar into east-west bioclimatic regions, suggesting there is a fundamental division between eastern wet-adapted and western dry-adapted taxa. An alternative model of ecogeographic constraints shows a north-south division. We test whether the diversification in a small arthropod with variable degrees of dispersal conform to either model of ecogeographic constraints proposed for vertebrate taxa. We employ a molecular taxonomic dataset using ~2 kilobases nuDNA (Wg, LW Rh, Abd-A, 28s) and 790 basepairs mtDNA (CO1), along with geographic and habitat data, to examine the diversification patterns of the ant genus Mystrium Roger, 1862, (Subfamily Amblyoponinae) from Madagascar. The nuclear and mitochondrial phylogenies were both congruent with morphospecies as indicated in a recent revision of the genus. Species of Mystrium practice different colony reproductive strategies (winged queens vs non-winged queens). Alternate reproductive strategies led to inequalities in female dispersal ability among species, providing an additional layer for examination of the impacts of vagility on divergence, especially when measured using a maternally inherited locus. Mystrium species distribution patterns support these models of ecogeographic constraints. Reproductive strategy effected how Mystrium mtDNA lineages were associated with large-scale habitat distinctions and various topographical features. Furthermore, in some cases we find microgeographic population structure which appears to have been impacted by localized habitat differences (tsingy limestone formations, littoral forest) on a scale much smaller than that found in vertebrates. The current system offers a finer scale look at species diversification on the island, and helps achieve a more universal understanding of the generation of biodiversity on Madagascar. PMID:26800442

  11. Phylogeography in Response to Reproductive Strategies and Ecogeographic Isolation in Ant Species on Madagascar: Genus Mystrium (Formicidae: Amblyoponinae).

    PubMed

    Graham, Natalie R; Fisher, Brian L; Girman, Derek J

    2016-01-01

    The bulk of models used to understand the species diversification on Madagascar have been constructed using vertebrate taxa. It is not clear how these models affect less vagile species that may interact at a variety of spatial scales. Several studies on vertebrates have divided Madagascar into east-west bioclimatic regions, suggesting there is a fundamental division between eastern wet-adapted and western dry-adapted taxa. An alternative model of ecogeographic constraints shows a north-south division. We test whether the diversification in a small arthropod with variable degrees of dispersal conform to either model of ecogeographic constraints proposed for vertebrate taxa. We employ a molecular taxonomic dataset using ~2 kilobases nuDNA (Wg, LW Rh, Abd-A, 28s) and 790 basepairs mtDNA (CO1), along with geographic and habitat data, to examine the diversification patterns of the ant genus Mystrium Roger, 1862, (Subfamily Amblyoponinae) from Madagascar. The nuclear and mitochondrial phylogenies were both congruent with morphospecies as indicated in a recent revision of the genus. Species of Mystrium practice different colony reproductive strategies (winged queens vs non-winged queens). Alternate reproductive strategies led to inequalities in female dispersal ability among species, providing an additional layer for examination of the impacts of vagility on divergence, especially when measured using a maternally inherited locus. Mystrium species distribution patterns support these models of ecogeographic constraints. Reproductive strategy effected how Mystrium mtDNA lineages were associated with large-scale habitat distinctions and various topographical features. Furthermore, in some cases we find microgeographic population structure which appears to have been impacted by localized habitat differences (tsingy limestone formations, littoral forest) on a scale much smaller than that found in vertebrates. The current system offers a finer scale look at species diversification on the island, and helps achieve a more universal understanding of the generation of biodiversity on Madagascar. PMID:26800442

  12. Understanding the persistence of plague foci in Madagascar.

    PubMed

    Andrianaivoarimanana, Voahangy; Kreppel, Katharina; Elissa, Nohal; Duplantier, Jean-Marc; Carniel, Elisabeth; Rajerison, Minoarisoa; Jambou, Ronan

    2013-11-01

    Plague, a zoonosis caused by Yersinia pestis, is still found in Africa, Asia, and the Americas. Madagascar reports almost one third of the cases worldwide. Y. pestis can be encountered in three very different types of foci: urban, rural, and sylvatic. Flea vector and wild rodent host population dynamics are tightly correlated with modulation of climatic conditions, an association that could be crucial for both the maintenance of foci and human plague epidemics. The black rat Rattus rattus, the main host of Y. pestis in Madagascar, is found to exhibit high resistance to plague in endemic areas, opposing the concept of high mortality rates among rats exposed to the infection. Also, endemic fleas could play an essential role in maintenance of the foci. This review discusses recent advances in the understanding of the role of these factors as well as human behavior in the persistence of plague in Madagascar. PMID:24244760

  13. Cretaceous may hold promise in Majunga basin, Madagascar

    SciTech Connect

    Lalaharisaina, J.V. ); Ferrand, N.J. )

    1994-08-01

    Recent drilling in the Majunga basin of northwestern Madagascar revealed unexpected light oil shows in excellent quality reservoir sands of Mid-Cretaceous age. Regional reconstructions show the development of a prograding clastic shelf from the Aptian until the Mid-Turonian that extended laterally from the northwest costs of Madagascar into Northwest India and Southeast Pakistan. Six untested play concepts have been identified in Cretaceous reservoirs of the Majunga basin. These plays offer multiple objectives in the depth range of 800--2,500 m within a well defined area. Further untested plays exist for Tertiary and Dogger objectives. The paper describes the geologic setting, exploration history the Cretaceous reservoirs, source rocks, and other potential plays. Political changes in Madagascar the last four years have led to an open door policy for foreign investment. Favorable terms are on offer for investment in the petroleum sector, and high potential exists for development on this island continent.

  14. First observational evidence of a North Madagascar Undercurrent

    NASA Astrophysics Data System (ADS)

    Ponsoni, Leandro; Aguiar-González, Borja; Nauw, Janine J.; Ridderinkhof, Herman; Maas, Leo R. M.

    2015-12-01

    In situ observations reveal a southeastward-directed North Madagascar Undercurrent (NMUC) below and opposite to the equatorward-directed North Madagascar Current (NMC) off Cape Amber, at the northern tip of Madagascar. Results show an undercurrent hugging the continental slope with its core at 460 m depth and velocities over 0.7 m s-1. Its volume transport is estimated to be 3.1-3.8 Sv, depending on the velocity extrapolation methods used to fill in the data gaps near the slope (no-slip and full-slip, respectively). The thermohaline characteristics show a saltier and warmer NMUC, compared to the surrounding offshore waters, transporting mainly South Indian Central Water. Also, strong horizontal gradients of density are found in the NMUC domain. An inshore cell of coastal downwelling due to Ekman Transport toward the coast is identified, which can explain, at least in part, the strong baroclinic pressure gradients as well as the NMUC development and possible persistence.

  15. Understanding the Persistence of Plague Foci in Madagascar

    PubMed Central

    Andrianaivoarimanana, Voahangy; Kreppel, Katharina; Elissa, Nohal; Duplantier, Jean-Marc; Carniel, Elisabeth; Rajerison, Minoarisoa; Jambou, Ronan

    2013-01-01

    Plague, a zoonosis caused by Yersinia pestis, is still found in Africa, Asia, and the Americas. Madagascar reports almost one third of the cases worldwide. Y. pestis can be encountered in three very different types of foci: urban, rural, and sylvatic. Flea vector and wild rodent host population dynamics are tightly correlated with modulation of climatic conditions, an association that could be crucial for both the maintenance of foci and human plague epidemics. The black rat Rattus rattus, the main host of Y. pestis in Madagascar, is found to exhibit high resistance to plague in endemic areas, opposing the concept of high mortality rates among rats exposed to the infection. Also, endemic fleas could play an essential role in maintenance of the foci. This review discusses recent advances in the understanding of the role of these factors as well as human behavior in the persistence of plague in Madagascar. PMID:24244760

  16. Deforestation and apparent extinctions of endemic forest beetles in Madagascar.

    PubMed

    Hanski, Ilkka; Koivulehto, Helena; Cameron, Alison; Rahagalala, Pierre

    2007-06-22

    Madagascar has lost about half of its forest cover since 1953 with much regional variation, for instance most of the coastal lowland forests have been cleared. We sampled the endemic forest-dwelling Helictopleurini dung beetles across Madagascar during 2002-2006. Our samples include 29 of the 51 previously known species for which locality information is available. The most significant factor explaining apparent extinctions (species not collected by us) is forest loss within the historical range of the focal species, suggesting that deforestation has already caused the extinction, or effective extinction, of a large number of insect species with small geographical ranges, typical for many endemic taxa in Madagascar. Currently, roughly 10% of the original forest cover remains. Species-area considerations suggest that this will allow roughly half of the species to persist. Our results are consistent with this prediction. PMID:17341451

  17. Current epidemiology of human plague in Madagascar.

    PubMed

    Chanteau, S; Ratsitorahina, M; Rahalison, L; Rasoamanana, B; Chan, F; Boisier, P; Rabeson, D; Roux, J

    2000-01-01

    From 1996 to 1998, 5,965 patients with suspected plague were identified in 38 districts of Madagascar (40% of the total population are exposed). Using standard bacteriology, 917 of them were confirmed or presumptive (C + P) cases. However, more than 2,000 plague cases could be estimated using F1 antigen assay. Two out of the 711 Yersinia pestis isolates tested were resistant to chloramphenicol and to ampicillin (both isolates found in the harbour of Mahajanga). Urban plague (Mahajanga harbour and Antananarivo city) accounted for 37.4% of the C + P cases. Bubonic plague represented 97.2% of the cases, and the lethality rate was still high (20%). In comparing the exposed population, plague was more prevalent in males (M:F sex ratio 1.3:1) and patients under 20 years (2.7% babies under two years). Buboes were mainly localised in the inguinal/femoral regions (55.8%). The epidemiological risk factors are discussed. PMID:10717537

  18. [Seroepidemiologic study of human plague in Madagascar].

    PubMed

    Leroy, F

    1997-01-01

    An IgG anti-F1 Enzyme linked immunosorbent assay (Elisa) has been developed for plague diagnosis in the Malagasy republic. The sensitivity of the test was 91.4% and the specificity 98.5%. This technique is cheap and the cross reaction with other infections diseases prevalent in Madagascar is very limited. During the urban plague outbreak (Mahajanga city, 1995), the positive predictive value and the negative predictive value were 95.2% and 97% respectively. During this outbreak, the usefulness of the Elisa test for retrospective individual serodiagnosis was confirmed. Furthermore, the test confirmed plague among suspect patients without bacteriological diagnosis. The test was used for a sero-epidemiological study. Eight villages in the endemic area were investigated and 900 persons were studied. The overall seroprevalence was 6 times the officially prevalence of plague, notified at the Central Plague Laboratory. A large disparity of the seroprevalence was observed in the endemic area, with variation from < 1.5% to 15.5%. A high incidence of asymptomatic infections due to Yersinia pestis was found. PMID:9309233

  19. Malagasy dialects and the peopling of Madagascar

    PubMed Central

    Serva, Maurizio; Petroni, Filippo; Volchenkov, Dima; Wichmann, Søren

    2012-01-01

    The origin of Malagasy DNA is half African and half Indonesian, nevertheless the Malagasy language, spoken by the entire population, belongs to the Austronesian family. The language most closely related to Malagasy is Maanyan (Greater Barito East group of the Austronesian family), but related languages are also in Sulawesi, Malaysia and Sumatra. For this reason, and because Maanyan is spoken by a population which lives along the Barito river in Kalimantan and which does not possess the necessary skill for long maritime navigation, the ethnic composition of the Indonesian colonizers is still unclear. There is a general consensus that Indonesian sailors reached Madagascar by a maritime trek, but the time, the path and the landing area of the first colonization are all disputed. In this research, we try to answer these problems together with other ones, such as the historical configuration of Malagasy dialects, by types of analysis related to lexicostatistics and glottochronology that draw upon the automated method recently proposed by the authors. The data were collected by the first author at the beginning of 2010 with the invaluable help of Joselinà Soafara Néré and consist of Swadesh lists of 200 items for 23 dialects covering all areas of the island. PMID:21632612

  20. Sterols from the Madagascar Sponge Fascaplysinopsis sp

    PubMed Central

    Aknin, Maurice; Gros, Emmanuelle; Vacelet, Jean; Kashman, Yoel; Gauvin-Bialecki, Anne

    2010-01-01

    The sponge Fascaplysinopsis sp. (order Dictyoceratida, Family Thorectidae) from the west coast of Madagascar (Indian Ocean) is a particularly rich source of bioactive nitrogenous macrolides. The previous studies on this organism led to the suggestion that the latter should originate from associated microsymbionts. In order to evaluate the influence of microsymbionts on lipid content, 10 samples of Fascaplysinopsis sp. were investigated for their sterol composition. Contrary to the secondary metabolites, the sterol patterns established were qualitatively and quantitatively stable: 14 sterols with different unsaturated nuclei, Δ5, Δ7 and Δ5,7, were identified; the last ones being the main sterols of the investigated sponges. The chemotaxonomic significance of these results for the order Dictyoceratida is also discussed in the context of the literature. The conjugated diene system in Δ5,7 sterols is known to be unstable and easily photo-oxidized during storage and/or experiments to produce 5α,8α-epidioxy sterols. However, in this study, no 5α,8α-epidioxysterols (or only trace amounts) were observed. Thus, it was supposed that photo-oxidation was avoided thanks to the natural antioxidants detected in Fascaplysinopsis sp. by both the DPPH and β-caroten bleaching assays. PMID:21339959

  1. Holocene Indian Ocean Cosmic Impacts: The Megatsunami Chevron Evidence From Madagascar

    NASA Astrophysics Data System (ADS)

    Masse, W.; Bryant, E.; Gusiakov, V.; Abbott, D.; Rambolamana, G.; Raza, H.; Courty, M.; Breger, D.; Gerard-Little, P.; Burckle, L.

    2006-12-01

    The 2.6 million year Quaternary period terrestrial physical record lacks definitive crater evidence for major regional catastrophic impacts by asteroids and comets other than the 10.5-km diameter Botsumtwi structure in Ghana and the 14.0-km diameter Zhamanshin structure in Kazakhstan [1] dating between about 900 and 1100 kya. Current cosmic impact rate models suggest that an average of between 3-6 globally catastrophic impacts should have occurred on the Earth during the Quaternary, along with several additional significant regional impacts in addition to Zhamanshin and Botsumtwi. These models and data indicate that the great majority of the "missing" major impact locations would likely have occurred in poorly studied oceanic settings. Only recently have Late Quaternary and Holocene period coastal paleo-megatsunami chevron deposits been defined in the Caribbean and along the western coasts of Australia, along with the suggestion that some may have been created by oceanic cosmic impacts in distinction to those caused by landslips, eruptions, and seismic events. We investigate the possibility that many or most megatsunami chevrons occurring along the southern coast of Madagascar were caused by two or more major Holocene Indian Ocean cosmic impacts. This hypothesis is based on an initial study of the worldwide archaeological and anthropological record, and the preliminary study of satellite images of the chevrons, selected Indian Ocean deep-sea cores, sea-floor bathymetry, and physical examination of the Madagascar deposits themselves. Candidate Indian Ocean impact structures are identified and correlated with the southern Madagascar megatsunami chevron deposits. [1] Masse, W.B. 2007 The Archaeology and Anthropology of Quaternary Period Cosmic Impact. In Bobrowsky, P.T. & Rickman, H. (eds.)Comets/Asteroid Impacts and Human Society. Springer, Berlin (in press).

  2. The structure of the lithosphere and asthenosphere beneath Mozambique and Madagascar from combined surface wave and ambient noise tomography

    NASA Astrophysics Data System (ADS)

    Shore, P.; Aleqabi, G. I.; Wysession, M. E.; Pratt, M. J.; Wiens, D. A.; Nyblade, A.; Rambolamana, G.; Rakotondraibe, T.; Sy Tanjona Andriampenomanana ny Ony, F.

    2013-12-01

    We present results based on applying the two-plane wave method to the observed amplitude and phase of fundamental mode surface waves from the NSF-funded MACOMO IRIS PASSCAL broadband seismometer deployment in Madagascar and Mozambique. The two-plane wave method (Forsyth and Li, 2005) involves modeling arriving surface waves by a two-plane-wave field. Combining this method with ambient noise will allow the joint inversion of phase velocities from 5 to 180 s, to generate a high-resolution 3-D shear wave velocity model from the surface to a depth of ~200 km beneath Madagascar, Mozambique and the surrounding regions. Using the two-plane wave method, the phase and amplitude of fundamental mode Rayleigh waves from distant earthquakes recorded at MACOMO are inverted for 2-D phase velocity maps at periods from 18 to 180 s. The ambient noise method (a separate study) is limited to short periods and therefore it is sensitive only to the crust and uppermost mantle structure. The 3-D shear-wave velocity structure beneath East Africa (Mozambique and Madagascar) where the East African Orogeny was instrumental in the amalgamation of Gondwana (~540 Ma) is investigated by using the implicit relation between phase-velocity dispersion and shear-wave structure. The phase velocities, at selected periods and at each node of the phase velocity maps, are inverted for a 1-D structure; the 1-D models at each node form the 3-D shear-wave model. Phase-velocity tomographic images show 2-D lateral variations in phase velocities at each period. Preliminary results show that above periods of 124 sec we noticed a rapid vertical transition to low phase velocities beneath southern Madagascar.

  3. A double-flowered variety of lesser periwinkle (Vinca minor fl. pl.) that has persisted in the wild for more than 160 years

    PubMed Central

    Wang, Yong-Qiang; Melzer, Rainer; Theißen, Günter

    2011-01-01

    Background and Aims Homeotic transitions are usually dismissed by population geneticists as credible modes of evolution due to their assumed negative impact on fitness. However, several lines of evidence suggest that such changes in organ identity have played an important role during the origin and subsequent evolution of the angiosperm flower. Better understanding of the performance of wild populations of floral homeotic varieties should help to clarify the evolutionary potential of homeotic mutants. Wild populations of plants with changes in floral symmetry, or with reproductive organs replacing perianth organs or sepals replacing petals have already been documented. However, although double-flowered varieties are quite popular as ornamental and garden plants, they are rarely found in the wild and, if they are, usually occur only as rare mutant individuals, probably because of their low fitness relative to the wild-type. We therefore investigated a double-flowered variety of lesser periwinkle, Vinca minor flore pleno (fl. pl.), that is reported to have existed in the wild for at least 160 years. To assess the merits of this plant as a new model system for investigations on the evolutionary potential of double-flowered varieties we explored the morphological details and distribution of the mutant phenotype. Methods The floral morphology of the double-flowered variety and of a nearby population of wild-type plants was investigated by means of visual inspection and light microscopy of flowers, the latter involving dissected or sectioned floral organs. Key Results The double-flowered variety was found in several patches covering dozens of square metres in a forest within the city limits of Jena (Germany). It appears to produce fewer flowers than the wild-type, and its flowers are purple rather than blue. Most sepals in the first floral whorl resemble those in the wild-type, although occasionally one sepal is broadened and twisted. The structure of second-whorl petals is very similar to that of the wild-type, but their number per flower is more variable. The double-flowered character is due to partial or complete transformation of stamens in the third whorl into petaloid organs. Occasionally, ‘flowers within flowers’ also develop on elongated pedicels in the double-flowered variety. Conclusions The flowers of V. minor fl. pl. show meristic as well as homeotic changes, and occasionally other developmental abnormalities such as mis-shaped sepals or loss of floral determinacy. V. minor fl. pl. thus adds to a growing list of natural floral homeotic varieties that have established persistent populations in the wild. Our case study documents that even mutant varieties that have reproductive organs partially transformed into perianth organs can persist in the wild for centuries. This finding makes it at least conceivable that even double-flowered varieties have the potential to establish new evolutionary lineages, and hence may contribute to macroevolutionary transitions and cladogenesis. PMID:21527418

  4. Structural mapping and analysis of a Madagascar Precambrian shear zone using enhanced Landsat Thematic Mapper Data

    SciTech Connect

    Kilmer, D.S.; Duncan, I.J. )

    1990-05-01

    Recently, the west coast of Madagascar has become a frontier region for petroleum exploration. Major structures in the Precambrian shield of Madagascar may have a strong control on the development of sedimentary basins, as has been documented in the Morondava basin. The 2.5-3.0+ Ga shield of Madagascar is an amphibolite- to granulite-grade metamorphic gneiss terrain, intruded by anorthosites and 550-Ma granites and pegmatites. Landsat Thematic Mapper data provides a cost-effective method for regional-scale structural mapping of this poorly known terrain. A five-component linear mixing model has been used to enhance the lithologic information in this six-band data. Lithologic component images thus produced utilize the full geologic spectral range of the data. A preliminary structural geologic map compiled from the component images has greater detail than existing maps at 1:100,000 scale, to which it has been compared. The Ankafotra-Saririaky shear zone has been identified as a north-northeast-trending, 15- to 20-km-wide region of appressed folds, attenuated layering, and subparallel faults on the western side of the shield. Two anorthosite massifs that occur within this shear zone have the structural characteristics of boudins in a ductile matrix. The shear deformed a preexisting terrain of poly-phase folding, characterized by tight folds and complex fold interference structures displayed by basins and domes on a scale of 10 km. Enhanced remote sensing data can be used to characterize the nature and mechanism of shear deformation in such zones.

  5. Hunting, Exotic Carnivores, and Habitat Loss: Anthropogenic Effects on a Native Carnivore Community, Madagascar.

    PubMed

    Farris, Zach J; Golden, Christopher D; Karpanty, Sarah; Murphy, Asia; Stauffer, Dean; Ratelolahy, Felix; Andrianjakarivelo, Vonjy; Holmes, Christopher M; Kelly, Marcella J

    2015-01-01

    The wide-ranging, cumulative, negative effects of anthropogenic disturbance, including habitat degradation, exotic species, and hunting, on native wildlife has been well documented across a range of habitats worldwide with carnivores potentially being the most vulnerable due to their more extinction prone characteristics. Investigating the effects of anthropogenic pressures on sympatric carnivores is needed to improve our ability to develop targeted, effective management plans for carnivore conservation worldwide. Utilizing photographic, line-transect, and habitat sampling, as well as landscape analyses and village-based bushmeat hunting surveys, we provide the first investigation of how multiple forms of habitat degradation (fragmentation, exotic carnivores, human encroachment, and hunting) affect carnivore occupancy across Madagascar's largest protected area: the Masoala-Makira landscape. We found that as degradation increased, native carnivore occupancy and encounter rates decreased while exotic carnivore occupancy and encounter rates increased. Feral cats (Felis species) and domestic dogs (Canis familiaris) had higher occupancy than half of the native carnivore species across Madagascar's largest protected landscape. Bird and small mammal encounter rates were negatively associated with exotic carnivore occupancy, but positively associated with the occupancy of four native carnivore species. Spotted fanaloka (Fossa fossana) occupancy was constrained by the presence of exotic feral cats and exotic small Indian civet (Viverricula indica). Hunting was intense across the four study sites where hunting was studied, with the highest rates for the small Indian civet (mean=90 individuals consumed/year), the ring-tailed vontsira (Galidia elegans) (mean=58 consumed/year), and the fosa (Cryptoprocta ferox) (mean=31 consumed/year). Our modeling results suggest hunters target intact forest where carnivore occupancy, abundance, and species richness, are highest. These various anthropogenic pressures and their effects on carnivore populations, especially increases in exotic carnivores and hunting, have wide-ranging, global implications and demand effective management plans to target the influx of exotic carnivores and unsustainable hunting that is affecting carnivore populations across Madagascar and worldwide. PMID:26375991

  6. A chronology for late prehistoric Madagascar.

    PubMed

    Burney, David A; Burney, Lida Pigott; Godfrey, Laurie R; Jungers, William L; Goodman, Steven M; Wright, Henry T; Jull, A J Timothy

    2004-01-01

    A database has been assembled with 278 age determinations for Madagascar. Materials 14C dated include pretreated sediments and plant macrofossils from cores and excavations throughout the island, and bones, teeth, or eggshells of most of the extinct megafaunal taxa, including the giant lemurs, hippopotami, and ratites. Additional measurements come from uranium-series dates on speleothems and thermoluminescence dating of pottery. Changes documented include late Pleistocene climatic events and, in the late Holocene, the apparently human-caused transformation of the environment. Multiple lines of evidence point to the earliest human presence at ca. 2300 14C yr BP (350 cal yr BC). A decline in megafauna, inferred from a drastic decrease in spores of the coprophilous fungus Sporormiella spp. in sediments at 1720+/-40 14C yr BP (230-410 cal yr AD), is followed by large increases in charcoal particles in sediment cores, beginning in the SW part of the island, and spreading to other coasts and the interior over the next millennium. The record of human occupation is initially sparse, but shows large human populations throughout the island by the beginning of the Second Millennium AD. Dating of the "subfossil" megafauna, including pygmy hippos, elephant birds, giant tortoises, and large lemurs, demonstrates that most if not all the extinct taxa were still present on the island when humans arrived. Many taxa overlapped chronologically with humans for a millennium or more. The extinct lemurs Hadropithecus stenognathus, Pachylemur insignis, Mesopropithecus pithecoides, and Daubentonia robusta, and the elephant birds Aepyornis spp. and Mullerornis spp., were still present near the end of the First Millennium AD. Palaeopropithecus ingens, Megaladapis edwardsi, and Archaeolemur sp. (cf. edwardsi) may have survived until the middle of the Second Millennium A.D. One specimen of Hippopotamus of unknown provenance dates to the period of European colonization. PMID:15288523

  7. Has Madagascar Lost Its Exceptional Leptospirosis Free-Like Status?

    PubMed Central

    Ratsitorahina, Maherisoa; Rahelinirina, Soanandrasana; Michault, Alain; Rajerison, Minoarisoa; Rajatonirina, Soatiana; Richard, Vincent

    2015-01-01

    Background Leptospirosis is a widespread but underreported cause of morbidity and mortality. It has rarely been reported in either humans or animals in Madagascar. Methods We conducted a cross-sectional survey of the inhabitants in Moramanga, Madagascar, in June 2011, to estimate the prevalence of human infection using the microscopic agglutination test (MAT). This activity was carried out as part of a workshop implemented by the Pasteur Institute of Madagascar, focusing on surveillance with a one week field study and targeting the health staff of the district level. Results In total, we sampled 678 inhabitants from 263 households. The sex ratio (M/F) was 0.65 and the mean age 26.7 years. We obtained a value of 2.9% for the first recorded seroprevalence of this disease in the human community of Moramanga. Questionnaire responses revealed frequent contacts between humans and rodents in Moramanga. However, activities involving cattle were identified as a risk factor significantly associated with seropositivity (OR=3). Conclusion Leptospirosis remains a neglected disease in Madagascar. This study highlights the need to quantify the public health impact of this neglected disease in a more large scale, in all the country and to establish point-of-care laboratories in remote areas. PMID:25874381

  8. Family Background, School Characteristics, and Children's Cognitive Achievement in Madagascar

    ERIC Educational Resources Information Center

    Glick, Peter; Randrianarisoa, Jean Claude; Sahn, David E.

    2011-01-01

    This paper uses linked household, school, and test score data from Madagascar to investigate the relation of household characteristics and school factors to the cognitive skills of children ages 8-10 and 14-16. In contrast to most achievement test studies in developing countries, the study uses representative rather than school-based samples of

  9. Autochthonous Melioidosis in Humans, Madagascar, 2012 and 2013

    PubMed Central

    Djaomazala, Innocente; Dubois-Cauwelaert, Natasha; Raharimanga, Vaomalala; Ralison, Fidiarivony; Herindrainy, Perlinot; Andriamalala, Nivosoa C.; Sarovich, Derek S.; Mayo, Mark; Kaestli, Mirjam; Currie, Bart J.

    2014-01-01

    Melioidosis is an often fatal infectious disease affecting humans and animals in the tropics. Only sporadic cases have been reported from Africa and the Indian Ocean region. We describe 2 confirmed autochthonous cases of human melioidosis in Madagascar, both from novel genotypes of Burkholderia pseudomallei. PMID:25272365

  10. Six new species of Microdon Meigen from Madagascar (Diptera: Syrphidae).

    PubMed

    Reemer, Menno; Bot, Sander

    2015-01-01

    Six new species of the myrmecophilous hoverfly genus Microdon Meigen (Diptera: Syrphidae) are described from Madagascar. Redescriptions are given for the three other Madagascan species of this genus. Keys are presented to the Madagascan genera of the subfamily Microdontinae and to the Madagascan species of Microdon. PMID:26624434

  11. Family Background, School Characteristics, and Children's Cognitive Achievement in Madagascar

    ERIC Educational Resources Information Center

    Glick, Peter; Randrianarisoa, Jean Claude; Sahn, David E.

    2011-01-01

    This paper uses linked household, school, and test score data from Madagascar to investigate the relation of household characteristics and school factors to the cognitive skills of children ages 8-10 and 14-16. In contrast to most achievement test studies in developing countries, the study uses representative rather than school-based samples of…

  12. Interannual variability of rainfall characteristics over southwestern Madagascar

    NASA Astrophysics Data System (ADS)

    Randriamahefasoa, T. S. M.; Reason, C. J. C.

    2016-01-01

    The interannual variability of daily frequency of rainfall [>1 mm/day] and heavy rainfall [>30 mm/day] is studied for the southwestern region of Madagascar, which is relatively arid compared to the rest of the island. Attention is focused on the summer rainy season from December to March at four stations (Morondava, Ranohira, Toliara and Taolagnaro), whose daily rainfall data covering the period 1970-2000 were obtained from the Madagascar Meteorological Service. El Niño Southern Oscillation (ENSO) was found to have a relatively strong correlation with wet day frequency at each station and, particularly, for Toliara in the extreme southwest. In terms of seasonal rainfall totals, most El Niño (La Niña) summers receive below (above) average amounts. An ENSO connection with heavy rainfall events was less clear. However, for heavy rainfall events, the associated atmospheric circulation displays a Southern Annular Mode-like pattern throughout the hemisphere. For ENSO years and the neutral seasons 1979/80, 1981/82 which had large anomalies in wet day frequency, regional atmospheric circulation patterns consisted of strong anomalies in low-level moisture convergence and uplift over and near southwestern Madagascar that made conditions correspondingly more or less favourable for rainfall. Dry (wet) summers in southern Madagascar were also associated with an equatorward (poleward) displacement of the ITCZ in the region.

  13. Low-temperature evolution of the Morondava rift basin shoulder in western Madagascar: An apatite fission track study

    NASA Astrophysics Data System (ADS)

    Giese, JRg; Seward, Diane; Schreurs, Guido

    2012-04-01

    The evolution of the rift shoulder and the sedimentary sequence of the Morondava basin in western Madagascar was mainly influenced by a Permo-Triassic continental failed rift (Karroo rift), and the early Jurassic separation of Madagascar from Africa. Karroo deposits are restricted to a narrow corridor along the basement-basin contact and parts of this contact feature a steep escarpment. Here, apatite fission track (AFT) analysis of a series of both basement and sediment samples across the escarpment reveals the low-temperature evolution of the exhuming Precambrian basement in the rift basin shoulder and the associated thermal evolution of the sedimentary succession. Seven basement and four Karroo sediment samples yield apparent AFT ages between 330 and 215 Ma and 260 and 95 Ma, respectively. Partially annealed fission tracks and thermal modeling indicate post-depositional thermal overprinting of both basement and Karroo sediment. Rocks presently exposed in the rift shoulder indicate temperatures of >60C associated with this reheating whereby the westernmost sample in the sedimentary plain experienced almost complete resetting of the detrital apatite grains at temperatures of about 90-100C. The younging of AFT ages westward indicates activity of faults, re-activating inherited Precambrian structures during Karroo sedimentation. Furthermore, our data suggest onset of final cooling/exhumation linked to (1) the end of Madagascar's drift southward relative to Africa during the Early Cretaceous, (2) activity of the Marion hot spot and associated Late Cretaceous break-up between Madagascar and India, and (3) the collision of India with Eurasia and subsequent re-organization of spreading systems in the Indian Ocean.

  14. Localization and Distribution of 'Candidatus Liberibacter asiaticus' in Citrus and Periwinkle by Direct Tissue Blot Immuno Assay with an Anti-OmpA Polyclonal Antibody.

    PubMed

    Ding, Fang; Duan, Yongping; Paul, Cristina; Brlansky, Ronald H; Hartung, John S

    2015-01-01

    'Candidatus Liberibacter asiaticus' (CaLas), a non-cultured member of the α-proteobacteria, is the causal agent of citrus Huanglongbing (HLB). Due to the difficulties of in vitro culture, antibodies against CaLas have not been widely used in studies of this pathogen. We have used an anti-OmpA polyclonal antibody based direct tissue blot immunoassay to localize CaLas in different citrus tissues and in periwinkle leaves. In citrus petioles, CaLas was unevenly distributed in the phloem sieve tubes, and tended to colonize in phloem sieve tubes on the underside of petioles in preference to the upper side of petioles. Both the leaf abscission zone and the junction of the petiole and leaf midrib had fewer CaLas bacteria compared to the main portions of the petiole and the midribs. Colonies of CaLas in phloem sieve tubes were more frequently found in stems with symptomatic leaves than in stems with asymptomatic leaves with an uneven distribution pattern. In serial sections taken from the receptacle to the peduncle, more CaLas were observed in the peduncle sections adjacent to the stem. In seed, CaLas was located in the seed coat. Many fewer CaLas were found in the roots, as compared to the seeds and petioles when samples were collected from trees with obvious foliar symptoms. The direct tissue blot immuno assay was adapted to whole periwinkle leaves infected by CaLas. The pathogen was distributed throughout the lateral veins and the results were correlated with results of qPCR. Our data provide direct spatial and anatomical information for CaLas in planta. This simple and scalable method may facilitate the future research on the interaction of CaLas and host plant. PMID:25946013

  15. Localization and Distribution of 'Candidatus Liberibacter asiaticus’ in Citrus and Periwinkle by Direct Tissue Blot Immuno Assay with an Anti-OmpA Polyclonal Antibody

    PubMed Central

    Ding, Fang; Duan, Yongping; Paul, Cristina; Brlansky, Ronald H.; Hartung, John S.

    2015-01-01

    ‘Candidatus Liberibacter asiaticus’ (CaLas), a non-cultured member of the α-proteobacteria, is the causal agent of citrus Huanglongbing (HLB). Due to the difficulties of in vitro culture, antibodies against CaLas have not been widely used in studies of this pathogen. We have used an anti-OmpA polyclonal antibody based direct tissue blot immunoassay to localize CaLas in different citrus tissues and in periwinkle leaves. In citrus petioles, CaLas was unevenly distributed in the phloem sieve tubes, and tended to colonize in phloem sieve tubes on the underside of petioles in preference to the upper side of petioles. Both the leaf abscission zone and the junction of the petiole and leaf midrib had fewer CaLas bacteria compared to the main portions of the petiole and the midribs. Colonies of CaLas in phloem sieve tubes were more frequently found in stems with symptomatic leaves than in stems with asymptomatic leaves with an uneven distribution pattern. In serial sections taken from the receptacle to the peduncle, more CaLas were observed in the peduncle sections adjacent to the stem. In seed, CaLas was located in the seed coat. Many fewer CaLas were found in the roots, as compared to the seeds and petioles when samples were collected from trees with obvious foliar symptoms. The direct tissue blot immuno assay was adapted to whole periwinkle leaves infected by CaLas. The pathogen was distributed throughout the lateral veins and the results were correlated with results of qPCR. Our data provide direct spatial and anatomical information for CaLas in planta. This simple and scalable method may facilitate the future research on the interaction of CaLas and host plant. PMID:25946013

  16. Phylogeography and Molecular Epidemiology of Yersinia pestis in Madagascar

    PubMed Central

    Vogler, Amy J.; Chan, Fabien; Wagner, David M.; Roumagnac, Philippe; Lee, Judy; Nera, Roxanne; Eppinger, Mark; Ravel, Jacques; Rahalison, Lila; Rasoamanana, Bruno W.; Beckstrom-Sternberg, Stephen M.; Achtman, Mark; Chanteau, Suzanne; Keim, Paul

    2011-01-01

    Background Plague was introduced to Madagascar in 1898 and continues to be a significant human health problem. It exists mainly in the central highlands, but in the 1990s was reintroduced to the port city of Mahajanga, where it caused extensive human outbreaks. Despite its prevalence, the phylogeography and molecular epidemiology of Y. pestis in Madagascar has been difficult to study due to the great genetic similarity among isolates. We examine island-wide geographic-genetic patterns based upon whole-genome discovery of SNPs, SNP genotyping and hypervariable variable-number tandem repeat (VNTR) loci to gain insight into the maintenance and spread of Y. pestis in Madagascar. Methodology/Principal Findings We analyzed a set of 262 Malagasy isolates using a set of 56 SNPs and a 43-locus multi-locus VNTR analysis (MLVA) system. We then analyzed the geographic distribution of the subclades and identified patterns related to the maintenance and spread of plague in Madagascar. We find relatively high levels of VNTR diversity in addition to several SNP differences. We identify two major groups, Groups I and II, which are subsequently divided into 11 and 4 subclades, respectively. Y. pestis appears to be maintained in several geographically separate subpopulations. There is also evidence for multiple long distance transfers of Y. pestis, likely human mediated. Such transfers have resulted in the reintroduction and establishment of plague in the port city of Mahajanga, where there is evidence for multiple transfers both from and to the central highlands. Conclusions/Significance The maintenance and spread of Y. pestis in Madagascar is a dynamic and highly active process that relies on the natural cycle between the primary host, the black rat, and its flea vectors as well as human activity. PMID:21931876

  17. Corps de la Paix Madagascar Livre du Formateur. Langue: Sakalava (Peace Corps Madagascar Teacher's Manual. Language: Sakalava).

    ERIC Educational Resources Information Center

    Tshiangale, Mupemba Wa

    This teacher's manual for Sakalava, a dialect of Malagasy, is designed for the specific language instruction needs of Peace Corps personnel in Madagascar. It is written primarily in French and Sakalava, with some titles in English. It consists of 29 topical lessons, each geared to a specific domain and competency and containing information on

  18. Corps de la Paix Madagascar Livre du Stagiare. Langue: Malagasy Ofisialy (Peace Corps Madagascar Volunteer Manual. Language: Official Malagasy).

    ERIC Educational Resources Information Center

    Tshiangale, Mupemba Wa

    This manual for Malagasy is designed for the specific language instruction needs of Peace Corps personnel working in Madagascar. It is written primarily in English and Malagasy, with introductory sections in French. It consists of 29 topical lessons, each geared to a specific domain and competency and containing information on needed materials,

  19. Mesoscale eddy variability in the southern extension of the East Madagascar Current: Seasonal cycle, energy conversion terms, and eddy mean properties

    NASA Astrophysics Data System (ADS)

    Halo, Issufo; Penven, Pierrick; Backeberg, Björn; Ansorge, Isabelle; Shillington, Frank; Roman, Raymond

    2014-10-01

    In this study, we used more than 17 years of satellite altimetry observations and output from an ocean model to investigate the mesoscale eddy variability and forcing mechanisms to the south of Madagascar. Analysis of energy conversion terms in the model has shown seasonality on eddy formation, both by barotropic and baroclinic instabilities: maximum in winter (JJA) and minimum in summer (DJF). The eddies were mainly formed in the upper ocean (0-300 m) and at intermediate depths (800-2000 m) by barotropic and baroclinic instabilities, respectively. The former dominated in the southeastern margin of Madagascar, and the latter to the southwest, where the South-East Madagascar Current (SEMC) separates from the continental shelf. Seasonality of the eddy formation appeared linked with the seasonal intensification of the SEMC. The energy conversion terms indicated that the eddies have a significant contribution to the large-scale circulation, but not being persistent throughout the year, occurring mainly during the fall season (MAM). Eddy demography from altimetry and model provided information on eddy preferential sites for birth, annual occurrence (6-13 per year), eddy mean diameter (124-178 km), mean amplitude (9-28 cm), life-time (90-183 days), and maximum traveling distances (325-1052 km). Eddies formed to the southwest of Madagascar exhibited distinct characteristics from those formed in the southeast. Nevertheless, all eddies were highly nonlinear, suggesting that they are potential vectors of connectivity between Madagascar and Africa. This may have a significant impact on the ecology of this region.

  20. The Application of TOMS Ozone, Aerosol and UV-B Data to Madagascar Air Quality Determination

    NASA Technical Reports Server (NTRS)

    Aikin, A.C.; Einaudi, Franco (Technical Monitor)

    2000-01-01

    Total Ozone Mapping Spectrometer (TOMS) data products for the area of Madagascar are presented. In addition to total ozone, aerosols and UV-B tropospheric ozone results are shown from 1979 to the present. Tropospheric ozone over Africa and Madagascar is enhanced by 10 to 15 DU in October. This maximum coincides with the time of maximum biomass area burning in Africa and Madagascar. Ozone observations were made from 1979 to 1999 using the TOMS tropospheric ozone convective cloud differential method. As a result of easterly trade winds, ozone originating on Madagascar is transported to the west over the Mozambique Channel. In El Nino years higher level westerly winds descend to transport low level ozone easterly. This results in African continental ozone being transported east of Madagascar. Long range transport of African ozone is observed during El Nino periods. The potential of TOMS and other space data for use in public education and research on Madagascar air quality is demonstrated.

  1. Prevalence and correlates of tobacco use among school-going adolescents in Madagascar.

    PubMed

    Veeranki, Sreenivas P; Mamudu, Hadii M; John, Rijo M; Ouma, Ahmed E O

    2015-09-01

    Approximately 90% of adults start smoking during adolescence, with limited studies conducted in low-and-middle-income countries where over 80% of global tobacco users reside. The study aims to estimate prevalence and identify predictors associated with adolescents' tobacco use in Madagascar. We utilized tobacco-related information of 1184 school-going adolescents aged 13-15 years, representing a total of 296,111 youth from the 2008 Madagascar Global Youth Tobacco Survey to determine the prevalence of tobacco use. Gender-wise multivariable logistic regression models were conducted to identify key predictors. Approximately 19% (30.7% males; 10.2% females) of adolescents currently smoke cigarettes, and 7% (8.5% males and 5.8% females) currently use non-cigarette tobacco products. Regardless of sex, peer smoking behavior was significantly associated with increased tobacco use among adolescents. In addition, exposures to tobacco industry promotions, secondhand smoke (SHS) and anti-smoking media messages were associated with tobacco use. The strong gender gap in the use of non-cigarette tobacco products, and the role of peer smoking and industry promotions in adolescent females' tobacco use should be of major advocacy and policy concern. A comprehensive tobacco control program integrating parental and peer education, creating social norms, and ban on promotions is necessary to reduce adolescents' tobacco use. PMID:26044844

  2. Rural livelihoods and access to natural capital: Differences between migrants and non-migrants in Madagascar

    PubMed Central

    Nawrotzki, Raphael J.; Hunter, Lori M.; Dickinson, Thomas W.

    2013-01-01

    BACKGROUND Although natural resources play a central role in rural livelihoods across the globe, little research has explored the relationship between migration and natural capital use, particularly in combination with other livelihood capitals (i.e., human, social, financial and physical). OBJECTIVE Grounded in the rural livelihood framework, this paper explores the association between the livelihood capital availability, especially natural capital, for migrants and non-migrants in rural Madagascar. METHODS Data from the 2008/2009 Demographic and Health Survey are used in combination with satellite imagery of vegetation coverage (Normalized Difference Vegetation Index, NDVI) to proxy natural resources. Hierarchical multilevel models allow for inclusion of cross-level interactions between migrant status and proximate natural resources as determinants of the status of livelihood assets. RESULTS Three key findings emerge. First, higher levels of proximate natural resources are associated with greater financial, human, and social capital for both migrants and non-migrants. Second, migrants have, on average, greater financial, physical, human, and social capital than non-migrants, and urban-to-rural migrants do exceptionally well on all capital asset categories. Third, migrants residing in areas with higher levels of natural capital tend to have significantly higher levels of human capital (education). CONCLUSION Although we cannot examine livelihood strategies per se, the results suggest variation in livelihood potential among migrants and non-migrants in rural Madagascar, with migrants tending to have greater capital assets. In addition, access to natural resources is a central livelihood strategy. PMID:25364297

  3. In situ observations of mesoscale undercurrents off eastern Madagascar

    NASA Astrophysics Data System (ADS)

    Ponsoni, Leandro; Aguiar-Gonzalez, Borja; Maas, Leo; van Aken, Hendrik; Nauw, Janine; Ridderinkhof, Herman

    2015-04-01

    The South-West Indian Ocean (SWIO) presents one of the most intriguing western boundary regions of all subtropical gyres. Unlike other gyres, in the SWIO the Madagascar island imposes a physical barrier to the westward flowing South Equatorial Current (SEC), which reaches the Madagascar coast between 17°S and 20°S. At this location, the SEC bifurcates into two branches: the poleward branch feeds into the East Madagascar Current (EMC), which further south will feed the Agulhas Current (AC); on the other hand, the poleward branch feeds into the North Madagascar Current (NMC), which turns around Cape Amber, at the northern tip of Madagascar, and continues westward towards the east coast of Africa. Besides the patterns of the boundary currents described above, undercurrents flowing opposite and beneath the mentioned surface currents are also reported to occur: the equatorward East Madagascar Undercurrent (EMUC) and the poleward North Madagascar Undercurrent (NMUC). This work is based on field studies of both undercurrents. We deployed a cross-slope array of five moorings at 23°S off eastern Madagascar, which was maintained from late 2010 till early 2013 (~2.5 years). A total of 6 Acoustic Doppler Current Profiles and 10 Recording Current Meters were coupled to the moorings. Direct measurements were made from near surface (~50 m) to deep in the water column (~4000 m). The observations reveal a recurring equatorward EMUC with its core hugging the continental slope, at a depth of 1260 m and at an approximate distance of 29 km from the coast. The core velocity has a mean value of 4.1 (±6.3) cm s-1, while maximum speeds reach up to 20 cm -1. The volume transport is estimated to be 1.33 (±1.14) Sv with maxima up to 6 Sv. At the northern tip of Madagascar, off Cape Ambar, we present the first observational evidence of a poleward NMUC. These results are based on a hydrographic cruise (March 2001), where vertical profiles of velocity were sampled across the continental slope. The data show an NMUC also hugging the continental slope, but its core is observed at 460 m depth. Its core velocity reaches over 0.7 m s-1 and its volume transport is estimated to be around 3.5 Sv. The thermohaline characteristics show a saltier and warmer NMUC, compared to the surrounding offshore waters, transporting mainly South Indian Central Water. Two dominant frequency bands were found in the time series of EMUC volume transport: nearly semi-annual and nearly bi-monthly. The NMUC is concurrent with an inshore cell of coastal downwelling due to Ekman Transport towards the coast, which may be associated, at least in part, with the NMUC variability. The comparison between both results stresses the importance of long-term direct observations at fixed locations.

  4. Possible Fruit Protein Effects on Primate Communities in Madagascar and the Neotropics

    PubMed Central

    Ganzhorn, Jörg U.; Arrigo-Nelson, Summer; Boinski, Sue; Bollen, An; Carrai, Valentina; Derby, Abigail; Donati, Giuseppe; Koenig, Andreas; Kowalewski, Martin; Lahann, Petra; Norscia, Ivan; Polowinsky, Sandra Y.; Schwitzer, Christoph; Stevenson, Pablo R.; Talebi, Mauricio G.; Tan, Chia; Vogel, Erin R.; Wright, Patricia C.

    2009-01-01

    Background The ecological factors contributing to the evolution of tropical vertebrate communities are still poorly understood. Primate communities of the tropical Americas have fewer folivorous but more frugivorous genera than tropical regions of the Old World and especially many more frugivorous genera than Madagascar. Reasons for this phenomenon are largely unexplored. We developed the hypothesis that Neotropical fruits have higher protein concentrations than fruits from Madagascar and that the higher representation of frugivorous genera in the Neotropics is linked to high protein concentrations in fruits. Low fruit protein concentrations in Madagascar would restrict the evolution of frugivores in Malagasy communities. Methodology/Principal Findings We reviewed the literature for nitrogen concentrations in fruits from the Neotropics and from Madagascar, and analyzed fruits from an additional six sites in the Neotropics and six sites in Madagascar. Fruits from the Neotropical sites contain significantly more nitrogen than fruits from the Madagascar sites. Nitrogen concentrations in New World fruits are above the concentrations to satisfy nitrogen requirements of primates, while they are at the lower end or below the concentrations to cover primate protein needs in Madagascar. Conclusions/Significance Fruits at most sites in the Neotropics contain enough protein to satisfy the protein needs of primates. Thus, selection pressure to develop new adaptations for foods that are difficult to digest (such as leaves) may have been lower in the Neotropics than in Madagascar. The low nitrogen concentrations in fruits from Madagascar may contribute to the almost complete absence of frugivorous primate species on this island. PMID:20016841

  5. A multidisciplinary study on lavaka (gully erosion) formation in Central Highlands, Madagascar

    NASA Astrophysics Data System (ADS)

    Raveloson, A.; Visnovitz, F.; Székely, B.; Molnár, G.; Udvardi, B.

    2012-04-01

    Madagascar is a very important place to study erosion. Due to some forms of gully erosion called lavaka the country is among the first regarding its erosion rate. Lavakas are very abundant in the highlands of Madagascar (they can reach up to 30/km2). Therefore they have been subject of many studies in the past 60 years. Lavaka formation seems to be triggered by many regional effects (thin laterite layer on thick saprolite layer, smoothly convex hills, climate) and local causes (rain attack, earth falls, lack of vegetation) both natural and anthropogenic (deforestation, roads, paths) but the real nature of these erosion features are not fully understood. Based on field surveys, photogrammetrical, geomorphological and lithological-sedimentological methods two different kinds of lavaka (toe-slope and mid-slope) were studied in Tsiafahy, Central Highlands. Our main goal was to understand the formation of lavakas in order to prevent their consequences such as the degradation of agricultural lands, villages and nearby roads. For this purpose we digitalized geological and hydrological maps of the country and compared them with maps showing the occurrence of lavakas in Madagascar. 3D (three-dimensional) modeling of the actual eroding surface was achieved with photogrammetric methods applying the few hundred photos we made during the field surveys. We tested several 3D modeling software and used the best ones (with higher accuracy and resolution) to model a toe-slope lavaka. In order to model a more complex mid-slope lavaka a new program has been developed in MATLAB as well. Such photogrammetric evaluation and 3D modeling of lavakas were achieved for the first time and therefore the results are yet preliminary. Sedimentological features (grain size distribution and mineral composition) of an active mid-slope lavaka were also investigated to define the difference between the lateritic and saprolitic layers of the lavaka. Preliminary results show that the most important causes of lavaka formation are the climate and the lithological features of these areas. According to our field surveys and analysis lavaka's saprolitic layer can be divided into two different units: a yellow colored saprolitic layer with smaller hydraulic conductivity and a reddish saprolitic layer which could be interpreted as the transition between the yellow saprolitic and the upper red lateritic layer. Field surveys and photos show that the complex structure of the lavakas strongly correlate to the distribution of these different saprolitic units. The understanding of 3D distribution of these material types is the key to the lavaka formation. Further studies will concentrate on improving the obtained models and using them for geomorphologic studies including calculating relief, aspects and volume.

  6. Spatial patterns of AFLP diversity in Bulbophyllum occultum (Orchidaceae) indicate long-term refugial isolation in Madagascar and long-distance colonization effects in La Réunion.

    PubMed

    Jaros, U; Fischer, G A; Pailler, T; Comes, H P

    2016-05-01

    Bulbophyllum occultum, an epiphytic orchid mainly distributed in the rainforests of (north)eastern Madagascar and La Réunion, represents an interesting model case for testing the effects of anthropogenic vs historical (e.g., climate induced) habitat isolation and long-distance colonization on the genetic structure of plant species with disjunct distributions in the Madagascan region. To this aim, we surveyed amplified fragment length polymorphisms (AFLPs) across 13 populations in Madagascar and nine in La Réunion (206 individuals in total). We found overall high levels of population subdivision (ΦPT=0.387) and low within-population diversity (HE, range: 0.026-0.124), indicating non-equilibrium conditions in a mainly selfing species. There was no impact of recent deforestation (Madagascar) or habitat disturbance (La Réunion) detectable on AFLP diversity. K-means clustering and BARRIER analyses identified multiple gene pools and several genetic breaks, both within and among islands. Inter-island levels of population genetic diversity and subdivision were similar, whereby inter-individual divergence in flower colour explained a significant part of gene pool divergence in La Réunion. Our results suggest that (i) B. occultum persisted across multiple isolated ('refugial') regions along the eastern rainforest corridor of Madagascar over recent climatic cycles and (ii) populations in La Réunion arose from either single or few independent introductions from Madagascar. High selfing rates and sufficient time for genetic drift likely promoted unexpectedly high population genetic and phenotypic (flower colour) differentiation in La Réunion. Overall, this study highlights a strong imprint of history on the genetic structure of a low-gene-dispersing epiphytic orchid from the Madagascan region. PMID:26883184

  7. Hydrogeology in The Semi-Arid South-West of Madagascar - a Multi-Scale Approach

    NASA Astrophysics Data System (ADS)

    Englert, A.; Dworak, L.; Rasoloariniaina, J.; Brinkmann, K.; Kobbe, S.; Buerkert, A.

    2014-12-01

    The project „Sustainable Land Management" (SuLaMa) aims at the participatory development and implementation of alternative land-use management practices to protect the ecosystem and its biodiversity and improve the livelihood of the local population in a sustainable manner. One critical aspect within this project is the availability of sustainable water resources. To approach reliable estimates about the availability and dynamics of the water resources, we started a study to understand in detail the hydrogeology of the South-West of Madagascar. As this area has an extend of about 40000 square kilometers, the study is based on a multi-scale approach. Rough large scale estimates are utilized to develop a general understanding of the hydrogeology in the South-West of Madagascar, which allows for large scale estimates of hydrogeology under changing boundary conditions like climate change. Detailed investigations at target villages of the SuLaMa project, combined with boundary conditions derived from the large scale hydrogeological model, allows for estimates of the local hydrogeology under changing boundary conditions like enhanced water abstraction. Although several governmental and nongovernmental institutions have been working on the water resources of the South-West of Madagascar in the past, only few sources on the hydrogeology of this area can be found in literature. To improve the data base we installed five automatic loggers in the area to measure groundwater levels as function of time and investigated in detail about one hundred wells in terms of geometry, groundwater level, electrical conductivity and pH. First preliminary results of the study show that the hydrogeology in the study area is dominated by four major hydrogeological units (fractured crystalline basement, karstic plateau, porous perched aquifers and a porous coastal area) and can be analyzed effectively by assuming a radial symmetric geometry. Ongoing efforts are the development of a model for a spatially variable groundwater recharge estimates and advanced hydrogeological models. The latter consisting of high resolution small scale and low resolution large scale estimates. Based on these models, we will develop numerical flow models to evaluate water resources as function of changing boundary conditions at multiple scales.

  8. [Indigenous medical assistance in Madagascar (1898-1950)].

    PubMed

    Merlin, J; Mafart, B; Triaud, J L

    2003-01-01

    The foundations of local health services in Madagascar were laid when the island was taken over by the French in 1896. Medical care was a major priority for the first colonial governor named General Galliéni. Local health services expanded greatly from 1896 to 1950 thanks notably to institutions such as the Tananarive Medical School and Pasteur Institute. These services played a crucial role in the fight against smallpox and bubonic plague. However they were also used for political purposes by both colonial and independent governments. In sum the history of local health services in Madagascar can be described as a battle between political power and scientific knowledge. The overall result is positive for some and controversial for others. PMID:12891743

  9. Antibodies to haemorrhagic fever viruses in Madagascar populations.

    PubMed

    Mathiot, C C; Fontenille, D; Georges, A J; Coulanges, P

    1989-01-01

    Sera of 381 adult people from 5 areas in Madagascar were tested by the indirect immunofluorescence method for antibodies against Congo-Crimean haemorrhagic fever and Rift Valley fever viruses (Bunyaviridae), Ebola (strains Zaire and Sudan) and Marburg viruses (Filoviridae), and Lassa virus (Arenaviridae). The highest prevalence rate was that of Ebola virus (4.5%). As no haemorrhagic syndrome has been found associated with this virus, the possible presence of a less pathogenic, antigenically related, strain is discussed. The prevalences of Congo-Crimean haemorrhagic fever and Rift Valley viruses were very low, despite previous viral isolations from potential vectors. No serum reacted against Lassa or Marburg antigens. The results are analysed in the light of the geographical and bioecological characteristics of Madagascar, which is a true 'microcontinent' very different from the African mainland. PMID:2515626

  10. Women's knowledge in Madagascar: a health needs assessment study.

    PubMed

    Dell, Evelyn M; Erikson, S L; Andrianirina, E; Smith, Gabrielle

    2012-01-01

    Nutritional and hygienic practices contribute to high morbidity and mortality rates related to malnutrition in Madagascar. This study, a research effort that brought together charitable organisations, non-governmental organisations (NGOs) and university collaborators, investigates women's health knowledge in the Anosy region of Madagascar. The needs assessment sought to characterise women's knowledge and understanding of nutrition and hygiene. Eight focus groups of 13-60 women each were conducted in the seven most impoverished communes of the Anosy region (n=373). Participants were recruited with the aid of a UK-Malagasy partnered NGO, Azafady. Study findings show that women fully understand the interplay between poor nutrition, hygiene and malnutrition but are unable to change everyday practices because the barriers to better nutrition and hygiene seem beyond their control. These findings may be used to prioritise projects and research seeking to improve nutrition and hygiene, thus reducing malnutrition in the Anosy region. PMID:21416417

  11. [Bacterial quality of the water supply in Madagascar].

    PubMed

    Ravaonindrina, N; Andrianantara, L; Rasolomandimby, R; Rajaomiarisoa, E; Rasolofonirina, N

    1994-01-01

    The results of 14371 drinking water analysis carried out in Madagascar between 1986 and 1993 by the water analysis and food microbiology laboratory of the Pasteur Institute of Madagascar are reported. After a history of the water analysis laboratory, methods and frequency of sampling, methods of analysis and standards applied are quoted and documented. Results for each province are reported and particularly indicated: the development of water samples and their portability along the years, the respective frequency of pollutant bacteria and their amounts according to sampling points. In spite of the lack of means in the country, the authors consider the results are satisfactory but they stress the importance of an organized surveillance system of drinking water quality. PMID:7575043

  12. Multiple Miocene Melastomataceae dispersal between Madagascar, Africa and India.

    PubMed

    Renner, Susanne S

    2004-10-29

    Melastomataceae sensu stricto (excluding Memecylaceae) comprise some 3000 species in the neotropics, 1000 in Asia, 240 in Africa, and 230 in Madagascar. Previous family-wide morphological and DNA analyses have shown that the Madagascan species belong to at least three unrelated lineages, which were hypothesized to have arrived by trans-oceanic dispersal. An alternative hypothesis posits that the ancestors of Madagascan, as well as Indian, Melastomataceae arrived from Africa in the Late Cretaceous. This study tests these hypotheses in a Bayesian framework, using three combined sequence datasets analysed under a relaxed clock and simultaneously calibrated with fossils, some not previously used. The new fossil calibration comes from a re-dated possibly Middle or Upper Eocene Brazilian fossil of Melastomeae. Tectonic events were also tentatively used as constraints because of concerns that some of the family's fossils are difficult to assign to nodes in the phylogeny. Regardless of how the data were calibrated, the estimated divergence times of Madagascan and Indian lineages were too young for Cretaceous explanations to hold. This was true even of the oldest ages within the 95% credibility interval around each estimate. Madagascar's Melastomeae appear to have arrived from Africa during the Miocene. Medinilla, with some 70 species in Madagascar and two in Africa, too, arrived during the Miocene, but from Asia. Gravesia, with 100 species in Madagascar and four in east and west Africa, also appears to date to the Miocene, but its monophyly has not been tested. The study afforded an opportunity to compare divergence time estimates obtained earlier with strict clocks and single calibrations, with estimates based on relaxed clocks and different multiple calibrations and taxon sampling. PMID:15519967

  13. Extinction Risks and the Conservation of Madagascar's Reptiles

    PubMed Central

    Jenkins, Richard K. B.; Tognelli, Marcelo F.; Bowles, Philip; Cox, Neil; Brown, Jason L.; Chan, Lauren; Andreone, Franco; Andriamazava, Alain; Andriantsimanarilafy, Raphali R.; Anjeriniaina, Mirana; Bora, Parfait; Brady, Lee D.; Hantalalaina, Elisoa F.; Glaw, Frank; Griffiths, Richard A.; Hilton-Taylor, Craig; Hoffmann, Michael; Katariya, Vineet; Rabibisoa, Nirhy H.; Rafanomezantsoa, Jeannot; Rakotomalala, Domoina; Rakotondravony, Hery; Rakotondrazafy, Ny A.; Ralambonirainy, Johans; Ramanamanjato, Jean-Baptiste; Randriamahazo, Herilala; Randrianantoandro, J. Christian; Randrianasolo, Harison H.; Randrianirina, Jasmin E.; Randrianizahana, Hiarinirina; Raselimanana, Achille P.; Rasolohery, Andriambolantsoa; Ratsoavina, Fanomezana M.; Raxworthy, Christopher J.; Robsomanitrandrasana, Eric; Rollande, Finoana; van Dijk, Peter P.; Yoder, Anne D.; Vences, Miguel

    2014-01-01

    Background An understanding of the conservation status of Madagascar's endemic reptile species is needed to underpin conservation planning and priority setting in this global biodiversity hotspot, and to complement existing information on the island's mammals, birds and amphibians. We report here on the first systematic assessment of the extinction risk of endemic and native non-marine Malagasy snakes, lizards, turtles and tortoises. Methodology/Principal Findings Species range maps from The IUCN Red List of Threatened Species were analysed to determine patterns in the distribution of threatened reptile species. These data, in addition to information on threats, were used to identify priority areas and actions for conservation. Thirty-nine percent of the data-sufficient Malagasy reptiles in our analyses are threatened with extinction. Areas in the north, west and south-east were identified as having more threatened species than expected and are therefore conservation priorities. Habitat degradation caused by wood harvesting and non-timber crops was the most pervasive threat. The direct removal of reptiles for international trade and human consumption threatened relatively few species, but were the primary threats for tortoises. Nine threatened reptile species are endemic to recently created protected areas. Conclusions/Significance With a few alarming exceptions, the threatened endemic reptiles of Madagascar occur within the national network of protected areas, including some taxa that are only found in new protected areas. Threats to these species, however, operate inside and outside protected area boundaries. This analysis has identified priority sites for reptile conservation and completes the conservation assessment of terrestrial vertebrates in Madagascar which will facilitate conservation planning, monitoring and wise-decision making. In sharp contrast with the amphibians, there is significant reptile diversity and regional endemism in the southern and western regions of Madagascar and this study highlights the importance of these arid regions to conserving the island's biodiversity. PMID:25111137

  14. Chapelieria magna, a new species of Rubiaceae from eastern Madagascar

    PubMed Central

    Kainulainen, Kent; Razafimandimbison, Sylvain G.

