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1

Opium poppy and Madagascar periwinkle: model non-model systems to investigate alkaloid biosynthesis in plants.  

PubMed

Alkaloids represent a large and diverse group of compounds that are related by the occurrence of a nitrogen atom within a heterocyclic backbone. Unlike other types of secondary metabolites, the various structural categories of alkaloids are unrelated in terms of biosynthesis and evolution. Although the biology of each group is unique, common patterns have become apparent. Opium poppy (Papaver somniferum), which produces several benzylisoquinoline alkaloids, and Madagascar periwinkle (Catharanthus roseus), which accumulates an array of monoterpenoid indole alkaloids, have emerged as the premier organisms used to study plant alkaloid metabolism. The status of these species as model systems results from decades of research on the chemistry, enzymology and molecular biology responsible for the biosynthesis of valuable pharmaceutical alkaloids. Opium poppy remains the only commercial source for morphine, codeine and semi-synthetic analgesics, such as oxycodone, derived from thebaine. Catharanthus roseus is the only source for the anti-cancer drugs vinblastine and vincristine. Impressive collections of cDNAs encoding biosynthetic enzymes and regulatory proteins involved in the formation of benzylisoquinoline and monoterpenoid indole alkaloids are now available, and the rate of gene discovery has accelerated with the application of genomics. Such tools have allowed the establishment of models that describe the complex cell biology of alkaloid metabolism in these important medicinal plants. A suite of biotechnological resources, including genetic transformation protocols, has allowed the application of metabolic engineering to modify the alkaloid content of these and related species. An overview of recent progress on benzylisoquinoline and monoterpenoid indole alkaloid biosynthesis in opium poppy and C. roseus is presented. PMID:18476877

Facchini, Peter J; De Luca, Vincenzo

2008-05-01

2

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...

3

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

PubMed

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

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

2012-04-20

4

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

PubMed

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 ?-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 ?-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

Nejat, Naghmeh; Vadamalai, Ganesan; Dickinson, Matthew

2012-02-21

5

Complete nucleotide sequences of two begomoviruses infecting Madagascar periwinkle (Catharanthus roseus) from Pakistan.  

PubMed

Though Catharanthus roseus (Madagascar periwinkle) is an ornamental plant, it is famous for its medicinal value. Its alkaloids are known for anti-cancerous properties, and this plant is studied mainly for its alkaloids. Here, this plant has been studied for its viral diseases. Complete DNA sequences of two begomoviruses infecting C. roseus originating from Pakistan were determined. The sequence of one begomovirus (clone KN4) shows the highest level of nucleotide sequence identity (86.5 %) to an unpublished virus, chili leaf curl India virus (ChiLCIV), and then (84.4 % identity) to papaya leaf curl virus (PaLCV), and thus represents a new species, for which the name "Catharanthus yellow mosaic virus" (CYMV) is proposed. The sequence of another begomovirus (clone KN6) shows the highest level of sequence identity (95.9 % to 99 %) to a newly reported virus from India, papaya leaf crumple virus (PaLCrV). Sequence analysis shows that KN4 and KN6 are recombinants of Pedilanthus leaf curl virus (PedLCV) and croton yellow vein mosaic virus (CrYVMV). PMID:23065111

Ilyas, Muhammad; Nawaz, Kiran; Shafiq, Muhammad; Haider, Muhammad Saleem; Shahid, Ahmad Ali

2012-10-12

6

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

PubMed

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

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

2013-05-22

7

Nuclear factors GT1 and 3AF1 interact with multiple sequences within the promoter of the Tdc gene from Madagascar periwinkle: GT1 is involved in UV light-induced expression  

Microsoft Academic Search

Plant secondary metabolites of the terpenoid indole alkaloid (TIA) class comprise several compounds with pharmaceutical applications.\\u000a A key step in the TIA biosynthetic pathway is catalysed by the enzyme tryptophan decarboxylase (TDC), which channels the primary\\u000a metabolite tryptophan into TIA metabolism. In Catharanthus roseus (Madagascar periwinkle), the Tdc gene is expressed throughout plant development. Moreover, Tdc gene expression is induced

P. B. F. Ouwerkerk; T. O. Trimborn; F. Hilliou; J. Memelink

1999-01-01

8

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

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.