    2015-01-01

    Abstract A new species of Chapelieria was discovered during a recent field trip to the Masoala National Park in eastern Madagascar, and is described here as Chapelieria magna Kainul., sp. nov. This species is readily distinguishable from previously described species of the genus by its quadrangular shoots, triangular-calyptrate stipules, sessile leaves, pubescent styles, and ridged fruits. It also differs in the larger number of ovules and the much larger size of leaves and fruits. PMID:25698895

  15. Multiple Miocene Melastomataceae dispersal between Madagascar, Africa and India.

    PubMed Central

    Renner, Susanne S

    2004-01-01

    Melastomataceae sensu stricto (excluding Memecylaceae) comprise some 3000 species in the neotropics, 1000 in Asia, 240 in Africa, and 230 in Madagascar. Previous family-wide morphological and DNA analyses have shown that the Madagascan species belong to at least three unrelated lineages, which were hypothesized to have arrived by trans-oceanic dispersal. An alternative hypothesis posits that the ancestors of Madagascan, as well as Indian, Melastomataceae arrived from Africa in the Late Cretaceous. This study tests these hypotheses in a Bayesian framework, using three combined sequence datasets analysed under a relaxed clock and simultaneously calibrated with fossils, some not previously used. The new fossil calibration comes from a re-dated possibly Middle or Upper Eocene Brazilian fossil of Melastomeae. Tectonic events were also tentatively used as constraints because of concerns that some of the family's fossils are difficult to assign to nodes in the phylogeny. Regardless of how the data were calibrated, the estimated divergence times of Madagascan and Indian lineages were too young for Cretaceous explanations to hold. This was true even of the oldest ages within the 95% credibility interval around each estimate. Madagascar's Melastomeae appear to have arrived from Africa during the Miocene. Medinilla, with some 70 species in Madagascar and two in Africa, too, arrived during the Miocene, but from Asia. Gravesia, with 100 species in Madagascar and four in east and west Africa, also appears to date to the Miocene, but its monophyly has not been tested. The study afforded an opportunity to compare divergence time estimates obtained earlier with strict clocks and single calibrations, with estimates based on relaxed clocks and different multiple calibrations and taxon sampling. PMID:15519967

  16. Sarandibrinus, a new genus of Saprininae subfamily from Madagascar (Coleoptera, Histeridae) (Second contribution to the knowledge of the Histeridae of Madagascar)

    PubMed Central

    Lackner, Tomáš; Gomy, Yves

    2014-01-01

    Abstract Sarandibrinus araceliae, a new genus and species of the Saprininae subfamily is described from southern Madagascar. The new taxon exhibits autapomorphic characters for the Saprininae subfamily and is unusual especially for its large and deep prosternal foveae and the shape of spiculum gastrale. The description is accompanied by color habitus images, SEM micrographs, mouthparts and antenna line drawings and drawings of the male genitalia. Key to the genera of the Saprininae of Madagascar and the adjacent archipelagos is given. Hypocaccus (Baeckmanniolus) rubiciliae (Lewis, 1899) is newly reported from Madagascar and Hypocaccus (Nessus) perparvulus (Desbordes, 1916) is new to Mauritius. PMID:25147466

  17. Xenopsylla cheopis (Siphonaptera: Pulicidae) Susceptibility to Deltamethrin in Madagascar

    PubMed Central

    Elissa, Nohal

    2014-01-01

    The incidence of bubonic plague in Madagascar is high. This study reports the susceptibility of 32 different populations of a vector, the flea Xenopsylla cheopis (Siphonaptera: Pulicidae), to the insecticide Deltamethrin. Despite the use of Deltamethrin against fleas, plague epidemics have re-emerged in Madagascar. The majority of the study sites were located in the Malagasy highlands where most plague cases have occurred over the last 10 years. X. cheopis fleas were tested for susceptibility to Deltamethrin (0.05%): only two populations were susceptible to Deltamethrin, four populations were tolerant and 26 populations were resistant. KD50 (50% Knock-Down) and KD90 (90% Knock-Down) times were determined, and differed substantially from 9.4 to 592.4 minutes for KD50 and 10.4 min to 854.3 minutes for KD90. Susceptibility was correlated with latitude, but not with longitude, history of insecticide use nor date of sampling. Combined with the number of bubonic plague cases, our results suggest that an immediate switch to an insecticide other than Deltamethrin is required for plague vector control in Madagascar. PMID:25369291

  18. Xenopsylla cheopis (Siphonaptera: Pulicidae) susceptibility to Deltamethrin in Madagascar.

    PubMed

    Boyer, Sebastien; Miarinjara, Adélaïde; Elissa, Nohal

    2014-01-01

    The incidence of bubonic plague in Madagascar is high. This study reports the susceptibility of 32 different populations of a vector, the flea Xenopsylla cheopis (Siphonaptera: Pulicidae), to the insecticide Deltamethrin. Despite the use of Deltamethrin against fleas, plague epidemics have re-emerged in Madagascar. The majority of the study sites were located in the Malagasy highlands where most plague cases have occurred over the last 10 years. X. cheopis fleas were tested for susceptibility to Deltamethrin (0.05%): only two populations were susceptible to Deltamethrin, four populations were tolerant and 26 populations were resistant. KD50 (50% Knock-Down) and KD90 (90% Knock-Down) times were determined, and differed substantially from 9.4 to 592.4 minutes for KD50 and 10.4 min to 854.3 minutes for KD90. Susceptibility was correlated with latitude, but not with longitude, history of insecticide use nor date of sampling. Combined with the number of bubonic plague cases, our results suggest that an immediate switch to an insecticide other than Deltamethrin is required for plague vector control in Madagascar. PMID:25369291

  19. Origin and Diversification of Dung Beetles in Madagascar

    PubMed Central

    Miraldo, Andreia; Wirta, Helena; Hanski, Ilkka

    2011-01-01

    Madagascar has a rich fauna of dung beetles (Scarabaeinae and Aphodiinae) with almost 300 species described to date. Like most other taxa in Madagascar, dung beetles exhibit an exceptionally high level of endemism (96% of the species). Here, we review the current knowledge of the origin and diversification of Malagasy dung beetles. Based on molecular phylogenies, the extant dung beetles originate from eight colonizations, of which four have given rise to extensive radiations. These radiations have occurred in wet forests, while the few extant species in the less successful radiations occur in open and semi-open habitats. We discuss the likely mechanisms of speciation and the ecological characteristics of the extant communities, emphasizing the role of adaptation along environmental gradients and allopatric speciation in generating the exceptionally high beta diversity in Malagasy dung beetles. Phylogeographic analyses of selected species reveal complex patterns with evidence for genetic introgression between old taxa. The introduction of cattle to Madagascar 1500 years ago created a new abundant resource, onto which a few species have shifted and thereby been able to greatly expand their geographical ranges. PMID:26467617

  20. Origin and Diversification of Dung Beetles in Madagascar.

    PubMed

    Miraldo, Andreia; Wirta, Helena; Hanski, Ilkka

    2011-01-01

    Madagascar has a rich fauna of dung beetles (Scarabaeinae and Aphodiinae) withalmost 300 species described to date. Like most other taxa in Madagascar, dung beetles exhibit an exceptionally high level of endemism (96% of the species). Here,we review the current knowledge of the origin and diversification of Malagasy dung beetles. Based on molecular phylogenies, the extant dung beetles originate from eight colonizations, of which four have given rise to extensive radiations. These radiations have occurred in wet forests, while the few extant species in the less successfulradiations occur in open and semi-open habitats. We discuss the likely mechanisms of speciation and the ecological characteristics of the extant communities, emphasizing the role of adaptation along environmental gradients and allopatric speciation in generating the exceptionally high beta diversity in Malagasy dung beetles. Phylogeographic analyses of selected species reveal complex patterns with evidence for genetic introgression between old taxa. The introduction of cattle to Madagascar 1500 years ago created a new abundant resource, onto which a few species haveshifted and thereby been able to greatly expand their geographical ranges. PMID:26467617

  1. Madagascar corals reveal Pacific multidecadal modulation of rainfall since 1708

    NASA Astrophysics Data System (ADS)

    Grove, C. A.; Zinke, J.; Peeters, F.; Park, W.; Scheufen, T.; Kasper, S.; Randriamanantsoa, B.; McCulloch, M. T.; Brummer, G.-J. A.

    2012-03-01

    The Pacific Ocean modulates Australian and North American rainfall variability on multidecadal timescales, in concert with the Pacific Decadal Oscillation (PDO). It has been suggested that Pacific decadal variability may also influence Indian Ocean surface temperature and rainfall in a far-field response, similar to the El Nio Southern Oscillation (ENSO) on interannual timescales. However, instrumental records of rainfall are too short and too sparse to confidently assess such multidecadal climatic teleconnections. Here, we present four climate archives spanning the past 300 yr from giant Madagascar corals. We decouple 20th century human deforestation effects from rainfall induced soil erosion using spectral luminescence scanning and geochemistry. The corals provide the first evidence for Pacific decadal modulation of rainfall over the Western Indian Ocean. We find that positive PDO phases are associated with increased Indian Ocean temperatures and rainfall in Eastern Madagascar, while precipitation in Southern Africa and Eastern Australia declines. Consequently, the negative PDO phase that started in 1998 should lead to reduced rainfall over Eastern Madagascar and increased precipitation in Southern Africa and Eastern Australia. We conclude that the PDO has important implications for future multidecadal variability of African rainfall, where water resource management is increasingly important under the warming climate.

  2. Morphometrics, sexual dimorphism, and growth in the Angonoka tortoise (Geochelone yniphora) of western Madagascar

    USGS Publications Warehouse

    Smith, Lora L.; Pedrono, Miguel; Dorazio, Robert M.; Bishko, Jack

    2001-01-01

    The most recent description of the morphology of the rare endemic Madagascar tortoise,Geochelone yniphora was based on fewer than 20 specimens. We collected morphological data for 200 free‐ranging tortoises from five populations over a four‐year period. Tortoises ranged in size from 43.5 mm carapace length at hatching to a maximum of 481 mm in an adult male. We were able to develop a logistic regression model to predict the sex of adult tortoises in one of the five populations using principal component analysis; the model correctly predicted the sex of 25 of 26 adult tortoises. Growth of 40 tortoises was monitored and as in other chelonians, the annual relative growth rate decreased with age. The relative growth rate in adults was approximately 5% per year as compared to approximately 16% in juveniles. Juvenile tortoises accrued one scute growth layer per year.

  3. Genome assembly and annotation of a Drosophila simulans strain from Madagascar

    PubMed Central

    PALMIERI, NICOLA; NOLTE, VIOLA; CHEN, JUN; SCHLTTERER, CHRISTIAN

    2015-01-01

    Drosophila simulans is a close relative of the genetic model D. melanogaster. Its worldwide distribution in combination with the absence of segregating chromosomal inversions makes this species an increasingly attractive model to study the molecular signatures of adaptation in natural and experimental populations. In an effort to improve the genomic resources for D. simulans, we assembled and annotated the genome of a strain originating from Madagascar (M252), the ancestral range of D. simulans. The comparison of the M252 genome to other available D. simulans assemblies confirmed its high quality, but also highlighted genomic regions that are difficult to assemble with NGS data. The annotation of M252 provides a clear improvement with alternative splicing for 52% of the multiple-exon genes, UTRs for 70% of the genes, 225 novel genes and 781 pseudogenes being reported. We anticipate that the M252 genome will be a valuable resource for many research questions. PMID:24961367

  4. Broken forest: Applying the integrated conservation and development paradigm to Madagascar's protected areas

    SciTech Connect

    Barbour, R.; Rabezandria, R.; Daviesson, R.; Guyton, W.; Rakotobe.

    1992-06-01

    The destruction of Madagascar's primary forests through agricultural clearing poses a grave threat to the island's biodiversity. The report assesses the potential of the planned Sustainable and Viable Environmental Management (SAVEM) Project to minimize this threat by implementing Integrated Conservation Development Projects (ICDP's), which link resource conservation to income-generating activities, in the peripheral zones of Madagascar's protected areas.

  5. Chow Down! Using Madagascar Hissing Cockroaches to Explore Basic Nutrition Concepts

    ERIC Educational Resources Information Center

    Wagler, Ron

    2009-01-01

    The Madagascar hissing cockroach ("Gromphadorhina portentosa") is one of the most exciting and enjoyable animals to incorporate into your science curriculum. Madagascar hissing cockroaches (MHCs) do not bite, are easy to handle, produce little odor compared to many terrarium animals, have a fascinating social structure, are easy to breed, teach…

  6. Chow Down! Using Madagascar Hissing Cockroaches to Explore Basic Nutrition Concepts

    ERIC Educational Resources Information Center

    Wagler, Ron

    2009-01-01

    The Madagascar hissing cockroach ("Gromphadorhina portentosa") is one of the most exciting and enjoyable animals to incorporate into your science curriculum. Madagascar hissing cockroaches (MHCs) do not bite, are easy to handle, produce little odor compared to many terrarium animals, have a fascinating social structure, are easy to breed, teach

  7. A geological synthesis of the Precambrian shield in Madagascar

    USGS Publications Warehouse

    Tucker, Robert D.; Roig, J.Y.; Moine, B.; Delor, C.; Peters, S.G.

    2014-01-01

    Available U–Pb geochronology of the Precambrian shield of Madagascar is summarized and integrated into a synthesis of the region’s geological history. The shield is described in terms of six geodynamic domains, from northeast to southwest, the Bemarivo, Antongil–Masora, Antananarivo, Ikalamavony, Androyan–Anosyan, and Vohibory domains. Each domain is defined by distinctive suites of metaigneous rocks and metasedimentary groups, and a unique history of Archean (∼2.5 Ga) and Proterozoic (∼1.0 Ga, ∼0.80 Ga, and ∼0.55 Ga) reworking. Superimposed within and across these domains are scores of Neoproterozoic granitic stocks and batholiths as well as kilometer long zones of steeply dipping, highly strained rocks that record the effects of Gondwana’s amalgamation and shortening in latest Neoproterozoic time (0.560–0.520 Ga). The present-day shield of Madagascar is best viewed as part of the Greater Dharwar Craton, of Archean age, to which three exotic terranes were added in Proterozoic time. The domains in Madagascar representing the Greater Dharwar Craton include the Antongil–Masora domain, a fragment of the Western Dharwar of India, and the Neoarchean Antananarivo domain (with its Tsaratanana Complex) which is broadly analogous to the Eastern Dharwar of India. In its reconstructed position, the Greater Dharwar Craton consists of a central nucleus of Paleo-Mesoarchean age (>3.1 Ga), the combined Western Dharwar and Antongil–Masora domain, flanked by mostly juvenile “granite–greenstone belts” of Neoarchean age (2.70–2.56 Ga). The age of the accretionary event that formed this craton is approximately 2.5–2.45 Ga. The three domains in Madagascar exotic to the Greater Dharwar Craton are the Androyan–Anosyan, Vohibory, and Bemarivo. The basement to the Androyan–Anosyan domain is a continental terrane of Paleoproterozoic age (2.0–1.78 Ga) that was accreted to the southern margin (present-day direction) of the Greater Dharwar Craton in pre-Stratherian time (>1.6 Ga), and rejuvenated at 1.03–0.93 Ga with the creation of the Ikalamavony domain. The Vohibory domain, an oceanic terrane of Neoproterozoic age was accreted to the Androyan–Anosyan domain in Cryogenian time (∼0.63–0.60 Ga). The Bemarivo domain of north Madagascar is a terrane of Cryogenian igneous rocks, with a cryptic Paleoproterozoic basement, that was accreted to the Greater Dharwar Craton in latest Ediacaran to earliest Cambrian time (0.53–0.51 Ga).

  8. The modern diatom spectra of Madagascar and diatom-inferred Late Quaternary climatic changes in northeastern and central Madagascar

    SciTech Connect

    Reyes, N.E.

    1993-01-01

    A study was conducted to classify diatoms in modern sediment surface samples in freshwater sites into assemblages and to assess the historical changes in lake level changes and climatic conditions in Madagascar during the Late Quaternary. Analysis of taxonomic percentages of diatoms in recently deposited sediments from various sites shows that diatom communities in these sites can be grouped by means of cluster analysis into distinct assemblages, some of which show similarities to groupings found in East Africa. pH and conductivity appear to be important factors correlating with differences in diatom communities in these study sites. Trends in diatom assemblages in a sediment core taken from Lake Alaotra, supplemented by those in sediments of the paleolake Ampasambazimba, suggest that the late Pleistocene in northeastern Madagascar was arid, though aridity was probably not as constant or as severe as in many areas of eastern and northern Africa; the Holocene was a period of moderate but variable conditions, marked by a distinct dry episode ca 5000 yr B.P. and a drying trend toward the late Holocene. Changes in diatom assemblages in a sediment core from Lake Kavitaha in central Madagascar suggest changes in the surrounding environment during at least two periods in the late Holocene. These coincide with increases in charcoal influx and, around 700 yr B.P., with the intensification of agricultural activity in the area.

  9. Predicting plant diversity patterns in Madagascar: understanding the effects of climate and land cover change in a biodiversity hotspot.

    PubMed

    Brown, Kerry A; Parks, Katherine E; Bethell, Colin A; Johnson, Steig E; Mulligan, Mark

    2015-01-01

    Climate and land cover change are driving a major reorganization of terrestrial biotic communities in tropical ecosystems. In an effort to understand how biodiversity patterns in the tropics will respond to individual and combined effects of these two drivers of environmental change, we use species distribution models (SDMs) calibrated for recent climate and land cover variables and projected to future scenarios to predict changes in diversity patterns in Madagascar. We collected occurrence records for 828 plant genera and 2186 plant species. We developed three scenarios, (i.e., climate only, land cover only and combined climate-land cover) based on recent and future climate and land cover variables. We used this modelling framework to investigate how the impacts of changes to climate and land cover influenced biodiversity across ecoregions and elevation bands. There were large-scale climate- and land cover-driven changes in plant biodiversity across Madagascar, including both losses and gains in diversity. The sharpest declines in biodiversity were projected for the eastern escarpment and high elevation ecosystems. Sharp declines in diversity were driven by the combined climate-land cover scenarios; however, there were subtle, region-specific differences in model outputs for each scenario, where certain regions experienced relatively higher species loss under climate or land cover only models. We strongly caution that predicted future gains in plant diversity will depend on the development and maintenance of dispersal pathways that connect current and future suitable habitats. The forecast for Madagascar's plant diversity in the face of future environmental change is worrying: regional diversity will continue to decrease in response to the combined effects of climate and land cover change, with habitats such as ericoid thickets and eastern lowland and sub-humid forests particularly vulnerable into the future. PMID:25856241

  10. Mapping the Traces of the Assembly and Multistage Breakup of Gondwanaland in the Lithosphere of Madagascar

    NASA Astrophysics Data System (ADS)

    Rindraharisaona, E. J.; Tilmann, F. J.; Yuan, X.; Rumpker, G.; Heit, B.; Rambolamanana, G.; Priestley, K. F.

    2014-12-01

    Madagascar is an ideal place to study the multistage assembly and break up of Gondwanaland, the supercontinent whose breakup also gave rise to most of present day continental regions. At the end of the Proterozoic the assembly of Gondwanaland has placed the Malagasy basement between the Antarctic, Dharwar, Arabo-Nubian and Nubian-Tanzanian cratons. The continental collision processes accompanying the assembly left their mark on the Malagasy basement, currently exposed in the Eastern two thirds of the island, in the form of metamorphic and mineral belts as well as massive ductile shear zones. During the Jurassic Madagascar, India and Seychelles were breaking up from African. Long after the breakaway of India and the Seychelles from Madagascar (Cretaceous time), volcanic activation has occurred in several locations of Madagascar mostly in the central and northern part (Neogene period). The surface traces of assembly and breakup processes have been studied extensively using geological methods in Madagascar but the imprint on the deep structure has so far not been studied in much detail. Between 2012 and 2014, 25 broadband stations were operated in the Southern Madagascar extending from East coast (Mananjary) to West coast (Toliary). The array crosses the Bongolava-Ranontsara shear zone, which is one of the major shear zones in Madagascar. In addition, between 2013 and 2014, 25 short period stations were deployed in the southeastern part of Madagascar. We will present preliminarily results of the lithosphere structure in the southern part of Madagascar based on surface wave dispersion analysis from both earthquakes and ambient noise combine with receiver function analysis. We will focus mostly on the contrast between the lithosphere structure in the eastern (Precambrian rocks) and the western (Sedimentary basins) parts of Madagascar.

  11. Linking coral river runoff proxies with climate variability, hydrology and land-use in Madagascar catchments.

    PubMed

    Maina, Joseph; de Moel, Hans; Vermaat, Jan E; Bruggemann, J Henrich; Guillaume, Mireille M M; Grove, Craig A; Madin, Joshua S; Mertz-Kraus, Regina; Zinke, Jens

    2012-10-01

    Understanding the linkages between coastal watersheds and adjacent coral reefs is expected to lead to better coral reef conservation strategies. Our study aims to examine the main predictors of environmental proxies recorded in near shore corals and therefore how linked near shore reefs are to the catchment physical processes. To achieve these, we developed models to simulate hydrology of two watersheds in Madagascar. We examined relationships between environmental proxies derived from massive Porites spp. coral cores (spectral luminescence and barium/calcium ratios), and corresponding time-series (1950-2006) data of hydrology, climate, land use and human population growth. Results suggest regional differences in the main environmental drivers of reef sedimentation: on annual time-scales, precipitation, river flow and sediment load explained the variability in coral proxies of river discharge for the northeast region, while El Niño-Southern Oscillation (ENSO) and temperature (air and sea surface) were the best predictors in the southwest region. PMID:22853989

  12. Evolution of high-pressure mafic granulites and pelitic gneisses from NE Madagascar: Tectonic implications

    NASA Astrophysics Data System (ADS)

    Ishwar-Kumar, C.; Sajeev, K.; Windley, B. F.; Kusky, T. M.; Feng, P.; Ratheesh-Kumar, R. T.; Huang, Y.; Zhang, Y.; Jiang, X.; Razakamanana, T.; Yagi, K.; Itaya, T.

    2015-11-01

    The occurrence of high-pressure mafic-ultramafic bodies within major shear zones is one of the indicators of paleo-subduction. In mafic granulites of the Andriamena complex (north-eastern Madagascar) we document unusual textures including garnet-clinopyroxene-quartz coronas that formed after the breakdown of orthopyroxene-plagioclase-ilmenite. Textural evidence and isochemical phase diagram calculations in the Na2O-CaO-K2O-FeO-MgO-Al2O3-SiO2-H2O-TiO2 system indicate a pressure-temperature (P-T) evolution from an isothermal (780 °C) pressure up to c. 24 kbar to decompression and cooling. Such a P-T trajectory is typically attained in a subduction zone setting where a gabbroic/ultramafic complex is subducted and later exhumed to the present crustal level during oceanic closure and final continental collision. The present results suggest that the presence of such deeply subducted rocks of the Andriamena complex is related to formation of the Betsimisaraka suture. LA-ICPMS U-Pb zircon dating of pelitic gneisses from the Betsimisaraka suture yields low Th/U ratios and protolith ages ranging from 2535 to 2625 Ma. A granitic gneiss from the Alaotra complex yields a zircon crystallization age of ca. 818 Ma and Th/U ratios vary from 1.08 to 2.09. K-Ar dating of muscovite and biotite from biotite-kyanite-sillimanite gneiss and garnet-biotite gneiss yields age of 486 ± 9 Ma and 459 ± 9 Ma respectively. We have estimated regional crustal thicknesses in NE Madagascar using a flexural inversion technique, which indicates the presence of an anomalously thick crust (c. 43 km) beneath the Antananarivo block. This result is consistent with the present concept that subduction beneath the Antananarivo block resulted in a more competent and thicker crust. The textural data, thermodynamic model, and geophysical evidence together provide a new insight to the subduction history, crustal thickening and evolution of the high-pressure Andriamena complex and its link to the terminal formation of the Betsimisaraka suture in north-eastern Madagascar.

  13. Changes in periwinkle (Littorina littorea) populations following the ban on TBT-based antifoulings on small boats in the United Kingdom.

    PubMed

    Matthiessen, P; Waldock, R; Thain, J E; Waite, M E; Scrope-Howe, S

    1995-03-01

    In 1987 the UK Government banned the use of tributyl tin (TBT)-based antifouling paints on small boats of less than 25 m. Following initial control measures taken in 1986, a program of research was started to monitor concentrations of TBT residues in estuarine waters and sediments and to observe faunistic changes in highly contaminated estuaries. As part of this program, the size-frequency and abundance of Littorina littorea populations have been recorded in the estuaries of the rivers Crouch (Essex) and Hamble (Hampshire). Since the TBT ban, the concentration of TBT residues in water and sediments has been steadily declining. In both L. littorea populations, the frequency of O-group individuals has increased markedly, and there has been a simultaneous decrease in TBT residues in L. littorea tissues. Furthermore, plankton surveys of the River Crouch show that the numbers of L. littorea eggs and veliger larvae have progressively increased, suggesting that TBT may have impaired periwinkle reproduction and/or survival of the eggs and larvae. Subsequent laboratory experiments have indeed shown that reduced egg production was the probable mechanism of action, but the imposex associated with exposure to TBT in dogwhelks (Nucella lapillus) has not been seen. PMID:7539373

  14. Molecular characterization of recombinant T1, a non-allergenic periwinkle (Catharanthus roseus) protein, with sequence similarity to the Bet v 1 plant allergen family.

    PubMed Central

    Laffer, Sylvia; Hamdi, Said; Lupinek, Christian; Sperr, Wolfgang R; Valent, Peter; Verdino, Petra; Keller, Walter; Grote, Monika; Hoffmann-Sommergruber, Karin; Scheiner, Otto; Kraft, Dietrich; Rideau, Marc; Valenta, Rudolf

    2003-01-01

    More than 25% of the population suffer from Type I allergy, an IgE-mediated hypersensitivity disease. Allergens with homology to the major birch ( Betula verrucosa ) pollen allergen, Bet v 1, belong to the most potent elicitors of IgE-mediated allergies. T1, a cytokinin-inducible cytoplasmic periwinkle ( Catharanthus roseus ) protein, with significant sequence similarity to members of the Bet v 1 plant allergen family, was expressed in Escherichia coli. Recombinant T1 (rT1) did not react with IgE antibodies from allergic patients, and failed to induce basophil histamine release and immediate-type skin reactions in Bet v 1-allergic patients. Antibodies raised against purified rT1 could be used for in situ localization of natural T1 by immunogold electron microscopy, but did not cross-react with most of the Bet v 1-related allergens. CD analysis showed significant differences regarding secondary structure and thermal denaturation behaviour between rT1 and recombinant Bet v 1, suggesting that these structural differences are responsible for the different allergenicity of the proteins. T1 represents a non-allergenic member of the Bet v 1 family that may be used to study structural requirements of allergenicity and to engineer hypo-allergenic plants by replacing Bet v 1-related allergens for primary prevention of allergy. PMID:12656672

  15. Lower and Middle Cenomanian ammonites from the Morondava Basin, Madagascar

    NASA Astrophysics Data System (ADS)

    Kennedy, William James; Walaszczyk, Ireneusz; Gale, Andrew S.; Dembicz, Krzysztof; Praszkier, Tomasz

    2013-12-01

    Kennedy, W.J., Walaszczyk, I., Gale, A.S., Dembicz, K. and Praszkier, T. 2013. Lower and Midle Cenomanian ammonites from the Morondava Basin, Madagascar. Acta Geologica Polonica, 63(4), 625-655. Warszawa. Lower and Middle Cenomanian ammonite assemblages have been collected on a bed-by-bed basis from localities at Vohipaly and Mahaboboka, Madagascar, as well as from outcrops around Berekata, all in the Morondava Basin, southwest Madagascar. These collections demonstrate the presence of the upper Lower Cenomanian Mantelliceras dixoni Zone and the lower Middle Cenomanian Cunningtoniceras inerme Zone of the north-western European standard sequence. These records indicate that the striking anomalies in the zonal assemblages of the classic divisions of the Madagascan Cenomanian are based on mixed assemblages, rather than a succession that differs radically from that elsewhere in the world. The dixoni Zone fauna is: Desmoceras cf. latidorsatum (Michelin, 1838), Pachydesmoceras kossmati Matsumoto, 1987, Forbesiceras sp., F. baylissiWright & Kennedy, 1984, F. largilliertianum (d'Orbigny, 1841), Mantelliceras cantianum Spath, 1926a, M. dixoni Spath, 1926b, M. mantelli (J. Sowerby, 1814), M. picteti Hyatt, 1903, M. saxbii (Sharpe, 1857), Sharpeiceras sp., S. falloti (Collignon, 1931), S. mocambiquense (Choffat, 1903), S. cf. florencae Spath, 1925, Acompsoceras renevieri (Sharpe, 1857), A. tenue Collignon, 1964, Calycoceras sp., Mrhiliceras lapparenti (Pervinquière, 1907), Mariella (Mariella) stolizcai (Collignon, 1964), Hypoturrilites taxyfabreae (Collignon, 1964), Turrilites scheuchzerianus Bosc, 1801, Sciponoceras cucullatum Collignon, 1964, and Sciponoceras antanimangaensis (Collignon, 1964). The presence of Calycoceras in a Lower Cenomanian association represents a precocious appearance of a genus typically Middle and Upper Cenomanian in occurrence, and matches records from Tunisia. The inerme Zone yields a more restricted assemblage: Pachydesmoceras kossmati, Forbesiceras baylissi, Acanthoceras sp. juv., Cunningtoniceras cunningtoni (Sharpe, 1855) and Hypoturrilites taxyfabreae.

  16. Long-term observations of the East Madagascar Undercurrent

    NASA Astrophysics Data System (ADS)

    Ponsoni, L.; Aguiar-Gonzlez, B.; Maas, L. R. M.; van Aken, H. M.; Ridderinkhof, H.

    2015-06-01

    An array of five moorings was deployed at 23S off eastern Madagascar and maintained for about 2.5 years as part of the "INdian-ATlantic EXchange in present and past climate" (INATEX) experiment. The observations reveal a recurrent equatorward undercurrent (during 692 of 888 days), the East Madagascar Undercurrent (EMUC), flowing below the poleward surface East Madagascar Current (EMC). The average core of the undercurrent was found near the continental slope, at a depth of 1260 m and at an approximate distance of 29 km from the coast, with mean velocities of 6.4 (4.8) cm s-1. Maximum speeds reach 20 cm s-1. The mean equatorward volume transport is estimated to be 1.33 (1.41) Sv with maxima up to 6 Sv. The baroclinic/barotropic partitioning of the geostrophic flow shows a persistent equatorward baroclinic velocity in the undercurrent core, which is sometimes inhibited by a stronger poleward barotropic contribution. The wavelet spectrum analysis of the transport time series displays two dominant frequency bands: (i) nearly bi-monthly (46-79 days), previously observed in the surface EMC, and attributed to the forcing of barotropic waves generated in the Mascarene Basin; and (ii) nearly semi-annual (132-187 days), which seems to be related to the semi-annual cycle in the equatorial winds near the Indian Ocean eastern boundary. A historical dataset of temperature-salinity Argo profiles was used to investigate the spatial variability of the thermohaline properties at intermediate levels. Lastly, Argo-derived velocities suggest an undercurrent flowing upstream until approximately 17S.

  17. Les aspergillomes pulmonaires: propos de 37 cas Madagascar

    PubMed Central

    Rakotoson, Jolson Lovaniaina; Razafindramaro, Notahiana; Rakotomizao, Jocelyn Robert; Vololontiana, Hanta Marie Danielle; Andrianasolo, Radonirina Lazasoa; Ravahatra, Kiady; Tiaray, Michel; Rajaoarifetra, Jobeline; Rakotoharivelo, Hendriniaina; Andrianarisoa, Ange Christophe Flix

    2011-01-01

    L'aspergillome pulmonaire est une colonisation par Aspergillus d'une cavit pulmonaire prforme. Nos objectifs taient de dfinir le profil pidmio-clinique et thrapeutique des aspergillomes pulmonaires et essayer de dgager les facteurs favorisants de cette affection Madagascar. Nous avons raliss une tude prospective, descriptive, analytique durant 59 mois sur les aspergillomes pulmonaires Antananarivo Madagascar. Etaient inclus dans cette tude les malades ayant un diagnostic d'aspergillome pulmonaire. Trente-sept (37) cas d'aspergillome pulmonaire taient recenss parmi les 8 392 patients hospitaliss dans le service de Pneumologie (0,44%). Il s'agit de 29 hommes (78,38%) et 8 femmes (21,61%), dge moyen de 43 ans. Les facteurs prdisposant taient domins par la tuberculose pulmonaire (89,19%). Le dlai moyen d'apparition de l'aspergillome chez les malades ayant un antcdent de tuberculose pulmonaire bacilloscopie positive (TPM+) tait de 8 ans et 6 mois avec un dlai extrme de un mois 23 ans. L'hmoptysie tait le mode de rvlation le plus frquent (91,89%). Le traitement tait mdical chez 27 patients (72,97%) et mdico-chirurgical chez 10 patients (27,03%). Vingt sept patients taient perdus de vue (72,97%), et pour les 10 patients suivis (27,02%), 70% avaient une volution favorable avec disparition des signes, et 30% prsentaient des hmoptysies rcidivantes. Le taux de mortalit postopratoire tait de 4% et 50% des patients avaient des complications postopratoires. La surveillance des lsions squellaires de tuberculose pulmonaire qui constituent les facteurs favorisants prdominant d'aspergillome pulmonaire Madagascar ncessite une attention particulire. La prise en charge de la tuberculose doit tre prcoce et adapte surtout dans les pays forte prvalence tuberculeuse. PMID:22187586

  18. Defining and explaining tropical deforestation: shifting cultivation and population growth in colonial Madagascar (1896-1940).

    PubMed

    Jarosz, L

    1993-10-01

    The case study of deforestation in Madagascar demonstrated how deforestation is a complex phenomenon that reflects interconnections between land-based resources, human groups, and global political economy; specifically, there is a link between changing land use practices affecting shifting cultivation and tropical deforestation. The general development model of exponential population growth and shifting cultivation causing deforestation and environmental degradation is too simplified, places undue blame on the victims, and isolates shifting cultivation practices from the reality of land use patterns in specific places at specific times. Problematic also is the way definition, delimitation, and discussion of environmental problems shapes possible solutions. This analysis suggests a theoretical view that links reconstructed regional geography with political ecology. The assertion is that deforestation is historically based on multiple social processes within Madagascar. Land use practices and resource access decisions during the colonial period affected land management and degradation. The colonial state policy played a role in the destruction of tropical flora by fire, shifting cultivation, and grazing, and the responses of Europeans and Malagasys. Context and multiplicity of motivations and practices were key. A review was presented of reconstructed regional geography and political ecology and global tropical deforestation. The description of the political economy of deforestation during colonial times focused on the movement of population into the forests after 1896 and French annexation. Famine resulted. Shifting cultivation laws were passed between 1881 and 1913, due to the desire for rational forest resource management. Ecologically and socially these rules were difficult to enforce; there were resistance due to the threat of the elimination of subsistence living for wage work. Destructive logging practices and forest product extraction after 1921 are described. During 1900-1941, population was below or at replacement level, but the government still blamed Malagasys. Shifting cultivation meant different things to the subsistence farmers, the state, and international agencies. Denial of context promotes an ideology of repression, fuels fear and prejudice, and promotes the wrong solutions. PMID:12318844

  19. Proterozoic tectonostratigraphy and paleogeography of central Madagascar derived from detrital zircon U-Pb age populations

    USGS Publications Warehouse

    Cox, R.; Coleman, D.S.; Chokel, C.B.; DeOreo, S.B.; Wooden, J.L.; Collins, A.S.; De Waele, B.; Kroner, A.

    2004-01-01

    Detrital zircon U-Pb ages determined by SHRIMP distinguish two clastic sequences among Proterozoic metasedimentary rocks from central Madagascar. The Itremo Group is older: zircon data, stromatolite characteristics, and carbon isotope data all point to a depositional age around 1500-1700 Ma. The Molo Group is younger, deposited between ???620 Ma (the age of the youngest zircon) and ???560 Ma (the age of metamorphic overgrowths on detrital cores). Geochronologic provenance analysis of the Itremo Group points to sources in East Africa as well as local sources in central and southern Madagascar but provides no evidence for a detrital contribution from northern and eastern Madagascar nor from southern India. Detrital zircon and sedimentologic similarities between rocks of the Itremo Group and the Zambian Muva Supergroup suggest a lithostratigraphic correlation between the two. The Molo Group has a strong 1000-1100 Ma detrital signature that also indicates an east African provenance and suggests a Neoproterozoic geographic connection with Sri Lanka but shows no indication of input from the Dharwar craton and eastern Madagascar. Central Madagascar was probably juxtaposed with the Tanzanian craton in the Paleo- and Mesoproterozoic, whereas northern and eastern Madagascar were connected to India. Internal assembly of Madagascar postdates Neoproterozoic Molo Group sedimentation and is likely to have occurred at about 560 Ma. ?? 2004 by The University of Chicago. All rights reserved.

  20. Biogeography of the two major arbovirus mosquito vectors, Aedes aegypti and Aedes albopictus (Diptera, Culicidae), in Madagascar

    PubMed Central

    2012-01-01

    Background In the past ten years, the Indian Ocean region has been the theatre of severe epidemics of chikungunya and dengue. These outbreaks coincided with a high increase in populations of Aedes albopictus that outcompete its sister taxon Aedes aegypti in most islands sampled. The objective of this work was to update the entomological survey of the two Aedes species in the island of Madagascar which has to face these arboviroses. Methods The sampling of Aedes mosquitoes was conducted during two years, from October 2007 to October 2009, in fifteen localities from eight regions of contrasting climates. Captured adults were identified immediately whereas immature stages were bred until adult stage for determination. Phylogenetic analysis was performed using two mtDNA genes, COI and ND5 and trees were constructed by the maximum likelihood (ML) method with the gene time reversible (GTR) model. Experimental infections with the chikungunya virus strain 06.21 at a titer of 107.5 pfu/mL were performed to evaluate the vector competence of field-collected mosquitoes. Disseminated infection rates were measured fourteen days after infection by immunofluorescence assay performed on head squashes. Results The species Aedes aegypti was detected in only six sites in native forests and natural reserves. In contrast, the species Aedes albopictus was found in 13 out of the 15 sites sampled. Breeding sites were mostly found in man-made environments such as discarded containers, used tires, abandoned buckets, coconuts, and bamboo cuts. Linear regression models showed that the abundance of Ae. albopictus was significantly influenced by the sampling region (F = 62.00, p < 2.2 10-16) and period (F = 36.22, p = 2.548 10-13), that are associated with ecological and climate variations. Phylogenetic analysis of the invasive Ae. albopictus distinguished haplotypes from South Asia and South America from those of Madagascar, but the markers used were not discriminant enough to discern Malagasy populations. The experimental oral infection method showed that six Ae. albopictus populations exhibited high dissemination infection rates for chikungunya virus ranging from 98 to 100%. Conclusion In Madagascar, Ae. albopictus has extended its geographical distribution whereas, Ae. aegypti has become rare, contrasting with what was previously observed. Changes are predominantly driven by human activities and the rainfall regime that provide suitable breeding sites for the highly anthropophilic mosquito Ae. albopictus. Moreover, these populations were found to be highly susceptible to chikungunya virus. In the light of this study, Ae. albopictus may have been involved in the recent outbreaks of chikungunya and dengue epidemics in Madagascar, and consequently, control measures should be promoted to limit its current expansion. PMID:22433186

  1. A Non-Stationary Relationship between Global Climate Phenomena and Human Plague Incidence in Madagascar

    PubMed Central

    Kreppel, Katharina S.; Caminade, Cyril; Telfer, Sandra; Rajerison, Minoarison; Rahalison, Lila; Morse, Andy; Baylis, Matthew

    2014-01-01

    Background Plague, a zoonosis caused by Yersinia pestis, is found in Asia and the Americas, but predominantly in Africa, with the island of Madagascar reporting almost one third of human cases worldwide. Plague's occurrence is affected by local climate factors which in turn are influenced by large-scale climate phenomena such as the El Niño Southern Oscillation (ENSO). The effects of ENSO on regional climate are often enhanced or reduced by a second large-scale climate phenomenon, the Indian Ocean Dipole (IOD). It is known that ENSO and the IOD interact as drivers of disease. Yet the impacts of these phenomena in driving plague dynamics via their effect on regional climate, and specifically contributing to the foci of transmission on Madagascar, are unknown. Here we present the first analysis of the effects of ENSO and IOD on plague in Madagascar. Methodology/principal findings We use a forty-eight year monthly time-series of reported human plague cases from 1960 to 2008. Using wavelet analysis, we show that over the last fifty years there have been complex non-stationary associations between ENSO/IOD and the dynamics of plague in Madagascar. We demonstrate that ENSO and IOD influence temperature in Madagascar and that temperature and plague cycles are associated. The effects on plague appear to be mediated more by temperature, but precipitation also undoubtedly influences plague in Madagascar. Our results confirm a relationship between plague anomalies and an increase in the intensity of ENSO events and precipitation. Conclusions/significance This work widens the understanding of how climate factors acting over different temporal scales can combine to drive local disease dynamics. Given the association of increasing ENSO strength and plague anomalies in Madagascar it may in future be possible to forecast plague outbreaks in Madagascar. The study gives insight into the complex and changing relationship between climate factors and plague in Madagascar. PMID:25299064

  2. Mountain Refugia Play a Role in Soil Arthropod Speciation on Madagascar: A Case Study of the Endemic Giant Fire-Millipede Genus Aphistogoniulus

    PubMed Central

    Wesener, Thomas; Raupach, Michael J.; Decker, Peter

    2011-01-01

    To elucidate the speciation mechanisms prevalent within hotspots of biodiversity, and the evolutionary processes behind the rise of their species-rich and endemic biota, we investigated the phylogeny of the giant fire-millipede genus Aphistogoniulus Silvestri, 1897, a Malagasy endemic. This study is the first comprehensive (molecular and morphological) phylogenetic study focusing on millipede (class Diplopoda) speciation on Madagascar. The morphological analysis is based on 35 morphological characters and incorporates ten described as well as two newly described species (A. rubrodorsalis n. sp. and A. jeekeli n. sp.) of Aphistogoniulus. The molecular analysis is based on both mitochondrial (COI and 16S), and nuclear genes (complete 18S rDNA), together comprised of 3031 base pairs, which were successfully sequenced for 31 individual specimens and eight species of Aphistogoniulus. In addition to the null-model (speciation by distance), two diversification models, mountain refugia and ecotone shift, were discovered to play a role in the speciation of soil arthropods on Madagascar. Mountain refugia were important in the speciation of the A. cowani clade, with three species occurring in the Andringitra and Ranomafana Mountains in the southeast (A. cowani), the Ambohijanahary and Ambohitantely Mountains in the mid-west (A. sanguineus), and the Marojejy Mountain in the northeast (A. rubrodorsalis n. sp.). An ecotone shift from the eastern rainforest to the unique subarid spiny forest of Mahavelo was discovered in the A. vampyrus - A. aridus species-pair. In the monophyletic A. diabolicus clade, evidence for divergent evolution of sexual morphology was detected: species with greatly enlarged gonopods are sister-taxa to species with normal sized gonopods. Among the large-bodied Spirobolida genera of Madagascar, Colossobolus and Sanguinobolus were found to be close sister-genera to Aphistogoniulus. Forest destruction has caused forest corridors between populations to disappear, which might limit the possible resolution of biogeographic analyses on Madagascar. PMID:22162998

  3. Extinction vulnerability of tropical montane endemism from warming and upslope displacement: a preliminary appraisal for the highest massif in Madagascar

    PubMed Central

    RAXWORTHY, CHRISTOPHER J; PEARSON, RICHARD G; RABIBISOA, NIRHY; RAKOTONDRAZAFY, ANDRY M; RAMANAMANJATO, JEAN-BAPTISTE; RASELIMANANA, ACHILLE P; WU, SHENGHAI; NUSSBAUM, RONALD A; STONE, DÁITHÍ A

    2008-01-01

    One of the predicted biological responses to climate warming is the upslope displacement of species distributions. In the tropics, because montane assemblages frequently include local endemics that are distributed close to summits, these species may be especially vulnerable to experiencing complete habitat loss from warming. However, there is currently a dearth of information available for tropical regions. Here, we present a preliminary appraisal of this extinction threat using the herpetological assemblage of the Tsaratanana Massif in northern Madagascar (the island's highest massif), which is rich with montane endemism. We present meteorological evidence (individual and combined regional weather station data and reanalysis forecast data) for recent warming in Madagascar, and show that this trend is consistent with recent climate model simulations. Using standard moist adiabatic lapse rates, these observed meteorological warming trends in northern Madagascar predict upslope species displacement of 17–74 m per decade between 1993 and 2003. Over this same period, we also report preliminary data supporting a trend for upslope distribution movements, based on two surveys we completed at Tsaratanana. For 30 species, representing five families of reptiles and amphibians, we found overall mean shifts in elevational midpoint of 19–51 m upslope (mean lower elevation limit 29–114 m; mean upper elevation limit −8 to 53 m). We also found upslope trends in mean and median elevational observations in seven and six of nine species analysed. Phenological differences between these surveys do not appear to be substantial, but these upslope shifts are consistent with the predictions based on meteorological warming. An elevational range displacement analysis projects complete habitat loss for three species below the 2 °C ‘dangerous’ warming threshold. One of these species is not contracting its distribution, but the other two were not resampled in 2003. A preliminary review of the other massifs in Madagascar indicates potential similar vulnerability to habitat loss and upslope extinction. Consequently, we urgently recommend additional elevational surveys for these and other tropical montane assemblages, which should also include, when possible, the monitoring of local meteorological conditions and habitat change.

  4. Summer climate of Madagascar and monsoon pulsing of its vortex

    NASA Astrophysics Data System (ADS)

    Jury, Mark R.

    2016-02-01

    This study analyzes the climate of Madagascar (12°-26°S, 43°-50°E) and its relation to the Indian Ocean during austral summer (Dec-Mar). Moisture converges onto a standing easterly wave and floods are prevalent in late summer. All-island daytime land temperatures exceed 38 °C in October and are ~4 °C above sea temperatures during summer. Analysis of thermally induced diurnal convection and circulation revealed inflow during the afternoon recirculated from the southeastern mountains and the warm Mozambique Channel. Summer rainfall follows latent and sensible heat flux during the first half of the day, and gains a surplus by evening via thunderstorms over the western plains. At the inter-annual time-scale, 2.3 years oscillations in all-island rainfall appear linked with the stratospheric quasi-biennial oscillation and corresponding 80 Dobson Unit ozone fluctuations during flood events. Wet spells at frequencies from 11-27 days derive from locally-formed tropical cyclones and NW-cloud bands. Flood case studies exhibit moisture recycling in the confluence zone between the sub-tropical anticyclone and the lee-side vortex. Hovmoller analysis of daily rainfall reinforces the concept of local generation and pulsing by cross-equatorial (Indian winter) monsoon flow rather than zonal atmospheric waves. Since the surface water budget is critical to agriculture in Madagascar, this study represents a further step to understand its meso-scale summer climate.

  5. Mangrove forest distributions and dynamics in Madagascar (1975-2005)

    USGS Publications Warehouse

    Giri, C.; Muhlhausen, J.

    2008-01-01

    Mangrove forests of Madagascar are declining, albeit at a much slower rate than the global average. The forests are declining due to conversion to other land uses and forest degradation. However, accurate and reliable information on their present distribution and their rates, causes, and consequences of change have not been available. Earlier studies used remotely sensed data to map and, in some cases, to monitor mangrove forests at a local scale. Nonetheless, a comprehensive national assessment and synthesis was lacking. We interpreted time-series satellite data of 1975, 1990, 2000, and 2005 using a hybrid supervised and unsupervised classification approach. Landsat data were geometrically corrected to an accuracy of ?? one-half pixel, an accuracy necessary for change analysis. We used a postclassification change detection approach. Our results showed that Madagascar lost 7% of mangrove forests from 1975 to 2005, to a present extent of ???2,797 km2. Deforestation rates and causes varied both spatially and temporally. The forests increased by 5.6% (212 km2) from 1975 to 1990, decreased by 14.3% (455 km 2) from 1990 to 2000, and decreased by 2.6% (73 km2) from 2000 to 2005. Similarly, major changes occurred in Bombekota Bay, Mahajamba Bay, the coast of Ambanja, the Tsiribihina River, and Cap St Vincent. The main factors responsible for mangrove deforestation include conversion to agriculture (35%), logging (16%), conversion to aquaculture (3%), and urban development (1%). ?? 2008 by MDPI.

  6. An updated checklist of mosquito species (Diptera: Culicidae) from Madagascar

    PubMed Central

    Tantely, Michaël Luciano; Le Goff, Gilbert; Boyer, Sébastien; Fontenille, Didier

    2016-01-01

    An updated checklist of 235 mosquito species from Madagascar is presented. The number of species has increased considerably compared to previous checklists, particularly the last published in 2003 (178 species). This annotated checklist provides concise information on endemism, taxonomic position, developmental stages, larval habitats, distribution, behavior, and vector-borne diseases potentially transmitted. The 235 species belong to 14 genera: Aedeomyia (3 species), Aedes (35 species), Anopheles (26 species), Coquillettidia (3 species), Culex (at least 50 species), Eretmapodites (4 species), Ficalbia (2 species), Hodgesia (at least one species), Lutzia (one species), Mansonia (2 species), Mimomyia (22 species), Orthopodomyia (8 species), Toxorhynchites (6 species), and Uranotaenia (73 species). Due to non-deciphered species complexes, several species remain undescribed. The main remarkable characteristic of Malagasy mosquito fauna is the high biodiversity with 138 endemic species (59%). Presence and abundance of species, and their association, in a given location could be a bio-indicator of environmental particularities such as urban, rural, forested, deforested, and mountainous habitats. Finally, taking into account that Malagasy culicidian fauna includes 64 species (27%) with a known medical or veterinary interest in the world, knowledge of their biology and host preference summarized in this paper improves understanding of their involvement in pathogen transmission in Madagascar. PMID:27101839

  7. Blood transcriptomes reveal novel parasitic zoonoses circulating in Madagascar's lemurs.

    PubMed

    Larsen, Peter A; Hayes, Corinne E; Williams, Cathy V; Junge, Randall E; Razafindramanana, Josia; Mass, Vanessa; Rakotondrainibe, Hajanirina; Yoder, Anne D

    2016-01-01

    Zoonotic diseases are a looming threat to global populations, and nearly 75% of emerging infectious diseases can spread among wildlife, domestic animals and humans. A 'One World, One Health' perspective offers us an ideal framework for understanding and potentially mitigating the spread of zoonoses, and the island of Madagascar serves as a natural laboratory for conducting these studies. Rapid habitat degradation and climate change on the island are contributing to more frequent contact among humans, livestock and wildlife, increasing the potential for pathogen spillover events. Given Madagascar's long geographical isolation, coupled with recent and repeated introduction of agricultural and invasive species, it is likely that a number of circulating pathogens remain uncharacterized in lemur populations. Thus, it is imperative that new approaches be implemented for de novo pathogen discovery. To this end, we used non-targeted deep sequencing of blood transcriptomes from two species of critically endangered wild lemurs (Indri indri and Propithecus diadema) to characterize blood-borne pathogens. Our results show several undescribed vector-borne parasites circulating within lemurs, some of which may cause disease in wildlife, livestock and humans. We anticipate that advanced methods for de novo identification of unknown pathogens will have broad utility for characterizing other complex disease transmission systems. PMID:26814226

  8. Mangrove Forest Distributions and Dynamics in Madagascar (19752005)

    PubMed Central

    Giri, Chandra; Muhlhausen, Joseph

    2008-01-01

    Mangrove forests of Madagascar are declining, albeit at a much slower rate than the global average. The forests are declining due to conversion to other land uses and forest degradation. However, accurate and reliable information on their present distribution and their rates, causes, and consequences of change have not been available. Earlier studies used remotely sensed data to map and, in some cases, to monitor mangrove forests at a local scale. Nonetheless, a comprehensive national assessment and synthesis was lacking. We interpreted time-series satellite data of 1975, 1990, 2000, and 2005 using a hybrid supervised and unsupervised classification approach. Landsat data were geometrically corrected to an accuracy of one-half pixel, an accuracy necessary for change analysis. We used a postclassification change detection approach. Our results showed that Madagascar lost 7% of mangrove forests from 1975 to 2005, to a present extent of ?2,797 km2. Deforestation rates and causes varied both spatially and temporally. The forests increased by 5.6% (212 km2) from 1975 to 1990, decreased by 14.3% (455 km2) from 1990 to 2000, and decreased by 2.6% (73 km2) from 2000 to 2005. Similarly, major changes occurred in Bombekota Bay, Mahajamba Bay, the coast of Ambanja, the Tsiribihina River, and Cap St Vincent. The main factors responsible for mangrove deforestation include conversion to agriculture (35%), logging (16%), conversion to aquaculture (3%), and urban development (1%).

  9. A Review of Mosquitoes Associated with Rift Valley Fever Virus in Madagascar

    PubMed Central

    Tantely, Luciano M.; Boyer, Sébastien; Fontenille, Didier

    2015-01-01

    Rift Valley fever (RVF) is a viral zoonotic disease occurring throughout Africa, the Arabian Peninsula, and Madagascar. The disease is caused by a Phlebovirus (RVF virus [RVFV]) transmitted to vertebrate hosts through the bite of infected mosquitoes. In Madagascar, the first RVFV circulation was reported in 1979 based on detection in mosquitoes but without epidemic episode. Subsequently, two outbreaks occurred: the first along the east coast and in the central highlands in 1990 and 1991 and the most recent along the northern and eastern coasts and in the central highlands in 2008 and 2009. Despite the presence of 24 mosquitoes species potentially associated with RVFV transmission in Madagascar, little associated entomological information is available. In this review, we list the RVFV vector, Culex antennatus, as well as other taxa as candidate vector species. We discuss risk factors from an entomological perspective for the re-emergence of RVF in Madagascar. PMID:25732680

  10. Genetic Diversity of the Ring-Tailed Lemur (Lemur catta) in South-Central Madagascar.

    PubMed

    Clarke, Tara A; Gray, Olivia; Gould, Lisa; Burrell, Andrew S

    2015-01-01

    Madagascar's lemurs, now deemed the most endangered group of mammals, represent the highest primate conservation priority in the world. Due to anthropogenic disturbances, an estimated 10% of Malagasy forest cover remains. The endangered Lemur catta is endemic to the southern regions of Madagascar and now occupies primarily fragmented forest habitats. We examined the influence of habitat fragmentation and isolation on the genetic diversity of L. catta across 3 different forest fragments in south-central Madagascar. Our analysis revealed moderate levels of genetic diversity. Genetic differentiation among the sites ranged from 0.05 to 0.11. These data suggest that the L. catta populations within south-central Madagascar have not yet lost significant genetic variation. However, due to ongoing anthropogenic threats faced by ring-tailed lemurs, continued conservation and research initiatives are imperative for long-term viability of the species. PMID:26022303

  11. STUDY OF LAND USE ISSUES CHARACTERIZING THE AMBALAVAO-ANDRINGITRA REGION OF MADAGASCAR

    EPA Science Inventory

    EPA Identifier: GF9500572
    Title: Study of Land Use Issues Characterizing the Ambalavao-Andringitra Region of Madagascar
    Fellow (Principal Investigator): Christian Arthur Kull
    Institution: University of Colorado
    EPA Grant Representati...

  12. Miocene Shark and Batoid Fauna from Nosy Makamby (Mahajanga Basin, Northwestern Madagascar).

    PubMed

    Andrianavalona, Tsiory H; Ramihangihajason, Tolotra N; Rasoamiaramanana, Armand; Ward, David J; Ali, Jason R; Samonds, Karen E

    2015-01-01

    Madagascar is well known for producing exceptional fossils. However, the record for selachians remains relatively poorly known. Paleontological reconnaissance on the island of Nosy Makamby, off northwest Madagascar, has produced a previously undescribed assemblage of Miocene fossils. Based on isolated teeth, ten taxonomic groups are identified: Otodus, Carcharhinus, Galeocerdo, Rhizoprionodon, Sphyrna, Hemipristis, Squatina, Rostroraja, Himantura and Myliobatidae. Six are newly described from Madagascar for the Cenozoic (Galeocerdo, Rhizoprionodon, Sphyrna, Squatina, Rostroraja and Himantura). In association with these specimens, remains of both invertebrates (e.g., corals, gastropods, bivalves) and vertebrates (e.g., bony fish, turtles, crocodylians, and sirenian mammals) were also recovered. The sedimentary facies are highly suggestive of a near-shore/coastal plain depositional environment. This faunal association shares similarities to contemporaneous sites reported from North America and Europe and gives a glimpse into the paleoenvironment of Madagascar's Miocene, suggesting that this region was warm, tropical shallow-water marine. PMID:26075723

  13. A review of mosquitoes associated with Rift Valley fever virus in Madagascar.

    PubMed

    Tantely, Luciano M; Boyer, Sbastien; Fontenille, Didier

    2015-04-01

    Rift Valley fever (RVF) is a viral zoonotic disease occurring throughout Africa, the Arabian Peninsula, and Madagascar. The disease is caused by a Phlebovirus (RVF virus [RVFV]) transmitted to vertebrate hosts through the bite of infected mosquitoes. In Madagascar, the first RVFV circulation was reported in 1979 based on detection in mosquitoes but without epidemic episode. Subsequently, two outbreaks occurred: the first along the east coast and in the central highlands in 1990 and 1991 and the most recent along the northern and eastern coasts and in the central highlands in 2008 and 2009. Despite the presence of 24 mosquitoes species potentially associated with RVFV transmission in Madagascar, little associated entomological information is available. In this review, we list the RVFV vector, Culex antennatus, as well as other taxa as candidate vector species. We discuss risk factors from an entomological perspective for the re-emergence of RVF in Madagascar. PMID:25732680

  14. Madagascar Flatidae (Hemiptera, Fulgoromorpha): state-of-the-art and research challenges

    PubMed Central

    Świerczewski, Dariusz; Stroiński, Adam

    2013-01-01

    Abstract The paper provides a historical review of the research on Flatidae in Madagascar and indicates future prospects. While the first two species of Madagascar Flatidae were described by Guérin-Méneville (1844), it was Signoret (1860) who made the first real attempt to enhance our knowledge of the Hemiptera fauna of Madagascar by describing several additional species. Over the following century and a half, several investigators have turned their attention to this group of insects, with the final number of species recorded for the island reaching 79. Despite this long history of research, it is evident that much still remains to be done. Detailed taxonomic research will allow the natural history of Madagascar and changes in the biological diversity of its endemic ecosystems to be better understood. This paper should be considered as an introduction to a complex study on the systematics and phylogeny of worldwide Flatidae planthoppers. PMID:24039526

  15. Spatial and temporal arrival patterns of Madagascar's vertebrate fauna explained by distance, ocean currents, and ancestor type

    PubMed Central

    Samonds, Karen E.; Godfrey, Laurie R.; Ali, Jason R.; Goodman, Steven M.; Vences, Miguel; Sutherland, Michael R.; Irwin, Mitchell T.; Krause, David W.

    2012-01-01

    How, when, and from where Madagascar's vertebrates arrived on the island is poorly known, and a comprehensive explanation for the distribution of its organisms has yet to emerge. We begin to break that impasse by analyzing vertebrate arrival patterns implied by currently existing taxa. For each of 81 clades, we compiled arrival date, source, and ancestor type (obligate freshwater, terrestrial, facultative swimmer, or volant). We analyzed changes in arrival rates, with and without adjusting for clade extinction. Probability of successful transoceanic dispersal is negatively correlated with distance traveled and influenced by ocean currents and ancestor type. Obligate rafters show a decrease in probability of successful transoceanic dispersal from the Paleocene onward, reaching the lowest levels after the mid-Miocene. This finding is consistent with a paleoceanographic model [Ali JR, Huber M (2010) Nature 463:653–656] that predicts Early Cenozoic surface currents periodically conducive to rafting or swimming from Africa, followed by a reconfiguration to present-day flow 15–20 million years ago that significantly diminished the ability for transoceanic dispersal to Madagascar from the adjacent mainland. PMID:22431643

  16. Reconstruction of Madagascar and Africa: Evidence from the Davie Fracture Zone and Western Somali Basin

    NASA Astrophysics Data System (ADS)

    Coffin, Millard F.; Rabinowitz, Philip D.

    1987-08-01

    New seismic reflection, gravity, and magnetic data from offshore East Africa allow the Davie Fracture Zone to be traced from ˜11°S to its intersection with the Kenyan coast at ˜2°S, constraining the relative motion of Madagascar and Africa. Seasat-derived free air gravity anomalies and slope/rise positive magnetic anomalies observed in shipboard data help to locate the continent-ocean boundaries (COB) off the shore of East Africa and Madagascar. Seismic reflection data further document a diapirprovince off Madagascar, presumably conjugate to that observed off Kenya and Somalia. The Dhow and Very Large Crude Carrier (VLCC) basement ridges are complex features and do not appear to be simple fracture zones owing their existence entirely to the separation of Madagascar and Africa. From these data we determine a predrift fit of Madagascar and Africa involving a 14.2° rotation of Madagascar to Africa about a pole at 10°N, 150°E. The geometry of the reconstruction adheres to seismic and potential field data indicating the oceanic nature and extent of the Comoros Basin and of the Somali Basin between Kenya and the Seychelles, and it does not conflict with onshore or offshore stratigraphy. Timing of the opening of the Western Somali Basin is constrained by Mesozoic marine magnetic anomalies and extrapolation to the interpreted COB and occurred between approximately 165 and 130 Ma.

  17. U-Pb zircon geochronology and geochemistry of Late Jurassic basalts in Maevatanana, Madagascar: Implications for the timing of separation of Madagascar from Africa

    NASA Astrophysics Data System (ADS)

    Yang, Xi-An; Chen, Yu-Chuan; Hou, Ke-Jun; Liu, Shan-Bao; Liu, Jia-Jun

    2014-12-01

    Magmatic zircon ages for the Maevatanana basalts in Madagascar indicate that Madagascar separated from Africa at 149.8 2.1 Ma. Rocks produced by this basaltic magmatism associated with rifting are characterized by low SiO2 (49.6-50.3 wt.%), high total FeO (>13.9 wt.%), TiO2 (>3.7 wt.%), and P2O5 (>0.5 wt.%), and extremely high Na2O/K2O (3.08-3.27). Geochemical variations can be ascribed to significant fractional crystallization of clinopyroxene and plagioclase. The mineralogical and geochemical characteristics of the Maevatanana basalts suggest affinities with calc-alkaline basalt. Additionally the basalts have distinct ocean-island-basalt-like geochemical features that may be related to the Marion plume. We speculate that the Maevatanana basalts are the product of the Marion mantle plume related to separation of Madagascar from Africa in the Late Jurassic.

  18. Urban epidemic of bubonic plague in Majunga, Madagascar: epidemiological aspects.

    PubMed

    Boisier, P; Rasolomaharo, M; Ranaivoson, G; Rasoamanana, B; Rakoto, L; Andrianirina, Z; Andriamahefazafy, B; Chanteau, S

    1997-05-01

    After an absence of 62 years, an epidemic of plague occurred in the harbour city of Majunga (Madagascar) from July 1995 to March 1996, following sporadic cases in March and May 1995. By 15 March 1996, 617 clinically suspected cases of bubonic plague had been notified. Laboratory testing was carried out for 394 individuals: 60 (15.2%) were confirmed to have bubonic plague and 48 (12.2%) were considered as presumptive cases. The incidence was significantly higher in males in all age groups and in both sexes in the 5-19 age group. Twenty-four deaths were related to plague, but early treatment with streptomycin has confirmed its effectiveness insofar as the case-farality ratio was only 8.7% among confirmed and presumptive cases admitted to hospital. The difficulty of clinically diagnosing bubonic plague was affirmed. The disease met favourable conditions through the poverty and low level of hygiene prevalent in most parts of Majunga. PMID:9217697

  19. [The reconquest of the Madagascar highlands by malaria].