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

2013-01-01

9

Characterization of the plastidial geraniol synthase from Madagascar periwinkle which initiates the monoterpenoid branch of the alkaloid pathway in internal phloem associated parenchyma.  

PubMed

Madagascar periwinkle (Catharanthus roseus [L.] G. Don, Apocynaceae) produces monoterpene indole alkaloids (MIAs), secondary metabolites of high interest due to their therapeutic value. A key step in the biosynthesis is the generation of geraniol from geranyl diphosphate (GPP) in the monoterpenoid branch of the MIA pathway. Here we report on the cloning and functional characterization of C. roseus geraniol synthase (CrGES). The full-length CrGES was over-expressed in Escherichia coli and the purified recombinant protein catalyzed the conversion of GPP into geraniol with a K(m) value of 58.5 ?M for GPP. In vivo CrGES activity was evaluated by heterologous expression in a Saccharomyces cerevisiae strain mutated in the farnesyl diphosphate synthase gene. Analysis of culture extracts by gas chromatography-mass spectrometry confirmed the excretion of geraniol into the growth medium. Transient transformation of C. roseus cells with a Yellow Fluorescent Protein-fusion construct revealed that CrGES is localized in plastid stroma and stromules. In aerial plant organs, RNA in situ hybridization showed specific labeling of CrGES transcripts in the internal phloem associated parenchyma as observed for other characterized genes involved in the early steps of MIA biosynthesis. Finally, when cultures of Catharanthus cells were treated with the alkaloid-inducing hormone methyl jasmonate, an increase in CrGES transcript levels was observed. This observation coupled with the tissue-specific expression and the subcellular compartmentalization support the idea that CrGES initiates the monoterpenoid branch of the MIA biosynthetic pathway. PMID:23102596

Simkin, Andrew J; Miettinen, Karel; Claudel, Patricia; Burlat, Vincent; Guirimand, Grégory; Courdavault, Vincent; Papon, Nicolas; Meyer, Sophie; Godet, Stéphanie; St-Pierre, Benoit; Giglioli-Guivarc'h, Nathalie; Fischer, Marc J C; Memelink, Johan; Clastre, Marc

2012-10-24

10

Madagascar.  

PubMed

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

1987-08-01

11

Pattern of diversity for morphological and alkaloid yield related traits among the periwinkle Catharanthus roseus accessions collected from in and around Indian subcontinent  

Microsoft Academic Search

Thirty two accessions of periwinkle Catharanthus roseus collected from different semitemperate to tropical geographical areas of Indian subcontinent, Madagascar, Singapore and Malaysia were characterized under field conditions for 53 growth, development, morphogenesis and alkaloid yield related characters over a few seasons at Lucknow, India. Large differences were observed among the accessions for each of the characters examined. The differences among

Parul Mishra; G. C. Uniyal; S. Sharma; Sushil Kumar

2001-01-01

12

Rapid identification of enzyme variants for reengineered alkaloid biosynthesis in periwinkle.  

PubMed

Monoterpene indole alkaloids from Catharanthus roseus (Madagascar periwinkle), such as the anticancer agents vinblastine and vincristine, have important pharmacological activities. Metabolic engineering of alkaloid biosynthesis can provide an efficient and environmentally friendly route to analogs of these synthetically challenging and pharmaceutically valuable natural products. However, the narrow substrate scope of strictosidine synthase, the enzyme at the entry point of the pathway, limits a pathway engineering approach. We demonstrate that with a different expression system and screening method it is possible to rapidly identify strictosidine synthase variants that accept tryptamine analogs not turned over by the wild-type enzyme. The variants are used in stereoselective synthesis of beta-carboline analogs and are assessed for biosynthetic competence within the terpene indole alkaloid pathway. These results present an opportunity to explore metabolic engineering of "unnatural" product production in the plant periwinkle. PMID:17719488