    PubMed

    Mouchet, J; Laventure, S; Blanchy, S; Fioramonti, R; Rakotonjanabelo, A; Rabarison, P; Sircoulon, J; Roux, J

    1997-01-01

    A strong malaria epidemic with a high mortality rate occurred on the Madagascar Highlands in 1986-88. Vector control and free access to antimalaria drugs controlled the disease. The authors have searched for the causes of the epidemic to propose a strategy avoiding such events. The Highlands on Madagascar were known as malaria free. In 1878 a very severe epidemic flooded all the country. Development of irrigated ricefields which house both An. arabiensis and An. funestus had created a new anthropic environment. Moreover manpower imported from malarious coastal areas for rice cultivation and also for building large temples, could have brought P. falciparum. After several outbreaks the disease became endemic up to 1949. In 1949 a malaria eradication programme based on DDT spraying and drug chemoprophylaxis and chemotherapy was launched. By 1960 malaria was eliminated and DDT spraying cancelled. Only 3 foci were kept under surveillance with irregular spraying until 1975. The prophylaxis and treatment centres ("centres de nivaquinisation") were kept open up to 1979. The catholic dispensary of Analaroa, 100 km N.E. of Tananarive, opened in 1971 and worked without interruption up to now. The malaria diagnosis has always been controlled by microscopy. Its registers are probably the more reliable source of information on malaria in the area. They show that malaria was already present on the Highlands in 1971 but at a low prevalence; in 1980 when the "centres de nivaquinisation" were closed the number of cases increased by three times the progressive increase of the number of cases became exponential from 1986 to 1988 which was the peak of the epidemic; malaria remained at a high level until the end of 1993; yearly DDT spraying since 1993 have decreased the number of malaria cases among the dispensary attendants by 90%. The epidemic peak of 1988 was well documented by the Pasteur Institute of Madagascar around Tananarive. Before the epidemic started it was observed a come back of An. funestus which had been previously eliminated of most of the villages by DDT spraying. More than an epidemic the malaria increase in 1988 was a reconquest by malaria of the land from which it had been eliminated in the years 1950. This episode became dramatic because the lack of immunity of the population and the shortage of medicaments. The global warming which was advocated to explain the epidemic has no responsibility because the temperature on the Madagascar Highlands has not changed during the last 30 years. Also the cyclones do not seem to have played any role. It is very likely that the gradual decline of control measures, first DDT spraying, later drug distributions, had the main responsibility in the Highlands drama. Everywhere An. funestus reached a high level during the time where the parasite reservoir was rebuilding. They synergised each other. These findings should be taken in account in drawing the strategy planning for the next years. PMID:9410249

  20. Recent emergence of new variants of Yersinia pestis in Madagascar.

    PubMed

    Guiyoule, A; Rasoamanana, B; Buchrieser, C; Michel, P; Chanteau, S; Carniel, E

    1997-11-01

    Yersinia pestis, the causative agent of plague, has been responsible for at least three pandemics. During the last pandemic, which started in Hong Kong in 1894, the microorganism colonized new, previously unscathed geographical areas where it has become well established. The aim of this longitudinal study was to investigate the genetic stability of Y. pestis strains introduced into a new environment just under a century ago and to follow the epidemiology of any new genetic variant detected. In the present study, 187 strains of Y. pestis isolated between 1939 and 1996 from different regions of Madagascar and responsible mainly for human cases of bubonic and pneumonic plague were studied. Our principal genotyping method was rRNA gene profiling (ribotyping), which has previously been shown to be an effective scheme for typing Y. pestis strains of different geographical origins. We report that all studied Y. pestis strains isolated in Madagascar before 1982 were of classical ribotype B, the ribotype attributed to the Y. pestis clone that spread around the world during the third pandemic. In 1982, 1983, and 1994, strains with new ribotypes, designated R, Q, and T, respectively, were isolated on the high-plateau region of the island. Analysis of other genotypic traits such as the NotI genomic restriction profiles and the EcoRV plasmid restriction profiles revealed that the new variants could also be distinguished by specific genomic and/or plasmid profiles. A follow-up of these new variants indicated that strains of ribotypes Q and R have become well established in their ecosystem and have a tendency to spread to new geographical areas and supplant the original classical strain. PMID:9350742

  1. Recent emergence of new variants of Yersinia pestis in Madagascar.

    PubMed Central

    Guiyoule, A; Rasoamanana, B; Buchrieser, C; Michel, P; Chanteau, S; Carniel, E

    1997-01-01

    Yersinia pestis, the causative agent of plague, has been responsible for at least three pandemics. During the last pandemic, which started in Hong Kong in 1894, the microorganism colonized new, previously unscathed geographical areas where it has become well established. The aim of this longitudinal study was to investigate the genetic stability of Y. pestis strains introduced into a new environment just under a century ago and to follow the epidemiology of any new genetic variant detected. In the present study, 187 strains of Y. pestis isolated between 1939 and 1996 from different regions of Madagascar and responsible mainly for human cases of bubonic and pneumonic plague were studied. Our principal genotyping method was rRNA gene profiling (ribotyping), which has previously been shown to be an effective scheme for typing Y. pestis strains of different geographical origins. We report that all studied Y. pestis strains isolated in Madagascar before 1982 were of classical ribotype B, the ribotype attributed to the Y. pestis clone that spread around the world during the third pandemic. In 1982, 1983, and 1994, strains with new ribotypes, designated R, Q, and T, respectively, were isolated on the high-plateau region of the island. Analysis of other genotypic traits such as the NotI genomic restriction profiles and the EcoRV plasmid restriction profiles revealed that the new variants could also be distinguished by specific genomic and/or plasmid profiles. A follow-up of these new variants indicated that strains of ribotypes Q and R have become well established in their ecosystem and have a tendency to spread to new geographical areas and supplant the original classical strain. PMID:9350742

  2. Capture, Movement, Trade, and Consumption of Mammals in Madagascar.

    PubMed

    Reuter, Kim E; Randell, Haley; Wills, Abigail R; Janvier, Totozafy Eric; Belalahy, Tertius Rodriguez; Sewall, Brent J

    2016-01-01

    Wild meat trade constitutes a threat to many animal species. Understanding the commodity chain of wild animals (hunting, transportation, trade, consumption) can help target conservation initiatives. Wild meat commodity chain research has focused on the formal trade and less on informal enterprises, although informal enterprises contribute to a large portion of the wild meat trade in sub-Saharan Africa. We aimed to provide a more comprehensive understanding of the formal and informal components of these commodity chains by focusing on the mammalian wild meat trade in Madagascar. Our objectives were to: (1) identify hunting strategies used to capture different wild mammals; (2) analyze patterns of movement of wild meat from the capture location to the final consumer; (3) examine wild meat prices, volumes, and venues of sale; and (4) estimate the volume of wild meat consumption. Data were collected in May-August 2013 using semi-structured interviews with consumers (n = 1343 households, 21 towns), meat-sellers (n = 520 restaurants, open-air markets stalls, and supermarkets, 9 towns), and drivers of inter-city transit vehicles (n = 61, 5 towns). We found that: (1) a wide range of hunting methods were used, though prevalence of use differed by animal group; (2) wild meat was transported distances of up to 166 km to consumers, though some animal groups were hunted locally (<10 km) in rural areas; (3) most wild meat was procured from free sources (hunting, gifts), though urban respondents who consumed bats and wild pigs were more likely to purchase those meats; and (4) wild meat was consumed at lower rates than domestic meat, though urban respondents consumed wild meat twice as much per year compared to rural respondents. Apart from the hunting stage, the consumption and trade of wild meat in Madagascar is also likely more formalized than previously thought. PMID:26926987

  3. Capture, Movement, Trade, and Consumption of Mammals in Madagascar

    PubMed Central

    Reuter, Kim E.; Randell, Haley; Wills, Abigail R.; Janvier, Totozafy Eric; Belalahy, Tertius Rodriguez; Sewall, Brent J.

    2016-01-01

    Wild meat trade constitutes a threat to many animal species. Understanding the commodity chain of wild animals (hunting, transportation, trade, consumption) can help target conservation initiatives. Wild meat commodity chain research has focused on the formal trade and less on informal enterprises, although informal enterprises contribute to a large portion of the wild meat trade in sub-Saharan Africa. We aimed to provide a more comprehensive understanding of the formal and informal components of these commodity chains by focusing on the mammalian wild meat trade in Madagascar. Our objectives were to: (1) identify hunting strategies used to capture different wild mammals; (2) analyze patterns of movement of wild meat from the capture location to the final consumer; (3) examine wild meat prices, volumes, and venues of sale; and (4) estimate the volume of wild meat consumption. Data were collected in May-August 2013 using semi-structured interviews with consumers (n = 1343 households, 21 towns), meat-sellers (n = 520 restaurants, open-air markets stalls, and supermarkets, 9 towns), and drivers of inter-city transit vehicles (n = 61, 5 towns). We found that: (1) a wide range of hunting methods were used, though prevalence of use differed by animal group; (2) wild meat was transported distances of up to 166 km to consumers, though some animal groups were hunted locally (<10 km) in rural areas; (3) most wild meat was procured from free sources (hunting, gifts), though urban respondents who consumed bats and wild pigs were more likely to purchase those meats; and (4) wild meat was consumed at lower rates than domestic meat, though urban respondents consumed wild meat twice as much per year compared to rural respondents. Apart from the hunting stage, the consumption and trade of wild meat in Madagascar is also likely more formalized than previously thought. PMID:26926987

  4. Preparer une firme-reseau dans le transport routier des hydrocarbures le cas de TOTAL Madagascar

    NASA Astrophysics Data System (ADS)

    Razakamanifidiny, Patrick Dany

    2009-12-01

    In a dynamic context, a network firm is more and more suggested in scientific writings as a prevalent strategy to develop several firms in subcontracting link in order to satisfy the needs of their customers asking for products which are complex to manufacture. However, due to lack of sufficient preparation, most of network organizations fail. That's why it seems legitimate to explore an avenue of research on the preparation step of a network firm. How a third intermediary can develop and try out a change process in order to stimulate the commitment of films to organize themselves in network? This study is developed inside the framework of an intervention-research applied to the case of the oil distribution company TOTAL Madagascar. 71 weeks of intervention actions carried out with 27 subcontracting firms of hydrocarbon road transport located to Antananarivo are recorded within this framework. One of the critical elements in the oil distribution in Madagascar is the scarcity of the subcontracting firms of hydrocarbon road transport which are able to meet the required quality criterions. A lack of management standards observed in several small and medium enterprises of hydrocarbon road transport, a growth of the number of tankers accidents, and an insufficiency of individual resources to develop competences constitute the main reasons which explain this scarcity. By this way, a preparation step of a network firm was developed in order to increase the management competences of the subcontracting firms of hydrocarbon road transport, and to develop their capacity of collective learning. This step comes from the evolutionary perspective which consists in elaborating and implementing uprooting, movement and rooting activities related to a change implementation model taking reactions of the participating enterprises into consideration, through a change understanding process from objection to exploration until engagement. The realization of theses activities had been allowed: 44 managers of 27 participating firms to be trained, certified and sensitized with the network firm practice, 78% of the participating firms to be enthusiastic to pass to the creation of a network firm, and the enterprise pivot TOTAL Madagascar to record a significant diminution of the number of tankers accidents which is passed from 10 (77% of the total number of the tankers accidents) at the beginning of the process in 2003 to 5 (36%) at the end of this process in 2005 and to 3 (27%) in 2007. These tangible and positive results seem to prove the commitment of firms participating in the preparation step of the network firm. In this way, it is appropriate to put the hypothesis according to the experience done within the framework of this study that could be considered as a learning trajectory type of the preparation step which efficiently stimulates the intention of the participating firms to be organized in network. This present case, through these results, strengthens the consideration according to the success of the network firm which depends in the efficiency of the change process related to its preparation. Thus, a main scientific contribution of this present step rely on its originality which is the integration of two change models (implementation and understanding) inside the same research conceptual framework. In a managerial side, the essential of this step may be transferable to the other contexts which look upon the determinant role of the researcher acting as a change co-leader. That shows the utility of this step within the framework of a doctorate applied in administration. Keywords: Subcontracting -- Change -- Network firm -- Hydrocarbon Road Transport -- Small and Medium Enterprises

  5. High resolution regional soil carbon mapping in Madagascar : towards easy to update maps

    NASA Astrophysics Data System (ADS)

    Grinand, Clovis; Dessay, Nadine; Razafimbelo, Tantely; Razakamanarivo, Herintsitoaina; Albrecht, Alain; Vaudry, Romuald; Tiberghien, Matthieu; Rasamoelina, Maminiaina; Bernoux, Martial

    2013-04-01

    The soil organic carbon plays an important role in climate change regulation through carbon emissions and sequestration due to land use changes, notably tropical deforestation. Monitoring soil carbon emissions from shifting-cultivation requires to evaluate the amount of carbon stored at plot scale with a sufficient level of accuracy to be able to detect changes. The objective of this work was to map soil carbon stocks (30 cm and 100 cm depths) for different land use at regional scale using high resolution satellite dataset. The Andohahela National Parc and its surroundings (South-Est Madagascar) - a region with the largest deforestation rate in the country - was selected as a pilot area for the development of the methodology. A three steps approach was set up: (i) carbon inventory using mid infra-red spectroscopy and stock calculation, (ii) spatial data processing and (iii) modeling and mapping. Soil spectroscopy was successfully used for measuring organic carbon in this region. The results show that Random Forest was the inference model that produced the best estimates on calibration and validation datasets. By using a simple and robust method, we estimated uncertainty levels of of 35% and 43% for 30-cm and 100-cm carbon maps respectively. The approach developed in this study was based on open data and open source software that can be easily replicated to other regions and for other time periods using updated satellite images.

  6. Hypertension, a Neglected Disease in Rural and Urban Areas in Moramanga, Madagascar

    PubMed Central

    Ratovoson, Rila; Rasetarinera, Ony Rabarisoa; Andrianantenaina, Ionimalala; Rogier, Christophe; Piola, Patrice; Pacaud, Pierre

    2015-01-01

    Background Hypertension is one of the main risk factors of cardiovascular diseases. In Madagascar, studies on hypertension in urban and rural communities are scarce. Objectives The aim of this study was to determine the prevalence of hypertension and identify associated risk factors in adults living in a health and demographic system in Moramanga, Madagascar. Methods The study included people aged 15 years old and above living in a health and demographic system in Moramanga. A household census was performed in 2012 to enumerate the population in 3 communities in Moramanga. In addition to the questionnaire used in the initial census, a standardized questionnaire and blood pressure were taken twice after 5 and 10 minutes of rest. In urban areas, heights and weights were also measured to calculate the body mass index. Results There were 3621 and 4010 participants respectively in rural and urban areas. Prevalence of hypertension in rural population was 27.0% (IC95% [25.6–28.5]) and 29.7% (IC95% [28.3–31.1]) in urban population. Among hypertensive subjects, 1.7% (17/979) and 5.3% (64/1191) were on antihypertensive treatment for at least 1 month before the survey in rural and urban population, respectively. In rural areas, increasing age (65 years and older vs 18–25 years OR = 11.81, IC95% [7.79–18.07]), giving more than 3 positive responses to the usual risks factors of hypertension (OR = 1.67, IC95% [1.14–2.42]) and singles in comparison with married people (OR = 1.61, IC95% [1.20–2.17]) were associated to hypertension in a logistic regression model. In urban areas, increasing age (65 years and older vs 18–25 years OR = 37.54, IC95% [24.81–57.92]), more than 3 positive responses to the usual risks of hypertension (OR = 3.47, IC95% [2.58–4.67]) and obesity (OR = 2.45, IC95% [1.56–3.87]) were found as risk factors. Conclusion Hypertension is highly prevalent in rural areas although it is significantly less treated. As a result, a major epidemic of cardiovascular diseases is at risk in Madagascar’s progressively aging society. PMID:26355997

  7. Education and Training in Madagascar: Toward a Policy Agenda for Economic Growth and Poverty Reduction. A World Bank Country Study.

    ERIC Educational Resources Information Center

    World Bank, Washington, DC.

    Madagascar is a poor, primarily rural country in which three-quarters of the population has subsisted below the poverty line for at least two decades. In view of the important role of education in the government's poverty reduction agenda, this report documents the current status of educational development in Madagascar and the key constraints on…

  8. Education and Training in Madagascar: Toward a Policy Agenda for Economic Growth and Poverty Reduction. A World Bank Country Study.

    ERIC Educational Resources Information Center

    World Bank, Washington, DC.

    Madagascar is a poor, primarily rural country in which three-quarters of the population has subsisted below the poverty line for at least two decades. In view of the important role of education in the government's poverty reduction agenda, this report documents the current status of educational development in Madagascar and the key constraints on

  9. Forecasting deforestation and carbon emissions in tropical developing countries facing demographic expansion: a case study in Madagascar.

    PubMed

    Vieilledent, Ghislain; Grinand, Clovis; Vaudry, Romuald

    2013-06-01

    Anthropogenic deforestation in tropical countries is responsible for a significant part of global carbon dioxide emissions in the atmosphere. To plan efficient climate change mitigation programs (such as REDD+, Reducing Emissions from Deforestation and forest Degradation), reliable forecasts of deforestation and carbon dioxide emissions are necessary. Although population density has been recognized as a key factor in tropical deforestation, current methods of prediction do not allow the population explosion that is occurring in many tropical developing countries to be taken into account. Here, we propose an innovative approach using novel computational and statistical tools, including R/GRASS scripts and the new phcfM R package, to model the intensity and location of deforestation including the effect of population density. We used the model to forecast anthropogenic deforestation and carbon dioxide emissions in five large study areas in the humid and spiny-dry forests of Madagascar. Using our approach, we were able to demonstrate that the current rapid population growth in Madagascar (+3.39% per year) will significantly increase the intensity of deforestation by 2030 (up to +1.17% per year in densely populated areas). We estimated the carbon dioxide emissions associated with the loss of aboveground biomass to be of 2.24 and 0.26 tons per hectare and per year in the humid and spiny-dry forest, respectively. Our models showed better predictive ability than previous deforestation models (the figure of merit ranged from 10 to 23). We recommend this approach to reduce the uncertainty associated with deforestation forecasts. We also underline the risk of an increase in the speed of deforestation in the short term in tropical developing countries undergoing rapid population expansion. PMID:23789079

  10. Forecasting deforestation and carbon emissions in tropical developing countries facing demographic expansion: a case study in Madagascar

    PubMed Central

    Vieilledent, Ghislain; Grinand, Clovis; Vaudry, Romuald

    2013-01-01

    Anthropogenic deforestation in tropical countries is responsible for a significant part of global carbon dioxide emissions in the atmosphere. To plan efficient climate change mitigation programs (such as REDD+, Reducing Emissions from Deforestation and forest Degradation), reliable forecasts of deforestation and carbon dioxide emissions are necessary. Although population density has been recognized as a key factor in tropical deforestation, current methods of prediction do not allow the population explosion that is occurring in many tropical developing countries to be taken into account. Here, we propose an innovative approach using novel computational and statistical tools, including R/GRASS scripts and the new phcfM R package, to model the intensity and location of deforestation including the effect of population density. We used the model to forecast anthropogenic deforestation and carbon dioxide emissions in five large study areas in the humid and spiny-dry forests of Madagascar. Using our approach, we were able to demonstrate that the current rapid population growth in Madagascar (+3.39% per year) will significantly increase the intensity of deforestation by 2030 (up to +1.17% per year in densely populated areas). We estimated the carbon dioxide emissions associated with the loss of aboveground biomass to be of 2.24 and 0.26 tons per hectare and per year in the humid and spiny-dry forest, respectively. Our models showed better predictive ability than previous deforestation models (the figure of merit ranged from 10 to 23). We recommend this approach to reduce the uncertainty associated with deforestation forecasts. We also underline the risk of an increase in the speed of deforestation in the short term in tropical developing countries undergoing rapid population expansion. PMID:23789079

  11. Predicting Plant Diversity Patterns in Madagascar: Understanding the Effects of Climate and Land Cover Change in a Biodiversity Hotspot

    PubMed Central

    Brown, Kerry A.; Parks, Katherine E.; Bethell, Colin A.; Johnson, Steig E.; Mulligan, Mark

    2015-01-01

    Climate and land cover change are driving a major reorganization of terrestrial biotic communities in tropical ecosystems. In an effort to understand how biodiversity patterns in the tropics will respond to individual and combined effects of these two drivers of environmental change, we use species distribution models (SDMs) calibrated for recent climate and land cover variables and projected to future scenarios to predict changes in diversity patterns in Madagascar. We collected occurrence records for 828 plant genera and 2186 plant species. We developed three scenarios, (i.e., climate only, land cover only and combined climate-land cover) based on recent and future climate and land cover variables. We used this modelling framework to investigate how the impacts of changes to climate and land cover influenced biodiversity across ecoregions and elevation bands. There were large-scale climate- and land cover-driven changes in plant biodiversity across Madagascar, including both losses and gains in diversity. The sharpest declines in biodiversity were projected for the eastern escarpment and high elevation ecosystems. Sharp declines in diversity were driven by the combined climate-land cover scenarios; however, there were subtle, region-specific differences in model outputs for each scenario, where certain regions experienced relatively higher species loss under climate or land cover only models. We strongly caution that predicted future gains in plant diversity will depend on the development and maintenance of dispersal pathways that connect current and future suitable habitats. The forecast for Madagascar’s plant diversity in the face of future environmental change is worrying: regional diversity will continue to decrease in response to the combined effects of climate and land cover change, with habitats such as ericoid thickets and eastern lowland and sub-humid forests particularly vulnerable into the future. PMID:25856241

  12. Amphibian Chytrid Fungus in Madagascar neither Shows Widespread Presence nor Signs of Certain Establishment

    PubMed Central

    Kolby, Jonathan E.; Skerratt, Lee F.

    2015-01-01

    The global spread of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) is associated with amphibian mass mortality, population decline, and extinction. Over the past decade, concern has been expressed for the potential introduction of Bd to Madagascar, a global hotspot of amphibian biodiversity. Following years without detection, widespread Bd presence in Madagascar has now been reported (Bletz et al. 2015a), raising international conservation concern. Before reacting to this finding with a significant management response, the accuracy and context of the data warrant cautious review. Re-examination of a 10-year dataset together with results from more recent surveillance (Kolby et al. 2015) does not yet demonstrate widespread Bd presence. Detection of Bd at “positive” locations in Madagascar has been inconsistent for unknown reasons. Whether Bd is established in Madagascar (i.e. populations are self-sustaining) or instead requires continued introduction to persist also remains uncertain. The deployment of emergency conservation rescue initiatives is expected to target areas where the distribution of Bd and the risk of chytridiomycosis endangering amphibians is believed to overlap. Thus, erroneous description of Bd presence would misdirect limited conservation resources. Standardized surveillance and confirmatory surveys are now imperative to reliably characterize the distribution, potential spread, virulence and overall risk of Bd to amphibians in Madagascar. PMID:26465924

  13. Amphibian Chytrid Fungus in Madagascar neither Shows Widespread Presence nor Signs of Certain Establishment.

    PubMed

    Kolby, Jonathan E; Skerratt, Lee F

    2015-01-01

    The global spread of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) is associated with amphibian mass mortality, population decline, and extinction. Over the past decade, concern has been expressed for the potential introduction of Bd to Madagascar, a global hotspot of amphibian biodiversity. Following years without detection, widespread Bd presence in Madagascar has now been reported (Bletz et al. 2015a), raising international conservation concern. Before reacting to this finding with a significant management response, the accuracy and context of the data warrant cautious review. Re-examination of a 10-year dataset together with results from more recent surveillance (Kolby et al. 2015) does not yet demonstrate widespread Bd presence. Detection of Bd at "positive" locations in Madagascar has been inconsistent for unknown reasons. Whether Bd is established in Madagascar (i.e. populations are self-sustaining) or instead requires continued introduction to persist also remains uncertain. The deployment of emergency conservation rescue initiatives is expected to target areas where the distribution of Bd and the risk of chytridiomycosis endangering amphibians is believed to overlap. Thus, erroneous description of Bd presence would misdirect limited conservation resources. Standardized surveillance and confirmatory surveys are now imperative to reliably characterize the distribution, potential spread, virulence and overall risk of Bd to amphibians in Madagascar. PMID:26465924

  14. Presence of the Amphibian Chytrid Fungus Batrachochytrium dendrobatidis in Native Amphibians Exported from Madagascar

    PubMed Central

    Kolby, Jonathan E.

    2014-01-01

    The emerging infectious disease chytridiomycosis is driven by the spread of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd), a highly virulent pathogen threatening global amphibian biodiversity. Although pandemic in distribution, previous intensive field surveys have failed to detect Bd in Madagascar, a biodiversity hotspot home to hundreds of endemic amphibian species. Due to the presence of Bd in nearby continental Africa and the ecological crisis that can be expected following establishment in Madagascar, enhanced surveillance is imperative. I sampled 565 amphibians commercially exported from Madagascar for the presence of Bd upon importation to the USA, both to assist early detection efforts and demonstrate the conservation potential of wildlife trade disease surveillance. Bd was detected in three animals via quantitative PCR: a single Heterixalus alboguttatus, Heterixalus betsileo, and Scaphiophryne spinosa. This is the first time Bd has been confirmed in amphibians from Madagascar and presents an urgent call to action. Our early identification of pathogen presence prior to widespread infection provides the necessary tools and encouragement to catalyze a swift, targeted response to isolate and eradicate Bd from Madagascar. If implemented before establishment occurs, an otherwise likely catastrophic decline in amphibian biodiversity may be prevented. PMID:24599336

  15. Why is Madagascar special? The extraordinarily slow evolution of pelican spiders (Araneae, Archaeidae).

    PubMed

    Wood, Hannah M; Gillespie, Rosemary G; Griswold, Charles E; Wainwright, Peter C

    2015-02-01

    Although Madagascar is an ancient fragment of Gondwana, the majority of taxa studied thus far appear to have reached the island through dispersal from Cenozoic times. Ancient lineages may have experienced a different history compared to more recent Cenozoic arrivals, as such lineages would have encountered geoclimatic shifts over an extended time period. The motivation for this study was to unravel the signature of diversification in an ancient lineage by comparing an area known for major geoclimatic upheavals (Madagascar) versus other areas where the environment has been relatively stable. Archaeid spiders are an ancient paleoendemic group with unusual predatory behaviors and spectacular trophic morphology that likely have been on Madagascar since its isolation. We examined disparities between Madagascan archaeids and their non-Madagascan relatives regarding timing of divergence, rates of trait evolution, and distribution patterns. Results reveal an increased rate of adaptive trait diversification in Madagascan archaeids. Furthermore, geoclimatic events in Madagascar over long periods of time may have facilitated high species richness due to montane refugia and stability, rainforest refugia, and also ecogeographic shifts, allowing for the accumulation of adaptive traits. This research suggests that time alone, coupled with more ancient geoclimatic events allowed for the different patterns in Madagascar. PMID:25491087

  16. Detection in and circulation of Bluetongue virus among domestic ruminants in Madagascar.

    PubMed

    Andriamandimby, Soa Fy; Viarouge, Cyril; Ravalohery, Jean-Pierre; Reynes, Jean-Marc; Sailleau, Corinne; Tantely, Michael Luciano; Elissa, Nohal; Cardinale, Eric; Sall, Amadou Alpha; Zientara, Stephan; Heraud, Jean-Michel

    2015-04-17

    So far, no published data was available concerning the circulation of Bluetongue virus (BTV) in Madagascar. During a survey on Rift Valley Fever, we were able to detect a virus belonging to BTV. Therefore, we conducted a study aiming at characterizing molecularly the BTV isolated and assess the importance of circulation of BTV in Madagascar. A total of 4393 sera from ruminants selected randomly by stratification and sampled in 30 districts of Madagascar were tested for BTV. Moreover, 175 cattle were followed during 11 months. Phylogenetic analyses were performed from virus isolated from unfed pools of mosquitoes. Overall, the estimated mean seroprevalence of infection at the national level was 95.9% (95% CI: [95.2-96.5]) in cattle and 83.7% (95% CI: [81.4-85.9]) in small ruminants. Estimation of incidence rate was 54 per 100 cattle-years assuming that the incidence rate is constant all year along. Phylogenetic analyses revealed that BTV detected belong to serotype 2. In conclusion, our results showed that BTV is endemic in Madagascar and highly prevalent among cattle. In our study we did not work on the vector involved in transmission of BTV in cattle. Thus, research should be conducted to better describe epidemiology of BTV in Madagascar including vectors and assess economic impact of the disease associated to BTV infections. PMID:25736861

  17. Cleft lip and palate in Madagascar 1998-2007.

    PubMed

    Rakotoarison, Richard Aurélien; Rakotoarivony, Andrianony Emmanuel; Rabesandratana, Norotiana; Razafindrabe, John Bam; Andriambololona, Raoelina; Andriambololo-Nivo, Rabetrano; Feki, Ahmed

    2012-07-01

    Our aim was to find out the prevalence of oral clefts in Madagascar, to compare it with elsewhere in the world, and to give the possible cause of the particular rate in the Vakinankaratra region where Antsirabe is situated. Data were collected from birth registers from 1998 to 2007 in the 10 most important hospitals of the 6 former provinces and of Antsirabe. A total of 150,973 consecutive live births were recorded in the 6 provinces, and 175,981 including those from Antsirabe. The general birth prevalence of oral clefts was 0.48‰ (about 1/2100, n=150,973) which was made up of 0.23‰, 0.12‰, and 0.11‰ for cleft lip and palate, isolated cleft lip, and isolated cleft palate, respectively. Prevalence was greater on the Central Highlands than in the coastal regions. Higher prevalence rates were found among girls than boys (64.4% compared with 35.6%, p<0.01). Of the clefts, 65.5% were unilateral, and left-sided ones were most common (77.8%). If the results obtained in Antsirabe are also considered, birth prevalence of oral clefts was 0.92‰ (about 1/1100, n=175,981) if Antsirabe is included, and 0.41-0.50‰ in the 6 former provinces; rates of associated, or syndromic, forms, or both, were 21.9% in the 6 provinces and 26.1% in Antsirabe. Overall, the prevalence of oral clefts in Madagascar does not differ from that in the rest of the world, except for the sex difference. There was a high prevalence of oral clefts in general and associated or syndromic forms, or both, in the Vakinankaratra region. There may be a link between these results and background high doses of ionising radiation in some areas because of the presence of former uranium mines. Further research is needed to obtain more precise data. PMID:21764188

  18. [Water and environment in the Southwest of Madagascar].

    PubMed

    Razanamparany, L

    1993-04-01

    The dry and arid southwest region of Madagascar is not a desert but resembles the Sahel region of West Africa. The chronic water deficit is aggravated by the heat and constant winds that accelerate evapotranspiration on the permeable soils. The dryness occurs because the southwest region lies outside the main pluviogenic systems. Erosion occurs at all seasons. In the winter the sun and winds are the main causes, while the rare storms are more conducive to run-off and to erosion than to absorption. The acute water shortage in the southwest has prompted hydrogeologic research and well-drilling, but the high salt content of the water and other impurities will be a limiting factor for development of the area. The population of the southwest is extremely mobile. Human settlements are concentrated in the valleys and depressions and along major roads. Customary rights to land under the control of the traditional chiefs regulate tenure in most areas. But especially in the river bottoms, the coming of cash crops cultivated with modern equipment has resulted in significant erosion which has aggravated ecological problems. Accelerating soil degradation has led peasants to extend their lands under cultivation to the detriment of forest cover. Cattle herding remains the principal economic activity in the southwest. Herding has progressed from nomadism to pastoralism, but it remains a sign of power and wealth. Transhumance is the strategy of herders faced with shortages of water and pasturage, demographic pressure, and environmental degradation. Raising of sheep and goats constitutes a supplemental food source, medium of exchange, and form of savings. But angora goats graze on everything in their path, devastating their surrounds. Fear of cattle thefts militates against efforts to improve the quality of the stock. The various problems together have prompted a wasteful exploitation of the forest resources. Development strategies for the area explored by the government have all been forced to consider the high cost of potable water. A water project forms part of the Environmental Plan of Action launched by Madagascar with the assistance of international organizations. PMID:12286688

  19. Sentinel surveillance system for early outbreak detection in Madagascar

    PubMed Central

    2010-01-01

    Background Following the outbreak of chikungunya in the Indian Ocean, the Ministry of Health directed the necessary development of an early outbreak detection system. A disease surveillance team including the Institut Pasteur in Madagascar (IPM) was organized to establish a sentinel syndromic-based surveillance system. The system, which was set up in March 2007, transmits patient data on a daily basis from the various voluntary general practitioners throughout the six provinces of the country to the IPM. We describe the challenges and steps involved in developing a sentinel surveillance system and the well-timed information it provides for improving public health decision-making. Methods Surveillance was based on data collected from sentinel general practitioners (SGP). The SGPs report the sex, age, visit date and time, and symptoms of each new patient weekly, using forms addressed to the management team. However, the system is original in that SGPs also report data at least once a day, from Monday to Friday (number of fever cases, rapid test confirmed malaria, influenza, arboviral syndromes or diarrhoeal disease), by cellular telephone (encrypted message SMS). Information can also be validated by the management team, by mobile phone. This data transmission costs 120 ariary per day, less than US$1 per month. Results In 2008, the sentinel surveillance system included 13 health centers, and identified 5 outbreaks. Of the 218,849 visits to SGPs, 12.2% were related to fever syndromes. Of these 26,669 fever cases, 12.3% were related to Dengue-like fever, 11.1% to Influenza-like illness and 9.7% to malaria cases confirmed by a specific rapid diagnostic test. Conclusion The sentinel surveillance system represents the first nationwide real-time-like surveillance system ever established in Madagascar. Our findings should encourage other African countries to develop their own syndromic surveillance systems. Prompt detection of an outbreak of infectious disease may lead to control measures that limit its impact and help prevent future outbreaks. PMID:20092624

  20. Quantifying the Short-Term Costs of Conservation Interventions for Fishers at Lake Alaotra, Madagascar

    PubMed Central

    Wallace, Andrea P. C.; Milner-Gulland, E. J.; Jones, Julia P. G.; Bunnefeld, Nils; Young, Richard; Nicholson, Emily

    2015-01-01

    Artisanal fisheries are a key source of food and income for millions of people, but if poorly managed, fishing can have declining returns as well as impacts on biodiversity. Management interventions such as spatial and temporal closures can improve fishery sustainability and reduce environmental degradation, but may carry substantial short-term costs for fishers. The Lake Alaotra wetland in Madagascar supports a commercially important artisanal fishery and provides habitat for a Critically Endangered primate and other endemic wildlife of conservation importance. Using detailed data from more than 1,600 fisher catches, we used linear mixed effects models to explore and quantify relationships between catch weight, effort, and spatial and temporal restrictions to identify drivers of fisher behaviour and quantify the potential effect of fishing restrictions on catch. We found that restricted area interventions and fishery closures would generate direct short-term costs through reduced catch and income, and these costs vary between groups of fishers using different gear. Our results show that conservation interventions can have uneven impacts on local people with different fishing strategies. This information can be used to formulate management strategies that minimise the adverse impacts of interventions, increase local support and compliance, and therefore maximise conservation effectiveness. PMID:26107284

  1. Formation and preservation of biotite-rich microdomains in high-temperature rocks from the Antananarivo Block, Madagascar

    NASA Astrophysics Data System (ADS)

    Cenki-Tok, Bndicte; Berger, Alfons; Gueydan, Frdric

    2015-10-01

    Highly restitic rocks from the Antananarivo Block in northern Madagascar are investigated in this study in order to unravel processes of H2O-rich biotite formation in HT rocks. Polyphase metamorphism and melt migration occurred at 0.6 GPa and 850 C. Biotite remains stable together with orthopyroxene and makes up to 45 vol% of the rock. In addition, three well-characterised and delimited microdomains having different textural, chemical and petrological characteristics are preserved. Thermodynamic models using the specific bulk compositions of the domains are in agreement with petrological observations. These rocks provide evidence that the lower crust may be strongly heterogeneous, locally associated to the formation of hydrous restites controlled by episodes of melt production and melt escape. This has significant consequences for understanding of the lower crust.

  2. Early initiation of and exclusive breastfeeding in large-scale community-based programmes in Bolivia and Madagascar.

    PubMed

    Baker, Elizabeth Jean; Sanei, Linda C; Franklin, Nadra

    2006-12-01

    About one-fourth to one-half of all infant deaths in developing countries occur in the first week of life. Immediate breastfeeding within the first hour, followed by early exclusive breastfeeding, improves the health and survival status of newborns. The aim of this study was to demonstrate that breastfeeding practices, crucial to infant health, can be improved at scale in developing countries. During 1999-2003, the LINKAGES Project, funded by the United States Agency for International Development, implemented its community-based model to bring about rapid change in individual behaviours and community norms regarding early and exclusive breastfeeding, at a scale [LINKAGES' definition of 'scale' was adapted from a CORE Group background paper on 'Scaling-up' maternal, newborn, and child health services, 11 July 2005] that could achieve significant public-health impact. 'Scale' was defined as bringing improved infant-feeding practices to more people over a wider geographic area, more quickly, more equitably, and with sustainability as a goal. During this time, country-specific programmes were designed and implemented in Bolivia and Madagascar, with catchment populations of one million and six million respectively. These country programmes were implemented with multiple local government, private voluntary organizations, and partners of non-governmental organizations (NGOs) through existing health and nutrition activities. Breastfeeding was an entry point to work at all levels of the healthcare system and, within communities, using policy/advocacy and training for healthcare workers, with a particular emphasis on front-line health workers and community members. Harmonized messages and materials, including mass media, were developed and used by partners. Timely initiation of breastfeeding was one indicator measured. Data collected through rapid assessment surveys showed statistically significant increases (p<0.001) in timely initiation of breastfeeding in both the countries. In Bolivia, timely initiation of breastfeeding went from 56% in 2000 to 69% in 2001 and reached 74% by the end of 2003. In Madagascar, the initiation rate went from 34% at baseline in 2000 to 69% in 2001, 76% in 2002, and rose to 78% in 2004. Exclusive breastfeeding during the first month of life was also measured. At baseline in Bolivia, the rate of exclusive breastfeeding for the first month of life was 81% (2000), decreased slightly in 2001, and then increased to 88% by the end of the Project in 2003. In Madagascar, it started high at 86% in 2000, increased during the implementation of the programme, and by 2004, was 91%. These results were achieved quickly and sustained over the course of the intervention. PMID:17591350

  3. Disappearing Lake Alaotra: Monitoring catastrophic erosion, waterway silting, and land degradation hazards in Madagascar using Landsat imagery

    NASA Astrophysics Data System (ADS)

    Bakoariniaina, Lao Nathalie; Kusky, Timothy; Raharimahefa, Tsilavo

    2006-02-01

    At the turn of the century the island of Madagascar was densely forested, but it has recently been dramatically deforested with most damage since French colonization of the island in 1896. When the French arrived many Malagasy people fled into the forest to survive and practiced deforestation to obtain land for cultivation. However, limited slash and burn had already been an historical practice even before French colonization. Over 90% of the Malagasy original forest is now gone. Severe environmental issues have arisen on the island caused by this deforestation including degradation of the landscape due to erosion followed by siltation of many streams and rivers, and loss of Madagascar's biodiversity. Only the humid eastern and northeastern forests remain in significant amounts and even these are concentrated in areas of steep slope and difficult access. Madagascar's largest lake, Lake Alaotra, is located at about 750 m elevation along the eastern escarpment, in the east-central part of the country. The lake is in a large fault-controlled basin and is known for the islands most fertile and productive rice fields. However, in the past 30 years, silt derived from erosion of the soil horizon, a consequence of the deforestation, has clogged the streams and rivers in the Lake Alaotra Basin, and has filled in most of the lake. Examination of sequential Landsat TM imagery, along with field and historical observations, has shown that the lake had shrunk to 60% of its former size by the 1960s, 40% of its former size by the 1980s, and 20% of its former size in 2000. Fieldwork in the lake basin in 2003 revealed that Lake Alaotra was essentially gone, leaving only small swampy areas and perhaps a shallow small remnant lake and surrounded by marsh transformed into rice-cultivation. Crop productivity in the basin has also dropped dramatically to about 40% of its former level as a consequence of the silting of the rivers and irrigation canals, yet clear-cutting and slash and burn clearing continues in the basin. The disappearance of Lake Alaotra and the loss of crop productivity are the result of the environmental degradation. Image analysis and GIS modeling is used to locate areas that are contributing the largest amount of silt to the basin so remedial action can be taken to reduce further loss and crop yield degradation, but no matter what is done, Lake Alaotra has filled with silt and will not easily return.

  4. Spatial linkages between coral proxies of terrestrial runoff across a large embayment in Madagascar

    NASA Astrophysics Data System (ADS)

    Grove, C. A.; Zinke, J.; Scheufen, T.; Maina, J.; Epping, E.; Boer, W.; Randriamanantsoa, B.; Brummer, G.-J. A.

    2012-03-01

    Coral cores provide vital climate reconstructions for site-specific temporal variability in river flow and sediment load. Yet, their ability to record spatial differences across multiple catchments is relatively unknown. Here, we investigate spatial linkages between four coral proxies of terrestrial runoff and their relationships between sites. Coral cores were drilled in and around Antongil Bay, the largest bay in Madagascar, and individually analysed for fifteen years of continuous luminescence (G/B), Ba/Ca, ?18Osw and ?13C data. Each coral core was drilled close to individual river mouths (? 7 km), and proxy data was compared to modelled river discharge and sediment runoff data for the three corresponding catchments. A reasonable agreement between terrestrial runoff proxies with modelled river discharge and sediment yield was observed. Some inconsistencies between proxy and modelled data we relate to proxy behaviour, watershed size and local environmental physiochemical parameters. In general, the further a coral resided from its river source, the weaker the proxy relationship was with modelled data and other corals, due to mixing gradients and currents. Nevertheless, we demonstrate that two coral Ba/Ca and luminescence (G/B) records influenced by the same watershed are reproducible. Furthermore, a strong Ba/Ca relationship was observed between two cores from distant watersheds, with baseline averages in agreement with modelled sediment runoff data. As humic acids behave conservatively in the water column, luminescence (G/B) data gave the highest regional correlations between cores, and most coherence with site specific modelled discharge. No statistical relationship was observed between cores in terms of interannual ?18Osw and ?13C, meaning corals were recording a localised signal at their respective sites. Comparing proxy baseline averages and mean seasonal cycles provided a good overview of the runoff dynamics of the bay system.

  5. Spatial linkages between coral proxies of terrestrial runoff across a large embayment in Madagascar

    NASA Astrophysics Data System (ADS)

    Grove, C. A.; Zinke, J.; Scheufen, T.; Maina, J.; Epping, E.; Boer, W.; Randriamanantsoa, B.; Brummer, G.-J. A.

    2012-08-01

    Coral cores provide vital climate reconstructions for site-specific temporal variability in river flow and sediment load. Yet, their ability to record spatial differences across multiple catchments is relatively unknown. Here, we investigate spatial linkages between four coral proxies of terrestrial runoff and their relationships between sites. Coral cores were drilled in and around Antongil Bay, the largest bay in Madagascar, and individually analysed for fifteen years of continuous luminescence (G / B), Ba / Ca, ?18Osw and ?13C data. Each coral core was drilled close to individual river mouths (? 7 km), and proxy data were compared to modelled river discharge and sediment runoff data for the three corresponding catchments. A reasonable agreement between terrestrial runoff proxies with modelled river discharge and sediment yield was observed. Some inconsistencies between proxy and modelled data are likely linked to proxy behaviour, watershed size and local environmental physiochemical parameters. In general, the further a coral resided from its river source, the weaker the proxy relationship was with modelled data and other corals, due to mixing gradients and currents. Nevertheless, we demonstrate that two coral Ba / Ca and luminescence (G / B) records influenced by the same watershed are reproducible. Furthermore, a strong Ba / Ca relationship was observed between two cores from distant watersheds, with baseline averages in agreement with modelled sediment runoff data. As humic acids behave conservatively in the water column, luminescence (G / B) data gave the highest regional correlations between cores, and showed the most consistent relationship with site specific modelled discharge. No statistical relationship was observed between cores in terms of interannual ?18Osw and ?13C, meaning corals were recording a localised signal at their respective sites, confounded by vital effects. Comparing proxy baseline averages and mean seasonal cycles provided a good overview of the runoff dynamics of the bay system.

  6. Climate change impacts and vegetation response on the island of Madagascar.

    PubMed

    Ingram, J Carter; Dawson, Terence P

    2005-01-15

    The island of Madagascar has been labelled the world's number one conservation 'hot spot' because of increasing anthropogenic degradation of its natural habitats, which support a high level of species endemism. However, climatic phenomena may also have a significant impact upon the island's flora and fauna. An analysis of 18 years of monthly satellite images from the National Oceanographic and Atmospheric Administration's (NOAA) Advanced Very High Resolution Radiometer (AVHRR) have demonstrated that there is a dynamic pattern in Madagascar's vegetative cover both annually and seasonally throughout 1982-1999. Over interannual time-scales, we show that this vegetation response, calculated using the normalized difference vegetation index (NDVI), has a strong negative correlation with the El Nino Southern Oscillation (ENSO), which can be attributable to drought events and associated wildfires. Global climate change is predicted to increase the frequency of the ENSO phenomenon, resulting in further decline of Madagascar's natural environment. PMID:15598621

  7. Miocene Shark and Batoid Fauna from Nosy Makamby (Mahajanga Basin, Northwestern Madagascar)

    PubMed Central

    Andrianavalona, Tsiory H.; Ramihangihajason, Tolotra N.; Rasoamiaramanana, Armand; Ward, David J.; Ali, Jason R.; Samonds, Karen E.

    2015-01-01

    Madagascar is well known for producing exceptional fossils. However, the record for selachians remains relatively poorly known. Paleontological reconnaissance on the island of Nosy Makamby, off northwest Madagascar, has produced a previously undescribed assemblage of Miocene fossils. Based on isolated teeth, ten taxonomic groups are identified: Otodus, Carcharhinus, Galeocerdo, Rhizoprionodon, Sphyrna, Hemipristis, Squatina, Rostroraja, Himantura and Myliobatidae. Six are newly described from Madagascar for the Cenozoic (Galeocerdo, Rhizoprionodon, Sphyrna, Squatina, Rostroraja and Himantura). In association with these specimens, remains of both invertebrates (e.g., corals, gastropods, bivalves) and vertebrates (e.g., bony fish, turtles, crocodylians, and sirenian mammals) were also recovered. The sedimentary facies are highly suggestive of a near-shore/coastal plain depositional environment. This faunal association shares similarities to contemporaneous sites reported from North America and Europe and gives a glimpse into the paleoenvironment of Madagascar’s Miocene, suggesting that this region was warm, tropical shallow-water marine. PMID:26075723

  8. The impact of advective transport by the South Indian Ocean Countercurrent on the Madagascar plankton bloom

    NASA Astrophysics Data System (ADS)

    Huhn, F.; von Kameke, A.; Prez-Muuzuri, V.; Olascoaga, M. J.; Beron-Vera, F. J.

    2012-03-01

    Based on ten years (1998-2007) of satellite ocean color data we analyze the spatiotemporal patterns in the seasonal Madagascar plankton bloom with respect to the advection of the recently discovered Southern Indian Ocean Countercurrent (SICC). In maps of Finite-time Lyapunov Exponents (FTLE) and Finite-Time Zonal Drift (FTZD) computed from altimetry derived velocities we observe a narrow zonal jet that starts at 25S at the southern tip of Madagascar, an important upwelling region, and extends to the east further than the largest plankton blooms (2500 km). In bloom years, the jet coincides with large parts of the northern boundary of the plankton bloom, acting as a barrier to meridional transport. Our findings suggest that advection is an important and so far underestimated mechanism for the eastward propagation and the extent of the plankton bloom. This supports the hypothesis of a single nutrient source south of Madagascar.

  9. Long-term survival despite low genetic diversity in the critically endangered Madagascar fish-eagle.

    PubMed

    Johnson, Jeff A; Tingay, Ruth E; Culver, Melanie; Hailer, Frank; Clarke, Michèle L; Mindell, David P

    2009-01-01

    The critically endangered Madagascar fish-eagle (Haliaeetus vociferoides) is considered to be one of the rarest birds of prey globally and at significant risk of extinction. In the most recent census, only 222 adult individuals were recorded with an estimated total breeding population of no more than 100-120 pairs. Here, levels of Madagascar fish-eagle population genetic diversity based on 47 microsatellite loci were compared with its sister species, the African fish-eagle (Haliaeetus vocifer), and 16 of these loci were also characterized in the white-tailed eagle (Haliaeetus albicilla) and the bald eagle (Haliaeetus leucocephalus). Overall, extremely low genetic diversity was observed in the Madagascar fish-eagle compared to other surveyed Haliaeetus species. Determining whether this low diversity is the result of a recent bottleneck or a more historic event has important implications for their conservation. Using a Bayesian coalescent-based method, we show that Madagascar fish-eagles have maintained a small effective population size for hundreds to thousands of years and that its low level of neutral genetic diversity is not the result of a recent bottleneck. Therefore, efforts made to prevent Madagascar fish-eagle extinction should place high priority on maintenance of habitat requirements and reducing direct and indirect human persecution. Given the current rate of deforestation in Madagascar, we further recommend that the population be expanded to occupy a larger geographical distribution. This will help the population persist when exposed to stochastic factors (e.g. climate and disease) that may threaten a species consisting of only 200 adult individuals while inhabiting a rapidly changing landscape. PMID:19140964

  10. Long-term survival despite low genetic diversity in the critically endangered Madagascar fish-eagle

    USGS Publications Warehouse

    Johnson, J.A.; Tingay, R.E.; Culver, M.; Hailer, F.; Clarke, M.L.; Mindell, D.P.

    2009-01-01

    The critically endangered Madagascar fish-eagle (Haliaeetus vociferoides) is considered to be one of the rarest birds of prey globally and at significant risk of extinction. In the most recent census, only 222 adult individuals were recorded with an estimated total breeding population of no more than 100-120 pairs. Here, levels of Madagascar fish-eagle population genetic diversity based on 47 microsatellite loci were compared with its sister species, the African fish-eagle (Haliaeetus vocifer), and 16 of these loci were also characterized in the white-tailed eagle (Haliaeetus albicilla) and the bald eagle (Haliaeetus leucocephalus). Overall, extremely low genetic diversity was observed in the Madagascar fish-eagle compared to other surveyed Haliaeetus species. Determining whether this low diversity is the result of a recent bottleneck or a more historic event has important implications for their conservation. Using a Bayesian coalescent-based method, we show that Madagascar fish-eagles have maintained a small effective population size for hundreds to thousands of years and that its low level of neutral genetic diversity is not the result of a recent bottleneck. Therefore, efforts made to prevent Madagascar fish-eagle extinction should place high priority on maintenance of habitat requirements and reducing direct and indirect human persecution. Given the current rate of deforestation in Madagascar, we further recommend that the population be expanded to occupy a larger geographical distribution. This will help the population persist when exposed to stochastic factors (e.g. climate and disease) that may threaten a species consisting of only 200 adult individuals while inhabiting a rapidly changing landscape. ?? 2008 The Authors.

  11. Seroepidemiology of human plague in the Madagascar highlands.

    PubMed

    Ratsitorahina, M; Rabarijaona, L; Chanteau, S; Boisier, P

    2000-02-01

    We conducted a seroepidemiological survey of human plague in the general population using random sampling in the area of Ambositra, the main focus of plague in the central highlands of Madagascar (520 confirmed and presumptive cases notified during the past 10 years). Sera were tested using an ELISA IgG F1 assay. Considering the internal validity of the assay and the sampling method, the overall corrected prevalence of F1 antibodies was 0.6% (95% CI: 0.2%-1.8%). Being nearly 0 up to the age of 40, the corrected prevalence increased markedly after 45 years to 6.2%. Six of 20 individuals who declared to have been treated for clinical suspicion of bubonic plague in the past had F1 antibodies. The seroprevalence did not differ according to gender except in individuals > 60, where antibodies were significantly more frequent in males. This study suggests that the number of clinically suspected cases of plague provided by the surveillance network was plausible, despite some true cases being missed and a significant number of false positives. We also confirm that Yersinia pestis infections may occur without marked clinical manifestations and patients may recover without treatment, in accordance with old observations of pestis minor. PMID:10747268

  12. Maternal health practices, beliefs and traditions in southeast Madagascar.

    PubMed

    Morris, Jessica L; Short, Samm; Robson, Laura; Andriatsihosena, Mamy Soafaly

    2014-09-01

    Contextualising maternal health in countries with high maternal mortality is vital for designing and implementing effective health interventions. A research project was therefore conducted to explore practices, beliefs and traditions around pregnancy, delivery and postpartum in southeast Madagascar. Interviews and focus groups were conducted with 256 pregnant women, mothers of young children, community members and stakeholders; transcripts were analysed to identify and explore predetermined and emerging themes. A questionnaire was also conducted with 373 women of reproductive age from randomly selected households. Data was analysed using STATA. Results confirmed high local rates of maternal mortality and morbidity and revealed a range of traditional health care practices and beliefs impacting on women's health seeking behaviours. The following socio-cultural barriers to health were identified: 1) lack of knowledge, 2) risky practices, 3) delays seeking biomedical care, and 4) family and community expectations. Recommendations include educational outreach and behaviour change communications targeted for women, their partners and family, increased engagement with traditional midwives and healers, and capacity building of formal health service providers. PMID:25438515

  13. [Anopheles funestus and rice agriculture in the Madagascar highlands].

    PubMed

    Marrama, L; Rajaonarivelo, E; Laventure, S; Rabarison, P

    1995-01-01

    An exhaustive study of the potential habitats of Anopheles funestus was led during 1992 in Ankazobe on the Plateau of Madagascar, 95 km northwest of the capital Tananarive. The rice fields provide more than 90% of the positive habitats versus less than 10% for the nonhuman biotopes. Larva are especially abundant on the surfaces of the rice during grain head formation and maturation. The dense vegetation coverage provides them with shade and protection against predators. After harvesting, the follows can be filled with water and wild vegetation, and then also provide an important share of the habitats. The rice fields are omnipresent on the Plateau where they supply the basis of local alimentation. A. funestus then constitutes a serious risk for all of the villages. The role of the rice fields as habitats for A. funestus has already been noted in Kenya but in West Africa the rice fields do not host this species, even if this species is very abundant in the other types of habitats. PMID:8784552

  14. Bioactive compounds from Stuhlmannia moavi from the Madagascar dry forest☆

    PubMed Central

    Liu, Yixi; Harinantenaina, Liva; Brodie, Peggy J.; Bowman, Jessica D.; Cassera, Maria B.; Slebodnick, Carla; Callmander, Martin W.; Randrianaivo, Richard; Rakotobe, Etienne; Rasamison, Vincent E.; Applequist, Wendy; Birkinshaw, Chris; Lewis, Gwilym P.; Kingston, David G. I.

    2013-01-01

    Bioassay-directed fractionation of the leaf and root extracts of the antiproliferative Madagascar plant Stuhlmannia moavi afforded 6-acetyl-5,8-dihydroxy-2-methoxy-7-methyl-1,4-naphthoquinone (stuhlmoavin, 1) as the most active compound, with an IC50 value of 8.1 µM against the A2780 human ovarian cancer cell line, as well as the known homoisoflavonoid bonducellin (2) and the stilbenoids 3,4,5'-trihydroxy-3'-methoxy-trans-stilbene (3), piceatannol (4), resveratrol (5), rhapontigenin (6), and isorhapontigenin (7). The structure elucidation of all compounds was based on NMR and mass spectroscopic data, and the structure of 1 was confirmed by a single crystal X-ray analysis. Compounds 2–5 showed weak A2780 activities, with IC50 values of 10.6, 54.0, 41.0, and 74.0 µM, respectively. Compounds 1–3 also showed weak antimalarial activity against Plasmodium falciparum with IC50 values of 23, 26, and 27 µM, respectively. PMID:24239390

  15. A new species of Ptychochromis from southeastern Madagascar (Teleostei: Cichlidae).

    PubMed

    Martinez, Christopher M; Arroyave, Jairo; Sparks, John S

    2015-01-01

    We describe a new species in the endemic Malagasy cichlid genus Ptychochromis. Ptychochromis mainty, new species, is known from four individuals, all collected in the Fort Dauphin region of southeastern Madagascar, and shares a palatine morphology (eastern-type palatine) with other eastern congeners. Ptychochromis mainty is distinguished from all congeners by a nearly uniform dark brown to black pigmentation pattern in preservation and by the presence of a relatively continuous and expansive black longitudinal midlateral blotch in life, extending from the posterior margin of the opercle to the caudal peduncle. The new species is further distinguished from other eastern Ptychochromis species by having minimal or no overlap of the first supraneural with the dorsoposterior region of the supraoccipital crest (vs. marked overlap). We present a molecular-based phylogeny for all available Ptychochromis species, which supports the hypothesis that P. mainty is a distinct taxon. The new species is recovered as the sister taxon to P. grandidieri within a clade comprising species with an eastern-type palatine morphology. We present a geometric morphometric analysis that provides additional evidence to distinguish P. mainty from congeners. PMID:26624703

  16. Atelier paludisme: an international malaria training course held in Madagascar

    PubMed Central

    Domarle, Olivier; Randrianarivelojosia, Milijaona; Duchemin, Jean-Bernard; Robert, Vincent; Ariey, Frédéric

    2008-01-01

    The Atelier Paludisme (Malaria Workshop) is an international training course organized by the Institut Pasteur de Madagascar, which has been held annually for the past five years. The course was designed for both young and experienced researchers, as well as for healthcare professionals, mostly from malaria-endemic countries. Its objective is to provide participants with a broad knowledge of all features of malaria, to improve their skills in project management, to break geographical isolation by using the Internet as a source of documentary information. This six-week course makes use of concepts of andragogy and problem-based learning, i.e. a relationship between participants and tutors, which promotes a process of exchange rather than the simple transmission of knowledge, where participants have to search actively for information. This approach to training, combined with the wide background and experience of those involved, creates positive dynamics and enables participants to acquire new skills, develop their critical and analytical abilities. This paper describes the course and the lessons learned from its evaluation. PMID:18471291

  17. Genetic diversity and population structure of Plasmodium vivax isolates from Sudan, Madagascar, French Guiana and Armenia.

    PubMed

    Menegon, Michela; Durand, Patrick; Menard, Didier; Legrand, Eric; Picot, Stéphane; Nour, Bakri; Davidyants, Vladimir; Santi, Flavia; Severini, Carlo

    2014-10-01

    Polymorphic genetic markers and especially microsatellite analysis can be used to investigate multiple aspects of the biology of Plasmodium species. In the current study, we characterized 7 polymorphic microsatellites in a total of 281 Plasmodium vivax isolates to determine the genetic diversity and population structure of P. vivax populations from Sudan, Madagascar, French Guiana, and Armenia. All four parasite populations were highly polymorphic with 3-32 alleles per locus. Mean genetic diversity values was 0.83, 0.79, 0.78 and 0.67 for Madagascar, French Guiana, Sudan, and Armenia, respectively. Significant genetic differentiation between all four populations was observed. PMID:25102032

  18. [HIV infection in tuberculosis patients in Madagascar. Situation in 1-93].

    PubMed

    Morvan, J M; Auregan, G; Rasamindrakotroka, A J; de Ravel, T; Roux, J F

    1994-01-01

    In Madagascar, the estimated incidence of tuberculosis is high (320 per 100,000) when human immunodeficiency virus (VIH) infection progress slowly. The authors have studied HIV seroprevalence in a group of tubercular patients and in two reference groups (general population and outpatients of the Clinical Biology Centre of Institut Pasteur). Circulation of HIV1 virus was observed with a low prevalence rate in all the 3 groups. There was no significant difference between tubercular patients and healthy population. Tubercular people ought to be a watch group for the epidemiological surveillance of HIV infection evolution in Madagascar. PMID:7575038

  19. An Unexpected Recurrent Transmission of Rift Valley Fever Virus in Cattle in a Temperate and Mountainous Area of Madagascar

    PubMed Central

    Chevalier, Veronique; Rakotondrafara, Toky; Jourdan, Marion; Heraud, Jean Michel; Andriamanivo, Harena Rasamoelina; Durand, Benoit; Ravaomanana, Julie; Rollin, Pierre E.; Rakotondravao, René

    2011-01-01

    Rift Valley fever is an acute, zoonotic viral disease of domestic ruminants, caused by a phlebovirus (Bunyaviridae family). A large outbreak occurred in Madagascar in 2008–2009. The goal of the present study was to evaluate the point prevalence of antibodies against Rift Valley Fever Virus (RVFV) in cattle in the Anjozorobe district, located in the wet and temperate highland region of Madagascar and yet heavily affected by the disease, and analyse environmental and trade factors potentially linked to RVFV transmission. A serological study was performed in 2009 in 894 bovines. For each bovine, the following variables were recorded: age, location of the night pen, minimum distance from the pen to the nearest water point and the forest, nearest water point type, and herd replacement practices. The serological data were analyzed using a generalized linear mixed model. The overall anti-RVFV IgG seroprevalence rate was 28% [CI95% 25–31]. Age was statistically linked to prevalence (p = 10−4), being consistent with a recurrent RVFV circulation. Distance from the night pen to the nearest water point was a protective factor (p = 5.10−3), which would be compatible with a substantial part of the virus transmission being carried out by nocturnal mosquito vectors. However, water point type did not influence the risk of infection: several mosquito species are probably involved. Cattle belonging to owners who purchase animals to renew the herd were significantly more likely to have seroconverted than others (p = 0.04): cattle trade may contribute to the introduction of the virus in this area. The minimum distance of the night pen to the forest was not linked to the prevalence. This is the first evidence of a recurrent transmission of RVFV in such an ecosystem that associates a wet, temperate climate, high altitude, paddy fields, and vicinity to a dense rain forest. Persistence mechanisms need to be further investigated. PMID:22206026

  20. Flexural Rigidity of the Lithosphere as a Powerful Tool for the Continental Correlation: A study on the Paleo-fit of India and Madagascar

    NASA Astrophysics Data System (ADS)

    Ratheesh Kumar, R. T.

    2014-12-01

    The temporal evolution and spatial configuration of continents can be analyzed through their response to long-term forces, as a function of the elastic property of the lithosphere, which is parameterized as effective elastic thickness (Te). The Te method has been widely used as a key proxy to examine the long-term strength/rigidity structure of the lithosphere. The present study employs the gravity inversion and flexure inversion techniques that operate in spatial domain in order to estimate the spatial variation of Te as well as the Moho configuration along the western continental margins of India (WCMI) and eastern continental margin of Madagascar (ECMM). The main objective of the present study is to understand the nature of isostasy and structure of the lithosphere along these conjugate passive margins. The results correlate well with the continental and oceanic regional-scale structures including ridges and basins in the WCMI and ECMM that reveal their mode of evolution. This study obtained comparable results from both the passive margins such as a linear zone of anomalously low-Te (1-5 km) along the WCMI (~1680 km long), which exactly correlates with the low-Te patterns obtained all along the ECMM. These low-Te zones along the passive margins are attributed as paleo-rift inception points of lithosphere thermally and mechanically weakened by the combined effects of the Marion hotspot and lithospheric extension due to rifting. When these conjugate passive margins were correlated by matching the mirrored low-Te linear zones, obtained a best fit position of Madagascar against India during the Gondwana Rifting time. The hence derived India-Madagascar paleo-fit model is well justified by the best close-fit of the crustal geometry and bathymetry of the continental shelf margins, and also by the matching of tectonic lineaments, lithology and geochronological belts along the margins of both the continents.

  1. Delimiting Species without Nuclear Monophyly in Madagascar's Mouse Lemurs

    PubMed Central

    Weisrock, David W.; Rasoloarison, Rodin M.; Fiorentino, Isabella; Ralison, José M.; Goodman, Steven M.; Kappeler, Peter M.; Yoder, Anne D.

    2010-01-01

    Background Speciation begins when populations become genetically separated through a substantial reduction in gene flow, and it is at this point that a genetically cohesive set of populations attain the sole property of species: the independent evolution of a population-level lineage. The comprehensive delimitation of species within biodiversity hotspots, regardless of their level of divergence, is important for understanding the factors that drive the diversification of biota and for identifying them as targets for conservation. However, delimiting recently diverged species is challenging due to insufficient time for the differential evolution of characters—including morphological differences, reproductive isolation, and gene tree monophyly—that are typically used as evidence for separately evolving lineages. Methodology In this study, we assembled multiple lines of evidence from the analysis of mtDNA and nDNA sequence data for the delimitation of a high diversity of cryptically diverged population-level mouse lemur lineages across the island of Madagascar. Our study uses a multi-faceted approach that applies phylogenetic, population genetic, and genealogical analysis for recognizing lineage diversity and presents the most thoroughly sampled species delimitation of mouse lemur ever performed. Conclusions The resolution of a large number of geographically defined clades in the mtDNA gene tree provides strong initial evidence for recognizing a high diversity of population-level lineages in mouse lemurs. We find additional support for lineage recognition in the striking concordance between mtDNA clades and patterns of nuclear population structure. Lineages identified using these two sources of evidence also exhibit patterns of population divergence according to genealogical exclusivity estimates. Mouse lemur lineage diversity is reflected in both a geographically fine-scaled pattern of population divergence within established and geographically widespread taxa, as well as newly resolved patterns of micro-endemism revealed through expanded field sampling into previously poorly and well-sampled regions. PMID:20360988

  2. Economic Valuation of Subsistence Harvest of Wildlife in Madagascar

    PubMed Central

    Golden, Christopher D.; Bonds, Matthew H.; Brashares, Justin S.; Rasolofoniaina, B. J. Rodolph; Kremen, Claire

    2014-01-01

    Wildlife consumption can be viewed as an ecosystem provisioning service (the production of a material good through ecological functioning) because of wildlife’s ability to persist under sustainable levels of harvest. We used the case of wildlife harvest and consumption in northeastern Madagascar to identify the distribution of these services to local households and communities to further our understanding of local reliance on natural resources. We inferred these benefits from demand curves built with data on wildlife sales transactions. On average, the value of wildlife provisioning represented 57% of annual household cash income in local communities from the Makira Natural Park and Masoala National Park, and harvested areas produced an economic return of U.S.$0.42 ha−1 · year−1. Variability in value of harvested wildlife was high among communities and households with an approximate 2 orders of magnitude difference in the proportional value of wildlife to household income. The imputed price of harvested wildlife and its consumption were strongly associated (p< 0.001), and increases in price led to reduced harvest for consumption. Heightened monitoring and enforcement of hunting could increase the costs of harvesting and thus elevate the price and reduce consumption of wildlife. Increased enforcement would therefore be beneficial to biodiversity conservation but could limit local people’s food supply. Specifically, our results provide an estimate of the cost of offsetting economic losses to local populations from the enforcement of conservation policies. By explicitly estimating the welfare effects of consumed wildlife, our results may inform targeted interventions by public health and development specialists as they allocate sparse funds to support regions, households, or individuals most vulnerable to changes in access to wildlife. PMID:24405165

  3. Human and environmental controls over aboveground carbon storage in Madagascar

    PubMed Central

    2012-01-01

    Background Accurate, high-resolution mapping of aboveground carbon density (ACD, Mg C ha-1) could provide insight into human and environmental controls over ecosystem state and functioning, and could support conservation and climate policy development. However, mapping ACD has proven challenging, particularly in spatially complex regions harboring a mosaic of land use activities, or in remote montane areas that are difficult to access and poorly understood ecologically. Using a combination of field measurements, airborne Light Detection and Ranging (LiDAR) and satellite data, we present the first large-scale, high-resolution estimates of aboveground carbon stocks in Madagascar. Results We found that elevation and the fraction of photosynthetic vegetation (PV) cover, analyzed throughout forests of widely varying structure and condition, account for 27-67% of the spatial variation in ACD. This finding facilitated spatial extrapolation of LiDAR-based carbon estimates to a total of 2,372,680 ha using satellite data. Remote, humid sub-montane forests harbored the highest carbon densities, while ACD was suppressed in dry spiny forests and in montane humid ecosystems, as well as in most lowland areas with heightened human activity. Independent of human activity, aboveground carbon stocks were subject to strong physiographic controls expressed through variation in tropical forest canopy structure measured using airborne LiDAR. Conclusions High-resolution mapping of carbon stocks is possible in remote regions, with or without human activity, and thus carbon monitoring can be brought to highly endangered Malagasy forests as a climate-change mitigation and biological conservation strategy. PMID:22289685

  4. Economic valuation of subsistence harvest of wildlife in Madagascar.

    PubMed

    Golden, Christopher D; Bonds, Matthew H; Brashares, Justin S; Rasolofoniaina, B J Rodolph; Kremen, Claire

    2014-02-01

    Wildlife consumption can be viewed as an ecosystem provisioning service (the production of a material good through ecological functioning) because of wildlife's ability to persist under sustainable levels of harvest. We used the case of wildlife harvest and consumption in northeastern Madagascar to identify the distribution of these services to local households and communities to further our understanding of local reliance on natural resources. We inferred these benefits from demand curves built with data on wildlife sales transactions. On average, the value of wildlife provisioning represented 57% of annual household cash income in local communities from the Makira Natural Park and Masoala National Park, and harvested areas produced an economic return of U.S.$0.42 ha(-1) · year(-1). Variability in value of harvested wildlife was high among communities and households with an approximate 2 orders of magnitude difference in the proportional value of wildlife to household income. The imputed price of harvested wildlife and its consumption were strongly associated (p< 0.001), and increases in price led to reduced harvest for consumption. Heightened monitoring and enforcement of hunting could increase the costs of harvesting and thus elevate the price and reduce consumption of wildlife. Increased enforcement would therefore be beneficial to biodiversity conservation but could limit local people's food supply. Specifically, our results provide an estimate of the cost of offsetting economic losses to local populations from the enforcement of conservation policies. By explicitly estimating the welfare effects of consumed wildlife, our results may inform targeted interventions by public health and development specialists as they allocate sparse funds to support regions, households, or individuals most vulnerable to changes in access to wildlife. PMID:24405165

  5. Understanding Mortality and the Life of the Ancestors in Rural Madagascar

    ERIC Educational Resources Information Center

    Astuti, Rita; Harris, Paul L.

    2008-01-01

    Across two studies, a wide age range of participants was interviewed about the nature of death. All participants were living in rural Madagascar in a community where ancestral beliefs and practices are widespread. In Study 1, children (8-17 years) and adults (19-71 years) were asked whether bodily and mental processes continue after death. The…

  6. Diverse Genotypes of Yersinia pestis Caused Plague in Madagascar in 2007

    PubMed Central

    Rajerison, Minoaerisoa; Andersen, Genevieve; Hall, Carina M.; Zimmermann, Thomas; Soanandrasana, Rahelinirina; Andrianaivoarimanana, Voahangy; Straubinger, Reinhard K.; Nottingham, Roxanne; Keim, Paul; Wagner, David M.; Scholz, Holger C.

    2015-01-01

    Background Yersinia pestis is the causative agent of human plague and is endemic in various African, Asian and American countries. In Madagascar, the disease represents a significant public health problem with hundreds of human cases a year. Unfortunately, poor infrastructure makes outbreak investigations challenging. Methodology/Principal Findings DNA was extracted directly from 93 clinical samples from patients with a clinical diagnosis of plague in Madagascar in 2007. The extracted DNAs were then genotyped using three molecular genotyping methods, including, single nucleotide polymorphism (SNP) typing, multi-locus variable-number tandem repeat analysis (MLVA), and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) analysis. These methods provided increasing resolution, respectively. The results of these analyses revealed that, in 2007, ten molecular groups, two newly described here and eight previously identified, were responsible for causing human plague in geographically distinct areas of Madagascar. Conclusions/Significance Plague in Madagascar is caused by numerous distinct types of Y. pestis. Genotyping method choice should be based upon the discriminatory power needed, expense, and available data for any desired comparisons. We conclude that genotyping should be a standard tool used in epidemiological investigations of plague outbreaks. PMID:26069964

  7. Which Advisory System to Support Innovation in Conservation Agriculture? The Case of Madagascar's Lake Alaotra

    ERIC Educational Resources Information Center

    Faure, Guy; Penot, Eric; Rakotondravelo, Jean Chrysostome; Ramahatoraka, Haja Andrisoa; Dugue, Patrick; Toillier, Aurelie

    2013-01-01

    Purpose: To promote sustainable agriculture, various development projects are encouraging farmers around Madagascar's Lake Alaotra to adopt conservation agriculture techniques. This article's objective is to analyze the capacity of a project-funded advisory system to accompany such an innovation and to design and implement an advisory method aimed…

  8. Home Sweet Home: How to Build a Madagascar Hissing Cockroach Habitat out of Recycled Materials

    ERIC Educational Resources Information Center

    Wagler, Ron

    2010-01-01

    Madagascar hissing cockroaches (MHC) are amazing insects that can be an integral part of an effective science learning and teaching environment. MHCs have a fascinating social structure. They make excellent pets, teach students how to properly care for animals, and their large size adds to their "wow" factor. These characteristics make them unique…

  9. Which Advisory System to Support Innovation in Conservation Agriculture? The Case of Madagascar's Lake Alaotra

    ERIC Educational Resources Information Center

    Faure, Guy; Penot, Eric; Rakotondravelo, Jean Chrysostome; Ramahatoraka, Haja Andrisoa; Dugue, Patrick; Toillier, Aurelie

    2013-01-01

    Purpose: To promote sustainable agriculture, various development projects are encouraging farmers around Madagascar's Lake Alaotra to adopt conservation agriculture techniques. This article's objective is to analyze the capacity of a project-funded advisory system to accompany such an innovation and to design and implement an advisory method aimed

  10. Dispersing towards Madagascar: Biogeography and evolution of the Madagascan endemics of the Spermacoceae tribe (Rubiaceae).

    PubMed

    Janssens, Steven B; Groeninckx, Inge; De Block, Petra J; Verstraete, Brecht; Smets, Erik F; Dessein, Steven

    2016-02-01

    Despite the close proximity of the African mainland, dispersal of plant lineages towards Madagascar remains intriguing. The composition of the Madagascan flora is rather mixed and shows besides African representatives, also floral elements of India, Southeast Asia, Australia, and the Neotropics. Due to its proportionally large number of Madagascan endemics, the taxonomically troublesome Spermacoceae tribe is an interesting group to investigate the origin and evolution of the herbaceous Rubiaceae endemic to Madagascar. The phylogenetic position of these endemics were inferred using four plastid gene markers. Age estimates were obtained by expanding the Spermacoceae dataset with representatives of all Rubiaceae tribes. This allowed incorporation of multiple fossil-based calibration points from the Rubiaceae fossil record. Despite the high morphological diversity of the endemic herbaceous Spermacoceae on Madagascar, only two colonization events gave rise to their current diversity. The first clade contains Lathraeocarpa, Phylohydrax and Gomphocalyx, whereas the second Madagascan clade includes the endemic genera Astiella, Phialiphora, Thamnoldenlandia and Amphistemon. The tribe Spermacoceae is estimated to have a Late Eocene origin, and diversified during Oligocene and Miocene. The two Madagascan clades of the tribe originated in the Oligocene and radiated in the Miocene. The origin of the Madagascan Spermacoceae cannot be explained by Gondwanan vicariance but only by means of Cenozoic long distance dispersal events. Interestingly, not only colonization from Africa occurred but also long distance dispersal from the Neotropics shaped the current diversity of the Spermacoceae tribe on Madagascar. PMID:26639100

  11. Understanding Mortality and the Life of the Ancestors in Rural Madagascar

    ERIC Educational Resources Information Center

    Astuti, Rita; Harris, Paul L.

    2008-01-01

    Across two studies, a wide age range of participants was interviewed about the nature of death. All participants were living in rural Madagascar in a community where ancestral beliefs and practices are widespread. In Study 1, children (8-17 years) and adults (19-71 years) were asked whether bodily and mental processes continue after death. The

  12. Examining the Environmental Awareness of Children and Adolescents in the Ranomafana Region, Madagascar

    ERIC Educational Resources Information Center

    Korhonen, Kaisa; Lappalainen, Anu

    2004-01-01

    This paper examines children's and adolescents' environmental awareness in rural Madagascar. Two types of school survey among 8- to 21-year-old students and pupils in 18 schools were used for data collection. The objective of this comparative study was to examine the environmental awareness and knowledge of children and adolescents living under

  13. THE subfossil occurrence and paleoecological significance of small mammals at ankilitelo cave, southwestern Madagascar

    USGS Publications Warehouse

    Muldoon, K.M.; De Blieux, D. D.; Simons, E.L.; Chatrath, P.S.

    2009-01-01

    Small mammals are rarely reported from subfossil sites in Madagascar despite their importance for paleoenvironmental reconstruction, especially as it relates to recent ecological changes on the island. We describe the uniquely rich subfossil small mammal fauna from Ankilitelo Cave, southwestern Madagascar. The Ankilitelo fauna is dated to the late Holocene (???500 years ago), documenting the youngest appearances of the extinct giant lemur taxa Palaeopropithecus, Megaladapis, and Archaeolemur, in association with abundant remains of small vertebrates, including bats, tenrecs, carnivorans, rodents, and primates. The Ankilitelo fauna is composed of 34 mammalian species, making it one of the most diverse Holocene assemblages in Madagascar. The fauna comprises the 1 st report of the short-tailed shrew tenrec (Microgale brevicaudata) and the ring-tailed mongoose (Galidia elegans) in southwestern Madagascar. Further, Ankilitelo documents the presence of southwestern species that are rare or that have greatly restricted ranges today, such as Nasolo's shrew tenrec (M. nasoloi), Grandidier's mongoose (Galidictis grandidieri), the narrow-striped mongoose (Mungotictis decemlineata), and the giant jumping rat (Hypogeomys antimena). A simple cause for the unusual small mammal occurrences at Ankilitelo is not obvious. Synergistic interactions between climate change, recent fragmentation and human-initiated degradation of forested habitats, and community-level processes, such as predation, most likely explain the disjunct distributions of the small mammals documented at Ankilitelo. ?? 2009 American Society of Mammalogists.

  14. Genetics of the Pig Tapeworm in Madagascar Reveal a History of Human Dispersal and Colonization

    PubMed Central

    Yanagida, Tetsuya; Carod, Jean-Franois; Sako, Yasuhito; Nakao, Minoru; Hoberg, Eric P.; Ito, Akira

    2014-01-01

    An intricate history of human dispersal and geographic colonization has strongly affected the distribution of human pathogens. The pig tapeworm Taenia solium occurs throughout the world as the causative agent of cysticercosis, one of the most serious neglected tropical diseases. Discrete genetic lineages of T. solium in Asia and Africa/Latin America are geographically disjunct; only in Madagascar are they sympatric. Linguistic, archaeological and genetic evidence has indicated that the people in Madagascar have mixed ancestry from Island Southeast Asia and East Africa. Hence, anthropogenic introduction of the tapeworm from Southeast Asia and Africa had been postulated. This study shows that the major mitochondrial haplotype of T. solium in Madagascar is closely related to those from the Indian Subcontinent. Parasitological evidence presented here, and human genetics previously reported, support the hypothesis of an Indian influence on Malagasy culture coinciding with periods of early human migration onto the island. We also found evidence of nuclear-mitochondrial discordance in single tapeworms, indicating unexpected cross-fertilization between the two lineages of T. solium. Analyses of genetic and geographic populations of T. solium in Madagascar will shed light on apparently rapid evolution of this organism driven by recent (<2,000 yr) human migrations, following tens of thousands of years of geographic isolation. PMID:25329310

  15. Home Sweet Home: How to Build a Madagascar Hissing Cockroach Habitat out of Recycled Materials

    ERIC Educational Resources Information Center

    Wagler, Ron

    2010-01-01

    Madagascar hissing cockroaches (MHC) are amazing insects that can be an integral part of an effective science learning and teaching environment. MHCs have a fascinating social structure. They make excellent pets, teach students how to properly care for animals, and their large size adds to their "wow" factor. These characteristics make them unique

  16. Examining the Environmental Awareness of Children and Adolescents in the Ranomafana Region, Madagascar

    ERIC Educational Resources Information Center

    Korhonen, Kaisa; Lappalainen, Anu

    2004-01-01

    This paper examines children's and adolescents' environmental awareness in rural Madagascar. Two types of school survey among 8- to 21-year-old students and pupils in 18 schools were used for data collection. The objective of this comparative study was to examine the environmental awareness and knowledge of children and adolescents living under…

  17. Drug-Resistant Malaria Parasites Introduced into Madagascar from Comoros Islands

    PubMed Central

    Randrianarivo-Solofoniaina, Armand Eugène; Ahmed, Bedja Said; Jahevitra, Martial; Andriantsoanirina, Landy Valérie; Rasolofomanana, Justin Ranjalahy; Rabarijaona, Léon Paul

    2007-01-01

    To determine risk for drug-resistant malaria parasites entering Madagascar from Comoros Islands, we screened travelers. For the 141 Plasmodium falciparum isolates detected by real-time PCR, frequency of mutant alleles of genes associated with resistance to chloroquine and pyrimethamine was high. International-level antimalarial policy and a regional antimalarial forum are needed. PMID:18217565

  18. Large-Scale Habitat Corridors for Biodiversity Conservation: A Forest Corridor in Madagascar

    PubMed Central

    Ramiadantsoa, Tanjona; Ovaskainen, Otso; Rybicki, Joel; Hanski, Ilkka

    2015-01-01

    In biodiversity conservation, habitat corridors are assumed to increase landscape-level connectivity and to enhance the viability of otherwise isolated populations. While the role of corridors is supported by empirical evidence, studies have typically been conducted at small spatial scales. Here, we assess the quality and the functionality of a large 95-km long forest corridor connecting two large national parks (416 and 311 km2) in the southeastern escarpment of Madagascar. We analyze the occurrence of 300 species in 5 taxonomic groups in the parks and in the corridor, and combine high-resolution forest cover data with a simulation model to examine various scenarios of corridor destruction. At present, the corridor contains essentially the same communities as the national parks, reflecting its breadth which on average matches that of the parks. In the simulation model, we consider three types of dispersers: passive dispersers, which settle randomly around the source population; active dispersers, which settle only in favorable habitat; and gap-avoiding active dispersers, which avoid dispersing across non-habitat. Our results suggest that long-distance passive dispersers are most sensitive to ongoing degradation of the corridor, because increasing numbers of propagules are lost outside the forest habitat. For a wide range of dispersal parameters, the national parks are large enough to sustain stable populations until the corridor becomes severely broken, which will happen around 2065 if the current rate of forest loss continues. A significant decrease in gene flow along the corridor is expected after 2040, and this will exacerbate the adverse consequences of isolation. Our results demonstrate that simulation studies assessing the role of habitat corridors should pay close attention to the mode of dispersal and the effects of regional stochasticity. PMID:26200351

  19. In or out-of-Madagascar?--Colonization patterns for large-bodied diving beetles (Coleoptera: Dytiscidae).

    PubMed

    Bukontaite, Rasa; Ranarilalatiana, Tolotra; Randriamihaja, Jacquelin Herisahala; Bergsten, Johannes

    2015-01-01

    High species diversity and endemism within Madagascar is mainly the result of species radiations following colonization from nearby continents or islands. Most of the endemic taxa are thought to be descendants of a single or small number of colonizers that arrived from Africa sometime during the Cenozoic and gave rise to highly diverse groups. This pattern is largely based on vertebrates and a small number of invertebrate groups. Knowledge of the evolutionary history of aquatic beetles on Madagascar is lacking, even though this species-rich group is often a dominant part of invertebrate freshwater communities in both standing and running water. Here we focus on large bodied diving beetles of the tribes Hydaticini and Cybistrini. Our aims with this study were to answer the following questions 1) How many colonization events does the present Malagasy fauna originate from? 2) Did any colonization event lead to a species radiation? 3) Where did the colonizers come from--Africa or Asia--and has there been any out-of-Madagascar event? 4) When did these events occur and were they concentrated to any particular time interval? Our results suggest that neither in Hydaticini nor in Cybistrini was there a single case of two or more endemic species forming a monophyletic group. The biogeographical analysis indicated different colonization histories for the two tribes. Cybistrini required at least eight separate colonization events, including the non-endemic species, all comparatively recent except the only lotic (running water) living Cybister operosus with an inferred colonization at 29 Ma. In Hydaticini the Madagascan endemics were spread out across the tree, often occupying basal positions in different species groups. The biogeographical analyses therefore postulated the very bold hypothesis of a Madagascan origin at a very deep basal node within Hydaticus and multiple out-of-Madagascar dispersal events. This hypothesis needs to be tested with equally intense taxon sampling of mainland Africa as for Madagascar. PMID:25794184

  20. Madagascar corals reveal a multidecadal signature of rainfall and river runoff since 1708

    NASA Astrophysics Data System (ADS)

    Grove, C. A.; Zinke, J.; Peeters, F.; Park, W.; Scheufen, T.; Kasper, S.; Randriamanantsoa, B.; McCulloch, M. T.; Brummer, G.-J. A.

    2013-03-01

    Pacific Ocean sea surface temperatures (SST) influence rainfall variability on multidecadal and interdecadal timescales in concert with the Pacific Decadal Oscillation (PDO) and Interdecadal Pacific Oscillation (IPO). Rainfall variations in locations such as Australia and North America are therefore linked to phase changes in the PDO. Furthermore, studies have suggested teleconnections exist between the western Indian Ocean and Pacific Decadal Variability (PDV), similar to those observed on interannual timescales related to the El Nio Southern Oscillation (ENSO). However, as instrumental records of rainfall are too short and sparse to confidently assess multidecadal climatic teleconnections, here we present four coral climate archives from Madagascar spanning up to the past 300 yr (1708-2008) to assess such decadal variability. Using spectral luminescence scanning to reconstruct past changes in river runoff, we identify significant multidecadal and interdecadal frequencies in the coral records, which before 1900 are coherent with Asian-based PDO reconstructions. This multidecadal relationship with the Asian-based PDO reconstructions points to an unidentified teleconnection mechanism that affects Madagascar rainfall/runoff, most likely triggered by multidecadal changes in North Pacific SST, influencing the Asian Monsoon circulation. In the 20th century we decouple human deforestation effects from rainfall-induced soil erosion by pairing luminescence with coral geochemistry. Positive PDO phases are associated with increased Indian Ocean temperatures and runoff/rainfall in eastern Madagascar, while precipitation in southern Africa and eastern Australia declines. Consequently, the negative PDO phase that started in 1998 may contribute to reduced rainfall over eastern Madagascar and increased precipitation in southern Africa and eastern Australia. We conclude that multidecadal rainfall variability in Madagascar and the western Indian Ocean needs to be taken into account when considering water resource management under a future warming climate.

  1. A new species of the genus Adapterops (Coleoptera: Anthribidae) from northern Madagascar, with a catalogue and key to species.

    PubMed

    Trzna, Milo; Ba?a?, Petr

    2015-01-01

    Anew species, Adapterops cedrici Trzna & Ba?a? sp. nov. (Anthribidae: Choraginae: Araecerini), from northern Madagascar is described and illustrated. A key and catalogue of the genus Adapterops Frieser, 2010 is given. PMID:26701447

  2. Temporal and Spatial Evolution of Dynamic Support From River Profiles: A Framework for Madagascar and Africa

    NASA Astrophysics Data System (ADS)

    Paul, J. D.; Roberts, G. G.; White, N.

    2012-04-01

    It is generally accepted that the surface topography of Africa is a manifestation of convective circulation in the sub-lithospheric mantle. Here, we present an inverse method whereby longitudinal river profiles are interrogated to extract quantitative estimates of spatial and temporal variations in the rate of tectonic uplift. Surface processes can provide an important window into transient convective circulation in the sub-lithospheric mantle. River profiles act as 'tectonic tape recorders': we assume the generation of broad, convex-upward knickzones to represent the effect of tectonic uplift shifting the river system into a state of disequilibrium. Profiles evolve through time primarily via the headward retreat of these knickzones. We use a conjugate gradient inverse algorithm to minimise the misfit between observed river profiles - derived from a regional Digital Elevation Model (DEM) - and calculated profiles obtained by varying the uplift rate history. We jointly invert a total of 98 Malagasy and 570 African river profiles to obtain a history of the cumulative tectonic uplift through geological time. We show that Africa has undergone two phases of rapid uplift: first in Eocene times; secondly, since 10 Ma. While the first gave rise to broad, long wavelength topography, the second led to more localised domal swells of high relief. We propose the existence of two wavelengths of dynamic support, reflecting a change in the style of convection in the upper mantle since 50 Ma. Our results correlate strongly with independent geological estimates of uplift across Africa and Madagascar, while our calculated landscape surface following 50 Myr of uplift corresponds closely to a surface fit across present-day drainage divides. Finally we calculate the solid sediment flux delivered to major African deltas as a function of time. This onshore record provides an important indirect constraint on the history of vertical motions at the surface, and agrees well with the offshore flux record, obtained from mapping the thickness of chronostratigraphic sediment packages at the deltas.

  3. Geological evolution of the Antongil Craton, NE Madagascar

    USGS Publications Warehouse

    Schofield, D.I.; Thomas, Ronald J.; Goodenough, K.M.; De Waele, B.; Pitfield, P.E.J.; Key, R.M.; Bauer, W.; Walsh, G.J.; Lidke, D.J.; Ralison, A.V.; Rabarimanana, M.; Rafahatelo, J.-M.; Randriamananjara, T.

    2010-01-01

    The Antongil Craton, along with the Masora and Antananarivo cratons, make up the fundamental Archaean building blocks of the island of Madagascar. They were juxtaposed during the late-Neoproterozoic to early Palaeozoic assembly of Gondwana. In this paper we give a synthesis of the geology of the Antongil Craton and present previously published and new geochemical and U-Pb zircon analyses to provide an event history for its evolution.The oldest rocks in the Antongil Craton form a nucleus of tonalitic gneiss, characteristic of Palaeo-Mesoarchaean cratons globally, including phases dated between 3320 ?? 14. Ma to 3231 ?? 6. Ma and 3187 ?? 2. Ma to 3154 ?? 5. Ma. A series of mafic dykes was intruded into the Mesoarchaean tonalites and a sedimentary succession was deposited on the craton prior to pervasive deformation and migmatisation of the region. The age of deposition of the metasediments has been constrained from a volcanic horizon to around 3178 ?? 2. Ma and subject to migmatisation at around 2597 ?? 49. Ma. A subsequent magmatic episode generated voluminous, weakly foliated granitic rocks, that also included additions from both reworked older crustal material and younger source components. An earlier granodiorite-dominated assemblage, dated between 2570 ?? 18. Ma and 2542 ?? 5. Ma, is largely exposed in xenoliths and more continuously in the northern part of the craton, while a later monzogranite-dominated phase, dated between 2531 ?? 13. Ma and 2513 ?? 0.4. Ma is more widely developed. Together these record the stabilisation of the craton, attested to by the intrusion of a younger dyke swarm, the age of which is constrained by a sample of metagabbro dated at 2147 ?? 6. Ma, providing the first evidence for Palaeoproterozoic rocks from the Antongil Craton.The youngest events recorded in the isotopic record of the Antongil Craton are reflected in metamorphism, neocrystallisation and Pb-loss at 792 ?? 130. Ma to 763 ?? 13. Ma and 553 ?? 68. Ma. These events are interpreted as being the only manifestation of the Pan-African orogeny seen in the craton, which led to the assembly of the tectonic blocks that comprise the island. ?? 2010 NERC.

  4. Accumulation of Monoterpenoid Indole Alkaloids in Periwinkle Seedlings ("Catharanthus roseus") as a Model for the Study of Plant-Environment Interactions

    ERIC Educational Resources Information Center

    Miranda-Ham, Maria de Lourdes; Islas-Flores, Ignacio; Vazquez-Flota, Felipe

    2007-01-01

    Alkaloids are part of the chemical arsenal designed to protect plants against an adverse environment. Therefore, their synthesis and accumulation are frequently induced in response to certain environmental conditions and are mediated by chemical signals, which are formed as the first responses to the external stimulus. A set of experiments using…

  5. Accumulation of Monoterpenoid Indole Alkaloids in Periwinkle Seedlings ("Catharanthus roseus") as a Model for the Study of Plant-Environment Interactions

    ERIC Educational Resources Information Center

    Miranda-Ham, Maria de Lourdes; Islas-Flores, Ignacio; Vazquez-Flota, Felipe

    2007-01-01

    Alkaloids are part of the chemical arsenal designed to protect plants against an adverse environment. Therefore, their synthesis and accumulation are frequently induced in response to certain environmental conditions and are mediated by chemical signals, which are formed as the first responses to the external stimulus. A set of experiments using

  6. Community management of natural resources: a case study from Ankarafantsika National Park, Madagascar.

    PubMed

    Aymoz, Benoît G P; Randrianjafy, Vololomboahangy R; Randrianjafy, Zarasoa J N; Khasa, Damase P

    2013-10-01

    We analyzed the management, resource use and conservation of the Ankarafantsika National Park (Madagascar) to develop a management plan, which provides a sustainable development strategy of the area while empowering the local residents. Using qualitative methodology we performed interviews with villagers and local organizations to assess the park's successes and failures from local stakeholders' perspectives. People living in a village with a permanent Madagascar National Parks (MNP) agent are more favorable to and supportive of the park conservation. People living in the park are supportive but are more divided. On the other hand, people living on the periphery of the park see conservation as more of a burden. Strategies like more equitable distribution of wealth, environment improvement and decentralization of power are discussed to achieve a more sustainable management plan based on community natural resources management. Short-term, medium, and long-term interventions from park authorities are needed to ensure the cooperation of local people in conservation endeavors. PMID:23494265

  7. Epidemiologic features of four successive annual outbreaks of bubonic plague in Mahajanga, Madagascar.

    PubMed

    Boisier, Pascal; Rahalison, Lila; Rasolomaharo, Monique; Ratsitorahina, Maherisoa; Mahafaly, Mahafaly; Razafimahefa, Maminirana; Duplantier, Jean-Marc; Ratsifasoamanana, Lala; Chanteau, Suzanne

    2002-03-01

    From 1995 to 1998, outbreaks of bubonic plague occurred annually in the coastal city of Mahajanga, Madagascar. A total of 1,702 clinically suspected cases of bubonic plague were reported, including 515 laboratory confirmed by Yersinia pestis isolation (297), enzyme-linked immunosorbent assay, or both. Incidence was higher in males and young persons. Most buboes were inguinal, but children had a higher frequency of cervical or axillary buboes. Among laboratory-confirmed hospitalized patients, the case-fatality rate was 7.9%, although all Y. pestis isolates were sensitive to streptomycin, the recommended antibiotic. In this tropical city, plague outbreaks occur during the dry and cool season. Most cases are concentrated in the same crowded and unsanitary districts, a result of close contact among humans, rats, and shrews. Plague remains an important public health problem in Madagascar, and the potential is substantial for spread to other coastal cities and abroad. PMID:11927030

  8. A pug-nosed crocodyliform from the Late Cretaceous of Madagascar.

    PubMed

    Buckley, G A; Brochu, C A; Krause, D W; Pol, D

    2000-06-22

    Although the image of crocodyliforms as 'unchanged living fossils' is naive, several morphological features of the group are thought to have varied only within narrow limits during the course of evolution. These include an elongate snout with an array of conical teeth, a dorsoventrally flattened skull and a posteriorly positioned jaw articulation, which provides a powerful bite force. Here we report an exquisitely preserved specimen of a new taxon from the Late Cretaceous of Madagascar that deviates profoundly from this Bauplan, possessing an extremely blunt snout, a tall, rounded skull, an anteriorly shifted jaw joint and clove-shaped, multicusped teeth reminiscent of those of some ornithischian dinosaurs. This last feature implies that the diet of the new taxon may have been predominantly if not exclusively herbivorous. A close relationship with notosuchid crocodyliforms, particularly Uruguaysuchus (Late Cretaceous, Uruguay) is suggested by several shared derived features; this supports a biogeographical hypothesis that Madagascar and South America were linked during the Late Cretaceous. PMID:10879533

  9. Epidemiologic Features of Four Successive Annual Outbreaks of Bubonic Plague in Mahajanga, Madagascar

    PubMed Central

    Rahalison, Lila; Rasolomaharo, Monique; Ratsitorahina, Maherisoa; Mahafaly, Mahafaly; Razafimahefa, Maminirana; Duplantier, Jean-Marc; Ratsifasoamanana, Lala; Chanteau, Suzanne

    2002-01-01

    From 1995 to 1998, outbreaks of bubonic plague occurred annually in the coastal city of Mahajanga, Madagascar. A total of 1,702 clinically suspected cases of bubonic plague were reported, including 515 laboratory confirmed by Yersinia pestis isolation (297), enzyme-linked immunosorbent assay, or both. Incidence was higher in males and young persons. Most buboes were inguinal, but children had a higher frequency of cervical or axillary buboes. Among laboratory-confirmed hospitalized patients, the case-fatality rate was 7.9%, although all Y. pestis isolates were sensitive to streptomycin, the recommended antibiotic. In this tropical city, plague outbreaks occur during the dry and cool season. Most cases are concentrated in the same crowded and insanitary districts, a result of close contact among humans, rats, and shrews. Plague remains an important public health problem in Madagascar, and the potential is substantial for spread to other coastal cities and abroad. PMID:11927030

  10. Collaboration, cholera, and cyclones: a project to improve point-of-use water quality in Madagascar.

    PubMed

    Dunston, C; McAfee, D; Kaiser, R; Rakotoarison, D; Rambeloson, L; Hoang, A T; Quick, R E

    2001-10-01

    In November 1999, CARE Madagascar, Population Services International (PSI), and the Centers for Disease Control and Prevention (CDC) selected 30 poor communities in urban Antananarivo as the target population for launch of the Safe Water System. The system consists of behavior change techniques along with point-of-use treatment and safe storage of water. The project was launched in March 2000, ahead of schedule, because a cholera epidemic struck Madagascar in January. Because of the enormous demand created by the cholera epidemic and by 3 cyclones that followed in the next 3 months, the project grew to national scale in less than a year. The combination of community mobilization and social marketing resulted in increased demand for and use of the Safe Water System. PMID:11574309

  11. Deforestation history of the eastern rain forests of madagascar from satellite images.

    PubMed

    Green, G M; Sussman, R W

    1990-04-13

    Madagascar is biologically one of the richest areas on Earth, and its plants and animals are among the most endangered. Satellite images and vegetation maps based on earlier aerial photographs were used to determine the extent of eastern rain forests in Madagascar and to monitor the rate of deforestation over a 35-year period. In 1985, 3.8 million hectares of rain forest remained, representing only 50 percent of the 7.6 million hectares existing in 1950 and 34 percent of the estimated orignal extent (11.2 million hectares). Between 1950 and 1985, the rate of deforestation averaged 111,000 hectares per year. Deforestation was most rapid in areas with low topographic relief and high population density. If cutting of forests continues at the same pace, only forests on the steepest slopes will survive the next 35 years. PMID:17740137

  12. Deforestation history of the eastern rain forests of Madagascar from satellite images

    SciTech Connect

    Green, G.M.; Sussman, R.W. )

    1990-04-13

    Madagascar is biologically one of the richest areas on Earth, and its plants and animals are among the most endangered. Satellite images and vegetation maps based on earlier aerial photographs were used to determine the extent of eastern rain forests in Madagascar and to monitor the rate of deforestation over a 35-year period. In 1985, 3.8 million hectares of rain forest remained, representing only 50% of the 7.6 million hectares existing in 1950 and 34% of the estimated original extent (11.2 million hectares). Between 1950 and 1985, the rate of deforestation averaged 111,000 hectares per year. Deforestation was most rapid in areas with low topographic relief and high population density. If cutting of forests continues at the same pace, only forests on the steepest slopes will survive the next 35 years.

  13. A likely microendemic new species of terrestrial iguana, genus Chalarodon, from Madagascar.

    PubMed

    Miralles, Aurelien; Glaw, Frank; Ratsoavina, Fanomezana M; Vences, Miguel

    2015-01-01

    A new species of the hitherto monotypic genus Chalarodon is described from southern Madagascar and a lectotype (ZMB 4360) is designated for C. madagascariensis Peters, 1854. The new species of terrestrial iguana, Chalarodon steinkampi sp. nov., is defined by several morphological characters and by concordant differentiation in mitochondrial and nuclear DNA with >5% uncorrected pairwise genetic distance in the 16S rRNA gene. It can be most clearly recognized by the presence of smooth (vs. keeled) gular and ventral scales, a spotted pattern extending from flanks onto belly, and an unpigmented throat. The new species is known from only a small area between the villages of Amboasary Sud and Esomony, located west of the Andohahela Massif, while C. madagascariensis appears to be widespread over much of southern and western Madagascar. We highlight the need for further exploration of this unprotected region which might host several other microendemic species. PMID:25947685

  14. Discovery of an island population of dwarf lemurs (Cheirogaleidae: Cheirogaleus) on Nosy Hara, far northern Madagascar.

    PubMed

    Gardner, Charlie J; Jasper, Louise D

    2015-10-01

    The species-level diversity of Madagascar's lemurs has increased hugely over the last two decades, growing from 32 species in 1994 to 102 species in 2014. This growth is primarily due to the application of molecular phylogenetic analyses and the phylogenetic species concept to known populations, and few previously unknown lemur populations have been discovered during this time. We report on a new population of dwarf lemurs (Cheirogaleus sp.) from Nosy Hara, a 312-ha island in far northern Madagascar, which constitutes the northernmost distribution record for the genus. The dwarf lemurs appeared to show two characteristics of island populations-insular dwarfism and predator navet-that suggest a long isolation, and may thus represent an undescribed taxon. If this is the case, the dwarf lemurs of Nosy Hara are probably one of the rarest primate taxa on Earth. PMID:26243504

  15. Raising awareness of amphibian Chytridiomycosis will not alienate ecotourists visiting Madagascar.

    PubMed

    Wollenberg, Katharina C; Jenkins, Richard K B; Randrianavelona, Roma; Ralisata, Mahefa; Rampilamanana, Roseline; Ramanandraibe, Andrianirina; Ravoahangimalala, Olga Ramilijaona; Vences, Miguel

    2010-06-01

    Chytridiomycosis (Bd) is contributing to amphibian extinctions worldwide but has so far not been detected in Madagascar. The high likelihood for Bd to spread to the island and efface this amphibian diversity and endemism hotspot requires respective conservation policies to be developed. Bd could be introduced by the large number of tourists that visit protected areas; therefore, increasing awareness among tourists and encouraging them to participate in safety measures should be a priority conservation action. However, concerns have been raised that tourists would not be able to distinguish between an amphibian disease harmless to humans and emerging diseases that would imply a danger for human health, invoking a negative image of Madagascar as an ecotourism destination. We evaluated whether informing tourists about this infectious animal disease would cause health scare and diminish trip satisfaction. Based on 659 respondents we found that most ecotourists favored to be informed about Bd and were proactive about participating in prevention measures, refuting previous concerns. PMID:20517634

  16. Neoproterozoic extension in the greater dharwar craton: A reevaluation of the "betsimisaraka suture" in madagascar

    USGS Publications Warehouse

    Tucker, R.D.; Roig, J.-Y.; Delor, C.; Amlin, Y.; Goncalves, P.; Rabarimanana, M.H.; Ralison, A.V.; Belcher, R.W.

    2011-01-01

    The Precambrian shield of Madagascar is reevaluated with recently compiled geological data and new U-Pb sensitive high-resolution ion microprobe (SHRIMP) geochronology. Two Archean domains are recognized: the eastern Antongil-Masora domain and the central Antananarivo domain, the latter with distinctive belts of metamafic gneiss and schist (Tsaratanana Complex). In the eastern domain, the period of early crust formation is extended to the Paleo-Mesoarchean (3.32-3.15 Ga) and a supracrustal sequence (Fenerivo Group), deposited at 3.18 Ga and metamorphosed at 2.55 Ga, is identified. In the central domain, a Neoarchean period of high-grade metamorphism and anatexis that affected both felsic (Betsiboka Suite) and mafic gneisses (Tsaratanana Complex) is documented. We propose, therefore, that the Antananarivo domain was amalgamated within the Greater Dharwar Craton (India + Madagascar) by a Neoarchean accretion event (2.55-2.48 Ga), involving emplacement of juvenile igneous rocks, high-grade metamorphism, and the juxtaposition of disparate belts of mafic gneiss and schist (metagreenstones). The concept of the "Betsimisaraka suture" is dispelled and the zone is redefined as a domain of Neoproterozoic metasedimentary (Manampotsy Group) and metaigneous rocks (Itsindro-Imorona Suite) formed during a period of continental extension and intrusive igneous activity between 840 and 760 Ma. Younger orogenic convergence (560-520 Ma) resulted in east-directed overthrusting throughout south Madagascar and steepening with local inversion of the domain in central Madagascar. Along part of its length, the Manampotsy Group covers the boundary between the eastern and central Archean domains and is overprinted by the Angavo-Ifanadiana high-strain zone that served as a zone of crustal weakness throughout Cretaceous to Recent times.

  17. Ecology and Conservation Status of Indian Ocean Humpback Dolphins (Sousa plumbea) in Madagascar.

    PubMed

    Cerchio, Salvatore; Andrianarivelo, Norbert; Andrianantenaina, Boris

    2015-01-01

    The Indian Ocean humpback dolphin (Sousa plumbea) has been studied in several range states in the Southwest Indian Ocean, however little information exists on populations in Madagascar. Here, we review available literature and describe a study on S. plumbea conducted between 2004 and 2013 on the west coast of Madagascar, involving boat-based field surveys in the southwest and northwest regions, and interview surveys with local fishers from villages along most of the west coast. Field surveys in the southwest region of Anakao/St. Augustine Bay revealed low encounter rates and mean group size, and markedly declining trends in both from 1999 to 2013. Conversely, in the northwest region around Nosy Be and Nosy Iranja, encounter rates were higher, as were mean group sizes, suggesting an apparently more abundant and less impacted population. Interview surveys revealed by-catch of coastal dolphins along the entire west coast, including S. plumbea, as well as other species. Directed hunting, including drive hunts of groups of dolphins, was reported primarily in the southern regions, in the range of the Vezo Malagasy ethnicity; however, there was evidence of hunting starting in one area in the northwest, where hunting dolphins is normally considered taboo for the predominant Sakalava ethnicity. Thus, the conservation status of S. plumbea in Madagascar appears to be spatially heterogeneous, with some areas where the local population is apparently more impacted than others. Conservation measures are recommended to mitigate further decline in the southwest of Madagascar, while protecting habitat and ensuring resilience in the northwest. PMID:26555626

  18. [Juvenile recto-colonic polyposis. Apropos of a case in Madagascar].

    PubMed

    Alandry, G; Le Quellec, B; Philippon, G; Gouot, E; Ribault, L

    1987-01-01

    The authors relate the first case of juvenile polyposis coli noticed in Madagascar. It is a sporadic case developing a serious clinic picture with an accidentally fatal end in a 7 years old Malagasy girl. They recall the principal epidemiological, anatomopathological, clinic and evolutive features which are typical of this polyposis. They wish that the way to medical progress will soon lead to better knowledge of the place of the intestinal polyposis in African countries. PMID:3586969

  19. Research, valorization and exploitation of biological resources for medicinal purposes in the Malagasy Republic (Madagascar).

    PubMed

    Randimbivololona, F

    1996-04-01

    Medicinal plants are widely used for treatment of diseases in Madagascar (the Malagasy Republic). Different types of users, including individuals, researchers, groups of researchers and State institutions use medicinal plants as crude materials either for trade, scientific investigations or export. To preserve these forest products for extended use, Malagasy legislation controls the collection of medicinal plants, especially those destined for export. However, according to the law, products coming from Malagasy medicinal plants are not patentable locally. PMID:9213616

  20. Aye-aye population genomic analyses highlight an important center of endemism in northern Madagascar

    PubMed Central

    Perry, George H.; Louis, Edward E.; Ratan, Aakrosh; Bedoya-Reina, Oscar C.; Burhans, Richard C.; Lei, Runhua; Johnson, Steig E.; Schuster, Stephan C.; Miller, Webb

    2013-01-01

    We performed a population genomics study of the aye-aye, a highly specialized nocturnal lemur from Madagascar. Aye-ayes have low population densities and extensive range requirements that could make this flagship species particularly susceptible to extinction. Therefore, knowledge of genetic diversity and differentiation among aye-aye populations is critical for conservation planning. Such information may also advance our general understanding of Malagasy biogeography, as aye-ayes have the largest species distribution of any lemur. We generated and analyzed whole-genome sequence data for 12 aye-ayes from three regions of Madagascar (North, West, and East). We found that the North population is genetically distinct, with strong differentiation from other aye-ayes over relatively short geographic distances. For comparison, the average FST value between the North and East aye-aye populationsseparated by only 248 kmis over 2.1-times greater than that observed between human Africans and Europeans. This finding is consistent with prior watershed- and climate-based hypotheses of a center of endemism in northern Madagascar. Taken together, these results suggest a strong and long-term biogeographical barrier to gene flow. Thus, the specific attention that should be directed toward preserving large, contiguous aye-aye habitats in northern Madagascar may also benefit the conservation of other distinct taxonomic units. To help facilitate future ecological- and conservation-motivated population genomic analyses by noncomputational biologists, the analytical toolkit used in this study is available on the Galaxy Web site. PMID:23530231

  1. A new perspective on the significance of the Ranotsara shear zone in Madagascar

    NASA Astrophysics Data System (ADS)

    Schreurs, Guido; Giese, Jrg; Berger, Alfons; Gnos, Edwin

    2010-12-01

    The Ranotsara shear zone in Madagascar has been considered in previous studies to be a >350-km-long, intracrustal strike-slip shear zone of Precambrian/Cambrian age. Because of its oblique strike to the east and west coast of Madagascar, the Ranotsara shear zone has been correlated with shear zones in southern India and eastern Africa in Gondwana reconstructions. Our assessment using remote sensing data and field-based investigations, however, reveals that what previously has been interpreted as the Ranotsara shear zone is in fact a composite structure with a ductile deflection zone confined to its central segment and prominent NW-SE trending brittle faulting along most of its length. We therefore prefer the more neutral term Ranotsara Zone. Lithologies, tectonic foliations, and axial trace trajectories of major folds can be followed from south to north across most of the Ranotsara Zone and show only a marked deflection along its central segment. The ductile deflection zone is interpreted as a result of E-W indentation of the Antananarivo Block into the less rigid, predominantly metasedimentary rocks of the Southwestern Madagascar Block during a late phase of the Neoproterozoic/Cambrian East African Orogeny (c. 550-520 Ma). The Ranotsara Zone shows significant NW-SE striking brittle faulting that reactivates part of the NW-SE striking ductile structures in the flexure zone, but also extends along strike toward the NW and toward the SE. Brittle reactivation of ductile structures along the central segment of the Ranotsara Zone, confirmed by apatite-fission track results, may have led to the formation of a shallow Neogene basin underlying the Ranotsara plain. The present-day drainage pattern suggests on-going normal fault activity along the central segment. The Ranotsara Zone is not a megascale intracrustal strike-slip shear zone that crosscuts the entire basement of southern Madagascar. It can therefore not be used as a piercing point in Gondwana reconstructions.

  2. Comprehensive Red List Assessment Reveals Exceptionally High Extinction Risk to Madagascar Palms

    PubMed Central

    Rakotoarinivo, Mijoro; Dransfield, John; Bachman, Steven P.; Moat, Justin; Baker, William J.

    2014-01-01

    The establishment of baseline IUCN Red List assessments for plants is a crucial step in conservation planning. Nowhere is this more important than in biodiversity hotspots that are subject to significant anthropogenic pressures, such as Madagascar. Here, all Madagascar palm species are assessed using the IUCN Red List categories and criteria, version 3.1. Our results indicate that 83% of the 192 endemic species are threatened, nearly four times the proportion estimated for plants globally and exceeding estimates for all other comprehensively evaluated plant groups in Madagascar. Compared with a previous assessment in 1995, the number of Endangered and Critically Endangered species has substantially increased, due to the discovery of 28 new species since 1995, most of which are highly threatened. The conservation status of most species included in both the 1995 and the current assessments has not changed. Where change occurred, more species have moved to lower threat categories than to higher categories, because of improved knowledge of species and their distributions, rather than a decrease in extinction risk. However, some cases of genuine deterioration in conservation status were also identified. Palms in Madagascar are primarily threatened by habitat loss due to agriculture and biological resource use through direct exploitation or collateral damage. The recent extension of Madagascar’s protected area network is highly beneficial for palms, substantially increasing the number of threatened species populations included within reserves. Notably, three of the eight most important protected areas for palms are newly designated. However, 28 threatened and data deficient species are not protected by the expanded network, including some Critically Endangered species. Moreover, many species occurring in protected areas are still threatened, indicating that threatening processes persist even in reserves. Definitive implementation of the new protected areas combined with local community engagement are essential for the survival of Madagascar’s palms. PMID:25075612

  3. The evolution of extinction risk: past and present anthropogenic impacts on the primate communities of Madagascar.

    PubMed

    Godfrey, Laurie R; Irwin, Mitchell T

    2007-01-01

    There are two possible approaches to understanding natural and human-induced changes in the primate communities of Madagascar. One is to begin with present-day and recent historic interactions and work backwards. A second is to begin with paleoecological records of Malagasy primate communities before and immediately following human arrival, and the associated evidence of human and nonhuman primate interactions, and work forwards. On the basis of biological and climatic studies, as well as historic and ethnohistoric records, we are beginning to understand the abiotic and biotic characteristics of Madagascar's habitats, the lemurs' ecological adaptations to these unique habitats, the extent of forest loss, fragmentation and hunting, and the differential vulnerability of extant lemur species to these pressures. On the basis of integrated paleoecological, archaeological and paleontological research, we have begun to construct a detailed chronology for late prehistoric Madagascar. We are beginning to understand the complex sequence of events that led to one of the most dramatic recent megafaunal extinction/extirpation events. Combining the perspectives of the past and the present, we see a complex set of interactions affecting an initially rich but vulnerable fauna. The total evidence refutes any simple, unicausal (e.g. hunting/habitat destruction/climate change) explanation of megafaunal extinctions, yet unequivocally supports a major role--both direct and indirect--for humans as the trigger of the extinction process. It also supports a change over time in the relative importance of hunting versus habitat loss, and in the trophic characteristics of the primate communities in Madagascar. PMID:17855790

  4. Current Perspectives on Plague Vector Control in Madagascar: Susceptibility Status of Xenopsylla cheopis to 12 Insecticides.

    PubMed

    Miarinjara, Adélaïde; Boyer, Sébastien

    2016-02-01

    Plague is a rodent disease transmissible to humans by infected flea bites, and Madagascar is one of the countries with the highest plague incidence in the world. This study reports the susceptibility of the main plague vector Xenopsylla cheopis to 12 different insecticides belonging to 4 insecticide families (carbamates, organophosphates, pyrethroids and organochlorines). Eight populations from different geographical regions of Madagascar previously resistant to deltamethrin were tested with a World Health Organization standard bioassay. Insecticide susceptibility varied amongst populations, but all of them were resistant to six insecticides belonging to pyrethroid and carbamate insecticides (alphacypermethrin, lambdacyhalothrin, etofenprox, deltamethrin, bendiocarb and propoxur). Only one insecticide (dieldrin) was an efficient pulicide for all flea populations. Cross resistances were suspected. This study proposes at least three alternative insecticides (malathion, fenitrothion and cyfluthrin) to replace deltamethrin during plague epidemic responses, but the most efficient insecticide may be different for each population studied. We highlight the importance of continuous insecticide susceptibility surveillance in the areas of high plague risk in Madagascar. PMID:26844772

  5. Searching for the oldest baobab of Madagascar: radiocarbon investigation of large Adansonia rubrostipa trees.

    PubMed

    Patrut, Adrian; von Reden, Karl F; Danthu, Pascal; Pock-Tsy, Jean-Michel Leong; Patrut, Roxana T; Lowy, Daniel A

    2015-01-01

    We extended our research on the architecture, growth and age of trees belonging to the genus Adansonia, by starting to investigate large individuals of the most widespread Malagasy species. Our research also intends to identify the oldest baobabs of Madagascar. Here we present results of the radiocarbon investigation of the two most representative Adansonia rubrostipa (fony baobab) specimens, which are located in south-western Madagascar, in the Tsimanampetsotse National Park. We found that the fony baobab called "Grandmother" consists of 3 perfectly fused stems of different ages. The radiocarbon date of the oldest sample was found to be 1136 ± 16 BP. We estimated that the oldest part of this tree, which is mainly hollow, has an age close to 1,600 yr. This value is comparable to the age of the oldest Adansonia digitata (African baobab) specimens. By its age, the Grandmother is a major candidate for the oldest baobab of Madagascar. The second investigated specimen, called the "polygamous baobab", consists of 6 partially fused stems of different ages. According to dating results, this fony baobab is 1,000 yr old. This research is the first investigation of the structure and age of Malagasy baobabs. PMID:25806967

  6. Conservation education in Madagascar: three case studies in the biologically diverse island-continent.

    PubMed

    Dolins, Francine L; Jolly, Alison; Rasamimanana, Hantanirina; Ratsimbazafy, Jonah; Feistner, Anna T C; Ravoavy, Florent

    2010-05-01

    Few Malagasy children and adults are aware of the rare and unique fauna and flora indigenous to their island-continent, including flagship lemur species. Even the Malagasy ancestral proverbs never mentioned lemurs, but these same proverbs talked about the now extinct hippopotamus. Madagascar's geography, history, and economic constraints contribute to severe biodiversity loss. Deforestation on Madagascar is reported to be over 100,000 ha/year, with only 10-15% of the island retaining natural forest [Green & Sussman, 1990]. Educating children, teacher-training, and community projects about environmental and conservation efforts to protect the remaining natural habitats of endangered lemur species provide a basis for long-term changes in attitudes and practices. Case studies of three conservation education projects located in different geographical regions of Madagascar, Centre ValBio, Madagacar Wildlife Conservation Alaotra Comic Book Project, and The Ako Book Project, are presented together with their ongoing stages of development, assessment, and outcomes. We argue that while nongovernmental organizational efforts are and will be very important, the Ministry of Education urgently needs to incorporate biodiversity education in the curriculum at all levels, from primary school to university. PMID:20039330

  7. Biodiversity conservation and drug discovery: Can they be combined? The Suriname and Madagascar experiences.

    PubMed

    Cao, Shugeng; Kingston, David G I

    2009-08-01

    The approach to new drugs through natural products has proved to be the single most successful strategy for the discovery of new drugs, but in recent years its use has been deemphasized by many pharmaceutical companies in favor of approaches based on combinatorial chemistry and genomics, among others.Drug discovery from natural sources requires continued access to plant, marine, and microbial biomass, and so the preservation of tropical rainforests is an important part of our drug discovery program. Sadly, many of the tropical forests of the world are under severe environmental pressure, and deforestation is a serious problem in most tropical countries. One way to combat this loss is to demonstrate their value as potential sources of new pharmaceutical or agrochemical products.As part of an effort to integrate biodiversity conservation and drug discovery with economic development, we initiated an International Cooperative biodiversity Group (ICBG) to discover potential pharmaceuticals from the plant biodiversity of Suriname and Madagascar. The Group, established with funding from agencies of the United States government, involved participants from the USA, Suriname, and Madagascar. The basic approach was to search for bioactive plants in the Suriname and Malagasy flora, and to isolate their bioactive constituents by the best available methods, but the work included capacity building as well as research. Progress on this project will be reported, drawing on results obtained from the isolation of bioactive natural products from Suriname and Madagascar. The benefits of this general approach to biodiversity and drug discovery will also be discussed. PMID:20161050

  8. Current Perspectives on Plague Vector Control in Madagascar: Susceptibility Status of Xenopsylla cheopis to 12 Insecticides

    PubMed Central

    Miarinjara, Adélaïde; Boyer, Sébastien

    2016-01-01

    Plague is a rodent disease transmissible to humans by infected flea bites, and Madagascar is one of the countries with the highest plague incidence in the world. This study reports the susceptibility of the main plague vector Xenopsylla cheopis to 12 different insecticides belonging to 4 insecticide families (carbamates, organophosphates, pyrethroids and organochlorines). Eight populations from different geographical regions of Madagascar previously resistant to deltamethrin were tested with a World Health Organization standard bioassay. Insecticide susceptibility varied amongst populations, but all of them were resistant to six insecticides belonging to pyrethroid and carbamate insecticides (alphacypermethrin, lambdacyhalothrin, etofenprox, deltamethrin, bendiocarb and propoxur). Only one insecticide (dieldrin) was an efficient pulicide for all flea populations. Cross resistances were suspected. This study proposes at least three alternative insecticides (malathion, fenitrothion and cyfluthrin) to replace deltamethrin during plague epidemic responses, but the most efficient insecticide may be different for each population studied. We highlight the importance of continuous insecticide susceptibility surveillance in the areas of high plague risk in Madagascar. PMID:26844772

  9. Springs and wire plants: anachronistic defences against Madagascar's extinct elephant birds.

    PubMed

    Bond, William J; Silander, John A

    2007-08-22

    The extinction of large vertebrates in the last few millennia has left a legacy of evolutionary anachronisms. Among these are plant structural defences that persist long after the extinction of the browsers. A peculiar, and controversial, example is a suite of traits common in divaricate (wide-angled branching) plants from New Zealand. Divaricate architecture has been interpreted as an adaptive response to cold climates or an anachronistic defence against the extinct moas. Madagascar, a larger tropical island, also had a fauna of large flightless birds, the elephant birds. If these extinct ratites selected for similar plant defences, we expected to find convergent features between New Zealand and Malagasy plants, despite their very different climates. We searched the southern thickets of Madagascar for plants with putative anti-ratite defences and scored candidate species for a number of traits common to many New Zealand divaricates. We found many Malagasy species in 25 families and 36 genera shared the same suite of traits, the 'wire plant' syndrome, as divaricates in New Zealand that resist ratite browsing. Neither ecologically, nor phylogenetically, matched species from South Africa shared these traits. Malagasy wire plants differ from many New Zealand divaricates in lacking the distinctive concentration of leaves in the interior of shrubs. We suggest that New Zealand divaricates have a unique amalgam of traits that acted as defences and also confer tolerance to cold. We conclude that many woody species in the thickets of southern Madagascar share, with New Zealand, anachronistic structural defences against large extinct bird browsers. PMID:17535797

  10. Preliminary findings on identification of mycorrhizal fungi from diverse orchids in the Central Highlands of Madagascar.

    PubMed

    Yokoya, Kazutomo; Zettler, Lawrence W; Kendon, Jonathan P; Bidartondo, Martin I; Stice, Andrew L; Skarha, Shannon; Corey, Laura L; Knight, Audrey C; Sarasan, Viswambharan

    2015-11-01

    The Orchid flora of Madagascar is one of the most diverse with nearly 1000 orchid taxa, of which about 90% are endemic to this biodiversity hotspot. The Itremo Massif in the Central Highlands of Madagascar with a Highland Subtropical climate range encompasses montane grassland, igneous and metamorphic rock outcrops, and gallery and tapia forests. Our study focused on identifying culturable mycorrhizae from epiphytic, lithophytic, and terrestrial orchid taxa to understand their diversity and density in a spatial matrix that is within the protected areas. We have collected both juvenile and mature roots from 41 orchid taxa for isolating their orchid mycorrhizal fungi (OMF), and to culture, identify, and store in liquid nitrogen for future studies. Twelve operational taxonomic units (OTUs), of three known orchid mycorrhizal genera, were recognized by analysis of internal transcribed spacer (ITS) sequences of 85 isolates, and, by comparing with GenBank database entries, each OTU was shown to have closely related fungi that were also found as orchid associates. Orchid and fungal diversity were greater in gallery forests and open grasslands, which is very significant for future studies and orchid conservation. As far as we know, this is the first ever report of detailed identification of mycorrhizal fungi from Madagascar. This study will help start to develop a programme for identifying fungal symbionts from this unique biodiversity hotspot, which is undergoing rapid ecosystem damage and species loss. The diversity of culturable fungal associates, their density, and distribution within the Itremo orchid hotspot areas will be discussed. PMID:25771863

  11. Natural selection for the Duffy-null allele in the recently admixed people of Madagascar.

    PubMed

    Hodgson, Jason A; Pickrell, Joseph K; Pearson, Laurel N; Quillen, Ellen E; Prista, António; Rocha, Jorge; Soodyall, Himla; Shriver, Mark D; Perry, George H

    2014-08-22

    While gene flow between distantly related populations is increasingly recognized as a potentially important source of adaptive genetic variation for humans, fully characterized examples are rare. In addition, the role that natural selection for resistance to vivax malaria may have played in the extreme distribution of the protective Duffy-null allele, which is nearly completely fixed in mainland sub-Saharan Africa and absent elsewhere, is controversial. We address both these issues by investigating the evolution of the Duffy-null allele in the Malagasy, a recently admixed population with major ancestry components from both East Asia and mainland sub-Saharan Africa. We used genome-wide genetic data and extensive computer simulations to show that the high frequency of the Duffy-null allele in Madagascar can only be explained in the absence of positive natural selection under extreme demographic scenarios involving high genetic drift. However, the observed genomic single nucleotide polymorphism diversity in the Malagasy is incompatible with such extreme demographic scenarios, indicating that positive selection for the Duffy-null allele best explains the high frequency of the allele in Madagascar. We estimate the selection coefficient to be 0.066. Because vivax malaria is endemic to Madagascar, this result supports the hypothesis that malaria resistance drove fixation of the Duffy-null allele in mainland sub-Saharan Africa. PMID:24990677

  12. Biodiversity conservation and drug discovery: Can they be combined? The Suriname and Madagascar experiences

    PubMed Central

    Cao, Shugeng; Kingston, David G. I.

    2009-01-01

    The approach to new drugs through natural products has proved to be the single most successful strategy for the discovery of new drugs, but in recent years its use has been deemphasized by many pharmaceutical companies in favor of approaches based on combinatorial chemistry and genomics, among others. Drug discovery from natural sources requires continued access to plant, marine, and microbial biomass, and so the preservation of tropical rainforests is an important part of our drug discovery program. Sadly, many of the tropical forests of the world are under severe environmental pressure, and deforestation is a serious problem in most tropical countries. One way to combat this loss is to demonstrate their value as potential sources of new pharmaceutical or agrochemical products. As part of an effort to integrate biodiversity conservation and drug discovery with economic development, we initiated an International Cooperative biodiversity Group (ICBG) to discover potential pharmaceuticals from the plant biodiversity of Suriname and Madagascar. The Group, established with funding from agencies of the United States government, involved participants from the USA, Suriname, and Madagascar. The basic approach was to search for bioactive plants in the Suriname and Malagasy flora, and to isolate their bioactive constituents by the best available methods, but the work included capacity building as well as research. Progress on this project will be reported, drawing on results obtained from the isolation of bioactive natural products from Suriname and Madagascar. The benefits of this general approach to biodiversity and drug discovery will also be discussed. PMID:20161050

  13. First monogenean flatworm from a microhylid frog host: Kankana, a new polystome genus from Madagascar.

    PubMed

    Raharivololoniaina, Liliane; Verneau, Olivier; Berthier, Pauline; Vences, Miguel; Du Preez, Louis

    2011-12-01

    Kankana manampoka n. gen., n. sp. (Monogenea, Polystomatidae), is described from the urinary bladder of the narrow-mouthed frog Platypelis pollicaris. This is the first record of a polystome from the Microhylidae and the third polystome genus from Madagascar, next to Metapolystoma and Madapolystoma. The extensive uterus and presence of hamuli resemble Metapolystoma but the vitellarium confined to the lateral fields in Kankana is different. Madapolystoma also has an extensive uterus but contain only up to 32 advanced developed larvae. Based on the extensive uterus filling the body proper and the vitellarium confined to two lateral fields posterior in the body this new polystome resembles Eupolystoma known from Africa and India. However, unlike Eupolystoma, the gonads are in the middle of the body, vaginae are lacking and a pair of hamuli is present. A molecular phylogenetic analysis of concatenated 18S and 28S ribosomal RNA gene sequences supplemented by genetic distances inferred from 28S and COI sequences showed that this new genus is more related to Madapolystoma, a genus only reported from Madagascar, than to Eupolystoma known from Africa and India and Metapolystoma known from Africa and Madagascar. PMID:21856439

  14. Searching for the Oldest Baobab of Madagascar: Radiocarbon Investigation of Large Adansonia rubrostipa Trees

    PubMed Central

    Patrut, Adrian; von Reden, Karl F.; Danthu, Pascal; Leong Pock-Tsy, Jean-Michel; Patrut, Roxana T.; Lowy, Daniel A.