Bernhardt, Peter; McCoy, Elizabeth; O'Connor, Sarah E

2007-08-01

13

The susceptibility of benthic microalgae to periwinkle ( Littorina littorea, Gastropoda) grazing in laboratory experiments  

Microsoft Academic Search

Periphyton with different biomass levels were grown in-situ in the Kiel Fjord and used for short-term laboratory experiments to study the grazing of the periwinkle Littorina littorea. Ingestion rates increased with biomass in a saturating function as described by Holling's type II functional response model, with a maximal ingestion rate of ca. 260?g chlorophyll day?1 for 2cm periwinkles. The half

Ulrich Sommer

1999-01-01

14

Madagascar 2  

NSDL National Science Digital Library

You will follow the directions of your teacher as you move through these different maps. Here is a link to the explanation of the project for teachers: Madagascar explanation You should have two copies of this map: Blank madagascar map to complete the exercise. Here's how you add a document from MyUEN to your IA project: Using UEN to link to a document from the IA Watch this movie about Madagascar. Think about where on this ...

Olsen, Mr.

2010-02-23

15

Madagascar 1  

NSDL National Science Digital Library

You will follow the directions of your teacher as you move through these different maps. Here is a link to the explanation of the project for teachers: Madagascar Explanation 1 You should have two copies of this map: Blank madagascar map to complete the exercise. Here's how you add a document from MyUEN to your IA project: Using UEN to link to a document from the IA Watch this movie about Madagascar. Think about where on this ...

Robertshaw, Brooke

2010-02-17

16

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

PubMed

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

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

2013-07-15

17

The boundary currents east and north of Madagascar 2. Direct measurements and model comparisons  

Microsoft Academic Search

Moored current measurements of 11-month duration were carried out in the boundary currents east of Madagascar, near 12°S at Cape Amber where the mean current flows northwestward and near 23°S where the mean current flows approximately southward. Transports derived from the moored current measurements in the depth range 150-1100 m compare resonably well with those derived from ship sections by

Friedrich Schott; Michèle Fieux; John Kindle; John Swallow; Rainer Zantopp

1988-01-01

18

Applications of ecological niche modeling for species delimitation: a review and empirical evaluation using day geckos (Phelsuma) from Madagascar.  

PubMed

Although the systematic utility of ecological niche modeling is generally well known (e.g., concerning the recognition and discovery of areas of endemism for biogeographic analyses), there has been little discussion of applications concerning species delimitation, and to date, no empirical evaluation has been conducted. However, ecological niche modeling can provide compelling evidence for allopatry between populations, and can also detect divergent ecological niches between candidate species. Here we present results for two taxonomically problematic groups of Phelsuma day geckos from Madagascar, where we integrate ecological niche modeling with mitochondrial DNA and morphological data to evaluate species limits. Despite relatively modest levels of genetic and morphological divergence, for both species groups we find divergent ecological niches between closely related species and parapatric ecological niche models. Niche models based on the new species limits provide a better fit to the known distribution than models based upon the combined (lumped) species limits. Based on these results, we elevate three subspecies of Phelsuma madagascariensis to species rank and describe a new species of Phelsuma from the P. dubia species group. Our phylogeny continues to support a major endemic radiation of Phelsuma in Madagascar, with dispersals to Pemba Island and the Mascarene Islands. We conclude that ecological niche modeling offers great potential for species delimitation, especially for taxonomic groups exhibiting low vagility and localized endemism and for groups with more poorly known distributions. In particular, niche modeling should be especially sensitive for detecting recent parapatric speciation driven by ecological divergence, when the environmental gradients driving speciation are represented within the ecological niche models. PMID:18066927