    2015-01-01

    We extended our research on the architecture, growth and age of trees belonging to the genus Adansonia, by starting to investigate large individuals of the most widespread Malagasy species. Our research also intends to identify the oldest baobabs of Madagascar. Here we present results of the radiocarbon investigation of the two most representative Adansonia rubrostipa (fony baobab) specimens, which are located in south-western Madagascar, in the Tsimanampetsotse National Park. We found that the fony baobab called Grandmother consists of 3 perfectly fused stems of different ages. The radiocarbon date of the oldest sample was found to be 1136 16 BP. We estimated that the oldest part of this tree, which is mainly hollow, has an age close to 1,600 yr. This value is comparable to the age of the oldest Adansonia digitata (African baobab) specimens. By its age, the Grandmother is a major candidate for the oldest baobab of Madagascar. The second investigated specimen, called the polygamous baobab, consists of 6 partially fused stems of different ages. According to dating results, this fony baobab is 1,000 yr old. This research is the first investigation of the structure and age of Malagasy baobabs. PMID:25806967

  15. Biogeography of the Malagasy Celastraceae: Multiple independent origins followed by widespread dispersal of genera from Madagascar.

    PubMed

    Bacon, Christine D; Simmons, Mark P; Archer, Robert H; Zhao, Liang-Cheng; Andriantiana, Jacky

    2016-01-01

    Of the 97 currently recognized genera of Celastraceae, 19 are native to Madagascar, including six endemics. In this study we conducted the most thorough phylogenetic analysis of Celastraceae yet completed with respect to both character and taxon sampling, and include representatives of five new endemic genera. Fifty-one new accessions, together with 328 previously used accessions of Celastrales, were sampled for morphological characters, two rDNA gene regions, and two plastid gene regions. The endemic Malagasy genera are resolved in two separate lineages-Xenodrys by itself and all other endemic genera in a clade that also includes four lineages inferred to have dispersed from Madagascar: Brexia madagascariensis (Mascarene Islands, coastal Africa), Elaeodendron (West Indies, Africa to New Caledonia), and Pleurostylia (Africa to New Caledonia). Of the 12 extant Malagasy Celastraceae lineages identified, eight are clearly of African origin. The origins of the remaining four lineages are less clear, but reasonable possibilities include America, Eurasia, Africa, southern India, Malesia, and Australia. Based on 95% credible age intervals from fossil-calibrated molecular dating, all 12 extant Malagasy Celastraceae lineages appear to have arisen following dispersal after the separation of Madagascar from other landmasses within the last 70 million years. PMID:26432393

  16. Natural selection for the Duffy-null allele in the recently admixed people of Madagascar

    PubMed Central

    Hodgson, Jason A.; Pickrell, Joseph K.; Pearson, Laurel N.; Quillen, Ellen E.; Prista, António; Rocha, Jorge; Soodyall, Himla; Shriver, Mark D.; Perry, George H.

    2014-01-01

    While gene flow between distantly related populations is increasingly recognized as a potentially important source of adaptive genetic variation for humans, fully characterized examples are rare. In addition, the role that natural selection for resistance to vivax malaria may have played in the extreme distribution of the protective Duffy-null allele, which is nearly completely fixed in mainland sub-Saharan Africa and absent elsewhere, is controversial. We address both these issues by investigating the evolution of the Duffy-null allele in the Malagasy, a recently admixed population with major ancestry components from both East Asia and mainland sub-Saharan Africa. We used genome-wide genetic data and extensive computer simulations to show that the high frequency of the Duffy-null allele in Madagascar can only be explained in the absence of positive natural selection under extreme demographic scenarios involving high genetic drift. However, the observed genomic single nucleotide polymorphism diversity in the Malagasy is incompatible with such extreme demographic scenarios, indicating that positive selection for the Duffy-null allele best explains the high frequency of the allele in Madagascar. We estimate the selection coefficient to be 0.066. Because vivax malaria is endemic to Madagascar, this result supports the hypothesis that malaria resistance drove fixation of the Duffy-null allele in mainland sub-Saharan Africa. PMID:24990677

  17. Hunting, Exotic Carnivores, and Habitat Loss: Anthropogenic Effects on a Native Carnivore Community, Madagascar

    PubMed Central

    Farris, Zach J.; Golden, Christopher D.; Karpanty, Sarah; Murphy, Asia; Stauffer, Dean; Ratelolahy, Felix; Andrianjakarivelo, Vonjy; Holmes, Christopher M.; Kelly, Marcella J.

    2015-01-01

    The wide-ranging, cumulative, negative effects of anthropogenic disturbance, including habitat degradation, exotic species, and hunting, on native wildlife has been well documented across a range of habitats worldwide with carnivores potentially being the most vulnerable due to their more extinction prone characteristics. Investigating the effects of anthropogenic pressures on sympatric carnivores is needed to improve our ability to develop targeted, effective management plans for carnivore conservation worldwide. Utilizing photographic, line-transect, and habitat sampling, as well as landscape analyses and village-based bushmeat hunting surveys, we provide the first investigation of how multiple forms of habitat degradation (fragmentation, exotic carnivores, human encroachment, and hunting) affect carnivore occupancy across Madagascar’s largest protected area: the Masoala-Makira landscape. We found that as degradation increased, native carnivore occupancy and encounter rates decreased while exotic carnivore occupancy and encounter rates increased. Feral cats (Felis species) and domestic dogs (Canis familiaris) had higher occupancy than half of the native carnivore species across Madagascar’s largest protected landscape. Bird and small mammal encounter rates were negatively associated with exotic carnivore occupancy, but positively associated with the occupancy of four native carnivore species. Spotted fanaloka (Fossa fossana) occupancy was constrained by the presence of exotic feral cats and exotic small Indian civet (Viverricula indica). Hunting was intense across the four study sites where hunting was studied, with the highest rates for the small Indian civet (x¯ = 90 individuals consumed/year), the ring-tailed vontsira (Galidia elegans) (x¯ = 58 consumed/year), and the fosa (Cryptoprocta ferox) (x¯ = 31 consumed/year). Our modeling results suggest hunters target intact forest where carnivore occupancy, abundance, and species richness, are highest. These various anthropogenic pressures and their effects on carnivore populations, especially increases in exotic carnivores and hunting, have wide-ranging, global implications and demand effective management plans to target the influx of exotic carnivores and unsustainable hunting that is affecting carnivore populations across Madagascar and worldwide. PMID:26375991

  18. Consuming sex: the association between modern goods, lifestyles and sexual behaviour among youth in Madagascar

    PubMed Central

    2013-01-01

    Background Ethnographic evidence suggests that transactional sex is sometimes motivated by youth’s interest in the consumption of modern goods as much as it is in basic survival. There are very few quantitative studies that examine the association between young people’s interests in the consumption of modern goods and their sexual behaviour. We examined this association in two regions and four residence zones of Madagascar: urban, peri-urban and rural Antananarivo, and urban Antsiranana. We expected risky sexual behaviour would be associated with interests in consuming modern goods or lifestyles; urban residence; and socio-cultural characteristics. Methods We administered a population-based survey to 2, 255 youth ages 15–24 in all four residence zones. Focus group discussions guided the survey instrument which assessed socio-demographic and economic characteristics, consumption of modern goods, preferred activities and sexual behaviour. Our outcomes measures included: multiple sexual partners in the last year (for men and women); and ever practicing transactional sex (for women). Results Overall, 7.3% of women and 30.7% of men reported having had multiple partners in the last year; and 5.9% of women reported ever practicing transactional sex. Bivariate results suggested that for both men and women having multiple partners was associated with perceptions concerning the importance of fashion and a series of activities associated with modern lifestyles. A subset of lifestyle characteristics remained significant in multivariate models. For transactional sex bivariate results suggested perceptions around fashion, nightclub attendance, and getting to know a foreigner were key determinants; and all remained significant in multivariate analysis. We found peri-urban residence more associated with transactional sex than urban residence; and ethnic origin was the strongest predictor of both outcomes for women. Conclusions While we found indication of an association between sexual behaviour and interest in modern goods, or modern lifestyles, such processes did not single-handedly explain risky sexual behaviour among youth; these behaviours were also shaped by culture and conditions of economic uncertainty. These determinants must all be accounted for when developing interventions to reduce risky transactional sex and vulnerability to HIV. PMID:23510104

  19. Proximal and distal styles of pegmatite-related metasomatic emerald mineralization at Ianapera, southern Madagascar

    NASA Astrophysics Data System (ADS)

    Andrianjakavah, Prosper Rakotovao; Salvi, Stefano; Béziat, Didier; Rakotondrazafy, Michel; Giuliani, Gaston

    2009-10-01

    The Ianapera emerald deposit is located in the Neoproterozoic Vohibory Block of southern Madagascar. The local geology consists of intercalated migmatitic gneissic units and calcareous metasedimentary rocks, containing boudinaged metamorphosed mafic/ultramafic lenses, all intruded by pegmatite veins. These units occur near the hinge of the tightly folded Ianapera antiform, within a few kilometers of the Ampanihy shear zone. Emerald mineralization is hosted by metasomatic phlogopite veins, and bodies developed within the mafic/ultramafic rocks. Based on field and textural relationships, we distinguish proximal and distal styles of mineralization. Proximal mineralization occurs at the contact of pegmatite veins with mafic/ultramafic units; in the distal style, pegmatites are not observed. Three types of emeralds could be distinguished, mainly on the basis of color and mineral zoning. Some of these emeralds have the most Al-depleted and Cr-rich composition ever recorded. Another characteristic feature to the Ianapera deposit and, to our knowledge, yet unreported, is the association of some emeralds with scapolite in metasomatised mafic rocks. Mineral inclusions are common in most emeralds and include phlogopite, carbonates, barite, K-feldspar, quartz, pyrite, zircon, monazite, bastnaesite, phenakite, plus Fe and Cr oxides. However, feldspar and rare earth element-bearing minerals occur predominantly in proximal emeralds, which also have a more incompatible trace-element signature than distal emeralds. We propose a model related to syn- to post-tectonic magmatic-hydrothermal activity. Pegmatitic bodies intruded units of the Ianapera antiform probably during tectonic relaxation. Exsolution of fluids rich in halogens and incompatible elements from the cooling pegmatites caused hydrothermal metasomatism of Cr-bearing mafic/ultramafic rocks in direct contact with the pegmatites. Local fracturing favored fluid infiltration, permitting the formation of distal mineralization. Emerald composition was controlled by the chemistry of the host rock. The presence of carbonate mineral inclusions in the emeralds and the high F-activity indicated by elevated F-contents in newly formed minerals suggest transport of Be as a fluoride-carbonate complex. It seems likely that beryl formation was triggered by precipitation of F-rich phlogopite, which removed the complexing ligand from the fluid.

  20. Dietary modification by common brown lemurs (Eulemur fulvus) during seasonal drought conditions in western Madagascar.

    PubMed

    Sato, Hiroki; Ichino, Shinichiro; Hanya, Goro

    2013-11-12

    Primates often modify dietary composition in relation to seasonal changes in food availability or climate conditions. We studied the feeding patterns of a troop of common brown lemurs (Eulemur fulvus), a semi-frugivorous strepsirhine, in a dry forest in northwestern Madagascar. To understand the mechanism of dietary modification, we recorded daily feeding times of diet items during 101full-day observations over 1year, and then conducted a linear model analysis to examine the effects of fruiting tree density in the forest, daily ambient temperature, and weekly rainfall (index of water retained in the forest) on the lemurs' daily feeding time. The lemurs spent dramatically more time on leaf-eating as well as total feeding time, and less time on fruit-eating during the late dry season (total 152min/day, frugivory 56min/day, folivory 77min/day), as compared with other seasons when the diet was highly frugivorous (total 96min/day, frugivory 81min/day, folivory 8min/day). Folivory increased as temperatures rose under the condition of low weekly rainfall, whereas frugivory was unrelated to fruiting tree density. Most (97.4%) diurnal folivory during the late dry season was spent consuming Lissochilus rutenbergianus, chewing the succulent leaves and licking the juice. Because the nutritional analysis showed that L. rutenbergianus is rich in water (80.1% of fresh weight) but poor in protein and nonstructural carbohydrates, its increased use was probably for rehydration. We conducted 13 full-night observations, because brown lemurs increase nocturnal activities during the dry season. At nighttime, the lemurs tended to spend more time eating fruit in the late dry season (32min/night) than in the early dry season (14min/night), and never consumed L.rutenbergianus. Fruits rich in nonstructural carbohydrates can be energy sources for Eulemur. They likely engaged in additional nocturnal frugivory for energy compensation. Brown lemurs have a flexible strategy of modifying their diet and feeding activities to cope with environmental stresses. PMID:24217743

  1. Risk factors for avian influenza and Newcastle disease in smallholder farming systems, Madagascar highlands.

    PubMed

    Rasamoelina Andriamanivo, H; Lancelot, R; Maminiaina, O F; Rakotondrafara, T F; Jourdan, M; Renard, J F; Gil, P; Servan de Almeida, R; Albina, E; Martinez, D; Tillard, E; Rakotondravao, R; Chevalier, V

    2012-04-01

    Newcastle disease (ND) and avian influenza (AI) are issues of interest to avian producers in Madagascar. Newcastle disease virus (NDV) is the major constraint for village aviculture, and avian influenza viruses type A (AIAV) are known to circulate in bird flocks. This study aims at classifying smallholder poultry farms, according to the combination of risk factors potentially associated with NDV and AIAV transmission and to assess the level of infection for each farm class. Two study sites, Lake Alaotra and Grand Antananarivo, were chosen with respect to their differences in terms of agro-ecological features and poultry productions. A typology survey involving 526 farms was performed to identify possible risk factors for (i) within-village, and (ii) between-village virus transmission. A cross-sectional serological study was also carried out in 270 farms to assess sero-prevalences of NDV and AIAV for each farm class and the link between them and risk factor patterns. For within-village transmission, four classes of farms were identified in Grand Antananarivo and five in Lake Alaotra. For between-village virus transmission, four classes of farms were identified for each site. In both sites, NDV sero-prevalence was higher than for AIAV. There was no evidence of the presence of H5 or H7 subtypes of AIAV. Sero-prevalences were significantly higher in Lake Alaotra than in Grand Antananarivo for both viruses (OR=2.4, p=0.02 for NDV, and OR=9.6, p<0.0001 for AIAV). For within-village NDV transmission in Grand Antananarivo, backyard chicken farms (OR=3.6, p<0.001), and chicken farms with biosecurity awareness (OR=3.4, p<0.01) had greater odds of having antibodies against NDV than the others. For between-village virus transmission, farms with multiple external contacts, and farms using many small markets had greater odds of having antibodies against NDV than the others (OR=5.4, p<0.01). For AIAV, there were no differences in sero-prevalences among farm classes. In Lake Alaotra, the observed high density of palmipeds and widespread rice paddies were associated with high sero-prevalences for both viruses, and a homogeneous risk of virus transmission between the different farm classes. In Grand Antananarivo, farm visits by collectors or animal health workers, and farm contacts with several markets were identified as potential risk factors for NDV transmission. Further studies are needed to identify the circulating virus genotypes, model their transmission risk, and provide adapted control measures. PMID:22130311

  2. Taenia solium porcine cysticercosis in Madagascar: Comparison of immuno-diagnostic techniques and estimation of the prevalence in pork carcasses traded in Antananarivo city.

    PubMed

    Porphyre, V; Betson, M; Rabezanahary, H; Mboussou, Y; Zafindraibe, N J; Rasamoelina-Andriamanivo, H; Costard, S; Pfeiffer, D U; Michault, A

    2016-03-30

    Taenia solium cysticercosis was reported in official veterinary and medical statistics to be highly prevalent in pigs and humans in Madagascar, but few estimates are available for pigs. This study aimed to estimate the seroprevalence of porcine cysticercosis among pigs slaughtered in Antananarivo abattoirs. Firstly, the diagnostic performance of two antigen-ELISA techniques (B158B60 Ag-ELISA and HP10 Ag-ELISA) and an immunoblotting method were compared with meat inspection procedures on a sample of pigs suspected to be infected with (group 1; n=250) or free of (group 2; n=250) T. solium based on direct veterinary inspection in Madagascar. Sensitivity and specificity of the antigen ELISAs were then estimated using a Bayesian approach for detection of porcine cysticercosis in the absence of a gold standard. Then, a third set of pig sera (group 3, n=250) was randomly collected in Antananarivo slaughterhouses and tested to estimate the overall prevalence of T. solium contamination in pork meat traded in Antananarivo. The antigen ELISAs showed a high sensitivity (>84%), but the B158B60 Ag-ELISA appeared to be more specific than the HP10 Ag-ELISA (model 1: 95% vs 74%; model 2: 87% vs 71%). The overall prevalence of porcine cysticercosis in Antananarivo slaughterhouses was estimated at 2.3% (95% credibility interval [95%CrI]: 0.09-9.1%) to 2.6% (95%CrI: 0.1-10.3%) depending on the model and priors used. Since the sample used in this study is not representative of the national pig population, village-based surveys and longitudinal monitoring at slaughter are needed to better estimate the overall prevalence, geographical patterns and main risk factors for T. solium contamination, in order to improve control policies. PMID:26342625

  3. Seroepidemiological Study of Interepidemic Rift Valley Fever Virus Infection Among Persons with Intense Ruminant Exposure in Madagascar and Kenya.

    PubMed

    Gray, Gregory C; Anderson, Benjamin D; LaBeaud, A Desirée; Heraud, Jean-Michel; Fèvre, Eric M; Andriamandimby, Soa Fy; Cook, Elizabeth A J; Dahir, Saidi; de Glanville, William A; Heil, Gary L; Khan, Salah U; Muiruri, Samuel; Olive, Marie-Marie; Thomas, Lian F; Merrill, Hunter R; Merrill, Mary L M; Richt, Juergen A

    2015-12-01

    In this cross-sectional seroepidemiological study we sought to examine the evidence for circulation of Rift Valley fever virus (RVFV) among herders in Madagascar and Kenya. From July 2010 to June 2012, we enrolled 459 herders and 98 controls (without ruminant exposures) and studied their sera (immunoglobulin G [IgG] and IgM through enzyme-linked immunosorbent assay [ELISA] and plaque reduction neutralization test [PRNT] assays) for evidence of previous RVFV infection. Overall, 59 (12.9%) of 459 herders and 7 (7.1%) of the 98 controls were positive by the IgG ELISA assay. Of the 59 ELISA-positive herders, 23 (38.9%) were confirmed by the PRNT assay (21 from eastern Kenya). Two of the 21 PRNT-positive study subjects also had elevated IgM antibodies against RVFV suggesting recent infection. Multivariate modeling in this study revealed that being seminomadic (odds ratio [OR] = 6.4, 95% confidence interval [CI] = 2.1-15.4) was most strongly associated with antibodies against RVFV. Although we cannot know when these infections occurred, it seems likely that some interepidemic RVFV infections are occurring among herders. As there are disincentives regarding reporting RVFV outbreaks in livestock or wildlife, it may be prudent to conduct periodic, limited, active seroepidemiological surveillance for RVFV infections in herders, especially in eastern Kenya. PMID:26458775

  4. Isolation and structural elucidation of cytotoxic compounds from the root bark of Diospyros quercina (Baill.) endemic to Madagascar

    PubMed Central

    Ruphin, Fatiany Pierre; Baholy, Robijaona; Emmanuel, Randrianarivo; Amelie, Raharisololalao; Martin, Marie-Therese; Koto–te-Nyiwa, Ngbolua

    2014-01-01

    Objective To isolate and characterize the cytotoxic compounds from Diospyros quercina (Baill.) G.E. Schatz & Lowry (Ebenaceae). Methods An ethno-botanical survey was conducted in the south of Madagascar from July to August 2010. Bio-guided fractionation assay was carried out on the root bark of Diospyros quercina, using cytotoxicity bioassay on murine P388 leukemia cell lines as model. The structures of the cytotoxic compounds were elucidated by 1D and 2D NMR spectroscopy and mass spectrometry. Results Biological experiments resulted in the isolation of three bioactive pure compounds (named TR-21, TR-22, and TR-23) which exhibited very good in vitro cytotoxic activities with the IC50 values of (0.017 5±0.0060) µg/mL, (0.089±0.005) µg/mL and (1.027±0.070) µg/mL respectively. Thus, they support the claims of traditional healers and suggest the possible correlation between the chemical composition of this plant and its wide use in Malagasy folk medicine to treat cancer. Conclusions The ability of isolated compounds in this study to inhibit cell growth may represent a rational explanation for the use of Diospyros quercina root bark in treating cancer by Malagasy traditional healers. Further studies are, therefore, necessary to evaluate the in vivo anti-neoplastic activity of these cytotoxic compounds as effective anticancer drugs. PMID:25182433

  5. Seroepidemiological Study of Interepidemic Rift Valley Fever Virus Infection among Persons with Intense Ruminant Exposure in Madagascar and Kenya

    PubMed Central

    Gray, Gregory C.; Anderson, Benjamin D.; LaBeaud, A. Desirée; Heraud, Jean-Michel; Fèvre, Eric M.; Andriamandimby, Soa Fy; Cook, Elizabeth A. J.; Dahir, Saidi; de Glanville, William A.; Heil, Gary L.; Khan, Salah U.; Muiruri, Samuel; Olive, Marie-Marie; Thomas, Lian F.; Merrill, Hunter R.; Merrill, Mary L. M.; Richt, Juergen A.

    2015-01-01

    In this cross-sectional seroepidemiological study we sought to examine the evidence for circulation of Rift Valley fever virus (RVFV) among herders in Madagascar and Kenya. From July 2010 to June 2012, we enrolled 459 herders and 98 controls (without ruminant exposures) and studied their sera (immunoglobulin G [IgG] and IgM through enzyme-linked immunosorbent assay [ELISA] and plaque reduction neutralization test [PRNT] assays) for evidence of previous RVFV infection. Overall, 59 (12.9%) of 459 herders and 7 (7.1%) of the 98 controls were positive by the IgG ELISA assay. Of the 59 ELISA-positive herders, 23 (38.9%) were confirmed by the PRNT assay (21 from eastern Kenya). Two of the 21 PRNT-positive study subjects also had elevated IgM antibodies against RVFV suggesting recent infection. Multivariate modeling in this study revealed that being seminomadic (odds ratio [OR] = 6.4, 95% confidence interval [CI] = 2.1–15.4) was most strongly associated with antibodies against RVFV. Although we cannot know when these infections occurred, it seems likely that some interepidemic RVFV infections are occurring among herders. As there are disincentives regarding reporting RVFV outbreaks in livestock or wildlife, it may be prudent to conduct periodic, limited, active seroepidemiological surveillance for RVFV infections in herders, especially in eastern Kenya. PMID:26458775

  6. Deep phylogenetic divergence between Scolytoplatypus and Remansus, a new genus of Scolytoplatypodini from Madagascar (Coleoptera, Curculionidae, Scolytinae).

    PubMed

    Jordal, Bjarte H

    2013-01-01

    Scolytoplatypodini Blandford is a monotypic tribe of ambrosia beetles found in Asia, Madagascar and Africa. Only three species are currently known from Madagascar and four additional species are here described as new to science. Phylogenetic analyses of morphological and molecular data revealed that four of the seven endemic species are deeply separated from all other species by genetic and distinct morphological characters and therefore placed in a new genus Remansus Jordal. The split between this ancient lineage and Scolytoplatypus Schaufuss was estimated to approximate Palaeocene age (63 Ma), extending the minimum age of ambrosia feeding for this tribe to the beginning of the Palaeocene‒Eocene thermal maximum (PETM). In addition to the ancient origin of Remansus in Madagascar during the Palaeocene, a second origin occurred in Scolytoplatypus no more than 13 Ma. A geographical origin of the latter in South-Eastern Africa was unequivocally inferred from the phylogenies. PMID:24294090

  7. Rapid human-induced landscape transformation in Madagascar at the end of the first millennium of the Common Era

    NASA Astrophysics Data System (ADS)

    Burns, Stephen J.; Godfrey, Laurie R.; Faina, Peterson; McGee, David; Hardt, Ben; Ranivoharimanana, Lovasoa; Randrianasy, Jeannot

    2016-02-01

    The environmental impact of the early human inhabitants of Madagascar remains heavily debated. We present results from a study using two stalagmites collected from Anjohibe Cave in northwestern Madagascar to investigate the paleoecology and paleoclimate of northwestern Madagascar over the past 1800 years. Carbon stable isotopic data indicate a rapid, complete transformation from a flora dominated by C3 plants to a C4 grassland system. This transformation is well replicated in both stalagmites, occurred at 890 CE and was completed within one century. We infer that the change was the result of a dramatic increase in the use of fire to promote the growth of grass for cattle fodder. Further, stalagmite oxygen isotope ratios show no significant variation across the carbon isotope excursion, demonstrating that the landscape transformation was not related to changes in precipitation. Our study illustrates the profound impact early inhabitants had on the environment, and implies that forest loss was one trigger of megafaunal extinction.

  8. Deep phylogenetic divergence between Scolytoplatypus and Remansus, a new genus of Scolytoplatypodini from Madagascar (Coleoptera, Curculionidae, Scolytinae)

    PubMed Central

    Jordal, Bjarte H.

    2013-01-01

    Abstract Scolytoplatypodini Blandford is a monotypic tribe of ambrosia beetles found in Asia, Madagascar and Africa. Only three species are currently known from Madagascar and four additional species are here described as new to science. Phylogenetic analyses of morphological and molecular data revealed that four of the seven endemic species are deeply separated from all other species by genetic and distinct morphological characters and therefore placed in a new genus Remansus Jordal. The split between this ancient lineage and Scolytoplatypus Schaufuss was estimated to approximate Palaeocene age (63 Ma), extending the minimum age of ambrosia feeding for this tribe to the beginning of the Palaeocene‒Eocene thermal maximum (PETM). In addition to the ancient origin of Remansus in Madagascar during the Palaeocene, a second origin occurred in Scolytoplatypus no more than 13 Ma. A geographical origin of the latter in South-Eastern Africa was unequivocally inferred from the phylogenies. PMID:24294090

  9. To Madagascar and back: long-distance, return migration across open ocean by a pregnant female bull shark Carcharhinus leucas.

    PubMed

    Lea, J S E; Humphries, N E; Clarke, C R; Sims, D W

    2015-12-01

    A large, pregnant, female bull shark Carcharhinus leucas was tracked migrating from Seychelles across open ocean to south-east Madagascar, c. 2000 km away, and back again. In Madagascar, the shark spent a prolonged period shallower than 5 m, consistent with entering estuarine habitat to pup, and upon return to Seychelles the shark was slender and no longer gravid. This represents an unprecedented return migration across the open ocean for a C. leucas and highlights the need for international collaboration to manage the regional C. leucas population sustainably. PMID:26511427

  10. Seismo and sequence stratigraphy of Cenozoic units of the Morondava Basin, offshore western Madagascar

    NASA Astrophysics Data System (ADS)

    Kaufmann, Dirk; Stollhofen, Harald; Klimke, Jennifer; Franke, Dieter

    2015-04-01

    The N-S trending Morondava Basin extends in width from western onshore Madagascar over about 350 km westwards to the offshore Davie Ridge in the Mozambique Channel. Although basin formation was initiated during Karoo times, the main basin evolution took place during Jurassic rifting and subsequent drifting until middle Cretaceous as a result of Gondwana breakup (Geiger et al., 2004). Contemporaneous to the separation of India and Madagascar widespread flood basalts were emplaced during the late Cretaceous (Storey et al., 1995). Present knowledge of the Morondava Basin is mainly based on outcrop studies, seismic surveys and borehole information (e.g. Geiger et al., 2004), gathered in western onshore Madagascar, although the fast majority of the basin, including its depocenter is located offshore in the Mozambique Channel, now at up to 3,500 m water depth. Almost all of the recent offshore studies of the Morondava Basin rely on industrial data but up to date publications of exploration results are generally rare and mostly anonymized. Our study aims to extend knowledge, particularly on the offshore seismic and sequence stratigraphy of the Morondava Basin. A key question is also to test the proposed tectonic stability of the Davie Ridge over the last 40 Ma. For this purpose 12 seismic profiles and bathymetric data, acquired in early 2014 by RV SONNE, are interpreted. Most of the profiles cover the distal deep marine areas of the northern Morondava Basin between the Davie Ridge and the shelf break of Madagascar. Top Cretaceous, Top Eocene, Top Oligocene, the Middle Miocene Unconformity and the Base Pliocene, are mapped as major seismic marker horizons. Especially shelf and slope sedimentary units are important resources to reconstruct the tectonostratigraphic basin evolution. At the continental slope diffuse to chaotic seismic pattern of Miocene and younger age are identified which are subdivided by laterally continuous, high frequency reflectors with a higher impedance contrast. Bounded by the Base Tertiary and the Base Pliocene these units can be used to develop and verify a sequence stratigraphic approach for the Cenozoic in the Morondava Basin. Prelimary results indicate that the major sedimentation at the continental slope moved after Early Pliocene significantly landwards. In general the thickness of post-Pliocene units increases to the east. Work in progress encompasses the application of seismo and sequence stratigraphic concept for Mesozoic sedimentary units and a correlation with other, potentially time-equivalent, basins in the area, such as the Mandawa Basin in northern Mozambique. References Geiger, M., Clark, D.N., und Mette, W., 2004, Reappraisal of the timing of the break-up of Gondwana based on sedimentological und seismic evidence from the Morondava Basin, SW Madagascar: Journal of African Earth Sciences, v. 38, p. 363-381. Storey, M., Mahoney, J. J., Saunders, A. D., Duncan, R. A., Kelley, S. P., und Coffin, M. F., 1995, Timing of Hot Spot--Related Volcanism und the Breakup of Madagascar und India: Science, v. 267, no. 5199, p. 852-855.

  11. Diagnosis of bubonic plague by PCR in Madagascar under field conditions.

    PubMed

    Rahalison, L; Vololonirina, E; Ratsitorahina, M; Chanteau, S

    2000-01-01

    The diagnostic value of a PCR assay that amplifies a 501-bp fragment of the Yersinia pestis caf1 gene has been determined in a reference laboratory with 218 bubo aspirates collected from patients with clinically suspected plague managed in a regional hospital in Madagascar. The culture of Y. pestis and the detection of the F1 antigen (Ag) by enzyme-linked immunosorbent assay (ELISA) were used as reference diagnostic methods. The sensitivity of PCR was 89% (57 of 64) for the Y. pestis-positive patients, and 80.7% (63 of 78) for the F1 Ag-positive patients. The specificity of PCR for the culture-, F1 Ag-, and antibody-negative patients (n = 105) was 100%. Because in Madagascar most patients with plague are managed and their clinical samples are collected in remote villages, the usefulness of PCR was evaluated for routine diagnostic use in the operational conditions of the control program. The sensitivity of PCR was 50% (25 of 50) relative to the results of culture and 35.2% (19 of 54) relative to the results of the F1 Ag immunocapture ELISA. The specificity of PCR under these conditions was 96%. In conclusion, the PCR method was found to be very specific but not as sensitive as culture or the F1 Ag detection method. The limitation in sensitivity may have been due to suboptimal field conditions and the small volumes of samples used for DNA extraction. This technique is not recommended as a routine diagnostic test for plague in Madagascar. PMID:10618097

  12. Comparison of Marine Spatial Planning Methods in Madagascar Demonstrates Value of Alternative Approaches

    PubMed Central

    Allnutt, Thomas F.; McClanahan, Timothy R.; Andréfouët, Serge; Baker, Merrill; Lagabrielle, Erwann; McClennen, Caleb; Rakotomanjaka, Andry J. M.; Tianarisoa, Tantely F.; Watson, Reg; Kremen, Claire

    2012-01-01

    The Government of Madagascar plans to increase marine protected area coverage by over one million hectares. To assist this process, we compare four methods for marine spatial planning of Madagascar's west coast. Input data for each method was drawn from the same variables: fishing pressure, exposure to climate change, and biodiversity (habitats, species distributions, biological richness, and biodiversity value). The first method compares visual color classifications of primary variables, the second uses binary combinations of these variables to produce a categorical classification of management actions, the third is a target-based optimization using Marxan, and the fourth is conservation ranking with Zonation. We present results from each method, and compare the latter three approaches for spatial coverage, biodiversity representation, fishing cost and persistence probability. All results included large areas in the north, central, and southern parts of western Madagascar. Achieving 30% representation targets with Marxan required twice the fish catch loss than the categorical method. The categorical classification and Zonation do not consider targets for conservation features. However, when we reduced Marxan targets to 16.3%, matching the representation level of the “strict protection” class of the categorical result, the methods show similar catch losses. The management category portfolio has complete coverage, and presents several management recommendations including strict protection. Zonation produces rapid conservation rankings across large, diverse datasets. Marxan is useful for identifying strict protected areas that meet representation targets, and minimize exposure probabilities for conservation features at low economic cost. We show that methods based on Zonation and a simple combination of variables can produce results comparable to Marxan for species representation and catch losses, demonstrating the value of comparing alternative approaches during initial stages of the planning process. Choosing an appropriate approach ultimately depends on scientific and political factors including representation targets, likelihood of adoption, and persistence goals. PMID:22359534

  13. Analysis of Patterns of Bushmeat Consumption Reveals Extensive Exploitation of Protected Species in Eastern Madagascar

    PubMed Central

    Jenkins, Richard K. B.; Keane, Aidan; Rakotoarivelo, Andrinajoro R.; Rakotomboavonjy, Victor; Randrianandrianina, Felicien H.; Razafimanahaka, H. Julie; Ralaiarimalala, Sylvain R.; Jones, Julia P. G.

    2011-01-01

    Understanding the patterns of wild meat consumption from tropical forests is important for designing approaches to address this major threat to biodiversity and mitigate potential pathways for transmission of emerging diseases. Bushmeat consumption has been particularly poorly studied in Madagascar, one of the world's hottest biodiversity hotspots. Studying bushmeat consumption is challenging as many species are protected and researchers must consider the incentives faced by informants. Using interviews with 1154 households in 12 communes in eastern Madagascar, as well as local monitoring data, we investigated the importance of socio-economic variables, taste preference and traditional taboos on consumption of 50 wild and domestic species. The majority of meals contain no animal protein. However, respondents consume a wide range of wild species and 95% of respondents have eaten at least one protected species (and nearly 45% have eaten more than 10). The rural/urban divide and wealth are important predictors of bushmeat consumption, but the magnitude and direction of the effect varies between species. Bushmeat species are not preferred and are considered inferior to fish and domestic animals. Taboos have provided protection to some species, particularly the Endangered Indri, but we present evidence that this taboo is rapidly eroding. By considering a variety of potential influences on consumption in a single study we have improved understanding of who is eating bushmeat and why. Evidence that bushmeat species are not generally preferred meats suggest that projects which increase the availability of domestic meat and fish may have success at reducing demand. We also suggest that enforcement of existing wildlife and firearm laws should be a priority, particularly in areas undergoing rapid social change. The issue of hunting as an important threat to biodiversity in Madagascar is only now being fully recognised. Urgent action is required to ensure that heavily hunted species are adequately protected. PMID:22194787

  14. The GLOBE/Madagascar Malaria Project: Creating Student/Educator/Scientist Partnerships With Regional Impact

    NASA Astrophysics Data System (ADS)

    Brooks, D.; Boger, R.; Rafalimanana, A.

    2006-05-01

    Malaria is a parasitic disease spread by mosquitoes in the genus Anopheles. It causes more than 300,000,000 acute illnesses and more than one million deaths annually, including the death of one African child every 30 seconds. Recent epidemiological trends include increases in malaria mortality and the emergence of drug-resistant parasites. Some experts believe that predicted climate changes during the 21st century will bring malaria to areas where it is not now common. The GLOBE Program is currently collaborating with students, educators, scientists, health department officials, and government officials in Madagascar to develop a program that combines existing GLOBE protocols for measuring atmospheric and water quality parameters with a new protocol for collecting and identifying mosquito larvae at the genus (Anopheles and non-Anopheles) level. There are dozens of Anopheles species and sub-species that are adapted to a wide range of micro-environmental conditions encountered in Madagascar's variable climate. Local data collection is essential because mosquitoes typically spend their entire lives within a few kilometers of their breeding sites. The GLOBE Program provides an ideal framework for such a project because it offers a highly structured system for defining experiment protocols that ensure consistent procedures, a widely dispersed network of observing sites, and a centralized data collection and reporting system. Following a series of training activities in 2005, students in Madagascar are now beginning to collect data. Basic environmental parameters and first attempts at larvae collection and identification are presented. Results from this project can be used to increase public awareness of malaria, to provide new scientific data concerning environmental impacts on mosquito breeding, and to provide better information for guiding effective mitigation strategies. Problems encountered include difficulties in visiting and communicating with remote school sites. These are typical problems in developing tropical countries where malaria is endemic and their solution benefits the entire scientific and educational infrastructure in those countries.

  15. Medicinal plants used by women from Agnalazaha littoral forest (Southeastern Madagascar)

    PubMed Central

    2013-01-01

    Background The country of Madagascar is renowned for its high level of biodiversity and endemism, as well as the overwhelming pressures and threats placed on the natural resources by a growing population and climate change. Traditional medicine plays an important role in the daily lives of the Malagasy for various reasons including limited access to healthcare, limited markets and traditional values. The objective of this study was to assess the modern utitilization of the Agnalazaha Forest by the local population in Mahabo-Mananivo, Madagascar, for medicinal plants used by women, and to establish a list of medicinal plants used by women sourced from Agnalazaha Forest. Methods Ethnobotanical studies were conducted over a period of five months in 2010 to determine the diversity of medicinal plants used by women in the commune of Mahabo-Mananivo. In all, 498 people were interviewed, both male and female ranging age from 15 to over 60 years old. Results 152 medicinal plants used by local people were collected during the ethnobotanical studies. Among the recorded species, eight native species are widely used by women. These species are known for their therapeutic properties in treating placental apposition and complications during childbirth as well as tropical illnesses such as malaria, filariasis, and sexual diseases like gonorrhea and syphilis. Conclusions Littoral forests are rare ecosystems that are highly threatened on the island nation of Madagascar. Our investigation into the use of medicinal plants sourced from and around the Agnalazaha Forest by the women of Mahabo-Mananivo reinforces the need for this natural resource as a first line of health care for rural families. PMID:24188563

  16. Comparison of marine spatial planning methods in Madagascar demonstrates value of alternative approaches.

    PubMed

    Allnutt, Thomas F; McClanahan, Timothy R; Andréfouët, Serge; Baker, Merrill; Lagabrielle, Erwann; McClennen, Caleb; Rakotomanjaka, Andry J M; Tianarisoa, Tantely F; Watson, Reg; Kremen, Claire

    2012-01-01

    The Government of Madagascar plans to increase marine protected area coverage by over one million hectares. To assist this process, we compare four methods for marine spatial planning of Madagascar's west coast. Input data for each method was drawn from the same variables: fishing pressure, exposure to climate change, and biodiversity (habitats, species distributions, biological richness, and biodiversity value). The first method compares visual color classifications of primary variables, the second uses binary combinations of these variables to produce a categorical classification of management actions, the third is a target-based optimization using Marxan, and the fourth is conservation ranking with Zonation. We present results from each method, and compare the latter three approaches for spatial coverage, biodiversity representation, fishing cost and persistence probability. All results included large areas in the north, central, and southern parts of western Madagascar. Achieving 30% representation targets with Marxan required twice the fish catch loss than the categorical method. The categorical classification and Zonation do not consider targets for conservation features. However, when we reduced Marxan targets to 16.3%, matching the representation level of the "strict protection" class of the categorical result, the methods show similar catch losses. The management category portfolio has complete coverage, and presents several management recommendations including strict protection. Zonation produces rapid conservation rankings across large, diverse datasets. Marxan is useful for identifying strict protected areas that meet representation targets, and minimize exposure probabilities for conservation features at low economic cost. We show that methods based on Zonation and a simple combination of variables can produce results comparable to Marxan for species representation and catch losses, demonstrating the value of comparing alternative approaches during initial stages of the planning process. Choosing an appropriate approach ultimately depends on scientific and political factors including representation targets, likelihood of adoption, and persistence goals. PMID:22359534

  17. Tectonic significance of granitoid plutons from the Andasibe paragneiss belt, east-central Madagascar

    NASA Astrophysics Data System (ADS)

    Raharimahefa, T.

    2013-12-01

    The understanding of the crustal evolution of the central Madagascar is of major significance in the study of the Precambrian basement of Madagascar and the greater Gondwana supercontinent. The study area, known as Andasibe paragneiss defines a fold belt that stretches from Ambatondrazaka to Soavina area in eastern Madagascar and is intruded by extensive granitoid intrusions. The western part of Andasibe paragneiss lies within the crustal scale Angavo shear zone, and is characterized by fine to medium-grained foliated paragneiss, which also include biotite-hornblende gneiss, migmatitic quartzofeldspathic gneiss, sillimanite-bearing gneiss, garnet-bearing gneiss, graphitic gneiss intercalates with schist, quartzite, muscovite-bearing gneiss and marble. Three samples of granitoid plutons intruding the Andasibe paragneiss yielded isotope dilution-thermal ionization mass spectrometry (ID-TIMS) U-Pb zircon ages of 801.23.8Ma, 776.54.4Ma and 772.14.2Ma. These dates are interpreted to represent the crystallization ages of these rocks and are comparable to other reported U-Pb emplacement ages for granitoid plutons within and along the north-central margin of the Angavo shear zone, which are suggested to be related to ca. 820 Ma successor-arc plutonism. These granitoids pre-dates the Angavo shear zone and folds affecting the plutons foliation are believed to have formed during the East-African Orogen, which in this part of the Malagasy Precambrian basement, is considered to have associated with Neoproterozoic extensive magmatism ca. 820 Ma to 540 Ma.

  18. New Material of Beelzebufo, a Hyperossified Frog (Amphibia: Anura) from the Late Cretaceous of Madagascar

    PubMed Central

    Evans, Susan E.; Groenke, Joseph R.; Jones, Marc E. H.; Turner, Alan H.; Krause, David W.

    2014-01-01

    The extant anuran fauna of Madagascar is exceptionally rich and almost completely endemic. In recent years, many new species have been described and understanding of the history and relationships of this fauna has been greatly advanced by molecular studies, but very little is known of the fossil history of frogs on the island. Beelzebufo ampinga, the first named pre-Holocene frog from Madagascar, was described in 2008 on the basis of numerous disarticulated cranial and postcranial elements from the Upper Cretaceous (Maastrichtian) Maevarano Formation of Madagascar. These specimens documented the presence of a hyperossified taxon that differed strikingly from extant Malagasy frogs in its large size and heavy coarse cranial exostosis. Here we describe and analyse new, articulated, and more complete material of the skull, vertebral column, and hind limb, as well as additional isolated elements discovered since 2008. μCT scans allow a detailed understanding of both internal and external morphology and permit a more accurate reconstruction. The new material shows Beelzebufo to have been even more bizarre than originally interpreted, with large posterolateral skull flanges and sculptured vertebral spine tables. The apparent absence of a tympanic membrane, the strong cranial exostosis, and vertebral morphology suggest it may have burrowed during seasonally arid conditions, which have been interpreted for the Maevarano Formation from independent sedimentological and taphonomic evidence. New phylogenetic analyses, incorporating both morphological and molecular data, continue to place Beelzebufo with hyloid rather than ranoid frogs. Within Hyloidea, Beelzebufo still groups with the South American Ceratophryidae thus continuing to pose difficulties with both biogeographic interpretations and prior molecular divergence dates. PMID:24489877

  19. Convergent evolution of chemical defense in poison frogs and arthropod prey between Madagascar and the Neotropics

    PubMed Central

    Clark, Valerie C.; Raxworthy, Christopher J.; Rakotomalala, Valérie; Sierwald, Petra; Fisher, Brian L.

    2005-01-01

    With few exceptions, aposematically colored poison frogs sequester defensive alkaloids, unchanged, from dietary arthropods. In the Neotropics, myrmicine and formicine ants and the siphonotid millipede Rhinotus purpureus are dietary sources for alkaloids in dendrobatid poison frogs, yet the arthropod sources for Mantella poison frogs in Madagascar remained unknown. We report GC-MS analyses of extracts of arthropods and microsympatric Malagasy poison frogs (Mantella) collected from Ranomafana, Madagascar. Arthropod sources for 11 “poison frog” alkaloids were discovered, 7 of which were also detected in microsympatric Mantella. These arthropod sources include three endemic Malagasy ants, Tetramorium electrum, Anochetus grandidieri, and Paratrechina amblyops (subfamilies Myrmicinae, Ponerinae, and Formicinae, respectively), and the pantropical tramp millipede R. purpureus. Two of these ant species, A. grandidieri and T. electrum, were also found in Mantella stomachs, and ants represented the dominant prey type (67.3% of 609 identified stomach arthropods). To our knowledge, detection of 5,8-disubstituted (ds) indolizidine iso-217B in T. electrum represents the first izidine having a branch point in its carbon skeleton to be identified from ants, and detection of 3,5-ds pyrrolizidine 251O in A. grandidieri represents the first ponerine ant proposed as a dietary source of poison frog alkaloids. Endemic Malagasy ants with defensive alkaloids (with the exception of Paratrechina) are not closely related to any Neotropical species sharing similar chemical defenses. Our results suggest convergent evolution for the acquisition of defensive alkaloids in these dietary ants, which may have been the critical prerequisite for subsequent convergence in poison frogs between Madagascar and the Neotropics. PMID:16087888

  20. [Resistance of Plasmodium falciparum to antimalarial drugs: impact on malaria pre-elimination in Madagascar].

    PubMed

    Andriantsoanirina, V; Ménard, D; Tuséo, L; Ratsimbasoa, A; Durand, R

    2011-06-01

    The purpose of this review was to provide up-to-date information on the resistance of Plasmodium falciparum to the main antimalarials used in Madagascar and to assist implementation of the malaria control and elimination program. In 2006, the failure rate for chloroquine treatment was 44% (n = 300) and was comparable to the rate observed in continental Africa. Most treatment failures occurred after the first week of follow-up. P. falciparum resistance to chloroquine appeared to be special in Madagascar with only 3.2% of isolates showing in vitro resistance (n = 372, 7 sentinel sites) and less than 1% harbouring mutant parasites within the Pfcrt gene. Conversely, the Pfmdr1 N86Y point mutation was found in 64.3% (n = 174) of isolates in 2006 and in 51.7% (n = 343) in 2007. Failure of combined sulfadoxine-pyrimethamine therapy, i.e., the recommended intermittent preventive treatment for malaria during pregnancy, and in vitro resistance to pyrimethamine were rare. However, the Pfdhfr 51I/59R/108N allele showed consistently high prevalence levels reaching 33.3% in 2008. Moreover, the single Pfdhfr 164L mutant allele, a haplotype unique to Madagascar, was discovered in 2006 and showed prevalence rates up to 30% in some locations (southeast) in 2008. Up to now, the quadruple mutant allele Pfdhfr 51I/59R/108N/164L has not been observed. Susceptibility to the other antimalarials tested appeared excellent but the number of isolates showing in vitro susceptibility to artemisinin derivatives has been fallen in recent years and this decline may herald a decrease in the efficacy of these drugs. PMID:21870564

  1. Rainforest Pharmacopeia in Madagascar Provides High Value for Current Local and Prospective Global Uses

    PubMed Central

    Golden, Christopher D.; Rasolofoniaina, B. J. Rodolph; Anjaranirina, E. J. Gasta; Nicolas, Lilien; Ravaoliny, Laurent; Kremen, Claire

    2012-01-01

    Botanical diversity provides value to humans through carbon sequestration, air and water purification, and the provisioning of wild foods and ethnomedicines. Here we calculate the value of botanical ethnomedicines in a rainforest region of Madagascar, the Makira Protected Area, using a substitution method that combines replacement costs and choice modeling. The Makira watershed may comprise approximately 0.8% of global botanical diversity and possesses enormous value both in its ability to provision botanical ethnomedicines to local people and as a source of potentially novel pharmaceutical drugs for society as a whole. Approximately 241 locally-recognized species are used as ethnomedicines, including 113 agricultural or weed species. We equated each ethnomedicinal treatment to the monetary value of a comparable pharmaceutical treatment adjusted by personal preferences in perceived efficacy (rather than from known or assumed medicinal equivalency). The benefit value of these botanical ethnomedicines per individual is $5.40–7.90 per year when using the value of highly subsidized Malagasy pharmaceuticals and $100.60–287.40 when using the value of American pharmaceuticals. Using local pharmaceuticals as substitutes, the value per household is $30.24–44.30 per year, equivalent to 43–63% of median annual household income, demonstrating their local importance. Using the value of American pharmaceuticals, the amount is equivalent to 22–63% of the median annual health care expenditures for American adults under 45 in 2006. The potential for developing novel biomedicines from the Makira watershed’s unique flora ranges in untapped benefit value from $0.3–5.7 billion for American pharmaceutical companies, non-inclusive of the importance of providing novel medicines and improved healthcare to society. This study provides evidence of the tremendous current local and prospective global value of botanical ethnomedicines and furthers arguments for the conservation of tropical forests for sustainable use. Botanique de la diversité apporte de la valeur à l’homme par la séquestration du carbone, de l’air et de purification de l’eau, et le provisionnement des aliments sauvages et ethnomedicines. Ici, nous calculons la valeur de ethnomedicines botaniques dans une région de forêt de Madagascar, la zone protégée de Makira, en utilisant une méthode de substitution qui combine les coûts de remplacement et la modélisation des choix. Le bassin versant de Makira peut comprendre environ 0,8% de la diversité botanique mondiale et possède une valeur énorme à la fois dans sa capacité à fournir ethnomedicines botaniques à la population locale et en tant que source de nouveaux médicaments potentiellement pharmaceutiques pour la société dans son ensemble. Environ 241 espèces localement reconnus sont utilisés comme ethnomedicines, y compris 113 espèces d’agricoles ou de mauvaises herbes. Nous assimilé chaque traitement ethnomédicales à la valeur monétaire d’un traitement comparable pharmaceutique ajusté en fonction des préférences personnelles en matière d’efficacité perçue (plutôt que de l’équivalence médicament connu ou supposé). La valeur de l’avantage de ces ethnomedicines botaniques par individu est de $5,40 à 7.90 par année lors de l’utilisation de la valeur des produits pharmaceutiques malgaches fortement subventionnés et de $100,60 à 287,40 lors de l’utilisation de la valeur des produits pharmaceutiques américains. Utilisation de produits pharmaceutiques locales comme des substituts, la valeur par ménage est de $30.24 à 44.30 par an, équivalent à 43–63% du revenu médian des ménages annuelle, ce qui démontre leur importance locale. Utilisation de la valeur des produits pharmaceutiques américaines, le montant est équivalent à 22–63% de la médiane des dépenses annuelles de soins de santé pour les adultes américains de moins de 45 en 2006. Le potentiel de développement de nouveaux biomédicaments des fourneaux dans le bassin versant de la flore Makira unqiue de la valeur des avantages inexploité de $0,3 à 5,7 milliards pour les sociétés pharmaceutiques américaines, non compris l’importance de fournir de nouveaux médicaments et de soins de santé amélioré à la société. Cette étude fournit une preuve de l’énorme valeur actuelle globale locale et prospective de ethnomedicines botaniques et des arguments fait avancer pour la conservation des forêts tropicales pour l’utilisation durable. PMID:22848447

  2. Lead (Pb) contamination of self-supply groundwater systems in coastal Madagascar and predictions of blood lead levels in exposed children.

    PubMed

    Akers, D Brad; MacCarthy, Michael F; Cunningham, Jeffrey A; Annis, Jonathan; Mihelcic, James R

    2015-03-01

    Thousands of households in coastal Madagascar rely on locally manufactured pitcher-pump systems to provide water for drinking, cooking, and household use. These pumps typically include components made from lead (Pb). In this study, concentrations of Pb in water were monitored at 18 household pitcher pumps in the city of Tamatave over three sampling campaigns. Concentrations of Pb frequently exceeded the World Health Organization's provisional guideline for drinking water of 10 μg/L. Under first-draw conditions (i.e., after a pump had been inactive for 1 h), 67% of samples analyzed were in excess of 10 μg/L Pb, with a median concentration of 13 μg/L. However, flushing the pump systems before collecting water resulted in a statistically significant (p < 0.0001) decrease in Pb concentrations: 35% of samples collected after flushing exceeded 10 μg/L, with a median concentration of 9 μg/L. Based on measured Pb concentrations, a biokinetic model estimates that anywhere from 15% to 70% of children living in households with pitcher pumps may be at risk for elevated blood lead levels (>5 μg/dL). Measured Pb concentrations in water were not correlated at statistically significant levels with pump-system age, well depth, system manufacturer, or season of sample collection; only the contact time (i.e., flushed or first-draw condition) was observed to correlate significantly with Pb concentrations. In two of the 18 systems, Pb valve weights were replaced with iron, which decreased the observed Pb concentrations in the water by 57-89% in one pump and by 89-96% in the other. Both systems produced samples exclusively below 10 μg/L after substitution. Therefore, relatively straightforward operational changes on the part of the pump-system manufacturers and pump users might reduce Pb exposure, thereby helping to ensure the continued sustainability of pitcher pumps in Madagascar. PMID:25608177

  3. [Madagascar: public health situation on the "Big Island" at the beginning of the 21st century].

    PubMed

    Andrianarisoa, A C E; Rakotoson, J; Randretsa, M; Rakotondravelo, S; Rakotoarimanana, R D; Rakotomizao, J; Aubry, P

    2007-02-01

    The main public health issue in Madagascar at the beginning of the 21st century still involves transmissible infectious diseases including re-emerging diseases such as bubonic plague and emerging diseases such as HIV/AIDS, dengue fever and Chikungunya virus infection. Health and hygiene especially access to clean water is still poor especially in rural areas. No improvement in the public health situation with regard to malaria, schistomosomiais or cysticercosis as well as non-infectious diseases such as protein-energy malnutrition is expected within the next decade. PMID:17506269

  4. A new Gephyromantis (Phylacomantis) frog species from the pinnacle karst of Bemaraha, western Madagascar

    PubMed Central

    Crottini, Angelica; Glaw, Frank; Casiraghi, Maurizio; Jenkins, Richard K.B.; Mercurio, Vincenzo; Randrianantoandro, Christian; Randrianirina, Jasmin E.; Andreone, Franco

    2011-01-01

    Abstract We describe a new mantellid frog of the subfamily Mantellinae from the karstic Bemaraha Plateau, western Madagascar. The new species belongs to the genus Gephyromantis, subgenus Phylacomantis, which previously included Gephyromantis azzurrae, Gephyromantis corvus and Gephyromantis pseudoasper. Gephyromantis atsingy sp. n. has a snout-vent length of 35–43 mm and is a scansorial frog living among the Tsingy de Bemaraha pinnacles and inside the caves present in the area. A morphological analysis and biomolecular comparison revealed the degree of differentiation between these four species of the Phylacomantis subgenus.The new species seems to be endemic to Tsingy de Bemaraha. PMID:21594161

  5. Antiproliferative Cardenolides of an Elaeodendron sp. from the Madagascar Rain Forest

    PubMed Central

    Cao, Shugeng; Brodie, Peggy J.; Miller, James S.; Ratovoson, Fidy; Callmander, Martin W.; Randrianasolo, Sennen; Rakotobe, Etienne; Rasamison, Vincent E.; Suh, Edward M.; TenDyke, Karen; Kingston, David G. I.

    2008-01-01

    Bioassay-guided fractionation of an ethanol extract obtained from the Madagascar plant Elaeodendron sp. led to the isolation of two new cardenolides, elaeodendrosides T and U (1 and 2). The structures of the new compounds were elucidated using 1D and 2D NMR experiments, and mass spectrometry. Compounds 1, 3, 4, and 5 showed significant antiproliferative activity against A2780 human ovarian cancer cells with IC50 values of 0.085, 0.019, 0.19, and 0.10 µM, respectively, while compounds 2 and 6 were less active. PMID:17547460

  6. Oxygen isotope systematics of gem corundum deposits in Madagascar: relevance for their geological origin

    NASA Astrophysics Data System (ADS)

    Giuliani, Gaston; Fallick, Anthony; Rakotondrazafy, Michel; Ohnenstetter, Daniel; Andriamamonjy, Alfred; Ralantoarison, Thogne; Rakotosamizanany, Saholy; Razanatseheno, Marie; Offant, Yohann; Garnier, Virginie; Dunaigre, Christian; Schwarz, Dietmar; Mercier, Alain; Ratrimo, Voahangy; Ralison, Bruno

    2007-02-01

    The oxygen isotopic composition of gem corundum was measured from 22 deposits and occurrences in Madagascar to provide a gemstone geological identification and characterization. Primary corundum deposits in Madagascar are hosted in magmatic (syenite and alkali basalt) and metamorphic rocks (gneiss, cordieritite, mafic and ultramafic rocks, marble, and calc-silicate rocks). In both domains the circulation of fluids, especially along shear zones for metamorphic deposits, provoked in situ transformation of the corundum host rocks with the formation of metasomatites such as phlogopite, sakenite, and corundumite. Secondary deposits (placers) are the most important economically and are contained in detrital basins and karsts. The oxygen isotopic ratios (18O/16O) of ruby and sapphire from primary deposits are a good indicator of their geological origin and reveal a wide range of ?18O (Vienna Standard Mean Ocean Water) between 1.3 and 15.6. Metamorphic rubies are defined by two groups of ?18O values in the range of 1.7 to 2.9 (cordieritite) and 3.8 to 6.1 (amphibolite). Magmatic rubies from pyroxenitic xenoliths contained in the alkali basalt of Soamiakatra have ?18O values ranging between 1.3 and 4.7. Sapphires are classified into two main groups with ?18O in the range of 4.7 to 9.0 (pyroxenite and feldspathic gneiss) and 10.7 to 15.6 (skarn in marble from Andranondambo). The ?18O values for gem corundum from secondary deposits have a wide spread between -0.3 and 16.5. The ruby and sapphire found in placers linked to alkali basalt environments in the northern and central regions of Madagascar have consistent ?18O values between 3.5 and 6.9. Ruby from the placers of Vatomandry and Andilamena has ?18O values of 5.9, and between 0.5 and 4.0, respectively. The placers of the Ilakaka area are characterized by a huge variety of colored sapphires and rubies, with ?18O values between -0.3 and 16.5, and their origin is debated. A comparison with oxygen isotope data obtained on gem corundum from Eastern Africa, India, and Sri Lanka is presented. Giant placer deposits from Sri Lanka, Madagascar, and Tanzania have a large variety of colored sapphires and rubies with a large variation in ?18O due to mingling of corundum of different origin: mafic and ultramafic rocks for ruby, desilicated pegmatites for blue sapphire, syenite for yellow, green, and blue sapphire, and skarn in marbles for blue sapphire.

  7. Monomia calla, a new species of swimming crab (Decapoda, Portunidae)
    from Madagascar and the Philippines.

    PubMed

    Koch, Milan; Nguyen, Thanh Son; ?uri, Zden?k

    2015-01-01

    A new species of portunid crab (Brachyura: Portunidae) from southern Madagascar and central Philippines is described. Monomia calla sp. nov. is most similar in morphology toM. lecromi (Moosa, 1996) from the Chesterfield Islands in the southwestern Pacific Ocean, and M. rubromarginata (Lanchester, 1900) from the South China Sea, Singapore, Malay Archipelago and the northern half of Australia. The new species can be easily distinguished from all congeners by the distinctive morphology of the male first gonopod. The number of species of the Indo-West Pacific genus Monomia now stands at 12. PMID:26250003

  8. Descriptions and biological notes on three unusual mantellid tadpoles (Amphibia: Anura: Mantellidae) from southeastern Madagascar

    USGS Publications Warehouse

    Altig, R.; McDiarmid, R.W.

    2006-01-01

    The morphologies of three unusual tadpoles from slow-flowing, sandy-bottomed, rain forest streams in southeastern Madagascar are described. The large oral apparatus of the tadpole of Boophis picturatus Glaw, Vences, Andreone, and Vallan, 2001 lacks all keratinized structures and has an elaborately-folded lower labium with five, radially oriented, flattopped ridges. The tadpole of Mantidactylus guttulatus (Boulenger, 1881) lacks all keratinized mouthparts and has three immense papillae where the upper jaw normally occurs. The tadpole of Mantidactylus lugubris (Dumeril, 1853) has an ornate oral apparatus involving greatly hypertrophied derivatives of jaw serrations and unique structures on the lower labium that resemble labial teeth.

  9. [Experience in the use of the malaria rapid diagnostic test in Madagascar].

    PubMed

    Rakotoarivelo, R A; Andrianasolo, R; Rakoto Sedson, R; Randria, M J D; Rapelanoro Rabenja, F

    2010-02-01

    Diagnosis of malaria cases depends on parasitological examination. Since 2006, the Department of Infectious Diseases at the Joseph Raseta Befelatanana University Hospital in Madagascar has been using the malaria rapid diagnostic test. The percentage of malaria cases (presumed or confirmed) in relation to the number of hospitalized patients has decreased. It was 23.4% in 2003, 10.3% in 2006 and 4.3% in 2008 (p<0.01532). To improve management of malaria cases and rationalize use of antimalarial agents, diagnosis should be confirmed by rapid diagnostic tests. PMID:20337134

  10. Analyse macro-sociolinguistique d'une situation de diglossie: le cas de Madagascar (A Macro-Sociolinguistic Analysis of a Diglossic Situation: The Case of Madagascar). Publication H-6.

    ERIC Educational Resources Information Center

    Rambelo, Michel

    The languages used in Madagascar are examined from the following perspectives: the linguistic varieties and functions socially recognized at the community level; the oppositions and complementarities that have become established between languages in contact; and the speakers' attitudes toward those varieties. The report focuses on the following…

  11. Isolation of 22 new Haliaeetus microsatellite loci and their characterization in the critically endangered Madagascar fish-eagle (Haliaeetus vociferoides) and three other Haliaeetus eagle species

    USGS Publications Warehouse

    Tingay, R.E.; Dawson, D.A.; Pandhal, J.; Clarke, M.L.; David, V.A.; Hailer, F.; Culver, M.

    2007-01-01

    We isolated a total of 22 microsatellite loci from two Haliaeetus species: the Madagascar fish-eagle (Haliaeetus vociferoides) and the bald eagle (Haliaeetus leucocephalus). Five loci were monomorphic in both the Madagascar fish-eagle (n = 24-43) and the bald eagle (n = 2-8) but were found to be polymorphic in other Haliaeetus species. Haliaeetus loci have proved useful for investigating gene flow in Haliaeetus and Aquila eagles. Ten loci were polymorphic in the critically endangered Madagascar fish-eagle and will be used to investigate the genetic population structure and mating system in this species. ?? 2007 The Authors.