Raxworthy, Christopher J; Ingram, Colleen M; Rabibisoa, Nirhy; Pearson, Richard G

2007-12-01

19

Cryopreservation of periwinkle, Catharanthus roseus cells cultured in vitro  

Microsoft Academic Search

A procedure for prolonged cryogenic storage of periwinkle cell cultures is described. Cells derived from periwinkle, Catharanthus roseus (L.) G. Don, and subcultured as suspension in 1-B5C nutrient medium have been frozen, stored in liquid nitrogen (-196°C) for 11 weeks, thawed and recultured. Maximal survival was achieved when 3–4 day-old cells precultured for 24 h in nutrient medium with 5%

K. K. Kartha; N. L. Leung; P. Gaudet-LaPrairie; F. Constabel

1982-01-01

20

Madagascar Agricultural Sector Assessment.  

National Technical Information Service (NTIS)

The report presents an analysis of the agricultural sector in Madagascar and provides a series of recommendations regarding the optimal role for the U.S. Agency for International Development/Madagascar (USAID/M) during 1990-1997. Maintaining soil fertilit...

L. Dash C. Steedman

1990-01-01

21

Responses of Mud Snails and Periwinkles to Environmental Odors and Disaccharide Mimics of Fish Odor  

Microsoft Academic Search

Estuarine snails, periwinkles (Littoraria irorata), and mud snails (Ilyanassa obsoleta) were tested for behavioral responses to aqueous extracts of tissue macerates, odors of living intact organisms, and to disaccharides derived from heparin. Extracts included salt-marsh cordgrass (Spartina alterniflora), pink shrimp (Penaeus duorarum), crushed periwinkles, and crushed mud snails. Odors included live periwinkles, mud snails, stone crab (Menippe mercenaria), striped hermit

Yasmin J. Rahman; Richard B. Forward; Dan Rittschof

2000-01-01

22

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

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

23

A null model for species richness gradients: bounded range overlap of butterflies and other rainforest endemics in Madagascar  

Microsoft Academic Search

Species richness has classically been thought to increase from the poles towards the Equator, and from high elevations down to sea-level. However, the largest radiation of butterflies in Madagascar, the subtribe Mycalesina (c. 67 spp.) does not exhibit such a monotonic pattern, either for empirical records or for interpolated species ranges. Instead, summation of mycalesine ranges generates a domed curve

DAVID C LEES; CLAIRE KREMEN; LANTO ANDRIAMAMPIANINA

1999-01-01

24

Mastopexy: Modification of periwinkle shell operation. Ten years of experience  

Microsoft Academic Search

Degrees I and II ptosis and atrophy of the female breast can definitively be corrected by the modified periwinkle shell operation. More problematic are the long-term results after correction of a degree III condition, especially when silastic prostheses for augmentation have been used. The long-term results can be optimized by a combination of dermal and glandular mastopexy and mammary implants.

Serge Krupp

1990-01-01

25

Digestive enzymes of the saltmarsh periwinkle Littorina irrorata (Mollusca: Gastropoda)  

Microsoft Academic Search

The saltmarsh periwinkleLittorina irrorata is well adapted for the digestion of a wide range of polysaccharides. Enzyme extracts attacked cellulose, pectin, xylan, bean gum and mannan (common in cell walls of higher plants), as well as starch and laminarin (representative of major polysaccharide classes in fungal, algal, and animal tissues). Activities were generally highes at a ph of 5 or

Felix Bärlocher; Thomas L. Arsuffi; Steven Y. Newell

1989-01-01

26

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

Microsoft Academic Search

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\\u000a were examined. B. crenatus growing on L. littorea increased snail volume up to

C. Buschbaum; K. Reise

1999-01-01

27

Molecular cloning and characterisation of two calmodulin isoforms of the Madagascar periwinkle Catharanthus roseus.  