  12. Well-Being Is a Process of Becoming: Respondent-Led Research with Organic Farmers in Madagascar

    ERIC Educational Resources Information Center

    Farnworth, Cathy Rozel

    2009-01-01

    Malagasy "players"--farmers, middle men, organic organisations and policy makers--see in export-orientated organic agriculture a way for Madagascar to build upon its historic export strengths: spices, essential oils, medicinal plants and tropical fruits. They point to the "de facto" organic status of most farming in the country and view organic

  13. Well-Being Is a Process of Becoming: Respondent-Led Research with Organic Farmers in Madagascar

    ERIC Educational Resources Information Center

    Farnworth, Cathy Rozel

    2009-01-01

    Malagasy "players"--farmers, middle men, organic organisations and policy makers--see in export-orientated organic agriculture a way for Madagascar to build upon its historic export strengths: spices, essential oils, medicinal plants and tropical fruits. They point to the "de facto" organic status of most farming in the country and view organic…

  14. A new species of the genus Basidissus (Coleoptera: Anthribidae) from east Madagascar, with a key to species..

    PubMed

    Trýzna Miloš; Baňař, Petr

    2013-01-01

    A new species, Basidissus bendai Trýzna & Baiat sp. nov. (Anthribidae: Anthribinae: Platyrhinini), from east Madagascar is described, female genitalia are studied and illustrated, and the mobility of the stylus of the toothed plate is discussed. Colour photographs as well as a key to Madagascan species of the genus Basidissus are provided. PMID:26120659

  15. Setting Up a Bibliographic Database from National Inventory of Scientific and Technical Literature. The CIDST Experience in Madagascar.

    ERIC Educational Resources Information Center

    Andriamparany, Louis Marius; And Others

    1991-01-01

    Describes the development of a bibliographic database in Madagascar through a national inventory of scientific and technical literature. The roles of the Ministry of Scientific and Technological Research for Development (MRSTD) and its information service, CIDST, are described; database products are discussed; and future prospects are suggested.

  16. Possessed and dispossessed youth: spirit possession of school children in northwest Madagascar.

    PubMed

    Sharp, L A

    1990-09-01

    Spirit possession is a common experience shared by many women in northwest Madagascar. In the town of Ambanja, possession by volatile and dangerous Njarinintsy spirits is an affliction which strikes young, adolescent schoolgirls. When Njarinintsy is contrasted with tromba, another well-known class of spirits found in this region, it becomes clear that Njarinintsy possession is a relatively recent phenomenon, and its victims form a discrete and unusual group. These girls are, in essence, young migrants, who have moved alone to town in order to attend school. Close examination of their experiences reveals that these young girls must cope, on their own, with the conflicts and contradictions that plague the shift from rural to town life, and from youth to adulthood. Such problems are further complicated by those associated with educational policy in Madagascar. These children, more than any other members of this community, suffer from the contradictions of a fragmented world. Possession provides them with a means through which to express the chaos inherent in their daily lives. PMID:2245639

  17. Susceptibility to Yersinia pestis experimental infection in wild Rattus rattus, reservoir of plague in Madagascar.

    PubMed

    Tollenaere, C; Rahalison, L; Ranjalahy, M; Duplantier, J-M; Rahelinirina, S; Telfer, S; Brouat, C

    2010-06-01

    In Madagascar, the black rat, Rattus rattus, is the main reservoir of plague (Yersinia pestis infection), a disease still responsible for hundreds of cases each year in this country. This study used experimental plague challenge to assess susceptibility in wild-caught rats to better understand how R. rattus can act as a plague reservoir. An important difference in plague resistance between rat populations from the plague focus (central highlands) and those from the plague-free zone (low altitude area) was confirmed to be a widespread phenomenon. In rats from the plague focus, we observed that sex influenced plague susceptibility, with males slightly more resistant than females. Other individual factors investigated (weight and habitat of sampling) did not affect plague resistance. When infected at high bacterial dose (more than 10⁵ bacteria injected), rats from the plague focus died mainly within 3-5 days and produced specific antibodies, whereas after low-dose infection (< 5,000 bacteria), delayed mortality was observed and surviving seronegative rats were not uncommon. These results concerning plague resistance level and the course of infection in the black rat would contribute to a better understanding of plague circulation in Madagascar. PMID:20443044

  18. Widespread presence of the pathogenic fungus Batrachochytrium dendrobatidis in wild amphibian communities in Madagascar

    PubMed Central

    Bletz, Molly C.; Rosa, Gonçalo M.; Andreone, Franco; Courtois, Elodie A.; Schmeller, Dirk S.; Rabibisoa, Nirhy H. C.; Rabemananjara, Falitiana C. E.; Raharivololoniaina, Liliane; Vences, Miguel; Weldon, Ché; Edmonds, Devin; Raxworthy, Christopher J.; Harris, Reid N.; Fisher, Matthew C.; Crottini, Angelica

    2015-01-01

    Amphibian chytridiomycosis, an emerging infectious disease caused by the fungus Batrachochytrium dendrobatidis (Bd), has been a significant driver of amphibian declines. While globally widespread, Bd had not yet been reported from within Madagascar. We document surveys conducted across the country between 2005 and 2014, showing Bd's first record in 2010. Subsequently, Bd was detected in multiple areas, with prevalence reaching up to 100%. Detection of Bd appears to be associated with mid to high elevation sites and to have a seasonal pattern, with greater detectability during the dry season. Lineage-based PCR was performed on a subset of samples. While some did not amplify with any lineage probe, when a positive signal was observed, samples were most similar to the Global Panzootic Lineage (BdGPL). These results may suggest that Bd arrived recently, but do not exclude the existence of a previously undetected endemic Bd genotype. Representatives of all native anuran families have tested Bd-positive, and exposure trials confirm infection by Bd is possible. Bd's presence could pose significant threats to Madagascar's unique “megadiverse” amphibians. PMID:25719857

  19. A new Stumpffia (Amphibia: Anura: Microhylidae) from the Ranomafana region, south-eastern Madagascar.

    PubMed

    Ndriantsoa, Serge H; Riemann, Jana C; Vences, Miguel; Klages, Johannes; Raminosoa, Noromalala R; Rödel, Mark-Oliver; Glos, Julian

    2013-01-01

    We describe a new species of small-sized frogs from degraded rainforest patches in the southern central east of Madagascar. Stumpffia miery sp. nov. has a snout-vent length of 13-15 mm and can be distinguished from all other nominal species of Stumpffia by its body size and absence of toe reduction combined with length reduction of fingers I, II and IV in external view. The advertisement call is a single tonal chirping note that ranges in duration between 51-88 ms and is emitted after relatively regular inter-note intervals (duration of 2679-4247 ms, call repetition rate 0.3/sec, frequency range 7700-8300 Hz, dominant frequency 7751-8225 Hz). Its type locality is the Ambolo forest fragment close to Ranomafana village in southeastern Madagascar. Molecular data from DNA sequences of one mitochondrial and one nuclear gene indicate a high divergence from all nominal species of Stumpffia, suggesting that it represents a strongly differentiated independent evolutionary unit. Stumnpffia miery sp. nov. is apparently able to tolerate some degree of habitat degradation and therefore is probably not threatened with extinction. PMID:26042312

  20. Multiple colonization of Madagascar and Socotra by colubrid snakes: evidence from nuclear and mitochondrial gene phylogenies.

    PubMed

    Nagy, Zoltán Tamás; Joger, Ulrich; Wink, Michael; Glaw, Frank; Vences, Miguel

    2003-12-22

    Colubrid snakes form a speciose group of unclarified phylogeny. Their almost cosmopolitan distribution could be interpreted as a product of plate-tectonic vicariance. We used sequences of the nuclear c-mos, the mitochondrial cytochrome b and the 16S rRNA genes in 41 taxa to elucidate the relationships between the endemic colubrid genera found in Madagascar and in the Socotra archipelago. The well-resolved trees indicate multiple origins of both the Malagasy and the Socotran taxa. The Malagasy genus Mimophis was nested within the Psammophiinae, and the Socotran Hemerophis was closely related to Old World representatives of the former genus Coluber. The remaining 14 genera of Malagasy colubrids formed a monophyletic sister group of the Socotran Ditypophis (together forming the Pseudoxyrhophiinae). Molecular-clock estimates place the divergence of Malagasy and Socotran colubrids from their non-insular sister groups into a time-frame between the Eocene and Miocene. Over-seas rafting is the most likely hypothesis for the origin of at least the Malagasy taxa. The discovery of a large monophyletic clade of colubrids endemic to Madagascar indicates a need for taxonomic changes. The relationship of this radiation to the Socotran Ditypophis highlights the potential of the Indian Ocean islands to act as an evolutionary reservoir for lineages that have become extinct in Africa and Asia. PMID:14728785

  1. Statut familial et inégalités face à la scolarisation à Madagascar

    NASA Astrophysics Data System (ADS)

    Delaunay, Valérie; Gastineau, Bénédicte; Andriamaro, Frédérique

    2013-12-01

    The impact of family status in Madagascar on inequalities in schooling - In this article, in the context of generalised access to primary education and parity between girls and boys, we analyse data from the Demographic and Health Survey (DHS) 2009 in Madagascar to examine inequalities in schooling related to children's status in the family. The results confirm the protective benefit for children of living with their biological parents. Fostered children are disadvantaged, especially and increasingly so depending on whether they live with an uncle or aunt, with a distant relative or a non-relative. Conversely, children who reside in the home of a brother or sister are not disadvantaged, a result which reflects the role of elder children in family education strategies. Grandparents play a moderately positive role in schooling. The death of the father is an important factor in dropping out. Finally, children whose parent or parents are not household heads are disadvantaged in terms of schooling compared to children of household heads.

  2. Primates as Predictors of Mammal Community Diversity in the Forest Ecosystems of Madagascar

    PubMed Central

    Muldoon, Kathleen M.; Goodman, Steven M.

    2015-01-01

    The geographic distribution of species is the typical metric for identifying priority areas for conservation. Since most biodiversity remains poorly studied, a subset of charismatic species, such as primates, often stand as surrogates for total biodiversity. A central question is therefore, how effectively do primates predict the pooled species richness of other mammalian taxa? We used lemurs as indicator species to predict total non-primate mammal community richness in the forest ecosystems of Madagascar. We combine environmental and species occurrence data to ascertain the extent to which primate diversity can predict (1) non-primate mammal α-diversity (species richness), (2) non-primate complementarity, and (3) non-primate β-diversity (species turnover). Our results indicate that primates are effective predictors of non-primate mammal community diversity in the forest ecosystems of Madagascar after controlling for habitat. When individual orders of mammals are considered, lemurs effectively predict the species richness of carnivorans and rodents (but not afrosoricids), complementarity of rodents (but not carnivorans or afrosoricids), and all individual components of β-diversity. We conclude that lemurs effectively predict total non-primate community richness. However, surrogate species alone cannot achieve complete representation of biodiversity. PMID:26334525

  3. Interannual variability of South Equatorial Current bifurcation and western boundary currents along the Madagascar coast

    NASA Astrophysics Data System (ADS)

    Yamagami, Y.; Tozuka, T.

    2015-12-01

    The South Equatorial Current (SEC) in the southern Indian Ocean bifurcates at the east coast of Madagascar into the Northeast and Southeast Madagascar Currents (NEMC and SEMC, respectively). In observational and reanalysis data, interannual variations of the NEMC and SEMC transports are strongly correlated with those of the SEC transport, rather than those of the SEC bifurcation latitude (SBL). Their dynamical mechanisms are then examined based on the Time-Dependent Island Rule for the first time. It is shown that interannual anomalies of the SBL as well as the NEMC and SEMC transports are predominantly a response to the anomalous inflow from the ocean interior that is determined by the meridional interior transport. This, in turn, is a result of westward propagating Rossby waves induced by wind stress curl anomalies mainly in 60°E-90°E. The above mechanism is contrasted with that of the seasonal variation, where the local transport driven by wind stress around the island plays a role. Furthermore, the interannual variations of the SBL and the NEMC and SEMC transports are significantly correlated with the Niño 3.4 index with 5-15 months lag. It is suggested that diabatic heating anomalies associated with the El Niño/Southern Oscillation (ENSO) along with a local process in the southeastern Indian Ocean may generate wind stress curl anomalies over the southern Indian Ocean.

  4. Effects of anthropogenic disturbance on indri (Indri indri) health in Madagascar.

    PubMed

    Junge, Randall E; Barrett, Meredith A; Yoder, Anne D

    2011-07-01

    Anthropogenic habitat disturbance impairs ecosystem health by fragmenting forested areas, introducing environmental contamination, and reducing the quality of habitat resources. The effect of this disturbance on wildlife health is of particular concern in Madagascar, one of the world's biodiversity hotspots, where anthropogenic pressures on the environment remain high. Despite the conservation importance of threatened lemur populations in Madagascar, few data exist on the effects of anthropogenic disturbance on lemur health. To examine these impacts, indri (Indri indri) populations were evaluated from two forest reserves that differ in their exposure to anthropogenic disturbance. We compared the health status of 36 indri individuals from two sites: one population from a protected, undisturbed area of lowland evergreen humid forest and the other population from a reserve exposed to frequent tourism and forest degradation. Comparison of indri health parameters between sites suggests an impact of anthropogenic disturbance, including significant differences in leukocyte count and differential, 12 serum parameters, 6 trace minerals, and a higher diversity of parasites, with a significant difference in the presence of the louse, Trichophilopterus babakotophilus. These data suggest that indri living in disturbed forests may experience physiological changes and increased susceptibility to parasitism, which may ultimately impair reproductive success and survival. PMID:21344463

  5. Performance of a receptive language test among young children in Madagascar.

    PubMed

    Weber, Ann M; Fernald, Lia C H; Galasso, Emanuela; Ratsifandrihamanana, Lisy

    2015-01-01

    Language tests developed and validated in one country may lose their desired properties when translated for use in another, possibly resulting in misleading estimates of ability. Using Item Response Theory (IRT) methodology, we assess the performance of a test of receptive vocabulary, the U.S.-validated Peabody Picture Vocabulary Test-Third Edition (PPVT-III), when translated, adapted, and administered to children 3 to 10 years of age in Madagascar (N = 1372), in the local language (Malagasy). Though Malagasy is considered a single language, there are numerous dialects spoken in Madagascar. Our findings were that test scores were positively correlated with age and indicators of socio-economic status. However, over half (57/96) of items evidenced unexpected response variation and/or bias by local dialect spoken. We also encountered measurement error and reduced differentiation among person abilities when we used the publishers' recommended stopping rules, largely because we lost the original item ordering by difficulty when we translated test items into Malagasy. Our results suggest that bias and testing inefficiency introduced from the translation of the PPVT can be significantly reduced with the use of methods based on IRT at both the pre-testing and analysis stages. We explore and discuss implications for cross-cultural comparisons of internationally recognized tests, such as the PPVT. PMID:25830221

  6. Miocene benthic foraminifera from Nosy Makamby and Amparafaka, Mahajanga Basin, northwestern Madagascar

    NASA Astrophysics Data System (ADS)

    Ramihangihajason, Tolotra N.; Andrianavalona, Tsiory H.; Razafimbelo, Rachel; Rahantarisoa, Lydia; Ali, Jason R.; Samonds, Karen E.

    2014-12-01

    Madagascar is well known for its fossil deposits and hosts one of the world's most important Upper Cretaceous terrestrial faunal sites (in the Mahajanga and Morondava Basins in the west and northwest of the island). Cenozoic marine fossils are also described from Madagascar, but these have received far less attention from the paleontological community, with most of this work dating from the 19th and early 20th centuries. Our study reports a new comprehensive microfossil assemblage from a Miocene sequence on the island of Nosy Makamby. After washing, sieving and sorting (∼30 kg), twenty-five genera of foraminifera were identified including Alveolina, Ammodiscus, Ammonia, Archaias, Bolivina, Borelis, Cassidulina, Cyclammina, Cycloforina, Dentalina, Elphidium, Hauerina, Lagena, Lepidocyclina, Nodosaria, Nonion, Nonionella, Peneroplis, Pyrgo, Quinqueloculina, Rhabdammina, Spirillina, Spirolina, Spiroloculina and Triloculina. Ostracods are found in association with the foraminifera, as well as many other macroinvertebrate fossils (including bivalves, gastropods, and echinoids) in addition to vertebrate fossils. Together, the assemblage indicates that during the late Miocene, Nosy Makamby was a tropical, near-shore environment, probably similar to that seen today. Furthermore, the existence of epiphytic foraminiferans (e.g., Elphidium) suggests that sea-grass beds were likely present.

  7. The Settlement of Madagascar: What Dialects and Languages Can Tell Us

    PubMed Central

    Serva, Maurizio

    2012-01-01

    The dialects of Madagascar belong to the Greater Barito East group of the Austronesian family and it is widely accepted that the Island was colonized by Indonesian sailors after a maritime trek that probably took place around 650 CE. The language most closely related to Malagasy dialects is Maanyan, but Malay is also strongly related especially for navigation terms. Since the Maanyan Dayaks live along the Barito river in Kalimantan (Borneo) and they do not possess the necessary skill for long maritime navigation, they were probably brought as subordinates by Malay sailors. In a recent paper we compared 23 different Malagasy dialects in order to determine the time and the landing area of the first colonization. In this research we use new data and new methods to confirm that the landing took place on the south-east coast of the Island. Furthermore, we are able to state here that colonization probably consisted of a single founding event rather than multiple settlements.To reach our goal we find out the internal kinship relations among all the 23 Malagasy dialects and we also find out the relations of the 23 dialects to Malay and Maanyan. The method used is an automated version of the lexicostatistic approach. The data from Madagascar were collected by the author at the beginning of 2010 and consist of Swadesh lists of 200 items for 23 dialects covering all areas of the Island. The lists for Maanyan and Malay were obtained from a published dataset integrated with the author's interviews. PMID:22363465

  8. Affordability of emergency obstetric and neonatal care at public hospitals in Madagascar.

    PubMed

    Honda, Ayako; Randaoharison, Pierana Gabriel; Matsui, Mitsuaki

    2011-05-01

    Timely access to emergency obstetric care is necessary to save the lives of women experiencing complications at delivery, and for newborn babies. Out-of-pocket costs are one of the critical factors hindering access to such services in low- and middle-income countries. This study measured out-of-pocket costs for caesarean section and neonatal care at an urban tertiary public hospital in Madagascar, assessed affordability in relation to household expenditure and investigated where families found the money to cover these costs. Data were collected for 103 women and 73 newborns at the Centre Hospitalier Universitaire de Mahajanga in the Boeny region of Madagascar between September 2007 and January 2008. Out-of-pocket costs for caesarean section were catastrophic for middle and lower socio-economic households, and treatment for neonatal complications also created a big financial burden, with geographical and other financial barriers further limiting access to hospital care. This study identified 12 possible cases where the mother required an emergency caesarean section and her newborn required emergency care, placing a double burden on the household. In an effort to make emergency obstetric and neonatal care affordable and available to all, including those living in rural areas and those of medium and lower socio-economic status, well-designed financial risk protection mechanisms and a strong commitment by the government to mobilise resources to finance the country's health system are necessary. PMID:21555082

  9. Performance of a Receptive Language Test among Young Children in Madagascar

    PubMed Central

    Weber, Ann M.; Fernald, Lia C. H.; Galasso, Emanuela; Ratsifandrihamanana, Lisy

    2015-01-01

    Language tests developed and validated in one country may lose their desired properties when translated for use in another, possibly resulting in misleading estimates of ability. Using Item Response Theory (IRT) methodology, we assess the performance of a test of receptive vocabulary, the U.S.-validated Peabody Picture Vocabulary Test-Third Edition (PPVT-III), when translated, adapted, and administered to children 3 to 10 years of age in Madagascar (N = 1372), in the local language (Malagasy). Though Malagasy is considered a single language, there are numerous dialects spoken in Madagascar. Our findings were that test scores were positively correlated with age and indicators of socio-economic status. However, over half (57/96) of items evidenced unexpected response variation and/or bias by local dialect spoken. We also encountered measurement error and reduced differentiation among person abilities when we used the publishers’ recommended stopping rules, largely because we lost the original item ordering by difficulty when we translated test items into Malagasy. Our results suggest that bias and testing inefficiency introduced from the translation of the PPVT can be significantly reduced with the use of methods based on IRT at both the pre-testing and analysis stages. We explore and discuss implications for cross-cultural comparisons of internationally recognized tests, such as the PPVT. PMID:25830221

  10. Primates as Predictors of Mammal Community Diversity in the Forest Ecosystems of Madagascar.

    PubMed

    Muldoon, Kathleen M; Goodman, Steven M

    2015-01-01

    The geographic distribution of species is the typical metric for identifying priority areas for conservation. Since most biodiversity remains poorly studied, a subset of charismatic species, such as primates, often stand as surrogates for total biodiversity. A central question is therefore, how effectively do primates predict the pooled species richness of other mammalian taxa? We used lemurs as indicator species to predict total non-primate mammal community richness in the forest ecosystems of Madagascar. We combine environmental and species occurrence data to ascertain the extent to which primate diversity can predict (1) non-primate mammal ?-diversity (species richness), (2) non-primate complementarity, and (3) non-primate ?-diversity (species turnover). Our results indicate that primates are effective predictors of non-primate mammal community diversity in the forest ecosystems of Madagascar after controlling for habitat. When individual orders of mammals are considered, lemurs effectively predict the species richness of carnivorans and rodents (but not afrosoricids), complementarity of rodents (but not carnivorans or afrosoricids), and all individual components of ?-diversity. We conclude that lemurs effectively predict total non-primate community richness. However, surrogate species alone cannot achieve complete representation of biodiversity. PMID:26334525

  11. DNA barcoding for effective biodiversity assessment of a hyperdiverse arthropod group: the ants of Madagascar

    PubMed Central

    Smith, M. Alex; Fisher, Brian L; Hebert, Paul D.N

    2005-01-01

    The role of DNA barcoding as a tool to accelerate the inventory and analysis of diversity for hyperdiverse arthropods is tested using ants in Madagascar. We demonstrate how DNA barcoding helps address the failure of current inventory methods to rapidly respond to pressing biodiversity needs, specifically in the assessment of richness and turnover across landscapes with hyperdiverse taxa. In a comparison of inventories at four localities in northern Madagascar, patterns of richness were not significantly different when richness was determined using morphological taxonomy (morphospecies) or sequence divergence thresholds (Molecular Operational Taxonomic Unit(s); MOTU). However, sequence-based methods tended to yield greater richness and significantly lower indices of similarity than morphological taxonomy. MOTU determined using our molecular technique were a remarkably local phenomenon—indicative of highly restricted dispersal and/or long-term isolation. In cases where molecular and morphological methods differed in their assignment of individuals to categories, the morphological estimate was always more conservative than the molecular estimate. In those cases where morphospecies descriptions collapsed distinct molecular groups, sequence divergences of 16% (on average) were contained within the same morphospecies. Such high divergences highlight taxa for further detailed genetic, morphological, life history, and behavioral studies. PMID:16214741

  12. Investigating Mantle Structure with Broadband Seismic Arrays in Madagascar and Mozambique

    NASA Astrophysics Data System (ADS)

    Wysession, M. E.; Wiens, D. A.; Nyblade, A.; Rambolamanana, G.

    2012-12-01

    Thirty-one broadband seismometers were installed in Madagascar (25) and Mozambique (6) in 2011-2012 as part of the 2-year MACOMO project of the IRIS PASSCAL program. A major goal is to investigate the occurrence of hot spot intraplate volcanism in Madagascar and its possible connection to other African volcanic activity and the lower mantle LLSVP (large low shear-velocity province). The African LLSVP is the largest seismic anomaly within the earth, and as an enormous thermochemical boundary layer between the mantle and, it plays a vitally important role in controlling the nature of vertical mass flux within the mantle, and therefore both mantle convection and its manifestation at the surface as plate tectonics. The African LLSVP is thought to play an important role in the abundant occurrence of hot spot volcanism on the African plate, but the mechanism by which this occurs is not known due to the extremely limited data sampling available at this location in the Southern Hemisphere. These arrays on the world's 4th-largest island (the first such array of its kind) and in Mozambique, together with existing African Array stations and concurrent temporary installations of land and OBS stations by French and German projects, is providing unprecedented data that will allow us to seismically map (using velocity and attenuation seismic tomography, shear-wave splitting, and receiver function analysis for topography variations on mantle boundaries, and other methods) the connection between surface hot spot volcanism and other mantle seismic anomalies such as the LLSVP.

  13. Impact of the high topography of Madagascar on the structure of the Findlater Jet

    NASA Astrophysics Data System (ADS)

    Moore, G. W. K.

    2013-05-01

    The cross-equatorial flow over the western Indian Ocean, known as the Findlater Jet, plays an important role in the monsoonal circulation of the region. During the boreal summer, there is southerly flow across the equator that is concentrated along the East African highlands. During the boreal winter, there is a reversal in wind direction across the equator. Madagascar, the world's fourth largest island, with heights in excess of 1 km represents a significant obstacle to the flow whose impact on this jet has not been fully characterized. Here we use diagnostic tools developed to investigate atmospheric flow distortion by Greenland's high topography to study this interaction. We show that there is a bifurcation of the Findlater Jet by Madagascar during the boreal summer and localized tip jets at the island's northern and southern ends. During the boreal winter, the northern tip jet reverses direction and weakens, while the southern tip jet maintains its direction and magnitude. We show that rotational effects are important for these interactions but not dominant and result in an enhancement of the northern tip jet; while allowing for existence of the southern tip jet. As will also be shown, this flow distortion has impacts on the meteorology and oceanography of the region including the forcing of oceanic eddies in the Mozambique Channel, a modulation of the southward displacement of the Inter-Tropical Convergence Zone (ITCZ) and a splitting of the boreal summer cross-equatorial mass transport associated with the Findlater Jet into two branches.

  14. Widespread presence of the pathogenic fungus Batrachochytrium dendrobatidis in wild amphibian communities in Madagascar.

    PubMed

    Bletz, Molly C; Rosa, Gonçalo M; Andreone, Franco; Courtois, Elodie A; Schmeller, Dirk S; Rabibisoa, Nirhy H C; Rabemananjara, Falitiana C E; Raharivololoniaina, Liliane; Vences, Miguel; Weldon, Ché; Edmonds, Devin; Raxworthy, Christopher J; Harris, Reid N; Fisher, Matthew C; Crottini, Angelica

    2015-01-01

    Amphibian chytridiomycosis, an emerging infectious disease caused by the fungus Batrachochytrium dendrobatidis (Bd), has been a significant driver of amphibian declines. While globally widespread, Bd had not yet been reported from within Madagascar. We document surveys conducted across the country between 2005 and 2014, showing Bd's first record in 2010. Subsequently, Bd was detected in multiple areas, with prevalence reaching up to 100%. Detection of Bd appears to be associated with mid to high elevation sites and to have a seasonal pattern, with greater detectability during the dry season. Lineage-based PCR was performed on a subset of samples. While some did not amplify with any lineage probe, when a positive signal was observed, samples were most similar to the Global Panzootic Lineage (BdGPL). These results may suggest that Bd arrived recently, but do not exclude the existence of a previously undetected endemic Bd genotype. Representatives of all native anuran families have tested Bd-positive, and exposure trials confirm infection by Bd is possible. Bd's presence could pose significant threats to Madagascar's unique "megadiverse" amphibians. PMID:25719857

  15. [Rice: source of life and death on the plateaux of Madagascar].

    PubMed

    Laventure, S; Mouchet, J; Blanchy, S; Marrama, L; Rabarison, P; Andrianaivolambo, L; Rajaonarivelo, E; Rakotoarivony, I; Roux, J

    1996-01-01

    Since the 17th century, Europeans travelling in Madagascar described the contrast between the fever-free Plateau and the fever-ridden coasts. The former were inhabited by people of Asiatic origins and the latter by African migrants. At the end of the 18th century, "Merina" kings developed land irrigation and rice cultivation, using manpower from the coasts. Since then, rice has become a monoculture covering most of the arable lands of the Highlands. The first malaria epidemic occurred in the Tananarive area in 1878, and rapidly spread throughout the Plateau. The mortality rate was high. A second epidemic in 1895 may have been a resurgence of the previous one. Subsequently, malaria became meso-epidemic despite control measures, mainly consisting of larvivorous fishes, quinine treatment and prophylaxis. In 1949, an eradication program was launched based on DDT house-spraying and chloroquine prophylaxis in children. It was very successful on the Highlands where malaria disappeared, in 1962. Spraying was cancelled and only three small foci remained under surveillance. In 1987 and 1988, a malaria outbreak devastated the plateau. Subsequently, intensive spraying operations brought the situation under control by 1993. The main malaria vector on the Madagascar Highlands is An. funestus. More than 95% of its breeding sites are in the rice fields just before the harvest and afterwards in the fallow lands. The vector peak and the corresponding peak of malaria cases occur between February and May, depending on the farming calender. The second but less important vector, An. arabiensis, breeds in the rice fields just after seeding when the surface water is sunlit. Although rice fields remain the main source of this vector, it also breeds in rainwater pods and borow-pits. Malaria vectors on the plateau are products of human activities of rice cultivation, which is the basis of the economy. The epidemiological importance of rice fields varies greatly from one country to another. In Southeast Asia, the rice fields harbor several anopheline species most of which are only vectors of P. vivax. In West Africa where malaria is holoendemic, they produce large populations of An. gambiae; however, the malaria pattern is unaltered and remains at peak levels. In the dry areas of southern Madagascar, the vector An. funestus and meso-hyperendemic malaria are restricted to areas of cultivated rice. In West and Central Africa, An. funestus is never found in rice fields even though it is common in marshes. In Madagascar, this vector breeds in irrigated rice fields. Because it is practically impossible to control anophelines in rice fields by chemical, biological and ecological methods on the Highlands of Madagascar, house-spraying remains the best method for mass malaria control. Bed-nets impregnated with pesticides may offer an alternative, but their use is resisted by the local population. PMID:8705134

  16. Endemism and diversification in freshwater insects of Madagascar revealed by coalescent and phylogenetic analysis of museum and field collections.

    PubMed

    Vuataz, Laurent; Sartori, Michel; Gattolliat, Jean-Luc; Monaghan, Michael T

    2013-03-01

    The biodiversity and endemism of Madagascar are among the most extraordinary and endangered in the world. This includes the island's freshwater biodiversity, although detailed knowledge of the diversity, endemism, and biogeographic origin of freshwater invertebrates is lacking. The aquatic immature stages of mayflies (Ephemeroptera) are widely used as bio-indicators and form an important component of Malagasy freshwater biodiversity. Many species are thought to be microendemics, restricted to single river basins in forested areas, making them particularly sensitive to habitat reduction and degradation. The Heptageniidae are a globally diverse family of mayflies (>500 species) but remain practically unknown in Madagascar except for two species described in 1996. The standard approach to understanding their diversity, endemism, and origin would require extensive field sampling on several continents and years of taxonomic work followed by phylogenetic analysis. Here we circumvent this using museum collections and freshly collected individuals in a combined approach of DNA taxonomy and phylogeny. The coalescent-based GMYC analysis of DNA barcode data (mitochondrial COI) revealed 14 putative species on Madagascar, 70% of which were microendemics. A phylogenetic analysis that included African and Asian species and data from two mitochondrial and four nuclear loci indicated the Malagasy Heptageniidae are monophyletic and sister to African species. The genus Compsoneuria is shown to be paraphyletic and the genus Notonurus is reinstalled for African and Malagasy species previously placed in Compsoneuria. A molecular clock excluded a Gondwanan vicariance origin and instead favoured a more recent overseas colonization of Madagascar. The observed monophyly and high microendemism highlight their conservation importance and suggest the DNA-based approach can rapidly provide information on the diversity, endemism, and origin of freshwater biodiversity. Our results underline the important role that museum collections can play in molecular studies, especially in critically endangered biodiversity hotspots like Madagascar where entire species or populations may go extinct very quickly. PMID:23261711

  17. In and out of Madagascar: Dispersal to Peripheral Islands, Insular Speciation and Diversification of Indian Ocean Daisy Trees (Psiadia, Asteraceae)

    PubMed Central

    Strijk, Joeri S.; Noyes, Richard D.; Strasberg, Dominique; Cruaud, Corinne; Gavory, Fredéric; Chase, Mark W.; Abbott, Richard J.; Thébaud, Christophe

    2012-01-01

    Madagascar is surrounded by archipelagos varying widely in origin, age and structure. Although small and geologically young, these archipelagos have accumulated disproportionate numbers of unique lineages in comparison to Madagascar, highlighting the role of waif-dispersal and rapid in situ diversification processes in generating endemic biodiversity. We reconstruct the evolutionary and biogeographical history of the genus Psiadia (Asteraceae), a plant genus with near equal numbers of species in Madagascar and surrounding islands. Analyzing patterns and processes of diversification, we explain species accumulation on peripheral islands and aim to offer new insights on the origin and potential causes for diversification in the Madagascar and Indian Ocean Islands biodiversity hotspot. Our results provide support for an African origin of the group, with strong support for non-monophyly. Colonization of the Mascarenes took place by two evolutionary distinct lineages from Madagascar, via two independent dispersal events, each unique for their spatial and temporal properties. Significant shifts in diversification rate followed regional expansion, resulting in co-occurring and phenotypically convergent species on high-elevation volcanic slopes. Like other endemic island lineages, Psiadia have been highly successful in dispersing to and radiating on isolated oceanic islands, typified by high habitat diversity and dynamic ecosystems fuelled by continued geological activity. Results stress the important biogeographical role for Rodrigues in serving as an outlying stepping stone from which regional colonization took place. We discuss how isolated volcanic islands contribute to regional diversity by generating substantial numbers of endemic species on short temporal scales. Factors pertaining to the mode and tempo of archipelago formation and its geographical isolation strongly govern evolutionary pathways available for species diversification, and the potential for successful diversification of dispersed lineages, therefore, appears highly dependent on the timing of arrival, as habitat and resource properties change dramatically over the course of oceanic island evolution. PMID:22900068

  18. In or Out-of-Madagascar?—Colonization Patterns for Large-Bodied Diving Beetles (Coleoptera: Dytiscidae)

    PubMed Central

    Bukontaite, Rasa; Ranarilalatiana, Tolotra; Randriamihaja, Jacquelin Herisahala; Bergsten, Johannes

    2015-01-01

    High species diversity and endemism within Madagascar is mainly the result of species radiations following colonization from nearby continents or islands. Most of the endemic taxa are thought to be descendants of a single or small number of colonizers that arrived from Africa sometime during the Cenozoic and gave rise to highly diverse groups. This pattern is largely based on vertebrates and a small number of invertebrate groups. Knowledge of the evolutionary history of aquatic beetles on Madagascar is lacking, even though this species-rich group is often a dominant part of invertebrate freshwater communities in both standing and running water. Here we focus on large bodied diving beetles of the tribes Hydaticini and Cybistrini. Our aims with this study were to answer the following questions 1) How many colonization events does the present Malagasy fauna originate from? 2) Did any colonization event lead to a species radiation? 3) Where did the colonizers come from—Africa or Asia—and has there been any out-of-Madagascar event? 4) When did these events occur and were they concentrated to any particular time interval? Our results suggest that neither in Hydaticini nor in Cybistrini was there a single case of two or more endemic species forming a monophyletic group. The biogeographical analysis indicated different colonization histories for the two tribes. Cybistrini required at least eight separate colonization events, including the non-endemic species, all comparatively recent except the only lotic (running water) living Cybister operosus with an inferred colonization at 29 Ma. In Hydaticini the Madagascan endemics were spread out across the tree, often occupying basal positions in different species groups. The biogeographical analyses therefore postulated the very bold hypothesis of a Madagascan origin at a very deep basal node within Hydaticus and multiple out-of-Madagascar dispersal events. This hypothesis needs to be tested with equally intense taxon sampling of mainland Africa as for Madagascar. PMID:25794184

  19. How to reach the poor? Surveillance in low-income countries, lessons from experiences in Cambodia and Madagascar.

    PubMed

    Goutard, F L; Binot, A; Duboz, R; Rasamoelina-Andriamanivo, H; Pedrono, M; Holl, D; Peyre, M I; Cappelle, J; Chevalier, V; Figuié, M; Molia, S; Roger, F L

    2015-06-01

    Surveillance of animal diseases in developing countries faces many constraints. Innovative tools and methods to enhance surveillance in remote and neglected areas should be defined, assessed and applied in close connection with local farmers, national stakeholders and international agencies. The authors performed a narrative synthesis of their own publications about surveillance in Madagascar and Cambodia. They analysed the data in light of their fieldwork experiences in the two countries' very challenging environments. The burden of animal and zoonotic diseases (e.g. avian influenza, African swine fever, Newcastle disease, Rift Valley fever) is huge in both countries which are among the poorest in the world. Being poor countries implies a lack of human and financial means to ensure effective surveillance of emerging and endemic diseases. Several recent projects have shown that new approaches can be proposed and tested in the field. Several advanced participatory approaches are promising and could be part of an innovative method for improving the dialogue among different actors in a surveillance system. Thus, participatory modelling, developed for natural resources management involving local stakeholders, could be applied to health management, including surveillance. Data transmission could benefit from the large mobile-phone coverage in these countries. Ecological studies and advances in the field of livestock surveillance should guide methods for enhancing wildlife monitoring and surveillance. Under the umbrella of the One Health paradigm, and in the framework of a risk-based surveillance concept, a combination of participatory methods and modern technologies could help to overcome the constraints present in low-income countries. These unconventional approaches should be merged in order to optimise surveillance of emerging and endemic diseases in challenging environments. PMID:25842000

  20. Sex determination in Madagascar geckos of the genus Paroedura (Squamata: Gekkonidae): are differentiated sex chromosomes indeed so evolutionary stable?

    PubMed

    Koubová, Martina; Johnson Pokorná, Martina; Rovatsos, Michail; Farkačová, Klára; Altmanová, Marie; Kratochvíl, Lukáš

    2014-12-01

    Among amniote vertebrates, geckos represent a clade with exceptional variability in sex determination; however, only a minority of species of this highly diverse group has been studied in this respect. Here, we describe for the first time a female heterogamety in the genus Paroedura, the group radiated in Madagascar and adjacent islands. We identified homomorphic ZZ/ZW sex chromosomes with a highly heterochromatic W chromosome in Paroedura masobe, Paroedura oviceps, Paroedura karstophila, Paroedura stumpffi, and Paroedura lohatsara. Comparative genomic hybridization (CGH) revealed that female-specific sequences are greatly amplified in the W chromosome of P. lohatsara and that P. gracilis seems to possess a derived system of multiple sex chromosomes. Contrastingly, neither CGH nor heterochromatin visualization revealed differentiated sex chromosomes in the members of the Paroedura picta-Paroedura bastardi-Paroedura ibityensis clade, which is phylogenetically nested within lineages with a heterochromatic W chromosome. As a sex ratio consistent with genotypic sex determination has been reported in P. picta, it appears that the members of the P. picta-P. bastardi-P. ibityensis clade possess homomorphic, poorly differentiated sex chromosomes and may represent a rare example of evolutionary loss of highly differentiated sex chromosomes. Fluorescent in situ hybridization (FISH) with a telomeric probe revealed a telomere-typical pattern in all species and an accumulation of telomeric sequences in the centromeric region of autosomes in P. stumpffi and P. bastardi. Our study adds important information for the greater understanding of the variability and evolution of sex determination in geckos and demonstrates how the geckos of the genus Paroedura provide an interesting model for studying the evolution of the sex chromosomes. PMID:25056523

  1. Cover sequences at the northern margin of the Antongil Craton, NE Madagascar

    USGS Publications Warehouse

    Bauer, W.; Walsh, G.J.; De Waele, B.; Thomas, Ronald J.; Horstwood, M.S.A.; Bracciali, L.; Schofield, D.I.; Wollenberg, U.; Lidke, D.J.; Rasaona, I.T.; Rabarimanana, M.H.

    2011-01-01

    The island of Madagascar is a collage of Precambrian, generally high-grade metamorphic basement domains, that are locally overlain by unmetamorphosed sedimentary rocks and poorly understood low-grade metasediments. In the Antalaha area of NE Madagascar, two distinct cover sequences rest on high-grade metamorphic and igneous basement rocks of the Archaean Antongil craton and the Neoproterozoic Bemarivo belt. The older of these two cover sequences, the Andrarona Group, consists of low-grade metasedimentary rocks. The younger sequence, the newly defined Ampohafana Formation, consists of unmetamorphosed sedimentary rocks. The Andrarona Group rests on Neoarchaean granites and monzogranites of the Antongil craton and consists of a basal metagreywacke, thick quartzites and an upper sequence of sericite-chlorite meta-mudstones, meta-sandstones and a volcaniclastic meta-sandstone. The depositional age of the volcaniclastic meta-sandstone is constrained in age by U–Pb laser-ablation ICP-MS analyses of euhedral zircons to 1875 ± 8 Ma (2σ). Detrital zircons of Archaean and Palaeoproterozoic age represent an input from the Antongil craton and a newly defined Palaeoproterozoic igneous unit, the Masindray tonalite, which underlies the Andrarona Group, and yielded a U–Pb zircon age of 2355 ± 11 Ma (2σ), thus constraining the maximum age of deposition of the basal part of the Andrarona Group. The Andrarona Group shows a low-grade metamorphic overprint in the area near Antalaha; illite crystallinity values scatter around 0.17°Δ2Θ CuKα, which is within the epizone. The Ampohafana Formation consists of undeformed, polymict conglomerate, cross-bedded sandstone, and red mudstone. An illite crystallinity value of >0.25°Δ2Θ CuKα obtained from the rocks is typical of the diagenetic zone. Occurrences of rhyodacite pebbles in the Ampohafana Formation and the intrusion of a basaltic dyke suggest a deposition in a WSW-ENE-trending graben system during the opening of the Indian Ocean in the Upper Cretaceous, that was characterized by extensive rhyolitic to basaltic magmatism along Madagascar's eastern coast.

  2. Combined teleseismic surface wave and receiver function analysis of the crust and upper mantle of Madagascar

    NASA Astrophysics Data System (ADS)

    Pratt, M. J.; Aleqabi, G. I.; Wysession, M. E.; Wiens, D. A.; Nyblade, A.; Shore, P.; Rambolamanana, G.; Tsiriandrimanana, R.; Andriampenomanana Ny Ony, F. S. T.

    2014-12-01

    The continental crust and upper mantle velocity structure beneath Madagascar remained poorly constrained until recent deployments of broadband seismic instrumentation across the island. The MACOMO (MAdagascar, COmoros and MOzambique), RHUM-RUM (Runion Hotspot and Upper Mantle - Runions Unterer Mantel) and the Madagascar Seismic Profile experiments have opened up this region to be studied in detail for the first time. The island is an amalgamation of an Archean craton, associated with the Western Dhawar craton of southern India, and a series of Proterozoic terranes that comprise the backbone of the island (Tucker et al., 2010). A receiver-function analysis has provided both the first Moho depth measurements and spatially discrete 1-D shear velocity results that matched well with known tectonic regions. To provide a more continuous 2-D and 3-D velocity structure map, teleseismic surface wave analysis is employed. Using Helmholtz tomography as implemented by the ASWMS package (Ge, Gaherty and Hutko; 2014), we are able to map phase velocities from the cross-correlation of station pairs at periods 20-100 s. At periods 20-40 s our results compare well with ambient noise analysis results (see poster by Wysession et al. (this meeting)). The prominent features of these results are a distinct low phase-velocity sector beneath the central Itasy region, with a secondary low phase-velocity region to the north of the island. Both the central part of the island and the northern region have experienced geothermal activity in recent times as well as volcanic activity within the last 10,000 years. This may suggest that the crust and underlying mantle in these regions remains at relatively higher temperatures than the surrounding rock. Combining this information with receiver-function analysis, we jointly invert our data for the shear velocity structure. These analyses will constrain the upper mantle seismic velocities in the region, allowing further analysis from body waves to probe the transition zone and determine whether or not these low-velocity zones extend into the deep mantle.

  3. Malagasyprinus, a new genus of the Saprininae from Madagascar with description of two new species (Coleoptera, Histeridae, Saprininae) (First contribution to the knowledge of the Histeridae of Madagascar)

    PubMed Central

    Lackner, Tomáš; Gomy, Yves

    2013-01-01

    Abstract Based on the results of recent phylogenetic analysis of the higher taxa of the Saprininae as well as external morphological characters, especially the presence of deep and large prosternal foveae, and the shape and position of the sensory organs of the antennal club, the species Saprinus (s.str.) caeruleatus Lewis, 1905 is excluded from the genus Saprinus and a new genus Malagasyprinus, exclusive to Madagascar, is established for it. The new genus shows mainly characters that are apomorphic for the subfamily and contains another two, highly similar allopatric species Malagasyprinus perrieri sp. n., and Malagasyprinus diana sp. n., described herein. The three species are best separated from each other by the structure of the prosternum and male terminalia, especially the shape of the aedeagus. We re-describe Malagasyprinus caeruleatus comb. n. and provide Malagasyprinus perrieri and Malagasyprinus diana with brief differential diagnoses. All taxon descriptions are accompanied with color habitat photographs, SEM micrographs and drawings of their male genitalia. A key to the species of Malagasyprinus is given. Sensory structures of the antenna of Malagasyprinus caeruleatus comb. n. are likewise depicted herein. The systematic position of the newly erected genus is discussed. A lectotype of Saprinus caeruleatus Lewis, 1905 is designated. PMID:24146560

  4. A new arboreal frog of the genus Guibemantis from the southeast of Madagascar (Anura: Mantellidae).

    PubMed

    Vences, Miguel; Jovanovic, Olga; Safarek, Goran; Glaw, Frank; Köhler, Jörn

    2015-01-01

    We describe a new species of arboreal frog of the genus Guibemantis, subgenus Guibemantis, from low altitude rainforest in Manombo Special Reserve, south-eastern Madagascar. Previously published phylogenetic analyses of mitochondrial DNA sequences have placed Guibemantis diphonus sp. nov. sister to G. timidus. The new species is distinguished from G. timidus and all other species in the subgenus by a substantial genetic differentiation (≥ 4.4% uncorrected p-distance in the mitochondrial 16S rRNA gene), strongly divergent advertisement call, and some limited morphological differences. It is the smallest known species in the subgenus, with 34-36 mm snout-vent length in adult males. Its advertisement call is unique among other species in the subgenus in being composed of two distinctly different note types (only one note type in the other species). PMID:26701579

  5. [Premarital sex in Antananarivo (Madagascar): how are students freeing themselves from the norms?].

    PubMed

    Gastineau, Bénédicte; Binet, Clotilde

    2013-06-01

    This paper aims to analyze the representations of premarital sexuality among young people in a context where they are strongly encouraged not to engage in premarital sexual relations. This link between prevention messages, representations and behaviours has been studied among a student population in Madagascar. The analysis is based on a socio-demographic survey conducted in 2006. Results show that young men and women share the ideal of abstinence before marriage. The promotion of premarital sexual abstinence within AIDS programs reinforces gender differences. It is mainly young women who are urged to be abstinent, whereas young men have the means--condom use--to transgress the taboo of premarital sex and protect themselves against health risks. Thus, young men have a dual strategy. On the one hand, they attach great importance to premarital abstinence with their future wife; on the other hand, they can have sex with occasional partners and are then protected by condoms. PMID:24069762

  6. Antiproliferative Cardenolide Glycosides of Elaeodendron alluaudianum from the Madagascar Rainforest1

    PubMed Central

    Hou, Yanpeng; Cao, Shugeng; Brodie, Peggy; Callmander, Martin; Ratovoson, Fidisoa; Randrianaivo, Richard; Rakotobe, Etienne; Rasamison, Vincent E.; Rakotonandrasana, Stephan; TenDyke, Karen; Suh, Edward M.; Kingston, David G. I.

    2010-01-01

    Bioassay-guided fractionation of an ethanol extract of a Madagascar collection of Elaeodendron alluaudianum led to the isolation of two new cardenolide glycosides (1 and 2). The 1H and 13C NMR spectra of both compounds were fully assigned using a combination of 2D NMR experiments, including 1H-1H COSY, HSQC, HMBC, and ROESY sequences. Both compounds 1 and 2 were tested against the A2780 human ovarian cancer cell line and the U937 human histiocytic lymphoma cell line assays, and showed significant antiproliferative activity with IC50 values of 0.12 and 0.07 μM against the A2780 human ovarian cancer cell line, and 0.15 and 0.08 μM against the U937 human histiocytic lymphoma cell line, respectively. PMID:19058971

  7. Anjozorobe Hantavirus, a New Genetic Variant of Thailand Virus Detected in Rodents from Madagascar

    PubMed Central

    Razafindralambo, Nadia Kaloina; Lacoste, Vincent; Olive, Marie-Marie; Barivelo, Tony Andrianaivo; Soarimalala, Voahangy; Heraud, Jean-Michel; Lavergne, Anne

    2014-01-01

    Abstract Until now, there was only serological evidence that hantaviruses were circulating in rodents and infecting humans from Madagascar. To assess the presence of a hantavirus on the island, between October, 2008, and March, 2010, we sampled 585 rodents belonging to seven species in the Anjozorobe-Angavo forest corridor, 70?km north from the capital city Antananarivo. A hantavirus was detected from organs of the ubiquist roof rat (Rattus rattus) and of the endemic Major's tufted-tailed rat (Eliurus majori). Amazingly, sequence analysis of the S (small), M (medium), and L (large) coding DNA sequence of this virus showed that the Anjozorobe strain (proposed name) was a new genetic variant of Thailand virus (THAIV) that comprises other variants found in Southeast Asia. Because THAIV is suspected of causing hemorrhagic fever with renal syndrome in humans, ongoing studies are addressing the risk of infection by this new variant in the Malagasy population. PMID:24575755

  8. Detection of a Novel DSPP Mutation by NGS in a Population Isolate in Madagascar

    PubMed Central

    Bloch-Zupan, Agnès; Huckert, Mathilde; Stoetzel, Corinne; Meyer, Julia; Geoffroy, Véronique; Razafindrakoto, Rabisoa W.; Ralison, Saholy N.; Randrianaivo, Jean-Claude; Ralison, Georgette; Andriamasinoro, Rija O.; Ramanampamaharana, Rija H.; Randrianazary, Solofomanantsoa E.; Richard, Béatrice; Gorry, Philippe; Manière, Marie-Cécile; Rakoto Alson, Simone; Dollfus, Hélène

    2016-01-01

    A large family from a small village in Madagascar, Antanetilava, is known to present with colored teeth. Through previous collaboration and 4 successive visits in 1994, 2004, 2005, and 2012, we provided dental care to the inhabitants and diagnosed dentinogenesis imperfecta. Recently, using whole exome sequencing we confirmed the clinical diagnosis by identifying a novel single nucleotide deletion in exon 5 of DSPP. This paper underlines the necessity of long run research, the importance of international and interpersonal collaborations as well as the major contribution of next generation sequencing tools in the genetic diagnosis of rare oro-dental anomalies. This study is registered in ClinicalTrials (https://clinicaltrials.gov) under the number NCT02397824. PMID:26973538

  9. Detection of a Novel DSPP Mutation by NGS in a Population Isolate in Madagascar.

    PubMed

    Bloch-Zupan, Agnès; Huckert, Mathilde; Stoetzel, Corinne; Meyer, Julia; Geoffroy, Véronique; Razafindrakoto, Rabisoa W; Ralison, Saholy N; Randrianaivo, Jean-Claude; Ralison, Georgette; Andriamasinoro, Rija O; Ramanampamaharana, Rija H; Randrianazary, Solofomanantsoa E; Richard, Béatrice; Gorry, Philippe; Manière, Marie-Cécile; Rakoto Alson, Simone; Dollfus, Hélène

    2016-01-01

    A large family from a small village in Madagascar, Antanetilava, is known to present with colored teeth. Through previous collaboration and 4 successive visits in 1994, 2004, 2005, and 2012, we provided dental care to the inhabitants and diagnosed dentinogenesis imperfecta. Recently, using whole exome sequencing we confirmed the clinical diagnosis by identifying a novel single nucleotide deletion in exon 5 of DSPP. This paper underlines the necessity of long run research, the importance of international and interpersonal collaborations as well as the major contribution of next generation sequencing tools in the genetic diagnosis of rare oro-dental anomalies. This study is registered in ClinicalTrials (https://clinicaltrials.gov) under the number NCT02397824. PMID:26973538

  10. Impact of the safe water system on water quality in cyclone-affected communities in Madagascar.

    PubMed

    Mong, Y; Kaiser, R; Ibrahim, D; Rasoatiana; Razafimbololona, L; Quick, R E

    2001-10-01

    Cyclone Hudah struck the northeastern coast of Madagascar in the spring of 2000. Over a 5-month period, 11 700 relief kits consisting of bottles of water disinfectant and foldable jerry cans were distributed to the affected population. Five months after the cyclone, a survey was conducted in 12 villages to determine the impact of these relief kits on water quality. Seventy-six percent of the surveyed households reported using jerry cans, and 65% reported using the disinfectant. Stored water in households using both products had significantly less microbiological contamination than stored water in other households. To improve the prospects for a sustainable intervention, the response plan for future disasters should incorporate a transition to recovery and development, including formative research into local customs, beliefs, and water handling habits, and funding support to initiate social marketing. PMID:11574310

  11. Brown Algae (Phaeophyceae) from the Coast of Madagascar: preliminary Bioactivity Studies and Isolation of Natural Products.

    PubMed

    Rahelivao, Marie Pascaline; Gruner, Margit; Andriamanantoanina, Hanta; Bauer, Ingmar; Knölker, Hans-Joachim

    2015-10-01

    Eight species of brown algae (Phaeophyceae) from the coast of Madagascar have been investigated for their chemical constituents. Fucosterol (3) was obtained as the most abundant compound. The brown alga Sargassum ilicifolium was the source for the first isolation of the terpenoid C27-alcohol 1,1',2-trinorsqualenol (1) from marine sources. From S. incisifolium we isolated the highly unsaturated glycolipid 1-O-palmitoyl-2-O-stearidonoyl-3-O-β-D-galactopyranosylglycerol (4) and we report the first full assignment of its (1)H and (13)C NMR data. Apo-9'-fucoxanthinone (8) along with 24-ketocholesterol (5), (22E)-3β-hydroxycholesta-5,22-dien-24-one (6), and saringosterol (7) were obtained from Turbinaria ornata. The crude extracts of all eight species of brown algae exhibited a pronounced antimicrobial activity against the Gram-positive bacteria Bacillus cereus, Staphylococcus aureus, and Streptococcus pneumoniae. PMID:26358714

  12. New species of Blaesodactylus (Squamata: Gekkonidae) from Tsingy karstic outcrops in Ankarana National Park, northern Madagascar.

    PubMed

    Jono, Teppei; Bauer, Aaron M; Brennan, Ian; Mori, Akira

    2015-01-01

    We describe a new gecko of the genus Blaesodactylus from a karstic outcrop in deciduous dry forest of Ankarana National Park, northern Madagascar. Blaesodactylus microtuberculatus sp. nov., the fifth recognized species of Blaesodactylus, is distinguished from all other congeners, B. ambonihazo, B. antongilensis, B. boivini and B. sakalava by a combination of small, homogeneous gular granules, unspotted venter and lack of tubercles on distal part of original tail. Mitochondrial (ND2 and ND4) and nuclear (RAG-1) DNA identify a consistent divergence between B. microtuberculatus and its allotopic sister species B. boivini. We highlight habitat partitioning in these allotopic congeners where Blaesodactylus microtuberculatus inhabits karstic outcrops in Tsingy massif, and B. boivini dwells on tree trunks in deciduous dry forest. PMID:26249960

  13. [Evaluation of a supervision program of health centers at the district level in Madagascar].

    PubMed

    Comolet, T M; Rakotomalala, R A; Rasolomahefa, D

    1997-01-01

    Poor supervision and follow-up have long been recognized as major weaknesses in the development of primary health care in many countries. A program has therefore been specifically developed to strengthen the supervision activities of 18 rural health centers in Madagascar. District health officers were appropriately trained and then conducted two-monthly supervision visits. The emphasis of the training program was on problem solving, program integration and on-site training. The effects of the supervision program was assessed quantitatively and objectively. Various activities of each health center were scored before intervention, and one year after implementation of the supervision program. The improvement in most health centers was substantial, both in quantitative coverage and qualitative practice. Nevertheless, some centers appear to have been resistant to change. PMID:9273116

  14. Gold deposit styles and placer gold characterisation in northern and east-central Madagascar

    USGS Publications Warehouse

    Pitfield, Peter E. J; Styles, Michael T.; Taylor, Cliff D.; Key, Roger M.; Bauer, Wilfried; Ralison, A, Vonimanitra

    2009-01-01

    Microchemical characterisation of bedrock and placer gold grains from six gold districts within the Archaean domains and intervening Neoproterozoic Anaboriana-Manampotsy belt of northern and east-central Madagascar show few opaque inclusions (e.g pyrrhotite, Bi tellurides) but wide range of Ag contents (40wt%). Some districts exhibit multiple source populations of grains. The ‘greenstone belt’ terranes have an orogenic gold signature locally with an intrusion-related to epithermal overprint. Proterozoic metasediments with felsic to ultramafic bodies yield dominantly intrusion-related gold. A high proportion of secondary gold (<0.5wt% Ag) is related to recycling of paleoplacers and erosion of post-Gondwana planation surfaces and indicates that some mesothermal gold systems were already partially to wholly removed by erosion by the PermoTriassic.

  15. Chemical composition of the essential oil from Croton kimosorum, an endemic species to Madagascar.

    PubMed

    Rabehaja, Delphin J R; Ihandriharison, Harilala; Ramanoelina, Panja A R; Benja, Rakotonirina; Ratsimamanga-Urverg, Suzanne; Bighelli, Ange; Casanova, Joseph; Tomi, Félix

    2014-01-01

    Croton kimosorum Leandri is an endemic species to Madagascar. The chemical composition of aerial parts, leaf and stem oils is reported for the first time. Analysis was carried out by combination of chromatographic (CC, GC), spectroscopic and spectrometric (MS, 13C NMR) techniques. In total, 76 compounds have been identified. Essential oil isolated from aerial parts contained mainly linalool (21.6%), sabinene (10.4%), 1,8-cineole (6.3%), beta-pinene (6.2%), (E)-beta-caryophyllene (5.9%), terpinen-4-ol (4.8%), geraniol (4,5%) and germacrene D (2.3%). In comparison with the first sample, the composition of leaf and stem oils varied slightly, while essential oil isolated by vapor distillation from a semi-industrial still exhibited similar composition. PMID:24660481

  16. Residues of medroxyprogesterone acetate detected in sows at a slaughterhouse, Madagascar.

    PubMed

    Porphyre, Vincent; Rakotoharinome, Michel; Randriamparany, Tantely; Pognon, Damien; Prévost, Stéphanie; Le Bizec, Bruno

    2013-01-01

    In Madagascar, little information about drug residues in animal products is available. However, recently, official veterinary services were informed about the misuse of human injectable contraceptives in pig farms as an alternative for chirurgical castration of adult sows before culling. We investigated pigs (n = 80) slaughtered in 7 Malagasy abattoirs and raised in 8 of the 22 Malagasy regions (1) to confirm the contamination of carcasses by anabolic hormones by using LC-MS/MS, (2) to identify the substances of concern and (3) to explore the consumers' exposure to hormone residues. Medroxyprogesterone acetate was the only synthetic hormone detected in kidney fat. Samples positive with medroxyprogesterone acetate were observed in 66.7% of the districts investigated and in 87.5% of the surveyed regions, confirming its large misuse in livestock. Public awareness campaigns and control improvement among the animal production sector and among the Malagasy public health sector are therefore urgent. PMID:24251849

  17. The impact of malaria chemoprophylaxis in Africa with special reference to Madagascar, Cameroon, and Senegal

    PubMed Central

    Laing, A. B. G.

    1984-01-01

    Some past and present experiences in the use of antimalarial drugs, particularly for chemoprophylaxis, are reviewed. The failure in the long term of mass chemoprophylaxis with weekly chloroquine in children in Madagascar, Cameroon, and Senegal is discussed, the reasons for failure being an increasing lack of resources to ensure regular drug distribution and lack of supervision of dosage. The increasing number of reports confirming chloroquine resistance from East Africa over the last decade poses a serious threat to the future usefulness of chloroquine as an antimalarial agent in Africa. There is now an urgent need for extensive drug sensitivity tests, which should also include alternative antimalarial drugs. To rely on mass chemoprophylaxis as the main method of controlling malaria would appear to be no longer tenable. PMID:6397276

  18. Red Algae (Rhodophyta) from the Coast of Madagascar: Preliminary Bioactivity Studies and Isolation of Natural Products

    PubMed Central

    Rahelivao, Marie Pascaline; Gruner, Margit; Andriamanantoanina, Hanta; Andriamihaja, Bakolinirina; Bauer, Ingmar; Knölker, Hans-Joachim

    2015-01-01

    Several species of red algae (Rhodophyta) from the coastal regions of Madagascar have been investigated for their natural products. The most abundant compound was cholesterol (5) in combination with a series of oxidized congeners. The brominated indoles 1–3 along with the sesquiterpene debilone (4) have been isolated from Laurencia complanata. For the first time, debilone (4) has been obtained from a marine plant. From the methanol extract of Calloseris sp., we have achieved the second isolation of the unusual A-ring contracted steroids (−)-2-ethoxycarbonyl-2β-hydroxy-A-nor-cholest-5-en-4-one (9) and phorbasterone B (10). The crude extracts of Laurencia complanata exhibited antimicrobial activity against Bacillus cereus, Staphylococcus aureus, Streptococcus pneumoniae, and Candida albicans. PMID:26198236

  19. Valuing tropical forests: Methodology and case study of madagascar. World Bank environment paper

    SciTech Connect

    Kramer, R.A.; Sharma, N.; Munasinghe, M.

    1995-08-01

    The loss of large areas of tropical forests has become a major concern of the world community. Although there are many causes of tropical deforestation and forest degradation, an important cause appears to be undervaluation of forests by markets and governments. This volume examines some causes of tropical deforestation and explores forest valuation issues in the context of a protected area project. Part A (Chapters 1 and 2) sets out the context of tropical deforestation and loss of diodiversity and provides a framework for examining the economic value of forests. Part B (Chapter 3 to 8) is devoted to a detailed case study of Madagascar that illustrates the practical application of the techniques of analysis of the valuation of forests described earlier. Finally, the main findings and conclusions of this volume are summarized in Part C.

  20. Red Algae (Rhodophyta) from the Coast of Madagascar: Preliminary Bioactivity Studies and Isolation of Natural Products.

    PubMed

    Rahelivao, Marie Pascaline; Gruner, Margit; Andriamanantoanina, Hanta; Andriamihaja, Bakolinirina; Bauer, Ingmar; Knölker, Hans-Joachim

    2015-07-01

    Several species of red algae (Rhodophyta) from the coastal regions of Madagascar have been investigated for their natural products. The most abundant compound was cholesterol (5) in combination with a series of oxidized congeners. The brominated indoles 1-3 along with the sesquiterpene debilone (4) have been isolated from Laurencia complanata. For the first time, debilone (4) has been obtained from a marine plant. From the methanol extract of Calloseris sp., we have achieved the second isolation of the unusual A-ring contracted steroids (-)-2-ethoxycarbonyl-2β-hydroxy-A-nor-cholest-5-en-4-one (9) and phorbasterone B (10). The crude extracts of Laurencia complanata exhibited antimicrobial activity against Bacillus cereus, Staphylococcus aureus, Streptococcus pneumoniae, and Candida albicans. PMID:26198236

  1. Checklist of Fishes from Madagascar Reef, Campeche Bank, México

    PubMed Central

    2014-01-01

    Abstract This study presents the first list of fish species from Madagascar Reef, Campeche Bank, Gulf of México. Field surveys and literature review identified 54 species belonging to 8 orders, 30 families and 43 genera, comprising both conspicuous and cryptic fishes. Species richness was lower at this reef site compared to reefs in the Mexican Caribbean, Veracruz or Tuxpan, but was similar to other reefs in the same region. Species composition was a mixture of species present in all the reef systems of the Mexican Atlantic. Hypoplectrus ecosur was recorded here for the first time in the Gulf of Mexico, Mycteroperca microlepis, Equetus lanceolatus and Chaetodipterus faber were new records for the reefs of the Campeche Bank, Elacatinus xanthiprora was recorded for the second time in Mexico and expanded its known distribution westwards from Alacranes Reef and Sanopus reticulatus, endemic of the Yucatan state, was recorded here for the first time on a reef. PMID:24891834

  2. Diagnosis and treatment of a pharyngeal squamous cell carcinoma in a Madagascar ground boa (Boa madagascariensis).

    PubMed

    Steeil, James C; Schumacher, Juergen; Hecht, Silke; Baine, Katherine; Ramsay, Edward C; Ferguson, Sylvia; Miller, Debra; Lee, Nathan D

    2013-03-01

    A 15-yr-old female Madagascar ground boa (Boa madagascariensis) presented with a history of anorexia, wheezing, and occasional open-mouth breathing. On oral examination, a firm, caseous mass was noted in the right caudoventral pharyngeal region, which was confirmed as a carcinoma on incisional biopsy. Advanced imaging (computed tomography and magnetic resonance imaging) was performed to evaluate local tumor invasion and to plan for palliative radiation therapy. However, following the second treatment (10 Gy), the mass had increased in size, and the snake was euthanatized. Radiation-associated vasculitis was noted within the soft tissues surrounding the mass and within muscles and the lung, which was verified on histopathology. The squamous cell carcinoma of the snake in this report was resistant to palliative radiation therapy. PMID:23505715

  3. A new and aberrant species of Dugesia (Platyhelminthes, Tricladida, Dugesiidae) from Madagascar

    PubMed Central

    Stocchino, Giacinta Angela; Sluys, Ronald; Manconi, Renata

    2014-01-01

    Abstract In this paper we report a new species of Dugesia of the family Dugesiidae from Madagascar, representing the fourth species of freshwater planarian known from this global biodiversity hotspot. In some respects the new species is aberrant, when compared with its congeners, being characterized by a head with smoothly rounded auricles, a peculiar course of the oviducts, including the presence of a common posterior extension, and by the asymmetrical openings of the vasa deferentia at about halfway along the seminal vesicle. Further, it is characterized by a ventral course of the ejaculatory duct with a terminal opening, very long spermiducal vesicles and unstalked cocoons. Its diploid chromosome complement with 18 chromosomes represents an uncommon feature among fissiparous species of Dugesia. PMID:25147450

  4. Antiproliferative Diterpenes from a Malleastrum sp. from the Madagascar dry forest.

    PubMed

    Liu, Yixi; Wiedle, C Houston; Brodie, Peggy J; Callmander, Martin W; Rakotondrajaona, R; Rakotobe, Etienne; Rasamison, Vincent E; Kingston, David G I

    2015-09-01

    An ethanol extract of leaves of the plant species Malleastrum sp. collected in northern Madagascar afforded the new clerodane diterpene 18-oxo-cleroda-3,13-dien-16,15-olide (1), together with the three known clerodane diterpenes 16,18-dihydroxykolavenic acid lactone (2), solidagolactone (3) and (-)-kolavenol (4), and the known labdane diterpene 3-oxo-ent-Iabda-8(17),13-dien-15,16-olide (5). Compounds 1, 3, and 4 showed moderate antiproliferative activities against the A2780 ovarian cancer cell line, with the IC50 values of 3.01 0.8, 7.84 0.2, and 17.9 3 M, respectively. The structure elucidations of all compounds were carried out based on analysis of NMR and mass spectroscopic data. The relative stereochemistry of compound 1 was determined by NOESY NMR spectrum. PMID:26594745

  5. A new genus and species of net-winged midge from Madagascar (Diptera: Blephariceridae: Blepharicerinae).

    PubMed

    Courtney, Gregory W

    2015-01-01

    Larvae of a species from the subfamily Blepharicerinae were first discovered in the 1950's, but the lack of additional records prevented description of the species. A recent study of important additional specimens from the late Brian Stuckenberg has provided the basis for describing this unusual fly. This paper provides a description of larvae, pupae, and adults of Aphromyia stuckenbergi gen. et sp. nov., and a brief discussion of its phylogenetic position within the family. The latter is confounded by marked adult colocephaly (reduction of the head) and concomitant reduction in mouthparts, and by lack of recent collections that would permit molecular analyses and further morphological study. Known from only two collections, the most recent nearly 60 years ago, this highly endemic and rare fly is arguably one the most endangered species in Madagascar. PMID:26624779

  6. Population Genetic Structure and Isolation by Distance of Helicobacter pylori in Senegal and Madagascar

    PubMed Central

    Linz, Bodo; Vololonantenainab, Clairette Romaine Raharisolo; Seck, Abdoulaye; Carod, Jean-François; Dia, Daouda; Garin, Benoit; Ramanampamonjy, Rado Manitrala; Thiberge, Jean-Michel; Raymond, Josette; Breurec, Sebastien

    2014-01-01

    Helicobacter pylori has probably infected the human stomach since our origins and subsequently diversified in parallel with their human hosts. The genetic population history of H. pylori can therefore be used as a marker for human migration. We analysed seven housekeeping gene sequences of H. pylori strains isolated from 78 Senegalese and 24 Malagasy patients and compared them with the sequences of strains from other geographical locations. H. pylori from Senegal and Madagascar can be placed in the previously described HpAfrica1 genetic population, subpopulations hspWAfrica and hspSAfrica, respectively. These 2 subpopulations correspond to the distribution of Niger-Congo speakers in West and most of subequatorial Africa (due to Bantu migrations), respectively. H. pylori appears as a single population in Senegal, indicating a long common history between ethnicities as well as frequent local admixtures. The lack of differentiation between these isolates and an increasing genetic differentiation with geographical distance between sampling locations in Africa was evidence for genetic isolation by distance. The Austronesian expansion that started from Taiwan 5000 years ago dispersed one of the 10 subgroups of the Austronesian language family via insular Southeast Asia into the Pacific and Madagascar, and hspMaori is a marker for the entire Austronesian expansion. Strain competition and replacement of hspMaori by hpAfrica1 strains from Bantu migrants are the probable reasons for the presence of hspSAfrica strains in Malagasy of Southeast Asian descent. hpAfrica1 strains appear to be generalist strains that have the necessary genetic diversity to efficiently colonise a wide host spectrum. PMID:24498084

  7. A Genome Sequence Resource for the Aye-Aye (Daubentonia madagascariensis), a Nocturnal Lemur from Madagascar

    PubMed Central

    Perry, George H.; Reeves, Darryl; Melsted, Páll; Ratan, Aakrosh; Miller, Webb; Michelini, Katelyn; Louis, Edward E.; Pritchard, Jonathan K.; Mason, Christopher E.; Gilad, Yoav

    2012-01-01

    We present a high-coverage draft genome assembly of the aye-aye (Daubentonia madagascariensis), a highly unusual nocturnal primate from Madagascar. Our assembly totals ∼3.0 billion bp (3.0 Gb), roughly the size of the human genome, comprised of ∼2.6 million scaffolds (N50 scaffold size = 13,597 bp) based on short paired-end sequencing reads. We compared the aye-aye genome sequence data with four other published primate genomes (human, chimpanzee, orangutan, and rhesus macaque) as well as with the mouse and dog genomes as nonprimate outgroups. Unexpectedly, we observed strong evidence for a relatively slow substitution rate in the aye-aye lineage compared with these and other primates. In fact, the aye-aye branch length is estimated to be ∼10% shorter than that of the human lineage, which is known for its low substitution rate. This finding may be explained, in part, by the protracted aye-aye life-history pattern, including late weaning and age of first reproduction relative to other lemurs. Additionally, the availability of this draft lemur genome sequence allowed us to polarize nucleotide and protein sequence changes to the ancestral primate lineage—a critical period in primate evolution, for which the relevant fossil record is sparse. Finally, we identified 293,800 high-confidence single nucleotide polymorphisms in the donor individual for our aye-aye genome sequence, a captive-born individual from two wild-born parents. The resulting heterozygosity estimate of 0.051% is the lowest of any primate studied to date, which is understandable considering the aye-aye's extensive home-range size and relatively low population densities. Yet this level of genetic diversity also suggests that conservation efforts benefiting this unusual species should be prioritized, especially in the face of the accelerating degradation and fragmentation of Madagascar's forests. PMID:22155688

  8. Early-warning health and process indicators for sentinel surveillance in Madagascar 2007-2011

    PubMed Central

    Rajatonirina, Soatiana; Rakotomanana, Fanjasoa; Randrianasolo, Laurence; Razanajatovo, Norosoa Harline; Andriamandimby, Soa Fy; Ravolomanana, Lisette; Randrianarivo-Solofoniaina, Armand Eugène; Reynes, Jean-Marc; Piola, Patrice; Finlay-Vickers, Alyssa; Heraud, Jean-Michel; Richard, Vincent

    2014-01-01

    Background: Epidemics pose major threats in resource-poor countries, and surveillance tools for their early detection and response are often inadequate. In 2007, a sentinel surveillance system was established in Madagascar, with the aim of rapidly identifying potential epidemics of febrile or diarrhoeal syndromes and issuing alerts. We present the health and process indicators for the five years during which this system was constructed, showing the spatiotemporal trends, early-warning sign detection capability and process evaluation through timely analyses of high-quality data. Methods: The Malagasy sentinel surveillance network is currently based on data for fever and diarrhoeal syndromes collected from 34 primary health centres and reported daily via the transmission of short messages from mobile telephones. Data are analysed daily at the Institut Pasteur de Madagascar to make it possible to issue alerts more rapidly, and integrated process indicators (timeliness, data quality) are used to monitor the system. Results: From 2007 to 2011, 917,798 visits were reported. Febrile syndromes accounted for about 11% of visits annually, but the trends observed differed between years and sentinel sites. From 2007 to 2011, 21 epidemic alerts were confirmed. However, delays in data transmission were observed (88% transmitted within 24 hours in 2008; 67% in 2011) and the percentage of forms transmitted each week for validity control decreased from 99.9% in 2007 to 63.5% in 2011. Conclusion: A sentinel surveillance scheme should take into account both epidemiological and process indicators. It must also be governed by the main purpose of the surveillance and by local factors, such as the motivation of healthcare workers and telecommunication infrastructure. Permanent evaluation indicators are required for regular improvement of the system. PMID:25598869

  9. Lost in translation: conflicting views of deforestation, land use and identity in western Madagascar.

    PubMed

    Scales, Ivan R

    2012-01-01

    This paper focuses on the interplay between environmental narratives, identity politics and the management of forest resources in Madagascar. While efforts to conserve the island's biological diversity have centred primarily on the designation of protected areas, policies have increasingly focused on local communities. The experiences of the last 20 years have shown that community-based approaches to conservation offer considerable challenges due to the complex politics of natural resource use, which involve multiple and diverse stakeholders, often with very different and sometimes conflicting values. In this paper, I focus on the environmental perceptions and values of two groups in the Central Menabe region of western Madagascar – conservation organisations and rural households – revealing a contrasting set of views regarding the region's forest. I show that the conservation discourse has changed over time, increasingly emphasising the biological diversity of the region's tropical dry-deciduous forest and prioritising non-consumptive uses of natural resources. Although policy has changed in response to changing values, I show that it has been underpinned by the notion that hatsake (‘slash-and-burn’ agriculture) is an irrational practice driven by necessity rather than choice. Policy has thus sought to provide livelihood alternatives, firstly through forestry, then through changes in cultivation and increasingly through tourism. This misunderstands the local view of the forest, which sees hatsake as a way to make the land productive, as long as it is carried out responsibly according to local fady (taboos). As well as facing problems of translating conservation goals into local values and misunderstanding the motives for forest clearance, policy has been based on a narrative that attaches particular land use practices to ethnic identities. I argue that this ignores the history and fluid reality of both identity and land use. PMID:22413174

  10. Forest Management Devolution: Gap Between Technicians' Design and Villagers' Practices in Madagascar

    NASA Astrophysics Data System (ADS)

    Rives, Fanny; Carrière, Stéphanie M.; Montagne, Pierre; Aubert, Sigrid; Sibelet, Nicole

    2013-10-01

    In the 1980s, tropical forest-management principles underwent a shift toward approaches giving greater responsibilities to rural people. One argument for such a shift were the long-term relations established between rural people and their natural resources. In Madagascar, a new law was drawn up in 1996 (Gelose law), which sought to integrate rural people into forest management. A gap was observed between the changes foreseen by the projects implementing the Gelose law and the actual changes. In this article, we use the concept of the social-ecological system (SES) to analyze that gap. The differences existing between the planned changes set by the Gelose contract in the village of Ambatoloaka (northwest of Madagascar) and the practices observed in 2010 were conceptualized as a gap between two SESs. The first SES is the targeted one (i.e., a virtual one); it corresponds to the designed Gelose contract. The second SES is the observed one. It is characterized by the heterogeneity of forest users and uses, which have several impacts on forest management, and by very dynamic social and ecological systems. The observed SES has been reshaped contingent on the constraints and opportunities offered by the Gelose contract as well as on other ecological and social components. The consequences and opportunities that such an SES reshaping would offer to improve the implementation of the Gelose law are discussed. The main reasons explaining the gap between the two SESs are as follows: (1) the clash between static and homogeneous perceptions in the targeted SES and the dynamics and heterogeneity that characterize the observed SES; and (2) the focus on one specific use of forest ecosystems (i.e., charcoal-making) in the targeted SES. Forest management in the observed SES depends on several uses of forest ecosystems.

  11. [The plague in Madagascar: epidemiologic data from 1989 to 1995 and the national control program].

    PubMed

    Champetier de Ribes, G; Rasoamanana, B; Randriambelosoa, J; Rakoto, L J; Rabescn, D; Chanteau, S

    1997-01-01

    After briefly reviewing the history and epidemiological cycle of the plague in Madagascar, we report a detailed analysis of 5,927 suspected cases of plague observed from 1989 to 1995 (average of 846 cases per year). Of those, 1,337 individuals (average of 191 cases per year) were confirmed (by isolation of Yersinia pestis) or indicated to be probable for plague (by positive smears). Since 1994, we observed an increasing number of confirmed and probable cases (252 cases in 1995). Most of the cases occurred between October and April in the central highlands, inside a geographical triangle limited by Alaotra lake, Itasy lake and the city of Fianarantsoa. Two exceptional epidemics occurred in the harbor of Majunga in 1991 and 1995. The bubonic plague was the most frequent clinical from (91.3%), with primarily an inguinal localization (67.8%). The mean case fatality rate was 19% of the confirmed or probable cases (14.8% for the bubonic form and 57.1% for the pneumonic form). The bubonic plague was significantly more frequent between the ages of 5 and 14 years, as compared to the general population, while the pneumonic plague was more frequent over 15 years of age. Males were more effected by the bubonic form, as the sex ratio (m:f) was 1.3. The national control program for plague is being strengthened to improve 1) the patient's early diagnosis and care system; 2) the measures for the prevention of epidemics; 3) the epidemiological surveillance; and 4) the studies on the biology of the plague vectors, rodents and fleas, and the agent, bacilli, in Madagascar. PMID:9172878

  12. Introducing auto-disable syringes to the national immunization programme in Madagascar.

    PubMed Central

    Drain, Paul K.; Ralaivao, Josoa S.; Rakotonandrasana, Alexander; Carnell, Mary A.

    2003-01-01

    OBJECTIVE: To evaluate the safety and coverage benefits of auto-disable (AD) syringes, weighed against the financial and logis- tical costs, and to create appropriate health policies in Madagascar. METHODS: Fifteen clinics in Madagascar, trained to use AD syringes, were randomized to implement an AD syringe only, mixed (AD syringes used only on non-routine immunization days), or sterilizable syringe only (control) programme. During a five-week period, data on administered vaccinations were collected, interviews were conducted, and observations were recorded. FINDINGS: The use of AD syringes improved coverage rates by significantly increasing the percentage of vaccines administered on non-routine immunization days (AD-only 4.3%, mixed 5.7%, control 1.1% (P<0.05)). AD-only clinics eliminated sterilization sessions for vaccinations, whereas mixed clinics reduced the number of sterilization sessions by 64%. AD syringes were five times more expensive than sterilizable syringes, which increased AD-only and mixed clinics' projected annual injection costs by 365% and 22%, respectively. However, introducing AD syringes for all vaccinations would only increase the national immunization budget by 2%. CONCLUSION: The use of AD syringes improved vaccination coverage rates by providing ready-to-use sterile syringes on non-routine immunization days and decreasing the number of sterilization sessions, thereby improving injection safety. The mixed programme was the most beneficial approach to phasing in AD syringes and diminishing logistical complications, and it had minimal costs. AD syringes, although more expensive, can feasibly be introduced into a developing country's immunization programme to improve vaccination safety and coverage. PMID:14576886

  13. Radiogenic heating to ultrahigh temperature: Geochronology and 4+ thermometry across southern Madagascar

    NASA Astrophysics Data System (ADS)

    Horton, F.; Hacker, B. R.; Kylander-Clark, A. R.

    2014-12-01

    As zones of focused metamorphism, melting, and ductile deformation, hot crustal sections are especially important for understanding the evolution of the lower crust in convergent orogens, such as Tibet. One of the best exposed crustal sections that reached ultrahigh-temperature (UHT: >900 C) is in southern Madagascar. There, the association of UHT mineral assemblages with exceptionally high concentrations of radioactive heat-producing elements begs the question of whether radiogenic heating caused UHT. Partial melting, retrogression and rapid elemental diffusion at high temperature, however, have left a complex record of radiometric dates that span 150 Myr (~650-500 Ma), making it difficult to address this question. We apply laser-ablation split-stream ICPMS (LASS) petrochronology and 4+ cation thermometry to better constrain the lengthscales and timescales over which high temperatures were sustained in southern Madagascar. By deciphering complex intragrain (re)crystallization textures of zircon and monazite from a broad geographical area, we deduce that orogenesis lasted >60 Myr. Specifically, 600-540 Ma zircon and monazite with HREE depletion suggest (re)crystallization in the presence of garnet. All monazite show negative Eu anomalies (compatible with the presence of plagioclase), but ~570 to ~530 Ma monazite has more-pronounced anomalies. Ti-in-zircon and Zr-in-rutile thermometry confirm ultrahigh temperatures within a restricted area of ~100 x 200 km. These thermal and chronologic constraints allow us to evaluate the potential causes of heating. Measured K, Th, and U contents of rocks within the UHT domain indicate an average heat-production rate of >4 ?W/m3, sufficient to produce UHT metamorphism in 60-km thick crust within 60 Myr. We conclude that high concentrations of heat-producing elements caused focused heat production in young metasedimentary rocks that were sandwiched between older crustal domains. We speculate that ultrahigh temperatures caused by radiogenic heating led to preferential crustal melting withinand ductile extrusion ofthe young metasediments.

  14. Geochronology and 4+ thermometry of ultrahigh-temperature (UHT) metamorphism in southern Madagascar

    NASA Astrophysics Data System (ADS)

    Horton, F.; Hacker, B. R.; Kylander-Clark, A. R.

    2013-12-01

    Ultrahigh temperature (UHT) metamorphism--regional metamorphism at >900 C--in a collisional setting requires some combination of: i) unusually radiogenic crust, ii) advection of heat by magmatism, iii) conduction of mantle-derived heat, and iv) shear heating. The Neoproterozoic continental collision zone exposed in Madagascar provides a good opportunity to investigate these potential causes; we use three 4+ thermometers (Zr-in-rutile, Ti-in-zircon, and Ti-in-quartz) and U/Th-Pb geochronology of monazite and zircon to evaluate the magnitude, timing, and duration of UHT metamorphism in southern Madagascar. U-Pb dates from metamorphic monazite and zircon with complex intragrain (re)crystallization textures range from ~600 Ma to ~500 Ma. Zircon and monazite with HREE depletion and dates of 600-540 Ma suggest (re)crystallization in the presence of garnet. All monazite shows negative Eu anomalies (compatible with the presence of plagioclase), but monazite with dates from ~570 to ~530 Ma has more pronounced anomalies. Zr-in-rutile temperatures span 700 to 960 C and Ti-in-quartz temperatures span 600 to 950 C. The UHT metamorphism is assumed to postdate both the accretion of an arc terrane to West Gondwana at ~600 Ma and the suturing of East and West Gondwana prior to ~570 Ma. The 40 Myr between distinct episodes of alkali plutonism at ~570 Ma (deformed) and ~530 Ma (nondeformed) coincide with more-negative Eu anomalies in monazite, and may reflect the period of orogenesis associated with UHT metamorphism. The measured K, Th, and U contents of rocks within the UHT domain [GAF-BGR, 2008] indicate an average heat production of >5 ?W/m3. This is sufficient to produce UHT metamorphism in 60-km thick crust within 40 Myr.

  15. Madagascar Highland erosion: What can we learn from the archive precipitation data?

    NASA Astrophysics Data System (ADS)

    Imola Szab, Amanda; Raveloson, Andrea; Szkely, Balzs

    2014-05-01

    In Madagascar, soil erosion is significant even when it is compared to world averages, resulting in special geomorphic forms known as lavakas appearing in the Highland regions of the island. The development of these features is due to rather unique multifactorial environmental conditions. Among many factors (geology, soil composition, human influence, etc.) the spatial and temporal distribution of precipitation is a key factor. The presence of the dry and wet season seems to be responsible for the enhanced generation of small cracks that might eventually lead to the development of a gully. However, the way of the development of such gully erosions are unknown. To what extent of the actual precipitation pattern to what extent the weather contributes to the aforementioned phenomenon has not yet been studied in great detail. The aim of our research is to study the climatic and weather conditions of lavaka-prone areas for the last decades. The typical cyclonal pattern affects the Madagascar Highlands in various ways. The precipitation and the soil moisture data show that the spatial distribution can be correlated with the appearance of lavakas to a given extent, however the local distribution cannot be explained only based on the precipitation pattern. The severity of the wet season varies strongly in the various decades leading to different precipitation maxima in January-March period. In general the effectiveness of the gully erosion is thought to be highly enhanced if the run-off of the area show large temporal variations. According to our studies this variability is quite high in certain seasons, and, despite of the low spatial resolution, related to the lavaka-prone areas. However, neither the amount of the precipitation, nor the variability alone cannot explain the high variation found in the spatial density and length distribution. Further multidisciplinary studies are necessary to draw conclusions about lavaka formation and describe the process of lavaka development. This is ILARG-contribution Nr. 11.

  16. The Burden of Acute Disease in Mahajanga, Madagascar A 21 Month Study

    PubMed Central

    Kannan, Vijay C.; Andriamalala, Clara N.; Reynolds, Teri A.

    2015-01-01

    Background Efforts to develop effective and regionally-appropriate emergency care systems in sub-Saharan Africa are hindered by a lack of data on both the burden of disease in the region and on the state of existing care delivery mechanisms. This study describes the burden of acute disease presenting to an emergency unit in Mahajanga, Madagascar. Methods and Findings Handwritten patient registries on all emergency department patients presenting between 1 January 2011 and 30 September 2012 were reviewed and data entered into a database. Data included age, sex, diagnosis, and disposition. We classified diagnoses into Clinical Classifications Software (CCS) multi-level categories. The population was 53.5% male, with a median age of 31 years. The five most common presenting conditions were 1) Superficial injury; contusion, 2) Open wounds of head; neck; and trunk, 3) Open wounds of extremities, 4) Intracranial injury, and 5) Unspecified injury and poisoning. Trauma accounted for 48%, Infectious Disease for 15%, Mental Health 6.1%, Noncommunicable 29%, and Neoplasms 1.2%. The acuity seen was high, with an admission rate of 43%. Trauma was the most common reason for admission, representing 19% of admitted patients. Conclusions This study describes the burden of acute disease at a large referral center in northern Madagascar. The Centre Hpitalier Universitaire de Mahajanga sees a high volume of acutely ill and injured patients. Similar to other reports from the region, trauma is the most common pathology observed, though infectious disease was responsible for the majority of adult mortality. Typhoid fever other intestinal infections were the most lethal CCS-coded pathologies. By utilizing a widely understood classification system, we are able to highlight contrasts between Mahajangas acute and overall disease burden as well as make comparisons between this region and the rest of the globe. We hope this study will serve to guide the development of context-appropriate emergency medicine systems in the region. PMID:25738300

  17. Immune Responses to Plague Infection in Wild Rattus rattus, in Madagascar: A Role in Foci Persistence?

    PubMed Central

    Andrianaivoarimanana, Voahangy; Telfer, Sandra; Rajerison, Minoarisoa; Ranjalahy, Michel A.; Andriamiarimanana, Fehivola; Rahaingosoamamitiana, Corinne; Rahalison, Lila; Jambou, Ronan

    2012-01-01

    Background Plague is endemic within the central highlands of Madagascar, where its main reservoir is the black rat, Rattus rattus. Typically this species is considered susceptible to plague, rapidly dying after infection inducing the spread of infected fleas and, therefore, dissemination of the disease to humans. However, persistence of transmission foci in the same area from year to year, supposes mechanisms of maintenance among which rat immune responses could play a major role. Immunity against plague and subsequent rat survival could play an important role in the stabilization of the foci. In this study, we aimed to investigate serological responses to plague in wild black rats from endemic areas of Madagascar. In addition, we evaluate the use of a recently developed rapid serological diagnostic test to investigate the immune response of potential reservoir hosts in plague foci. Methodology/Principal Findings We experimentally infected wild rats with Yersinia pestis to investigate short and long-term antibody responses. Anti-F1 IgM and IgG were detected to evaluate this antibody response. High levels of anti-F1 IgM and IgG were found in rats one and three weeks respectively after challenge, with responses greatly differing between villages. Plateau in anti-F1 IgM and IgG responses were reached for as few as 500 and 1500 colony forming units (cfu) inoculated respectively. More than 10% of rats were able to maintain anti-F1 responses for more than one year. This anti-F1 response was conveniently followed using dipsticks. Conclusion/Significance Inoculation of very few bacteria is sufficient to induce high immune response in wild rats, allowing their survival after infection. A great heterogeneity of rat immune responses was found within and between villages which could heavily impact on plague epidemiology. In addition, results indicate that, in the field, anti-F1 dipsticks are efficient to investigate plague outbreaks several months after transmission. PMID:22719908

  18. Anthropophilic mosquitoes and malaria transmission in the eastern foothills of the central highlands of Madagascar.

    PubMed

    Andrianaivolambo, Lala; Domarle, Olivier; Randrianarivelojosia, Milijaona; Ratovonjato, Jocelyn; Le Goff, Gilbert; Talman, Arthur; Ariey, Frédéric; Robert, Vincent

    2010-12-01

    Malaria remains a major public health problem in Madagascar, as it is the first cause of morbidity in health care facilities. Its transmission remains poorly documented. An entomological study was carried out over 1 year (October 2003-September 2004) in Saharevo, a village located at an altitude of 900m on the eastern edge of the Malagasy central highlands. Mosquitoes were sampled weekly upon landing on human volunteers and in various resting-places. Out of 5515 mosquitoes collected on humans, 3219 (58.4%) were anophelines. Eleven anopheline species were represented, among which Anopheles funestus, Anopheles gambiae, Anopheles arabiensis and Anopheles mascarensis. Out of 677 mosquitoes collected in bedrooms by pyrethrum spray catches and in Muirhead-Thomson pits, 656 (96.9%) were anopheline belonging to these four latter species. The proportion of mosquitoes that fed on human varied according to the resting-places and the mosquito species: 86% of An. funestus resting in bedrooms fed on humans, whereas only 16% of An. funestus and 0% of An. mascarensis resting in pits fed on humans. The proportion of anopheline mosquitoes infected with human Plasmodium was measured by circumsporozoite protein-ELISA: 10/633 An. funestus (1.58%), 1/211 An. gambiae s.l. (0.48%) and 2/268 An. mascarensis (0.75%). The annual entomological inoculation rate (number of bites of infected anophelines per adult) was estimated at 2.78. The transmission was mainly due to An. funestus and only observed in the second half of the rainy season, from February to May. These results are discussed in the context of the current malaria vector control policy in Madagascar. PMID:20804715

  19. The origin and dispersion of human parasitic diseases in the old world (Africa, Europe and Madagascar).

    PubMed

    Nozais, Jean-Pierre

    2003-01-01

    The ancestors of present-day man (Homo sapiens sapiens) appeared in East Africa some three and a half million years ago (Australopithecs), and then migrated to Europe, Asia, and later to the Americas, thus beginning the differentiation process. The passage from nomadic to sedentary life took place in the Middle East in around 8000 BC. Wars, spontaneous migrations and forced migrations (slave trade) led to enormous mixtures of populations in Europe and Africa and favoured the spread of numerous parasitic diseases with specific strains according to geographic area. The three human plasmodia (Plasmodium falciparum, P. vivax, and P. malariae) were imported from Africa into the Mediterranean region with the first human migrations, but it was the Neolithic revolution (sedentarisation, irrigation, population increase) which brought about actual foci for malaria. The reservoir for Leishmania infantum and L. donovani--the dog--has been domesticated for thousands of years. Wild rodents as reservoirs of L. major have also long been in contact with man and probably were imported from tropical Africa across the Sahara. L. tropica, by contrast, followed the migrations of man, its only reservoir. L. infantum and L. donovani spread with man and his dogs from West Africa. Likewise, for thousands of years, the dog has played an important role in the spread and the endemic character of hydatidosis through sheep (in Europe and North Africa) and dromadary (in the Sahara and North Africa). Schistosoma haematobium and S. mansoni have existed since prehistoric times in populations living in or passing through the Sahara. These populations then transported them to countries of Northern Africa where the specific, intermediary hosts were already present. Madagascar was inhabited by populations of Indonesian origin who imported lymphatic filariosis across the Indian Ocean (possibly of African origin since the Indonesian sailors had spent time on the African coast before reaching Madagascar). Migrants coming from Africa and Arabia brought with them the two African forms of bilharziosis: S. haematobium and S. mansoni. PMID:12687757

  20. Assumption Trade-Offs When Choosing Identification Strategies for Pre-Post Treatment Effect Estimation: An Illustration of a Community-Based Intervention in Madagascar

    PubMed Central

    van der Laan, Mark J.; Petersen, Maya L.

    2015-01-01

    Failure (or success) in finding a statistically significant effect of a large-scale intervention may be due to choices made in the evaluation. To highlight the potential limitations and pitfalls of some common identification strategies used for estimating causal effects of community-level interventions, we apply a roadmap for causal inference to a pre-post evaluation of a national nutrition program in Madagascar. Selection into the program was non-random and strongly associated with the pre-treatment (lagged) outcome. Using structural causal models (SCM), directed acyclic graphs (DAGs) and simulated data, we illustrate that an estimand with the outcome defined as the post-treatment outcome controls for confounding by the lagged outcome but not by possible unmeasured confounders. Two separate differencing estimands (of the pre- and post-treatment outcome) have the potential to adjust for a certain type of unmeasured confounding, but introduce bias if the additional identification assumptions they rely on are not met. In order to illustrate the practical impact of choice between three common identification strategies and their corresponding estimands, we used observational data from the community nutrition program in Madagascar to estimate each of these three estimands. Specifically, we estimated the average treatment effect of the program on the community mean nutritional status of children 5 years and under and found that the estimate based on the post-treatment estimand was about a quarter of the magnitude of either of the differencing estimands (0.066 SD vs. 0.26–0.27 SD increase in mean weight-for-age z-score). Choice of estimand clearly has important implications for the interpretation of the success of the program to improve nutritional status of young children. A careful appraisal of the assumptions underlying the causal model is imperative before committing to a statistical model and progressing to estimation. However, knowledge about the data-generating process must be sufficient in order to choose the identification strategy that gets us closest to the truth. PMID:26097800

  1. Petrogenesis of high-K metagranites in the Kerala Khondalite Belt, southern India: a possible magmatic-arc link between India, Sri Lanka, and Madagascar

    NASA Astrophysics Data System (ADS)

    Sreejith, C.; Ravindra Kumar, G. R.

    2013-01-01

    The Proterozoic Kerala Khondalite Belt (KKB), southern India preserves a distinct high-grade terrain that is interpreted to have been situated adjacent to Madagascar and Sri Lanka during Gondwana assembly. As such, it has become a major focus for testing models of supercontinent amalgamation and dispersal. The lithounits of KKB have remarkable petrological similarities to the Highland Complex (HC) of Sri Lanka and south-central Madagascar. However, there is no well-constrained petrogenetic model for the KKB that fits explicitly within a supercontinent reconstruction model. We present here results from our on-going studies on the origin and evolution of K-rich (potassic, where K2O/Na2O > 1) gneisses of KKB in relation to Proterozoic supercontinent events. Our results show, in a major departure from earlier metasedimentary origin, that potassic gneisses are metamorphosed granitoids. The metagranitoid samples display high K2O contents and low Al2O3/(FeO + MgO + TiO2) values. They are moderate to strongly peraluminous (ASI values ranging from 1.05 to 1.47) rocks showing mineralogical, petrological, and geochemical characteristics distinctive of the high-K calc-alkaline suites. Typical of igneous suites, the high-K metagranites show minor variation in chemical compositions with most oxides showing negative correlation with SiO2. Geochemistry illustrates distinctive features of arc-related magmas with LILE (K, Rb, and Th) and LREE enriched patterns and considerable depletion of HSFE (Nb, Zr, and Ti). The high-K metagranites are further characterized by strong negative anomalies of Eu (Eu/Eu* = 0.10-0.44) and Sr, suggesting melting in plagioclase stability field and retention of plagioclase in the residual phase. Petrogenetic discrimination for granitoids, using major and trace elements demonstrates that the high-K metagranites of the KKB formed by partial melting of igneous source in lower- to middle-crust levels. Overall the geochemical features are supportive of origin in relation to a convergent margin setting, possibly in a continental magmatic arc system, which can be connected to the amalgamation and dispersal of continental fragments in a supercontinent event. This study, therefore, provides a lead towards more robust comparisons between the Proterozoic supercontinent events and processes.

  2. Tracing Arab-Islamic Inheritance in Madagascar: Study of the Y-chromosome and Mitochondrial DNA in the Antemoro

    PubMed Central

    Capredon, Mélanie; Brucato, Nicolas; Tonasso, Laure; Choesmel-Cadamuro, Valérie; Ricaut, François-Xavier; Razafindrazaka, Harilanto; Rakotondrabe, Andriamihaja Bakomalala; Ratolojanahary, Mamisoa Adelta; Randriamarolaza, Louis-Paul; Champion, Bernard; Dugoujon, Jean-Michel

    2013-01-01

    Madagascar is located at the crossroads of the Asian and African worlds and is therefore of particular interest for studies on human population migration. Within the large human diversity of the Great Island, we focused our study on a particular ethnic group, the Antemoro. Their culture presents an important Arab-Islamic influence, but the question of an Arab biological inheritance remains unresolved. We analyzed paternal (n=129) and maternal (n=135) lineages of this ethnic group. Although the majority of Antemoro genetic ancestry comes from sub-Saharan African and Southeast Asian gene pools, we observed in their paternal lineages two specific haplogroups (J1 and T1) linked to Middle Eastern origins. This inheritance was restricted to some Antemoro sub-groups. Statistical analyses tended to confirm significant Middle Eastern genetic contribution. This study gives a new perspective to the large human genetic diversity in Madagascar. PMID:24278350

  3. Tracing Arab-Islamic inheritance in Madagascar: study of the Y-chromosome and mitochondrial DNA in the Antemoro.

    PubMed

    Capredon, Mélanie; Brucato, Nicolas; Tonasso, Laure; Choesmel-Cadamuro, Valérie; Ricaut, François-Xavier; Razafindrazaka, Harilanto; Rakotondrabe, Andriamihaja Bakomalala; Ratolojanahary, Mamisoa Adelta; Randriamarolaza, Louis-Paul; Champion, Bernard; Dugoujon, Jean-Michel

    2013-01-01

    Madagascar is located at the crossroads of the Asian and African worlds and is therefore of particular interest for studies on human population migration. Within the large human diversity of the Great Island, we focused our study on a particular ethnic group, the Antemoro. Their culture presents an important Arab-Islamic influence, but the question of an Arab biological inheritance remains unresolved. We analyzed paternal (n=129) and maternal (n=135) lineages of this ethnic group. Although the majority of Antemoro genetic ancestry comes from sub-Saharan African and Southeast Asian gene pools, we observed in their paternal lineages two specific haplogroups (J1 and T1) linked to Middle Eastern origins. This inheritance was restricted to some Antemoro sub-groups. Statistical analyses tended to confirm significant Middle Eastern genetic contribution. This study gives a new perspective to the large human genetic diversity in Madagascar. PMID:24278350

  4. Newcastle disease virus in Madagascar: identification of an original genotype possibly deriving from a died out ancestor of genotype IV.

    PubMed

    Maminiaina, Olivier F; Gil, Patricia; Briand, François-Xavier; Albina, Emmanuel; Keita, Djénéba; Andriamanivo, Harentsoaniaina Rasamoelina; Chevalier, Véronique; Lancelot, Renaud; Martinez, Dominique; Rakotondravao, R; Rajaonarison, Jean-Joseph; Koko, M; Andriantsimahavandy, Abel A; Jestin, Véronique; Servan de Almeida, Renata

    2010-01-01

    In Madagascar, Newcastle disease (ND) has become enzootic after the first documented epizootics in 1946, with recurrent annual outbreaks causing mortality up to 40%. Four ND viruses recently isolated in Madagascar were genotypically and pathotypically characterised. By phylogenetic inference based on the F and HN genes, and also full-genome sequence analyses, the NDV Malagasy isolates form a cluster distant enough to constitute a new genotype hereby proposed as genotype XI. This new genotype is presumably deriving from an ancestor close to genotype IV introduced in the island probably more than 50 years ago. Our data show also that all the previously described neutralising epitopes are conserved between Malagasy and vaccine strains. However, the potential implication in vaccination failures of specific amino acid substitutions predominantly found on surface-exposed epitopes of F and HN proteins is discussed. PMID:21085573

  5. Newcastle Disease Virus in Madagascar: Identification of an Original Genotype Possibly Deriving from a Died Out Ancestor of Genotype IV

    PubMed Central

    Maminiaina, Olivier F.; Gil, Patricia; Briand, François-Xavier; Albina, Emmanuel; Keita, Djénéba; Andriamanivo, Harentsoaniaina Rasamoelina; Chevalier, Véronique; Lancelot, Renaud; Martinez, Dominique; Rakotondravao, R.; Rajaonarison, Jean-Joseph; Koko, M.; Andriantsimahavandy, Abel A.; Jestin, Véronique; Servan de Almeida, Renata

    2010-01-01

    In Madagascar, Newcastle disease (ND) has become enzootic after the first documented epizootics in 1946, with recurrent annual outbreaks causing mortality up to 40%. Four ND viruses recently isolated in Madagascar were genotypically and pathotypically characterised. By phylogenetic inference based on the F and HN genes, and also full-genome sequence analyses, the NDV Malagasy isolates form a cluster distant enough to constitute a new genotype hereby proposed as genotype XI. This new genotype is presumably deriving from an ancestor close to genotype IV introduced in the island probably more than 50 years ago. Our data show also that all the previously described neutralising epitopes are conserved between Malagasy and vaccine strains. However, the potential implication in vaccination failures of specific amino acid substitutions predominantly found on surface-exposed epitopes of F and HN proteins is discussed. PMID:21085573

  6. Rapid Response to Evaluate the Presence of Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) and Ranavirus in Wild Amphibian Populations in Madagascar

    PubMed Central

    Kolby, Jonathan E.; Smith, Kristine M.; Ramirez, Sara D.; Rabemananjara, Falitiana; Pessier, Allan P.; Brunner, Jesse L.; Goldberg, Caren S.; Berger, Lee; Skerratt, Lee F.

    2015-01-01

    We performed a rapid response investigation to evaluate the presence and distribution of amphibian pathogens in Madagascar following our identification of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) and ranavirus in commercially exported amphibians. This targeted risk-based field surveillance program was conducted from February to April 2014 encompassing 12 regions and 47 survey sites. We simultaneously collected amphibian and environmental samples to increase survey sensitivity and performed sampling both in wilderness areas and commercial amphibian trade facilities. Bd was not detected in any of 508 amphibian skin swabs or 68 water filter samples, suggesting pathogen prevalence was below 0.8%, with 95% confidence during our visit. Ranavirus was detected in 5 of 97 amphibians, including one adult Mantidactylus cowanii and three unidentified larvae from Ranomafana National Park, and one adult Mantidactylus mocquardi from Ankaratra. Ranavirus was also detected in water samples collected from two commercial amphibian export facilities. We also provide the first report of an amphibian mass-mortality event observed in wild amphibians in Madagascar. Although neither Bd nor ranavirus appeared widespread in Madagascar during this investigation, additional health surveys are required to disentangle potential seasonal variations in pathogen abundance and detectability from actual changes in pathogen distribution and rates of spread. Accordingly, our results should be conservatively interpreted until a comparable survey effort during winter months has been performed. It is imperative that biosecurity practices be immediately adopted to limit the unintentional increased spread of disease through the movement of contaminated equipment or direct disposal of contaminated material from wildlife trade facilities. The presence of potentially introduced strains of ranaviruses suggests that Madagascar's reptile species might also be threatened by disease. Standardized population monitoring of key amphibian and reptile species should be established with urgency to enable early detection of potential impacts of disease emergence in this global biodiversity hotspot. PMID:26083349

  7. High Prevalence of West Nile Virus in Domestic Birds and Detection in 2 New Mosquito Species in Madagascar.

    PubMed

    Maquart, Marianne; Boyer, Sébastien; Rakotoharinome, Vincent Michel; Ravaomanana, Julie; Tantely, Michael Luciano; Heraud, Jean-Michel; Cardinale, Eric

    2016-01-01

    West Nile virus is an arthropod-borne zoonosis transmitted by a large number of mosquito species, and birds play a key role as reservoir of the virus. Its distribution is largely widespread over Africa, Asia, the Americas and Europe. Since 1978, it has frequently been reported in Madagascar. Studies described a high seroprevalence level of the virus in humans in different areas of the island and a human fatal case of WNV infection was reported in 2011. Despite these reports, the epidemiology of WNV in Madagascar, in particular, viral circulation remains unclear. To explore the transmission of WNV in two rural human populations of Madagascar, we investigated local mosquitoes and poultry for evidence of current infections, and determined seroprevalence of candidate sentinel species among the local poultry. These 2 areas are close to lakes where domestic birds, migratory wild birds and humans coexist. Serological analysis revealed WNV antibodies in domestic birds (duck, chicken, goose, turkey and guinea fowl) sampled in both districts (Antsalova 29.4% and Mitsinjo 16.7%). West Nile virus nucleic acid was detected in one chicken and in 8 pools of mosquitoes including 2 mosquito species (Aedeomyia madagascarica and Anopheles pauliani) that have not been previously described as candidate vectors for WNV. Molecular analysis of WNV isolates showed that all viruses detected were part of the lineage 2 that is mainly distributed in Africa, and were most closely matched by the previous Malagasy strains isolated in 1988. Our study showed that WNV circulates in Madagascar amongst domestic birds and mosquitoes, and highlights the utility of poultry as a surveillance tool to detect WNV transmission in a peri-domestic setting. PMID:26807720

  8. Rapid Response to Evaluate the Presence of Amphibian Chytrid Fungus (Batrachochytrium dendrobatidis) and Ranavirus in Wild Amphibian Populations in Madagascar.

    PubMed

    Kolby, Jonathan E; Smith, Kristine M; Ramirez, Sara D; Rabemananjara, Falitiana; Pessier, Allan P; Brunner, Jesse L; Goldberg, Caren S; Berger, Lee; Skerratt, Lee F

    2015-01-01

    We performed a rapid response investigation to evaluate the presence and distribution of amphibian pathogens in Madagascar following our identification of amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd) and ranavirus in commercially exported amphibians. This targeted risk-based field surveillance program was conducted from February to April 2014 encompassing 12 regions and 47 survey sites. We simultaneously collected amphibian and environmental samples to increase survey sensitivity and performed sampling both in wilderness areas and commercial amphibian trade facilities. Bd was not detected in any of 508 amphibian skin swabs or 68 water filter samples, suggesting pathogen prevalence was below 0.8%, with 95% confidence during our visit. Ranavirus was detected in 5 of 97 amphibians, including one adult Mantidactylus cowanii and three unidentified larvae from Ranomafana National Park, and one adult Mantidactylus mocquardi from Ankaratra. Ranavirus was also detected in water samples collected from two commercial amphibian export facilities. We also provide the first report of an amphibian mass-mortality event observed in wild amphibians in Madagascar. Although neither Bd nor ranavirus appeared widespread in Madagascar during this investigation, additional health surveys are required to disentangle potential seasonal variations in pathogen abundance and detectability from actual changes in pathogen distribution and rates of spread. Accordingly, our results should be conservatively interpreted until a comparable survey effort during winter months has been performed. It is imperative that biosecurity practices be immediately adopted to limit the unintentional increased spread of disease through the movement of contaminated equipment or direct disposal of contaminated material from wildlife trade facilities. The presence of potentially introduced strains of ranaviruses suggests that Madagascar's reptile species might also be threatened by disease. Standardized population monitoring of key amphibian and reptile species should be established with urgency to enable early detection of potential impacts of disease emergence in this global biodiversity hotspot. PMID:26083349

  9. Systematics of the Madagascar Anelosimus spiders: remarkable local richness and endemism, and dual colonization from the Americas.

    PubMed

    Agnarsson, Ingi; Jencik, Brian B; Veve, Giselle M; Hanitriniaina, Sahondra; Agostini, Diego; Goh, Seok Ping; Pruitt, Jonathan; Kuntner, Matjaž

    2015-01-01

    Despite the alarming rates of deforestation and forest fragmentation, Madagascar still harbors extraordinary biodiversity. However, in many arthropod groups, such as spiders, this biodiversity remains mostly unexplored and undescribed. The first subsocial Madagascan species of the theridiid spider genus Anelosimus were described in 2005 when six new species were found to coexist in the Périnet forest fragment within Andasibe-Mantadia NP. However, this discovery was based only on a few specimens and the extent of this Madagascan radiation has remained unknown. We here report on a thorough survey of >350 colonies from Périnet, and three pilot surveys into additional Madagascar forests (Ambohitantely, Ranamofana, and Montagne d'Ambre). The morphological, molecular and natural history data from these surveys facilitated a revised taxonomy and phylogenetic hypothesis of Madagascan Anelosimus. This subsocial clade currently comprises six previously known (Anelosimusandasibe Agnarsson & Kuntner, 2005, Anelosimusmay Agnarsson, 2005, Anelosimusnazariani Agnarsson & Kuntner, 2005, Anelosimussallee Agnarsson & Kuntner, 2005, Anelosimussalut Agnarsson & Kuntner, 2005, Anelosimusvondrona Agnarsson & Kuntner, 2005) and 10 new species: Anelosimusata sp. n., Anelosimusbuffoni sp. n., Anelosimusdarwini sp. n., Anelosimushookeri sp. n., Anelosimushuxleyi sp. n., Anelosimuslamarcki sp. n., Anelosimusmoramora sp. n., Anelosimustita sp. n., Anelosimustorfi sp. n., Anelosimuswallacei sp. n.. With the exception of Anelosimusmay and Anelosimusvondrona, all other species appear to be single forest endemics. While additional sampling is necessary, these data imply a much higher local richness and endemism in Madagascan forests than in any other comparable area globally. The phylogenetic results establish a sister clade relationship between the subsocial Anelosimus in Madagascar and the American 'eximius group', and between the solitary Anelosimusdecaryi on Madagascar and a solitary American clade. These findings imply duplicate colonizations from America, an otherwise rare biogeographical pattern, calling for more detailed investigation of Anelosimus biogeography. PMID:26175602

  10. Systematics of the Madagascar Anelosimus spiders: remarkable local richness and endemism, and dual colonization from the Americas

    PubMed Central

    Agnarsson, Ingi; Jencik, Brian B.; Veve, Giselle M.; Hanitriniaina, Sahondra; Agostini, Diego; Goh, Seok Ping; Pruitt, Jonathan; Kuntner, Matjaž

    2015-01-01

    Abstract Despite the alarming rates of deforestation and forest fragmentation, Madagascar still harbors extraordinary biodiversity. However, in many arthropod groups, such as spiders, this biodiversity remains mostly unexplored and undescribed. The first subsocial Madagascan species of the theridiid spider genus Anelosimus were described in 2005 when six new species were found to coexist in the Périnet forest fragment within Andasibe-Mantadia NP. However, this discovery was based only on a few specimens and the extent of this Madagascan radiation has remained unknown. We here report on a thorough survey of >350 colonies from Périnet, and three pilot surveys into additional Madagascar forests (Ambohitantely, Ranamofana, and Montagne d’Ambre). The morphological, molecular and natural history data from these surveys facilitated a revised taxonomy and phylogenetic hypothesis of Madagascan Anelosimus. This subsocial clade currently comprises six previously known (Anelosimus andasibe Agnarsson & Kuntner, 2005, Anelosimus may Agnarsson, 2005, Anelosimus nazariani Agnarsson & Kuntner, 2005, Anelosimus sallee Agnarsson & Kuntner, 2005, Anelosimus salut Agnarsson & Kuntner, 2005, Anelosimus vondrona Agnarsson & Kuntner, 2005) and 10 new species: Anelosimus ata sp. n., Anelosimus buffoni sp. n., Anelosimus darwini sp. n., Anelosimus hookeri sp. n., Anelosimus huxleyi sp. n., Anelosimus lamarcki sp. n., Anelosimus moramora sp. n., Anelosimus tita sp. n., Anelosimus torfi sp. n., Anelosimus wallacei sp. n.. With the exception of Anelosimus may and Anelosimus vondrona, all other species appear to be single forest endemics. While additional sampling is necessary, these data imply a much higher local richness and endemism in Madagascan forests than in any other comparable area globally. The phylogenetic results establish a sister clade relationship between the subsocial Anelosimus in Madagascar and the American ‘eximius group’, and between the solitary Anelosimus decaryi on Madagascar and a solitary American clade. These findings imply duplicate colonizations from America, an otherwise rare biogeographical pattern, calling for more detailed investigation of Anelosimus biogeography. PMID:26175602

  11. High Prevalence of West Nile Virus in Domestic Birds and Detection in 2 New Mosquito Species in Madagascar

    PubMed Central

    Rakotoharinome, Vincent Michel; Ravaomanana, Julie; Tantely, Michael Luciano; Heraud, Jean-Michel; Cardinale, Eric

    2016-01-01

    West Nile virus is an arthropod-borne zoonosis transmitted by a large number of mosquito species, and birds play a key role as reservoir of the virus. Its distribution is largely widespread over Africa, Asia, the Americas and Europe. Since 1978, it has frequently been reported in Madagascar. Studies described a high seroprevalence level of the virus in humans in different areas of the island and a human fatal case of WNV infection was reported in 2011. Despite these reports, the epidemiology of WNV in Madagascar, in particular, viral circulation remains unclear. To explore the transmission of WNV in two rural human populations of Madagascar, we investigated local mosquitoes and poultry for evidence of current infections, and determined seroprevalence of candidate sentinel species among the local poultry. These 2 areas are close to lakes where domestic birds, migratory wild birds and humans coexist. Serological analysis revealed WNV antibodies in domestic birds (duck, chicken, goose, turkey and guinea fowl) sampled in both districts (Antsalova 29.4% and Mitsinjo 16.7%). West Nile virus nucleic acid was detected in one chicken and in 8 pools of mosquitoes including 2 mosquito species (Aedeomyia madagascarica and Anopheles pauliani) that have not been previously described as candidate vectors for WNV. Molecular analysis of WNV isolates showed that all viruses detected were part of the lineage 2 that is mainly distributed in Africa, and were most closely matched by the previous Malagasy strains isolated in 1988. Our study showed that WNV circulates in Madagascar amongst domestic birds and mosquitoes, and highlights the utility of poultry as a surveillance tool to detect WNV transmission in a peri-domestic setting. PMID:26807720

  12. Nesogordonia tricarpellata (Dombeyaceae), a new species from Madagascar that compels modification of the morphological circumscription of the genus

    PubMed Central

    Skema, Cynthia; Dorr, Laurence J.

    2011-01-01

    Abstract Nesogordonia tricarpellata Skema & Dorr, sp. nov., a new species from southeastern Madagascar, is described and illustrated. It differs from all other species of Nesogordonia Baill. in having 69 stamens, 3 staminodes, a 3-carpellate ovary, and a 3-valved capsule. These androecial and gynoecial characters require modification of the long-standing circumscription of the genus. The new species also has the southernmost geographic range of any species in the genus. PMID:22171171

  13. Genetic evidence for Rift Valley fever outbreaks in Madagascar resulting from virus introductions from the East African mainland rather than enzootic maintenance.

    PubMed

    Carroll, Serena A; Reynes, Jean-Marc; Khristova, Marina L; Andriamandimby, Soa Fy; Rollin, Pierre E; Nichol, Stuart T

    2011-07-01

    Rift Valley fever virus (RVFV), a mosquito-borne phlebovirus, has been detected in Madagascar since 1979, with occasional outbreaks. In 2008 to 2009, a large RVFV outbreak was detected in Malagasy livestock and humans during two successive rainy seasons. To determine whether cases were due to enzootic maintenance of the virus within Madagascar or to importation from the East African mainland, nine RVFV whole genomic sequences were generated for viruses from the 1991 and 2008 Malagasy outbreaks. Bayesian coalescent analyses of available whole S, M, and L segment sequences were used to estimate the time to the most recent common ancestor for the RVFVs. The 1979 Madagascar isolate shared a common ancestor with strains on the mainland around 1972. The 1991 Madagascar isolates were in a clade distinct from that of the 1979 isolate and shared a common ancestor around 1987. Finally, the 2008 Madagascar viruses were embedded within a large clade of RVFVs from the 2006-2007 outbreak in East Africa and shared a common ancestor around 2003 to 2004. These results suggest that the most recent Madagascar outbreak was caused by a virus likely arriving in the country some time between 2003 and 2008 and that this outbreak may be an extension of the 2006-2007 East African outbreak. Clustering of the Malagasy sequences into subclades indicates that the viruses have continued to evolve during their short-term circulation within the country. These data are consistent with the notion that RVFV outbreaks in Madagascar result not from emergence from enzootic cycles within the country but from recurrent virus introductions from the East African mainland. PMID:21507967

  14. How to use local resources to fight malnutrition in Madagascar? A study combining a survey and a consumer test.

    PubMed

    Ramaroson Rakotosamimanana, Vonimihaingo; Valentin, Dominique; Arvisenet, Gaëlle

    2015-12-01

    This study aimed to understand consumers' habits and belief structures concerning local food products and to develop a new snack as a way to fight against children malnutrition in Madagascar. A large variety of natural food resources grow in Madagascar, like Moringa oleifera (MO) which leaves are rich in nutrients but not consumed. First, a survey conducted in four areas of Madagascar revealed that MO leaves are known for their health benefits but infrequently consumed, probably because of their low satiating power and strong odor. In the studied areas, different levels of consumption were observed, which may be linked to varying levels of familiarity with MO by the local populations, this in turn resulting from different situations regarding geographical and historical availability. In contrary, resources such as cassava are perceived as having negative effects on health but are widely consumed because they are cheap, liked by children and satiating. The second step in the study aimed to propose products that could increase MO consumption without completely changing food practices. The acceptability of snacks associating cassava roots and MO was evaluated by means of hedonic tests performed by children. Between the snacks tested, the preferred snack contained the highest quantity of MO and was sweetened. There was no effect of area on the acceptance of the formulated snacks. This work is an evaluation of the potential of MO in the diet of malnourished population. PMID:26297469

  15. Retrospective study of methylmercury and other metal(loid)s in Madagascar unpolished rice (Oryza sativa L.).

    PubMed

    Rothenberg, Sarah E; Mgutshini, Nomathamsanqa L; Bizimis, Michael; Johnson-Beebout, Sarah E; Ramanantsoanirina, Alain

    2015-01-01

    The rice ingestion rate in Madagascar is among the highest globally; however studies concerning metal(loid) concentrations in Madagascar rice are lacking. For Madagascar unpolished rice (n = 51 landraces), levels of toxic elements (e.g., total mercury, methylmercury, arsenic and cadmium) as well as essential micronutrients (e.g., zinc and selenium) were uniformly low, indicating potentially both positive and negative health effects. Aside from manganese (Wilcoxon rank sum, p < 0.01), no significant differences in concentrations for all trace elements were observed between rice with red bran (n = 20)and brown bran (n = 31) (Wilcoxon rank sum, p = 0.06-0.91). Compared to all elements in rice,rubidium (i.e., tracer for phloem transport) was most positively correlated with methylmercury (Pearson'sr = 0.33, p < 0.05) and total mercury (r = 0.44, p < 0.05), while strontium (i.e., tracer for xylemtransport) was least correlated with total mercury and methylmercury (r < 0.01 for both), suggesting inorganic mercury and methylmercury were possibly more mobile in phloem compared to xylem. PMID:25463705

  16. Hibernation in the pygmy slow loris (Nycticebus pygmaeus): multiday torpor in primates is not restricted to Madagascar

    PubMed Central

    Ruf, Thomas; Streicher, Ulrike; Stalder, Gabrielle L.; Nadler, Tilo; Walzer, Chris

    2015-01-01

    Hibernation and short daily torpor are states of energy conservation with reduced metabolism and body temperature. Both hibernation, also called multiday torpor, and daily torpor are common among mammals and occur in at least 11 orders. Within the primates, there is a peculiar situation, because to date torpor has been almost exclusively reported for Malagasy lemurs. The single exception is the African lesser bushbaby, which is capable of daily torpor, but uses it only under extremely adverse conditions. For true hibernation, the geographical restriction was absolute. No primate outside of Madagascar was previously known to hibernate. Since hibernation is commonly viewed as an ancient, plesiomorphic trait, theoretically this could mean that hibernation as an overwintering strategy was lost in all other primates in mainland Africa, Asia, and the Americas. However, we hypothesized that a good candidate species for the use of hibernation, outside of Madagascar should be the pygmy slow loris (Nycticebus pygmaeus), a small primate inhabiting tropical forests. Here, we show that pygmy slow lorises exposed to natural climatic conditions in northern Vietnam during winter indeed undergo torpor lasting up to 63 h, that is, hibernation. Thus, hibernation has been retained in at least one primate outside of Madagascar. PMID:26633602

  17. [Drug resistance of Plasmodium falciparum along the borders of the highlands in Madagascar: outlook for a national control program].

    PubMed

    Milijaona, R; Raharimalala, L; Ramambanirina, L; Ranaivo, L H; Jambou, R

    1998-01-01

    Resistance of Plasmodium falciparum to chloroquine was first suspected in Madagascar in 1975 and later confirmed in vivo and in vitro. During the period from 1985 and 1990, the network of public health monitoring stations reported that 1% of the population living on the central Highlands of Madagascar died of malaria. Thereafter the National Malaria Control Program achieved good success by spraying homes with insecticide and reorganizing distribution of chloroquine in all villages. However data recorded between 1996 and 1998 indicates that, after four years of widespread chloroquine use, resistance to amino-4-quinolones is progressing in Madagascar. The tests described in this report were performed on patients with documented malaria included in cohorts and followed year round by a physician. The three villages studied were located along the borders of the highlands between the plateaus and coastal areas. In vivo tests showed that the incidence of chloroquine resistance was 0% in Mahakary, 32% in Ankazobe and 30% in Saharivo. Clinically, however, treatment was unsuccessful in only 16% and 8% of cases respectively. In vitro tests demonstrated chloroquine sensitivity in 79% of the 153 strains tested. No resistance to quinine or halofantrine was observed. In vitro tests indicated an onset of resistance to mefloquine. Although the success rate of chloroquine treatment is nearly 80%, spread of strongly chloroquine-resistant strains is a risk especially in subjects with mild immunity to malaria. PMID:10088103

  18. Hibernation in the pygmy slow loris (Nycticebus pygmaeus): multiday torpor in primates is not restricted to Madagascar.

    PubMed

    Ruf, Thomas; Streicher, Ulrike; Stalder, Gabrielle L; Nadler, Tilo; Walzer, Chris

    2015-01-01

    Hibernation and short daily torpor are states of energy conservation with reduced metabolism and body temperature. Both hibernation, also called multiday torpor, and daily torpor are common among mammals and occur in at least 11 orders. Within the primates, there is a peculiar situation, because to date torpor has been almost exclusively reported for Malagasy lemurs. The single exception is the African lesser bushbaby, which is capable of daily torpor, but uses it only under extremely adverse conditions. For true hibernation, the geographical restriction was absolute. No primate outside of Madagascar was previously known to hibernate. Since hibernation is commonly viewed as an ancient, plesiomorphic trait, theoretically this could mean that hibernation as an overwintering strategy was lost in all other primates in mainland Africa, Asia, and the Americas. However, we hypothesized that a good candidate species for the use of hibernation, outside of Madagascar should be the pygmy slow loris (Nycticebus pygmaeus), a small primate inhabiting tropical forests. Here, we show that pygmy slow lorises exposed to natural climatic conditions in northern Vietnam during winter indeed undergo torpor lasting up to 63 h, that is, hibernation. Thus, hibernation has been retained in at least one primate outside of Madagascar. PMID:26633602

  19. The Hippoboscidae (Insecta: Diptera) from Madagascar, with new records from the “Parc National de Midongy Befotaka”

    PubMed Central

    Rahola, N.; Goodman, S.M.; Robert, V.

    2011-01-01

    The Hippoboscidae or “louse-flies” is a family of pupiparous Diptera, which in their adult stage are ectoparasites of mammals and birds. This paper presents a comprehensive review of Malagasy Hippoboscidae. In total, amongst the 213 species of this family known worldwide, 14 have been reported in Madagascar, among which six are considered as endemic to the Malagasy region. In addition, data are presented from a collection of 17 Hippoboscidae obtained from seven species of forest-dwelling birds in the “Parc National de Midongy Befotaka”, southeastern Madagascar, in 2003. The flies in this collection belong to three different species: Icosta malagasii (one), Ornithoica podicipis (ten) and Ornithoctona laticornis (six). The two former species were previously only known from single specimens in museum collections; the later species is distributed across much of the Afrotropical region and the records presented herein are the first for Madagascar. All the seven bird species are new hosts for hippoboscids. We present the first description of the male of Icosta malagasii. An illustrated dichotomous determination key of the 14 Malagasy species, based on morphological criteria only, is presented. PMID:21678788

  20. Stable carbon isotope values document how a Late Holocene expansion in grasslands impacted vertebrates in northwestern Madagascar

    NASA Astrophysics Data System (ADS)

    Crowley, B. E.; Samonds, K.

    2012-12-01

    Madagascar is home to some of the world's most distinctive plants and animals. Unfortunately, forest loss and habitat degradation has had a dramatic impact on both floral and faunal communities. Here we use carbon isotope values in radiocarbon-dated bones to examine how the vertebrate community at Anjohibe Cave, northwestern Madagascar, responded to a Late Holocene increase in C4 grass abundance. Our data demonstrate that major changes in the vegetation and animal community are recent phenomena at Anjohibe. Extinct lemurs and hippopotamuses were present until ca. 1500 years ago. These taxa relied exclusively on C3 resources. Locally extirpated fauna were present until 300 years ago. The majority of these species also relied on C3 resources. Their presence strongly suggests that the region surrounding the cave was more wooded than it is now, possibly as recently as 300 years ago. All introduced individuals are modern. Rats (Rattus sp.), shrews (Suncus murinus), and the giant frog Hoplobatrachus cf. tigrinus, have remarkably high carbon isotope values, implicating substantial ingestion of C4 foods. It is possible that grass abundance has increased dramatically in the past 100 years. Alternatively, opportunistically granivorous rats and shrews may selectively consume seeds from C4 grasses. In agreement with previous studies, stable isotope data reveal details of vegetation and faunal turnover in Northwestern Madagascar. Grasses have increased, forest dwelling species have vanished, and introduced taxa are exploiting a novel niche.

  1. RETROSPECTIVE STUDY OF METHYLMERCURY AND OTHER METAL(LOID)S IN MADAGASCAR UNPOLISHED RICE (Oryza sativa L.)

    PubMed Central

    Rothenberg, Sarah E.; Mgutshini, Noma L.; Bizimis, Michael; Johnson-Beebout, Sarah E.; Ramanantsoanirina, Alain

    2014-01-01

    The rice ingestion rate in Madagascar is among the highest globally; however studies concerning metal(loid) concentrations in Madagascar rice are lacking. For Madagascar unpolished rice (n=51 landraces), levels of toxic elements (e.g., total mercury, methylmercury, arsenic and cadmium) as well as essential micronutrients (e.g., zinc and selenium) were uniformly low, indicating potentially both positive and negative health effects. Aside from manganese (Wilcoxon rank sum, p<0.01), no significant differences in concentrations for all trace elements were observed between rice with red bran (n=20) and brown bran (n=31) (Wilcoxon rank sum, p=0.06–0.91). Compared to all elements in rice, rubidium (i.e., tracer for phloem transport) was most positively correlated with methylmercury (Pearson's r=0.33, p<0.05) and total mercury (r=0.44, p<0.05), while strontium (i.e., tracer for xylem transport) was least correlated with total mercury and methylmercury (r<0.01 for both), suggesting inorganic mercury and methylmercury were possibly more mobile in phloem compared to xylem. PMID:25463705

  2. Geochemistry of phlogopite, diopside, calcite, anhydrite and apatite pegmatites and syenites of southern Madagascar: evidence for crustal silicocarbonatitic (CSC) melt formation in a Panafrican collisional tectonic setting

    NASA Astrophysics Data System (ADS)

    Morteani, G.; Kostitsyn, Y. A.; Gilg, H. A.; Preinfalk, C.; Razakamanana, T.

    2013-04-01

    The phlogopite, diopside, calcite, anhydrite and apatite pegmatites of Ampandrandava and Beraketa are examples for the many other pegmatites of similar silicocarbonatitic composition found in the Bekily and Betroka-Beraketa Precambrian belts of southern Madagascar. The two studied pegmatites and associated syenites crystallised from immiscible silicocarbonatitic and peralkaline syenitic melts in a time span between 515 and 504 Ma in the final extensional phase of the Panafrican continental collision and connected metamorphic/metasomatic event. Model T Nd ages suggest that the melts were produced by partial melting of 3.5 Ga partially evaporitic continental crust. The studied pegmatites and genetically associated syenitic rocks are very rare examples for crustal silicocarbonatitic melts generated in a Panafrican collisional setting. The overwhelming majority of carbonatites and associated peralkaline rocks are mantle derived, much poorer in phosphate and sulfate and found in a cratonic environment. In light of the present results, genetic models for other sulfate- and phosphate-rich magmatic rocks (e.g., phlogopite-apatite-calcite mineralisations in the Grenville-Hasting formation in Canada and in the Sludyanka group in Eastern Siberia) should be reevaluated.

  3. “Tazomoka Is Not a Problem”. Local Perspectives on Malaria, Fever Case Management and Bed Net Use in Madagascar

    PubMed Central

    Raboanary, Emma; Kesteman, Thomas; Piola, Patrice; Randrianarivelojosia, Milijaona; Rogier, Christophe

    2016-01-01

    Background Although its incidence has been decreasing during the last decade, malaria is still a major public health issue in Madagascar. The use of Long Lasting Insecticidal Nets (LLIN) remains a key malaria control intervention strategy in Madagascar, however, it encounters some obstacles. The present study aimed to explore the local terminology related to malaria, information channels about malaria, attitude towards bed nets, and health care seeking practices in case of fever. This article presents novel qualitative findings about malaria. Until now, no such data has been published for Madagascar. Methods A comparative qualitative study was carried out at four sites in Madagascar, each differing by malaria epidemiology and socio-cultural background of the populations. Seventy-one semi-structured interviews were conducted with biomedical and traditional caregivers, and members of the local population. In addition, observations of the living conditions and the uses of bed net were conducted. Results Due to the differences between local and biomedical perspectives on malaria, official messages did not have the expected impact on population in terms of prevention and care seeking behaviors. Rather, most information retained about malaria was spread through informal information circulation channels. Most interviewees perceived malaria as a disease that is simple to treat. Tazomoka (“mosquito fever”), the Malagasy biomedical word for malaria, was not used by populations. Tazo (“fever”) and tazomahery (“strong fever”) were the terms more commonly used by members of the local population to refer to malaria related symptoms. According to local perceptions in all areas, tazo and tazomahery were not caused by mosquitos. Each of these symptoms required specific health recourse. The usual fever management strategies consisted of self-medication or recourse to traditional and biomedical caregivers. Usage of bed nets was intermittent and was not directly linked to protection against malaria in the eyes of most Malagasy people. Conclusions This article highlights the conflicting understanding of malaria between local perceptions and the biomedical establishment in Madagascar. Local perceptions of malaria present a holistic vision of the disease that includes various social and cultural dimensions, rather than reflecting one universal understanding, as in the biomedical image. The consideration of this “holistic vision” and other socio-cultural aspects surrounding the understanding of malaria is essential in implementing successful control intervention strategies. PMID:26943672

  4. Sedimentological features of lateritic and saprolitic horizons in a mid-slope lavaka, Central Highlands, Madagascar

    NASA Astrophysics Data System (ADS)

    Udvardi, B.; Raveloson, A.; Visnovitz, F.; Szabó, Cs.; Kovács, I.; Székely, B.

    2012-04-01

    Madagascar is characterized by a world-record erosion rate, especially in the Central Highlands and the vicinity of Lake Alaotra. As a consequence of the high erosion rate several specific erosional landforms develop in the area. Among them an inverted teardrop-shaped geomorphic feature, the lavaka, meaning 'hole' in Malagasy, is very typical in the hilly landscape. These unique features are widespread in Madagascar though somewhat similar patterns can also be found in Congo, South Africa and Brazil. In these areas, material from the lavakas is washed down from the hillsides into the streams and rivers after every heavy rain (1500-1800 mm/yr). The high sediment load from the eroded lavakas can damage the infrastructure (collapses roads, bridges and buildings) and may destroy agricultural land (swamp fields). The distribution of lavakas is very diverse: despite the same climatologic, geological environment and anthropogenic effects a large difference in density of lavakas can be observed. For this reason it cannot be fully constrained how lavakas form and develop. Their formation is affected by natural factors (hydrological and climatic effects, geology, tectonics, vegetation, etc.) and also by anthropogenic influences (deforestation, grassland burning, overgrazing). The basic condition for the formation of lavakas often includes the petrographic characteristics of the area. Lavaka-generating substrates can be separated into two main weathered units: thin upper laterite (less than one meter) and thicker deeper saprolite (several tens of meters) on the crystalline basement. This study focuses on a mid-slope lavaka, in the area of Tsiafahy, in Madagascar's Central Highlands. To ascertain the composition of the material and to evaluate the hydraulic conductivity of the lateritic and saprolitic profile on precambrian magmatic basement, we investigated the grain size distribution and mineral composition of an active lavaka. Our results show the significance of water on slope stability. The calculated hydraulic conductivity values from laterite indicate (at least one order of magnitude) higher value than in the saprolite, but each layer have very low hydraulic conductivity. In the saprolite can be also identified two separated horizons. The difference between laterite and saprolite are reflected also in the mineralogical compositions, primarily through the presence of gibbsite in the lateritic profile. In the total profile quartz and kaolinite are predominant. The observed features can be interpreted as an indication for ferrallitization which generates a deep weathered ferralsol zone. The preferable leakage in the saprolite is enhanced by the higher modal abundance of the coarser grains relative to the laterite. The coarser grains are cemented by kaolinite, iron-oxihidroxide and calcite. These minerals are dominant in the fine-grained fraction which may be easily mobilized by water causing high erodibility that facilitates headward erosion of deeper saprolitic horizon. Due to its low hydraulic conductivity the penetration of the rainfall through the laterite is a slow process. Thus, the top layer protects the lower strata from erosional removal; however, presence of cracks in the lateritic horizon may speed up the removal of the top layer paving the way to reach the lower, more erodible saprolite.

  5. Violences conjugales à Antananarivo (Madagascar): un enjeu de santé publique

    PubMed Central

    Gastineau, Bénédicte; Gathier, Lucy

    2012-01-01

    Introduction La violence conjugale a été étudiée dans beaucoup de pays développés mais peu en Afrique subsaharienne. Madagascar est un pays où ce phénomène est peu documenté. Méthodes En 2007, une enquête sur la violence conjugale à Antananarivo (ELVICA) a été menée sur la violence conjugale envers les femmes dans la capitale malgache. ELVICA a interrogé 400 femmes en union, de 15 à 59 ans. Des informations sur les caractéristiques démographiques, socioéconomiques des couples ont été collectées ainsi que sur les actes de violences physiques des hommes sur leurs épouses. L’objectif de cet article est d’identifier les facteurs de risques de la violence conjugale grave, celle qui a des conséquences sur la santé physique des femmes. Résultats Trente-cinq pour cent des femmes qui ont déclaré avoir subi au moins une forme de violence physique au cours des 12 mois précédent l’enquête. Presque la moitié (46%) des femmes violentées ont déclaré avoir déjà eu des hématomes, et environ un quart (23%) des plaies avec saignement. Vingt-deux pour cent ont déjà dû consulter un médecin. Parmi les nombreuses variables socioéconomiques et démographiques testées, quelques-unes sont associées positivement au risque de violence conjugale grave: le fait pour une femme d’être en union consensuelle et d’avoir une activité professionnelle. Il y aussi un lien entre la violence subie et l’autonomie des femmes (liberté accordée par le mari de travailler, de circuler, de voir sa famille). Conclusion A Madagascar, comme ailleurs, la lutte contre les violences conjugales est un élément majeur de l’amélioration du statut et de la santé des femmes. PMID:22514757

  6. [The National Order of Veterinary Doctors of Madagascar and the quality control of private veterinarians].

    PubMed

    Ranaivosolofo, F

    2004-04-01

    Veterinary medicine was introduced into Madagascar with the arrival of French settlers in the early 1900s. At first, veterinary practitioners were all French, and they trained Madagascan veterinary auxiliaries. The first Madagascan veterinarians were trained in French veterinary schools. The idea of organising the profession dates back to the 1970s, but only in 1991 was the Animal Health Law, covering the veterinary profession, adopted by the National Assembly; it was promulgated by President Ratsiraka on July 25 of that same year. Thus, the National Order of Veterinary Doctors of Madagascar (ONDVM: Ordre national des docteurs vétérinaires malagasy) was instituted by a decree in February 1992. All veterinarians and paraprofessionals were employed in the public sector at the time and this new structure proved vital for the private exercise of the veterinary profession. With the adoption of a new national livestock policy, vaccination against major cattle and swine diseases became a profitable activity. One of the objectives of the sectoral livestock programme was that a total of 90 new posts for veterinarians should be created and located throughout the different regions and rural townships of the country. The Centre de promotion vétérinaire (Centre for Veterinary Promotion), which was created in 1992, was the organisation charged with carrying out this task. In 1998, once the private veterinarians were installed, a survey was undertaken with the aim of making an exhaustive assessment of all private veterinarians, collecting data from the public veterinary stations in zones covered by private veterinarians, and establishing a programme of disengagement and withdrawal of the decentralised services, particularly the public veterinary stations. More recently, the Administration and the ONDVM have been facing various organisational problems, notably with regard to the different levels of animal health staff working in the field. Thus, the Order is currently waging a mobilisation and awareness campaign for the adoption of a new animal health law. All new measures would be aimed at strengthening the management of artificial insemination centres and border protection and improving the work of all those involved in animal health: official and private veterinarians and members of the Order of Veterinary Doctors and the Order of Veterinary Paraprofessionals. PMID:15200098

  7. Imaging the Lithosphere-Asthenosphere Boundary beneath South Africa and Madagascar using S receiver functions

    NASA Astrophysics Data System (ADS)

    Sodoudi, F.; Kaestle, E.; Kind, R.

    2012-12-01

    South Africa's lithosphere preserves a nearly un-interrupted geological history of more than 3.5 billion years. It was formed during the break-up of the supercontinent Gondwana over a period of 80 million years and therefore is the longest, best-preserved geological record of the planet Earth. Investigation of the thickness of continental roots, which migrate coherently with plates, therefore belongs to the most systematic keys in order to understand the continental evolution. This goal will be achieved using the novel technique of S receiver function. This technique employing S-to-P conversions appears promising for detecting the LAB and has already proven its power for mapping the LAB in the tectonically different regions. We used the available data from more than 85 temporary and permanent broadband stations in South Africa and Madagascar to detect the lithosphere-asthenosphere boundary (LAB). Our results obtain detailed images of the LAB with improved resolution. S receiver functions clearly resolve the Moho boundary at depths ranging between 35 and 45 km beneath South Africa in good agreement with the previous studies. Even though we can not find any correlation between the crustal thickness and the age of the terrains. Deeper structure can be also well imaged by S receiver functions. Our results clearly show the presence of more than one negative converted phase beneath Kalahari Craton. On the other hand, they reveal the presence of two distinct lithospheric layers throughout the stable part of the South African continent. The first discontinuity can be seen at depths ranging between 160-220 km beneath the Archean Cratons and surrounding Phanerozoic belts, whereas the deeper discontinuity at about 300 km can be only imaged beneath the Archean Cratons. We interpret the deeper boundary at 300 km as the LAB of the old Archean Craton beneath South Africa. The shallower discontinuity at 160-220 km depth may show a mid-lithospheric boundary, which probably reveals a relict of the old mantle lithosphere. Our results obtained from the stations located in Madagascar can only confirm the presence of the mid-lithopheric boundary at 170 km depth.

  8. Imaging the Lithosphere-Asthenosphere Boundary beneath South Africa and Madagascar using S receiver functions

    NASA Astrophysics Data System (ADS)

    Sodoudi, F.; Kaestle, E.; Kind, R.

    2012-04-01

    South Africa's lithosphere preserves a nearly un-interrupted geological history of more than 3.5 billion years. It was formed during the break-up of the supercontinent Gondwana over a period of 80 million years and therefore is the longest, best-preserved geological record of the planet Earth. Investigation of the thickness of continental roots, which migrate coherently with plates, therefore belongs to the most systematic keys in order to understand the continental evolution. This goal will be achieved using the novel technique of S receiver function. This technique employing S-to-P conversions appears promising for detecting the LAB and has already proven its power for mapping the LAB in the tectonically different regions. We used the available data from more than 85 temporary and permanent broadband stations in South Africa and Madagascar to detect the lithosphere-asthenosphere boundary (LAB). Our results obtain detailed images of the LAB with improved resolution. S receiver functions clearly resolve the Moho boundary at depths ranging between 35 and 45 km beneath South Africa in good agreement with the previous studies. Even though we can not find any correlation between the crustal thickness and the age of the terrains. Deeper structure can be also well imaged by S receiver functions. Our results clearly show the presence of more than one negative converted phase beneath Kalahari Craton. On the other hand, they reveal the presence of two distinct lithospheric layers throughout the stable part of the South African continent. The first discontinuity can be seen at depths ranging between 160-230 km beneath the Archean Cratons and surrounding Phanerozoic belts, whereas the deeper discontinuity at 300 km can be only imaged beneath the Archean Cratons. We interpret the deeper boundary at 300 km as the LAB of the old Archean Craton beneath South Africa. The shallower discontinuity at 160-230 km depth may show a mid-lithospheric boundary, which probably reveals a relict of the old mantle lithosphere. Our results obtained from the stations located in Madagascar can only confirm the presence of the mid-lithopheric boundary at 170 km depth.

  9. Campylobacter infection in a cohort of rural children in Moramanga, Madagascar

    PubMed Central

    2014-01-01

    Background Campylobacter infection is the most common cause of bacterial gastroenteritis in developing countries, including Madagascar. Reports of pathogenicity have not been consistent and repeated exposures over time seem to lead to the development of protective immunity in developing areas. We conducted this study to support evidence for these hypotheses by exploring the association between infection and age, the reoccurrence of infection and the pathogenicity of Campylobacter. Methods We carried out a community-based longitudinal study of children under the age of 24months in two rural villages in Moramanga, Madagascar. Children were visited twice a week and a stool specimen was collected in cases of diarrhoea. Stools specimens were collected bimonthly from all children enrolled, regardless of symptoms. Children were followed-up until the age of 36months. Results Between January 2010 and May 31st 2012, 508 children were included in the cohort. We detected 319 episodes of Campylobacter infection in total, and 43.3% (n?=?220) of the children had at least one episode of intestinal Campylobacter infection. The rate of Campylobacter isolation from stool specimens was 9.3%. The annual incidence rate for symptomatic Campylobacter infection was 0.05 episodes/child. The probability of Campylobacter infection was highest between the ages of six and 23months. Taking children under six months of age as the reference group, the age-specific odds ratio for the association was 5.0 (95% CI: 2.9-8.6) for children aged six to 11months, 5.7 (95% CI: 3.3-10.0) for children aged 12 to 17months and 3.3 (95% CI: 1.8-5.8) for children aged 18 to 23months. A second episode of infection occurred 63days after the first episode in children with primary infections, and after 137days in children with multiple infections (p?

  10. Himalaya gneiss dome formation, focused radiogenic heating in southern Madagascar, and fertilization of the Neoproterozoic ocean by mantle-derived phosphorus

    NASA Astrophysics Data System (ADS)

    Horton, Forrest Miller

    (I) Geochronology, thermochronology, and structural observations across Gianbul gneiss dome provide insight about the exhumation of middle crust in the India-Asia collision zone: Doming (1) initiated during the early stages of extension; (2) was driven by a positive feedback among dehydration melting, buoyancy, and decompression; and (3) culminated with the injection of anatectic melts into the upper levels of the dome. The dome was subsequently exhumed as part of a footwall block beneath a brittle normal fault. (II) Focused internal heating led to melting, metamorphism, and crustal weakening during the Neoproterozoic continent-continent collision between East and West Gondwana. Numerical models based on chronologic and thermal constraints across southern Madagascar indicate that radioactive decay of thorium was the principal heat source responsible for regional metamorphism at temperatures >900° C in the middle to lower crust. (III) The Neoproterozoic era was punctuated by profound tectonic, evolutionary, and environmental change. Biologic and climatic conditions may have been especially sensitive to fluxes of phosphorus (P) from the weathering of continental crust. Large igneous provinces-containing abundant P and highly susceptible to chemical weathering-occurred regularly during the breakup of the Rodinia supercontinent. An estimated bioavailable P flux to the ocean from the weathering of basalt peaked at ˜720 Ma, immediately prior to rapid biologic diversification and the Sturtian glaciation; I postulate that the burial of organic carbon that resulted from this unprecedented P flux helped facilitate glaciation and triggered the oxidation of the ocean-atmosphere system.

  11. An eco-epidemiological study of Morbilli-related paramyxovirus infection in Madagascar bats reveals host-switching as the dominant macro-evolutionary mechanism.

    PubMed

    Mélade, Julien; Wieseke, Nicolas; Ramasindrazana, Beza; Flores, Olivier; Lagadec, Erwan; Gomard, Yann; Goodman, Steven M; Dellagi, Koussay; Pascalis, Hervé

    2016-01-01

    An eco-epidemiological investigation was carried out on Madagascar bat communities to better understand the evolutionary mechanisms and environmental factors that affect virus transmission among bat species in closely related members of the genus Morbillivirus, currently referred to as Unclassified Morbilli-related paramyxoviruses (UMRVs). A total of 947 bats were investigated originating from 52 capture sites (22 caves, 18 buildings, and 12 outdoor sites) distributed over different bioclimatic zones of the island. Using RT-PCR targeting the L-polymerase gene of the Paramyxoviridae family, we found that 10.5% of sampled bats were infected, representing six out of seven families and 15 out of 31 species analyzed. Univariate analysis indicates that both abiotic and biotic factors may promote viral infection. Using generalized linear modeling of UMRV infection overlaid on biotic and abiotic variables, we demonstrate that sympatric occurrence of bats is a major factor for virus transmission. Phylogenetic analyses revealed that all paramyxoviruses infecting Malagasy bats are UMRVs and showed little host specificity. Analyses using the maximum parsimony reconciliation tool CoRe-PA, indicate that host-switching, rather than co-speciation, is the dominant macro-evolutionary mechanism of UMRVs among Malagasy bats. PMID:27068130

  12. An eco-epidemiological study of Morbilli-related paramyxovirus infection in Madagascar bats reveals host-switching as the dominant macro-evolutionary mechanism

    PubMed Central

    Mélade, Julien; Wieseke, Nicolas; Ramasindrazana, Beza; Flores, Olivier; Lagadec, Erwan; Gomard, Yann; Goodman, Steven M.; Dellagi, Koussay; Pascalis, Hervé

    2016-01-01

    An eco-epidemiological investigation was carried out on Madagascar bat communities to better understand the evolutionary mechanisms and environmental factors that affect virus transmission among bat species in closely related members of the genus Morbillivirus, currently referred to as Unclassified Morbilli-related paramyxoviruses (UMRVs). A total of 947 bats were investigated originating from 52 capture sites (22 caves, 18 buildings, and 12 outdoor sites) distributed over different bioclimatic zones of the island. Using RT-PCR targeting the L-polymerase gene of the Paramyxoviridae family, we found that 10.5% of sampled bats were infected, representing six out of seven families and 15 out of 31 species analyzed. Univariate analysis indicates that both abiotic and biotic factors may promote viral infection. Using generalized linear modeling of UMRV infection overlaid on biotic and abiotic variables, we demonstrate that sympatric occurrence of bats is a major factor for virus transmission. Phylogenetic analyses revealed that all paramyxoviruses infecting Malagasy bats are UMRVs and showed little host specificity. Analyses using the maximum parsimony reconciliation tool CoRe-PA, indicate that host-switching, rather than co-speciation, is the dominant macro-evolutionary mechanism of UMRVs among Malagasy bats. PMID:27068130

  13. Phanerozoic upper crustal tectono-thermal development of basement rocks from central Madagascar: An integrated fission-track and structural study

    NASA Astrophysics Data System (ADS)

    Emmel, B.; Jacobs, J.; Kastowski, M.; Graser, G.

    2006-01-01

    An integrated study of fission-track (FT) dating and structural geology revealed a complex tectono-thermal history preserved in basement rocks of central Madagascar since the amalgamation of Gondwana at the end of the Cambrian. A detailed study of five domains argues for several cooling steps with associated brittle deformations during the separation of Madagascar. Titanite and apatite FT ages range between 483 Ma and 266 Ma and between 460 Ma and 79 Ma, respectively. The titanite FT data indicate that the final cooling after the latest metamorphic overprint was terminated at c. 500 Ma (FC1). A 150 Myr phase of minor cooling (SC2), possibly related to a phase of tectonic quiescence and isostatic compensation, followed episode FC1. Between the Carboniferous and Early Jurassic, when an intracontinental rift developed between East Africa and Madagascar, complex brittle deformation effected the western margin of Madagascar and led to differential cooling of small basement blocks (FC3-FC5). During this period, ductile structural trends were reactivated at the western basement margin and in the centre of the island. A Late Cretaceous thermal event (T1) affected apatite FT data of samples from western-central and the eastern margin of Madagascar. These ages are related to the Madagascar-India/Seychelles break-up, whereby the thermal penetration along the eastern coast was restricted to the west by the Angavo shear zone (AGSZ). The Cretaceous evolution of the eastern margin was associated with minor erosion and was triggered by vertical displacements along brittle structures.

  14. Treatment of an amelanotic melanoma using radiation therapy in a lesser Madagascar hedgehog tenrec (Echinops telfairi).

    PubMed

    Harrison, Tara M; Dominguez, Pedro; Hanzlik, Kim; Sikarskie, James G; Agnew, Dalen; Bergin, Ingrid; Fitzgerald, Scott D; Kitchell, Barbara E; McNiel, Elizabeth

    2010-03-01

    A 15-yr-old, male lesser Madagascar hedgehog tenrec (Echinops telfairi) presented with a mass caudal to the right ear. Cytology suggested a sarcoma. Surgical removal was attempted. Histology was consistent with a soft tissue sarcoma. The mass recurred within 331 days post operation. Radiation therapy was initiated. Computed tomography was used for staging in conjunction with three-dimensional computerized treatment planning software to permit accurate lesion localization and to optimize normal tissue sparing. A total dose of 6,480 cGy was administered in 24 fractions over 46 days. Transient hind limb paresis developed during the course of the radiation therapy, but resolved after 7 days with prednisone treatment. Minimal acute radiation toxicity was observed. The mass responded with at least a 90% reduction in volume following radiation treatment. The animal survived 266 days from the initiation of treatment. On necropsy, a small mass and granulation tissue were found at the site of the initial neoplasm, indicating good regional control of the tumor; however, extensive metastases to the spleen and liver were present. Immunohistochemically, the original, recurrent, and metastatic populations were strongly positive for HMB 45 and weakly positive for S-100, and the final diagnosis was metastatic amelanotic melanoma. PMID:20722271

  15. Anatomical Correlates to Nectar Feeding among the Strepsirrhines of Madagascar: Implications for Interpreting the Fossil Record

    PubMed Central

    Muchlinski, Magdalena N.; Perry, Jonathan M. G.

    2011-01-01

    One possible ecological scenario for the origin of primates is the archaic pollination and coevolution hypothesis. Its proponents contend that the consumption of nectar by some early primates and the resulting cross-pollination is an example of coevolution that drove adaptive radiations in some primates. This hypothesis is perhaps ecologically sound, but it lacks the morphology-behavior links that would allow us to test it using the fossil record. Here we attempt to identify cranial adaptations to nectar feeding among the strepsirrhines of Madagascar in order to provide such links. Many Malagasy strepsirrhines are considered effective cross-pollinators of the flowers they feed from, and nectar consumption represents as much as 75% of total feeding time. Previous studies identified skeletal correlates to nectar feeding in the crania of nonprimate mammals; from these, nine cranial measurements were chosen to be the focus of the present study. Results indicate that Cheirogaleus, Varecia, and Eulemur mirror other nectar-feeding mammals in having elongated crania and/or muzzles. These strepsirrhines might be effective cross-pollinators, lending support to the coevolution hypothesis. PMID:22567292

  16. Focused radiogenic heating of middle crust caused ultrahigh temperatures in southern Madagascar

    NASA Astrophysics Data System (ADS)

    Horton, Forrest; Hacker, Bradley; Kylander-Clark, Andrew; Holder, Robert; Jöns, Niels

    2016-02-01

    Internal heating can cause melting, metamorphism, and crustal weakening in convergent orogens. This study evaluates the role of radiogenic heat production (RHP) in a Neoproterozoic ultrahigh-temperature metamorphic (UHTM) terrane exposed in southern Madagascar. Monazite and zircon geochronology indicates that the Paleoproterozoic Androyen and Anosyen domains (i) collided with the oceanic Vohibory Arc at ~630 Ma, (ii) became incorporated into the Gondwanan collisional orogen by ~580 Ma, and (iii) were exhumed during crustal thinning at 525-510 Ma. Ti-in-quartz and Zr-in-rutile thermometry reveals that UHTM occurred over >20,000 km2, mostly within the Anosyen domain. Assuming that U, Th, and K contents of samples from the field area are representative of the middle to lower crust during orogenesis, RHP was high enough—locally >5 μW/m3—to cause regional UHTM in <60 Myr. We conclude that, due in large part to the stability and insolubility of monazite at high crustal temperatures, RHP was the principal heat source responsible for UHTM, obviating the need to evoke external heat sources. Focused RHP probably thermally weakened portions of the middle crust, gravitationally destabilizing the orogen and facilitating thinning via lateral extrusion of hot crustal sections.

  17. Biomedical evaluation of Verreaux's sifaka (Propithecus verreauxi) from Kirindy Mitea National Park in Madagascar.

    PubMed

    Rasambainarivo, Fidisoa T; Junge, Randall E; Lewis, Rebecca J

    2014-06-01

    Evaluation of the health, prevalence, and incidence of diseases in wild populations is a critical component of wildlife management. In addition, the establishment of reference physiologic parameters can Verreaux's sifaka (Propithecus verreauxi) from Kirindy Mitea National Park, Madagascar, during two field captures incontribute to the assessment of population risks. Complete medical evaluations were performed on 33 wild June 2010 and June 2011. Each animal received a complete physical examination: weight, body temperature, heart rate, and respiratory rate were recorded, and ectoparasites collected. Blood samples were collected for complete blood cell count, differential white blood cell count, hemoparasite examination, serum biochemical profile, fat-soluble vitamin analysis, trace mineral analysis, and toxoplasmosis and viral serology. Fecal samples were collected for bacterial culture and endoparasite examination. Significant differences exist between age classes for neutrophil and lymphocyte count, alkaline phosphatase, and creatinine values. Parasites detected were Callistoura sp., Bertiella lemuriformis, and Dipetalonema petteri. This publication reports the first complete biomedical evaluation of the P. verreauxi and provides a basis for hematologic and biochemical comparisons of P. verreauxi in the wild. PMID:25000684

  18. Seroprevalence of malaria in inhabitants of the urban zone of Antananarivo, Madagascar

    PubMed Central

    Domarle, Olivier; Razakandrainibe, Romy; Rakotomalala, Emma; Jolivet, Laurence; Randremanana, Rindra Vatosoa; Rakotomanana, Fanjasoa; Ramarokoto, Charles Emile; Soares, Jean-Louis; Ariey, Frédéric

    2006-01-01

    Background Antananarivo, the capital of Madagascar, is located at an altitude of over 1,200 m. The environment at this altitude is not particularly favourable to malaria transmission, but malaria nonetheless remains a major public health problem. The aim of this study was to evaluate exposure to malaria in the urban population of Antananarivo, by measuring the specific seroprevalence of Plasmodium falciparum. Methods Serological studies specific for P. falciparum were carried out with an indirect fluorescent antibody test (IFAT). In a representative population of Antananarivo, 1,059 healthy volunteers were interviewed and serum samples were taken. Results The seroprevalence of IgG+IgA+IgM was 56.1% and that of IgM was 5.9%. The major risk factor associated with a positive IgG+IgA+IgM IFAT was travel outside Antananarivo, whether in the central highlands or on the coast. The abundance of rice fields in certain urban districts was not associated with a higher seroprevalence. Conclusion Malaria transmission levels are low in Antananarivo, but seroprevalence is high. Humans come into contact with the parasite primarily when travelling outside the city. Further studies are required to identify indigenous risk factors and intra-city variations more clearly. PMID:17096830

  19. [Recrudescence and geographic extension of the plague in Madagascar from 1980 to 1999].

    PubMed

    Ratsitorahina, M; Migliani, R; Ratsifasoamanana, L; Ratsimba, M; Chan Ho Thin, F; Rahalison, L; Chanteau, S

    2001-01-01

    Plague was introduced to Madagascar in 1898, and it has been characterized by a predominant distribution to the central highlands in the following decades. An increase of plague cases has been observed in the past 20 years, in particular in the capital, Antananarivo, and in the coastal town, Mahajanga, after long periods of silence in 28 and 63 years, respectively. A total of 2,982 confirmed or presumptive cases were reviewed in order to describe the changes in the epidemiological pattern of the disease from 1980 through 1999. The mean annual number of plague cases has increased from 33 during the 1980-1984 period to 298 during the 1995-1999 period. A similar trend of distribution has been observed from the first period to the second by an increase of endemic districts above 800 m altitude from 17 to 37. However, the lethality rate has in the same 20 years observation period decreased from 41.6% to 20.7%, probably due to re-enforcing measures as part of the national control program. PMID:12471740

  20. CCR5 polymorphism and plague resistance in natural populations of the black rat in Madagascar.

    PubMed

    Tollenaere, C; Rahalison, L; Ranjalahy, M; Rahelinirina, S; Duplantier, J-M; Brouat, C

    2008-12-01

    Madagascar remains one of the world's largest plague foci. The black rat, Rattus rattus, is the main reservoir of plague in rural areas. This species is highly susceptible to plague in plague-free areas (low-altitude regions), whereas rats from the plague focus areas (central highlands) have evolved a disease-resistance polymorphism. We used the candidate gene CCR5 to investigate the genetic basis of plague resistance in R. rattus. We found a unique non-synonymous substitution (H184R) in a functionally important region of the gene. We then compared (i) CCR5 genotypes of dying and surviving plague-challenged rats and (ii) CCR5 allelic frequencies in plague focus and plague-free populations. Our results suggested a higher prevalence of the substitution in resistant animals compared to susceptible individuals, and a tendency for higher frequencies in plague focus areas compared to plague-free areas. Therefore, the CCR5 polymorphism may be involved in Malagasy black rat plague resistance. CCR5 and other undetermined plague resistance markers may provide useful biological information about host evolution and disease dynamics. PMID:18703167

  1. Effective Stimulus Parameters for Directed Locomotion in Madagascar Hissing Cockroach Biobot

    PubMed Central

    Erickson, Jonathan C.; Shingiro, Aristide; Bowen, Thomas

    2015-01-01

    Swarms of insects instrumented with wireless electronic backpacks have previously been proposed for potential use in search and rescue operations. Before deploying such biobot swarms, an effective long-term neural-electric stimulus interface must be established, and the locomotion response to various stimuli quantified. To this end, we studied a variety of pulse types (mono- vs. bipolar; voltage- vs. current-controlled) and shapes (amplitude, frequency, duration) to parameters that are most effective for evoking locomotion along a desired path in the Madagascar hissing cockroach (G. portentosa) in response to antennal and cercal stimulation. We identified bipolar, 2 V, 50 Hz, 0.5 s voltage controlled pulses as being optimal for evoking forward motion and turns in the expected contraversive direction without habituation in ≈50% of test subjects, a substantial increase over ≈10% success rates previously reported. Larger amplitudes for voltage (1–4 V) and current (50–150 μA) pulses generally evoked larger forward walking (15.6–25.6 cm; 3.9–5.6 cm/s) but smaller concomitant turning responses (149 to 80.0 deg; 62.8 to 41.2 deg/s). Thus, the radius of curvature of the initial turn-then-run locomotor response (≈10–25 cm) could be controlled in a graded manner by varying the stimulus amplitude. These findings could be used to help optimize stimulus protocols for swarms of cockroach biobots navigating unknown terrain. PMID:26308337

  2. Carcinome basocellulaire de la face: à propos de quatre cas rapportés à Madagascar

    PubMed Central

    Razafindrakoto, Rex Mario; Razafindranaivo, Mananjara Nandrianina; Schammirah, Mahamad Rojovolaarivony; Randriamboavonjy, Rado

    2015-01-01

    Les carcinomes basocellulaires, fréquemment rencontrés dans la race blanche, sont plus rares chez les sujets de race noire. Les zones exposées de la tête sont des sites préférentiels, et une intense exposition aux rayons solaires ultraviolets a été évoquée dans leur étiopathogénie. Les métastases sont exceptionnelles. Les objectifs ont été de démontrer l'existence de carcinomes basocellulaires à Madagascar et d'en évaluer la prise en charge. Les auteurs ont rapporté quatre cas de carcinomes basocellulaires faciaux vus au service d'Oto-rhino-laryngologie du Centre Hospitalier Universitaire d'Antananarivo, avec deux hommes et deux femmes, âgés entre 46 et 70 ans (âge moyen= 53,5 ans). Une exérèse chirurgicale a été pratiquée chez trois patients tandis qu'un patient albinos a été traité par radiothérapie. L’épidémiologie, l’étiologie, l'anatomie pathologique et le traitement des carcinomes basocellulaires de la face ont été discutées à travers une revue de la littérature. PMID:26848344

  3. Case-Control Study of the Etiology of Infant Diarrheal Disease in 14 Districts in Madagascar

    PubMed Central

    Dubois, Natasha; Razafindratsimandresy, Richter; Hariniana, Elisoa Ratsima; Garin, Benoit; Randriamanantena, Arthur; Rakotonirina, Hanitra Clara; Ramparany, Lovasoa; Ramarokoto, Charles Emile; Rakotomanana, Fanjasoa; Ratsitorahina, Maherisoa; Rajatonirina, Soatiana; Talarmin, Antoine; Richard, Vincent

    2012-01-01

    Background Acute diarrhea is a major cause of childhood morbidity and mortality worldwide. Its microbiological causes and clinico-epidemiological aspects were examined during the rainy seasons from 2008 to 2009 in 14 districts in Madagascar. Methods Stool specimens of 2196 children with acute diarrhea and 496 healthy children were collected in a community setting. Intestinal parasites were diagnosed by microscopy and bacteria by culturing methods. Rota-, astro and adenoviruses were identified using commercially available ELISA kits and rotaviruses were confirmed using reverse transcriptase polymerase chain reaction (RT-PCR). Results Intestinal microorganisms were isolated from 54.6% of diarrheal patients and 45.9% of healthy subjects (p = <0.01). The most common pathogens in diarrheic patients were intestinal parasites (36.5%). Campylobacter spp. and Rotavirus were detected in 9.7% and 6.7% of diarrheic patients. The detection rates of Entamoeba histolytica, Trichomonas intestinalis and Giardia lamblia were much greater in diarrheal patients than in non diarrheal subjects (odds ratios of 5.1, 3.2, 1.7 respectively). The abundance of other enteropathogens among the non diarrheal group may indicate prolonged excretion or limited pathogenicity. Conclusion In developing countries, where the lack of laboratory capacities is great, cross sectional studies of enteropathogens and their spatial distribution, including diarrheal and non diarrheal subjects, are interesting tools in order to advise regional policies on treatment and diarrheic patient management. PMID:23028555

  4. Extreme vulnerability of smallholder farmers to agricultural risks and climate change in Madagascar.

    PubMed

    Harvey, Celia A; Rakotobe, Zo Lalaina; Rao, Nalini S; Dave, Radhika; Razafimahatratra, Hery; Rabarijohn, Rivo Hasinandrianina; Rajaofara, Haingo; Mackinnon, James L

    2014-04-01

    Across the tropics, smallholder farmers already face numerous risks to agricultural production. Climate change is expected to disproportionately affect smallholder farmers and make their livelihoods even more precarious; however, there is limited information on their overall vulnerability and adaptation needs. We conducted surveys of 600 households in Madagascar to characterize the vulnerability of smallholder farmers, identify how farmers cope with risks and explore what strategies are needed to help them adapt to climate change. Malagasy farmers are particularly vulnerable to any shocks to their agricultural system owing to their high dependence on agriculture for their livelihoods, chronic food insecurity, physical isolation and lack of access to formal safety nets. Farmers are frequently exposed to pest and disease outbreaks and extreme weather events (particularly cyclones), which cause significant crop and income losses and exacerbate food insecurity. Although farmers use a variety of risk-coping strategies, these are insufficient to prevent them from remaining food insecure. Few farmers have adjusted their farming strategies in response to climate change, owing to limited resources and capacity. Urgent technical, financial and institutional support is needed to improve the agricultural production and food security of Malagasy farmers and make their livelihoods resilient to climate change. PMID:24535397

  5. A-type stratoid granites of Madagascar: evidence of Rodinia rifting at ca 790 Ma

    NASA Astrophysics Data System (ADS)

    Nedelec, Anne; Paquette, Jean-Louis; Bouchez, Jean-Luc

    2015-04-01

    The so-called stratoid granites are sheet-like granites emplaced as conformable sills in the Precambrian basement of central Madagascar. Most of them have A-type affinities (Nédélec et al. 1995). They are everywhere characterized by the same structural pattern evidencing two stages of deformation. The first one (foliations mildly dipping to the west and lineations trending WSW) is regarded as the consequence of synkinematic magma emplacement. The second stage, characterized by interference folds, steeply dipping foliations and subhorizontal lineations trending to the north, corresponds to a more or less pronounced reworking in ductile conditions, regarded as the result of Late Pan-African transcurrent tectonics. To the north of Antananarivo, the stratoid granites are associated with comagmatic quartz-syenites. New U-Pb zircons ages obtained by in situ analyses reveal two group of ages: upper intercept ages of ca 790 Ma, and younger ages of ca 550 Ma corresponding to crystal rims. These new data question the geological significance of former TIMS ages of ca 630 Ma formerly obtained from the same rocks (Paquette & Nédélec 1998). It is suggested that the stratoid granites and syenites were emplaced during a crustal thinning event corresponding to an early Rodinia rifting stage. The Pan-African imprint on these rocks is therefore limited to reheating, tectonic reworking and deep fluid transfer in the vicinity of Late-Neoproterozoic shear zones at ca 550 Ma (Nédélec et al. 2014).

  6. AMS Radiocarbon Dating of Large Za Baobabs (Adansonia za) of Madagascar.

    PubMed

    Patrut, Adrian; Patrut, Roxana T; Danthu, Pascal; Leong Pock-Tsy, Jean-Michel; Rakosy, Laszlo; Lowy, Daniel A; von Reden, Karl F

    2016-01-01

    The article reports the radiocarbon investigation of Anzapalivoro, the largest za baobab (Adansonia za) specimen of Madagascar and of another za, namely the Big cistern baobab. Several wood samples collected from the large inner cavity and from the outer part/exterior of the tree were investigated by AMS (accelerator mass spectrometry) radiocarbon dating. For samples collected from the cavity walls, the age values increase with the distance into the wood up to a point of maximum age, after which the values decrease toward the outer part. This anomaly of age sequences indicates that the inner cavity of Anzapalivoro is a false cavity, practically an empty space between several fused stems disposed in a ring-shaped structure. The radiocarbon date of the oldest sample was 780 ± 30 bp, which corresponds to a calibrated age of around 735 yr. Dating results indicate that Anzapalivoro has a closed ring-shaped structure, which consists of 5 fused stems that close a false cavity. The oldest part of the biggest za baobab has a calculated age of 900 years. We also disclose results of the investigation of a second za baobab, the Big cistern baobab, which was hollowed out for water storage. This specimen, which consists of 4 fused stems, was found to be around 260 years old. PMID:26760300

  7. Bartonella spp. in Fruit Bats and Blood-Feeding Ectoparasites in Madagascar

    PubMed Central

    Brook, Cara E.; Bai, Ying; Dobson, Andrew P.; Osikowicz, Lynn M.; Ranaivoson, Hafaliana C.; Zhu, Qiyun

    2015-01-01

    We captured, ectoparasite-combed, and blood-sampled cave-roosting Madagascan fruit bats (Eidolon dupreanum) and tree-roosting Madagascan flying foxes (Pteropus rufus) in four single-species roosts within a sympatric geographic foraging range for these species in central Madagascar. We describe infection with novel Bartonella spp. in sampled Eidolon dupreanum and associated bat flies (Cyclopodia dubia), which nest close to or within major known Bartonella lineages; simultaneously, we report the absence of Bartonella spp. in Thaumapsylla sp. fleas collected from these same bats. This represents the first documented finding of Bartonella infection in these species of bat and bat fly, as well as a new geographic record for Thaumapsylla sp. We further relate the absence of both Bartonella spp. and ectoparasites in sympatrically sampled Pteropus rufus, thus suggestive of a potential role for bat flies in Bartonella spp. transmission. These findings shed light on transmission ecology of bat-borne Bartonella spp., recently demonstrated as a potentially zoonotic pathogen. PMID:25706653

  8. [A contribution to the history of understanding the epidemiology of plague in Madagascar].

    PubMed

    Blanchy, S

    1995-01-01

    Plague appeared in Madagascar in 1898, the pandemic coinciding with the French conquest. Until 1921, harbor epidemics occurred in Tamatave, Majunga, Diégo-Suarez, Fort-Dauphin, Vatomandry. In 1921, probably favored by the building of roads and railways, plague takes root on the High Lands where it becomes endemic above 800 meters. The vaccine achievement by Girard and Robic with the EV strain, and its mass application from 1935 by Estrade, Milliau, Brault, Seyberlich and Jan Keguistel, allowed to control the disease. The D.D.T. and sulfamids discovery makes the urban epidemics almost disappear, allowing it to subsist as only rural sporadic or familial cases with a low mortality. The mass vaccination can be stopped in 1959. Since 1988 the diseases incidence has been increasing, probably in relation with the quasi disappearance of deinsectisation and antibiotics. Nevertheless, urban epidemics are still rare and limited in a parallel direction to the substitution, in the city, of Rattus rattus, main reservoir and victim of the disease, by Rattus norvegicus, less sensitive to the infection. PMID:11625936

  9. Status and distribution of the angonoka tortoise (Geochelone yniphora) of western Madagascar

    USGS Publications Warehouse

    Smith, Lora L.; Reid, Don; Robert, Bourou; Joby, Mahatoly; Clement, Sibo

    1999-01-01

    From 1993 to 1995, field surveys were conducted in western Madagascar to assess the current status of the angonoka tortoise (Geochelone yniphora) in the wild. Tortoise presence was documented at 10 of 11 localities surveyed. These localities represent at least five populations, all within a 30-km radius of Baly Bay, near the town of Soalala. The populations occur on fragments of habitat ranging from <50 to 4–6000 ha in size. One hundred and forty-five tortoises were marked in the five populations. Hatchling or juvenile tortoises were observed in all populations, indicating that reproduction was occurring. Most of the 145 tortoises (68%) were marked on Cape Sada, where monthly surveys were conducted. The tortoise density on the c. 150 ha peninsula was 0.66 tortoises/ha. The remains of 22 dead juveniles were found on Cape Sada over the 2-year period. This evidence, combined with the low number of juveniles in intermediate size classes in the Cape Sada population suggests that juvenile mortality may be high.

  10. AMS Radiocarbon Dating of Large Za Baobabs (Adansonia za) of Madagascar

    PubMed Central

    Patrut, Adrian; Patrut, Roxana T.; Danthu, Pascal; Leong Pock-Tsy, Jean-Michel; Rakosy, Laszlo; Lowy, Daniel A.; von Reden, Karl F.

    2016-01-01

    The article reports the radiocarbon investigation of Anzapalivoro, the largest za baobab (Adansonia za) specimen of Madagascar and of another za, namely the Big cistern baobab. Several wood samples collected from the large inner cavity and from the outer part/exterior of the tree were investigated by AMS (accelerator mass spectrometry) radiocarbon dating. For samples collected from the cavity walls, the age values increase with the distance into the wood up to a point of maximum age, after which the values decrease toward the outer part. This anomaly of age sequences indicates that the inner cavity of Anzapalivoro is a false cavity, practically an empty space between several fused stems disposed in a ring-shaped structure. The radiocarbon date of the oldest sample was 780 ± 30 bp, which corresponds to a calibrated age of around 735 yr. Dating results indicate that Anzapalivoro has a closed ring-shaped structure, which consists of 5 fused stems that close a false cavity. The oldest part of the biggest za baobab has a calculated age of 900 years. We also disclose results of the investigation of a second za baobab, the Big cistern baobab, which was hollowed out for water storage. This specimen, which consists of 4 fused stems, was found to be around 260 years old. PMID:26760300

  11. Elephantis, a new genus for Caridina natalensis Bouvier, 1925 from eastern rivers of Madagascar.

    PubMed

    Castelin, Magalie; Marquet, Gerard; Klotz, Werner

    2013-01-01

    Elephantis, new genus, is established for Caridina natalensis Bouvier, 1925 hitherto known only from South Africa with one male specimen. Recently, three surveys by electric fishing (2004, 2008 and 2010) of some eastern rivers from Madagascar have permitted to discover numerous specimens of this species. Caridina natalensis is different from all other known species of Caridina by its remarkably broad endopod of the male first pleopod, a long clubbed appendix masculina on the male second pleopod reaching beyond distal end of endopod and strong third pereiopods. Therefore a new genus name is proposed for this species. In addition to detailed description of diagnostic morphological characters, molecular sequences obtained from mitochondrial 16S gene are provided for six specimens of this species. These DNA sequences are integrated to the 16S molecular phylogeny of atyid freshwater shrimps recently published by von Rintelen et al. (2012). Elephantis natalensis comb. nov. sequences formed a divergent group supported in maximum likelihood analysis. The availability of DNA samples could be used as reference and integrated in further phylogenetic studies on atyid freshwater shrimps. PMID:26146747

  12. Bartonella spp. in fruit bats and blood-feeding Ectoparasites in Madagascar.

    PubMed

    Brook, Cara E; Bai, Ying; Dobson, Andrew P; Osikowicz, Lynn M; Ranaivoson, Hafaliana C; Zhu, Qiyun; Kosoy, Michael Y; Dittmar, Katharina

    2015-02-01

    We captured, ectoparasite-combed, and blood-sampled cave-roosting Madagascan fruit bats (Eidolon dupreanum) and tree-roosting Madagascan flying foxes (Pteropus rufus) in four single-species roosts within a sympatric geographic foraging range for these species in central Madagascar. We describe infection with novel Bartonella spp. in sampled Eidolon dupreanum and associated bat flies (Cyclopodia dubia), which nest close to or within major known Bartonella lineages; simultaneously, we report the absence of Bartonella spp. in Thaumapsylla sp. fleas collected from these same bats. This represents the first documented finding of Bartonella infection in these species of bat and bat fly, as well as a new geographic record for Thaumapsylla sp. We further relate the absence of both Bartonella spp. and ectoparasites in sympatrically sampled Pteropus rufus, thus suggestive of a potential role for bat flies in Bartonella spp. transmission. These findings shed light on transmission ecology of bat-borne Bartonella spp., recently demonstrated as a potentially zoonotic pathogen. PMID:25706653

  13. Bark essential oil of Cedrelopsis grevei from Madagascar: investigation of steam-distillation conditions.

    PubMed

    Rakotobe, Miarantsoa; Menut, Chantal; Andrianoelisoa, Hanitriniaina Sahondra; Rahajanirina, Voninavoko; Tsy, Jean Michel Leong Pock; Rakotoarimanana, Vonjison; Ramavovololona, Perle; Danthu, Pascal

    2014-02-01

    The effect of the distillation time on the yield and chemical composition of the bark essential oil of Cedrelopsis grevei Baill. was investigated. Distillation kinetics were determined for three batches of bark sampled from two sites, i.e., Itampolo (batches IT1 and IT2) and Salary (SAL), located in a region in the south of Madagascar with characteristically large populations of C. grevei. The bark samples were subjected to steam distillation, and the essential oil was collected at 3-h intervals. The total yield (calculated after 14 h of distillation) varied from 0.9 to 1.7%, according to the batch tested. Moreover, the essential oils obtained were characterized by GC-FID and GC/MS analyses. During the course of the distillation, the relative percentages of the most volatile components (monoterpenes and sesquiterpene hydrocarbons) diminished progressively, whereas the least volatile ones (oxygenated derivatives) increased at a consistent rate. Principal component analysis (PCA) and agglomerative hierarchical clustering analysis (AHC) of the results, performed on 13 principal components, allowed distinguishing three chemical groups, corresponding to the three batches, irrespective of the distillation time. This indicated that the chemical variability currently observed with commercial samples is not mainly linked to the experimental conditions of the extraction process, as the distillation time did not significantly alter the chemical composition of the essential oils. PMID:24591320

  14. Etiologies des pleurésies exsudatives: à propos de 424 cas à Madagascar

    PubMed Central

    Rakotoson, Joëlson Lovaniaina; Andrianasolo, Radonirina Lazasoa; Rakotomizao, Robert Jocelyn; Vololontiana, Marie Danielle Hanta; Ravahatra, Kiady; Rajaoarifetra, Jobeline; Andrianarisoa, Christophe Félix Ange

    2011-01-01

    Introduction La pleurésie constitue un motif fréquent de consultation en pneumologie. Notre travail a pour objectif de déterminer les étiologies des pleurésies exsudatives afin d'en faciliter les démarches étiologiques. Méthodes Il s'agit d'une étude rétrospective réalisée chez des patients ayant une pleurésie exsudative et bénéficiant une biopsie pleurale à l'aveugle à l'aide de l'aiguille de Castelain, pendant une période de 5 ans (2005 à 2009). Résultats Parmi les 424 patients inclus, 259 hommes (61,08%) et 165 femmes (38,91%) étaient individualisés. Les pleurésies étaient d'origine tuberculeuse dans 298 cas (70, 28%), métastatique dans 63 cas (14,85%), inflammation non spécifique dans 51 cas (12,02%). Des fibres musculaires striées étaient biopsiées dans 12 cas (2,83%). Conclusion La biopsie pleurale occupe une place prépondérante dans la recherche étiologique des pleurésies d'exsudatives à Madagascar où la tuberculose sévit encore en mode endémique. PMID:22145067

  15. Antiproliferative and Antiplasmodial Dimeric Phloroglucinols from Mallotus oppositifolius from the Madagascar Dry Forest1#

    PubMed Central

    Harinantenaina, Liva; Bowman, Jessica D.; Brodie, Peggy J.; Slebodnick, Carla; Callmander, Martin W.; Rakotobe, Etienne; Randrianaivo, Richard; Rasamison, Vincent E.; Gorka, Alexander; Roepe, Paul D.; Cassera, Maria B.; Kingston, David G. I.

    2013-01-01

    Bioassay-guided fractionation of an ethanol extract of the leaves and inflorescence of Mallotus oppositifolius collected in Madagascar led to the isolation of the two new bioactive dimeric phloroglucinols, mallotojaponins B (1) and C (2), together with the known mallotophenone (3). The structures of the new compounds were determined on the basis of spectroscopic evidence, including their 1- and 2D-NMR spectra, mass spectrometry, and an X-ray crystal structure. Compounds 1 and 2 showed potent antimalarial activity against chloroquine-resistant Plasmodium falciparum, with IC50 values of 0.75 ± 0.30 and 0.14 ± 0.04 μM, while 3 was inactive in this assay. Compounds 1–3 also displayed strong antiproliferative activity against the A2780 human ovarian cancer cell line (IC50 1.10 ± 0.05, 1.3 ± 0.1 and 6.3 ± 0.4 μM, respectively). PMID:23286240

  16. Distribution and Abundance of the World's Smallest Primate, Microcebus berthae, in Central Western Madagascar.

    PubMed

    Schffler, Livia; Kappeler, Peter M

    2014-01-01

    The distribution of most recently discovered or described lemur species remains poorly known, but many appear to have small geographical ranges, making them vulnerable to extinction. Research can contribute to future conservation actions on behalf of these species by providing accurate information on local distribution and abundance. The distribution of the world's smallest primate, the endangered Madame Berthe's mouse lemur (Microcebus berthae), is limited to the Menabe Central region of western Madagascar. This species was discovered in the 1990s, but many fundamental aspects of its ecology remain unknown. The aims of our study were therefore to determine the actual distribution of Microcebus berthae across the forests of this region, to estimate population density, and to examine the species' response to anthropogenic activities. We established 35 1-km line transects across Menabe Central, on which we surveyed mouse lemurs by distance sampling and live trapping. Microcebus berthae does not occur in all remaining forests of this small region and its population density is highly heterogeneous, both across its geographic range and locally. Within its area of occupancy, the population of Microcebus berthae not only was distributed according to spatial heterogeneities of the habitat, but also responded to anthropogenic disturbances and varied seasonally. Our results indicate that Microcebus berthae is susceptible to habitat degradation and avoids human environments spatially. As none of the forest remnants in which the species still occurs were officially protected until recently, immediate conservation actions should focus on effectively protecting Kirindy and Ambadira forests. PMID:24719496

  17. Gastro-intestinal parasites of red-fronted lemurs in Kirindy Forest, western Madagascar.

    PubMed

    Clough, Dagmar

    2010-04-01

    Although parasites are important regulatory factors in animal populations, basic knowledge on their fauna in many vertebrate taxa is lacking. In particular, parasite infections of primate species have gained little attention. Here, I present data on the gastro-intestinal fauna of a population of wild red-fronted lemurs ( Eulemur fulvus rufus; Primates: Lemuriformes) monitored over a total of 8 mo during 2 consecutive field seasons in 2006 and 2007 in Kirindy Forest, western Madagascar. Using fecal samples for parasite analyses, I identified 10 parasite species, including 6 nematodes (Lemuricola vauceli, Trichuris sp., 2 species of Callistoura, 1 trichostrongylid, and 1 strongyloid), 1 anoplocephalid cestode, a dicrocoeliid trematode, as well as 2 protozoans (Entamoeba sp. and Balantidium coli). The population in Kirindy Forest had the highest prevalence and number of parasite species ever recorded for species of lemurs. Additionally, prevalence of some parasite species differed between the social groups studied. These findings lead to 2 conclusions. First, it is important to extend a parasitological study to several social groups of a host population, since groups may differ in parasite fauna as a result of minor microclimatic or habitat parameters, and, second, short-term assessments of lemur health might underestimate the real parasite burden. PMID:19954263

  18. Extreme vulnerability of smallholder farmers to agricultural risks and climate change in Madagascar

    PubMed Central

    Harvey, Celia A.; Rakotobe, Zo Lalaina; Rao, Nalini S.; Dave, Radhika; Razafimahatratra, Hery; Rabarijohn, Rivo Hasinandrianina; Rajaofara, Haingo; MacKinnon, James L.

    2014-01-01

    Across the tropics, smallholder farmers already face numerous risks to agricultural production. Climate change is expected to disproportionately affect smallholder farmers and make their livelihoods even more precarious; however, there is limited information on their overall vulnerability and adaptation needs. We conducted surveys of 600 households in Madagascar to characterize the vulnerability of smallholder farmers, identify how farmers cope with risks and explore what strategies are needed to help them adapt to climate change. Malagasy farmers are particularly vulnerable to any shocks to their agricultural system owing to their high dependence on agriculture for their livelihoods, chronic food insecurity, physical isolation and lack of access to formal safety nets. Farmers are frequently exposed to pest and disease outbreaks and extreme weather events (particularly cyclones), which cause significant crop and income losses and exacerbate food insecurity. Although farmers use a variety of risk-coping strategies, these are insufficient to prevent them from remaining food insecure. Few farmers have adjusted their farming strategies in response to climate change, owing to limited resources and capacity. Urgent technical, financial and institutional support is needed to improve the agricultural production and food security of Malagasy farmers and make their livelihoods resilient to climate change. PMID:24535397

  19. Geometry and kinematics of the late Proterozoic Angavo Shear Zone, Central Madagascar: Implications for Gondwana Assembly

    NASA Astrophysics Data System (ADS)

    Raharimahefa, Tsilavo; Kusky, Timothy M.; Toraman, Erkan; Rasoazanamparany, Christine; Rasaonina, Imboarina

    2013-04-01

    This paper documents the 20 to 60 km wide N-S trending Angavo Shear Zone (ASZ) in central Madagascar and its tectonic implications by examining its structural styles, kinematics and geometry. Our study indicates that the ASZ is characterized by at least two ductile Late Proterozoic deformation events (D1 and D2) followed by a brittle neotectonic deformation (D3). The early D1 event produced a regionally extensive S1 foliation, stretching/flattening mineral lineation L1 and symmetrical structural fabrics such as recumbent and isoclinal intra-folial folds (F1), implying a flattening deformation. D1 deformational fabrics are locally overprinted by D2 structures. D2 is characterized by a penetrative S2 foliation, shallow south plunging L2 lineation, asymmetric and sheath folds (F2) consistent with a right lateral sense of movement exhibited by delta- and sigma-type porphyroclast systems and asymmetric boudinage fabrics. D2 represents a non-coaxial flow regime formed in a dextral west over east shear zone during a partitioned transpression in response to east-west-directed compression during the assembly of Gondwana. A close resemblance with the Achankovil shear zone in India is noticed; however the continuation of the ASZ in Africa is uncertain.

  20. Assessing hygienic behavior of Apis mellifera unicolor (Hymenoptera: Apidae), the endemic honey bee from Madagascar.

    PubMed

    Rasolofoarivao, H; Delatte, H; Raveloson Ravaomanarivo, L H; Reynaud, B; Clmencet, J

    2015-01-01

    Hygienic behavior (HB) is one of the natural mechanisms of honey bee for limiting the spread of brood diseases and Varroa destructor parasitic mite. Objective of our study was to measure HB of Apis mellifera unicolor colonies (N = 403) from three geographic regions (one infested and two free of V. destructor) in Madagascar. The pin-killing method was used for evaluation of the HB. Responses were measured from 3 h 30 min to 7 h after perforation of the cells. Colonies were very effective in detecting perforated cells. In the first 4 h, on average, they detected at least 50% of the pin-killed brood. Six hours after cell perforation, colonies tested (N = 91) showed a wide range of uncapped (0 to 100%) and cleaned cells (0 to 82%). Global distribution of the rate of cleaned cells at 6 h was multimodal and hygienic responses could be split in three classes. Colonies from the three regions showed a significant difference in HB responses. Three hypotheses (geographic, genetic traits, presence of V. destructor) are further discussed to explain variability of HB responses among the regions. Levels of HB efficiency of A. mellifera unicolor colonies are among the greatest levels reported for A. mellifera subspecies. Presence of highly hygienic colonies is a great opportunity for future breeding program in selection for HB. PMID:26125787

  1. Post-collisional magmatism in the central East African Orogen: The Maevarano Suite of north Madagascar

    USGS Publications Warehouse

    Goodenough, K.M.; Thomas, Ronald J.; De Waele, B.; Key, R.M.; Schofield, D.I.; Bauer, W.; Tucker, R.D.; Rafahatelo, J.-M.; Rabarimanana, M.; Ralison, A.V.; Randriamananjara, T.

    2010-01-01

    Late tectonic, post-collisional granite suites are a feature of many parts of the Late Neoproterozoic to Cambrian East African Orogen (EAO), where they are generally attributed to late extensional collapse of the orogen, accompanied by high heat flow and asthenospheric uprise. The Maevarano Suite comprises voluminous plutons which were emplaced in some of the tectonostratigraphic terranes of northern Madagascar, in the central part of the EAO, following collision and assembly during a major orogeny at ca. 550 Ma. The suite comprises three main magmatic phases: a minor early phase of foliated gabbros, quartz diorites, and granodiorites; a main phase of large batholiths of porphyritic granitoids and charnockites; and a late phase of small-scale plutons and sheets of monzonite, syenite, leucogranite and microgranite. The main phase intrusions tend to be massive, but with variably foliated margins. New U-Pb SHRIMP zircon data show that the whole suite was emplaced between ca. 537 and 522 Ma. Geochemically, all the rocks of the suite are enriched in the LILE, especially K, and the LREE, but are relatively depleted in Nb, Ta and the HREE. These characteristics are typical of post-collisional granitoids in the EAO and many other orogenic belts. It is proposed that the Maevarano Suite magmas were derived by melting of sub-continental lithospheric mantle that had been enriched in the LILE during earlier subduction events. The melting occurred during lithospheric delamination, which was associated with extensional collapse of the East African Orogen. ?? 2009 Natural Environment Research Council.

  2. Polyphase Neoproterozoic orogenesis within the east Africa- Antarctica orogenic belt in central and northern Madagascar