PubMed

Involvement of Ca(2+) signalling in regulation of the biosynthesis of monoterpene indole alkaloids (MIA) in Catharanthus roseus has been extensively studied in recent years, albeit no protein of this signalling pathway has been isolated. Using a PCR strategy, two C. roseus cDNAs encoding distinct calmodulin (CAM) isoforms were cloned and named CAM1 and CAM2. The deduced 149 amino acid sequences possess four Ca(2+) binding domains and exhibit a close identity with Arabidopsis CAM isoforms (>91%). The ability of CAM1 and CAM2 to bind Ca(2+) was demonstrated following expression of the corresponding recombinant proteins. Furthermore, transient expression of CAM1-GFP and CAM2-GFP in C. roseus cells showed a typical nucleo-cytoplasm localisation of both CAMs, in agreement with the wide distribution of CAM target proteins. Using RNA blot analysis, we showed that CAM1 and CAM2 genes had a broad pattern of expression in C. roseus organs and are constitutively expressed during a C. roseus cell culture cycle, with a slight inhibitory effect of auxin for CAM1. Using RNA in situ hybridisation, we also detected CAM1 and CAM2 mRNA in the vascular bundle region of young seedling cotyledons. Finally, using specific inhibitors, we also showed that CAMs are required for MIA biosynthesis in C. roseus cells by acting on regulation of expression of genes encoding enzymes that catalyse early steps of MIA biosynthesis, such as 1-deoxy-d-xylulose 5-phosphate reductoisomerase and geraniol 10-hydroxylase. PMID:21143723

Poutrain, P; Guirimand, G; Mahroug, S; Burlat, V; Melin, C; Ginis, O; Oudin, A; Giglioli-Guivarc'h, N; Pichon, O; Courdavault, V

2011-01-01

28

Madagascar Fauna Group  

NSDL National Science Digital Library

This is the homepage of the Madagascar Fauna Group, an "international consortium of zoos and related organizations that pool their talents and resources to work together in one of the world's most endangered places." Readers will find loads of information about the island and its diverse assortment of animal species, many of which are "bizarrely beautiful" and found nowhere else. The site also offers a number of Web links for general information about Madagascar, educational sites about lemurs and other animals, and links geared towards kids.

29

Mammalian biodiversity on Madagascar controlled by ocean currents.  

PubMed

Madagascar hosts one of the world's most unusual, endemic, diverse and threatened concentrations of fauna. To explain its unique, imbalanced biological diversity, G. G. Simpson proposed the 'sweepstakes hypothesis', according to which the ancestors of Madagascar's present-day mammal stock rafted there from Africa. This is an important hypothesis in biogeography and evolutionary theory for how animals colonize new frontiers, but its validity is questioned. Studies suggest that currents were inconsistent with rafting to Madagascar and that land bridges provided the migrants' passage. Here we show that currents could have transported the animals to the island and highlight evidence inconsistent with the land-bridge hypothesis. Using palaeogeographic reconstructions and palaeo-oceanographic modelling, we find that strong surface currents flowed from northeast Mozambique and Tanzania eastward towards Madagascar during the Palaeogene period, exactly as required by the 'sweepstakes process'. Subsequently, Madagascar advanced north towards the equatorial gyre and the regional current system evolved into its modern configuration with flows westward from Madagascar to Africa. This may explain why no fully non-aquatic land mammals have colonized Madagascar since the arrival of the rodents and carnivorans during the early-Miocene epoch. One implication is that rafting may be the dominant means of overseas dispersal in the Cenozoic era when palaeocurrent directions are properly considered. PMID:20090678

Ali, Jason R; Huber, Matthew

2010-01-20

30

Madagascar Forms in Africa  

Microsoft Academic Search

A PARAGRAPH in a recent number of NATURE (p. 470) mentions the discovery of a new species of Ouvirandra in Eastern Africa, the genus being hitherto supposed to be peculiar to Madagascar. The plant in question, which was collected by Dr. Hildebrandt, is, however, as has been pointed out by Dr. Trimen and myself (Gardeners' Chronicle, February 1, p. 149),

W. T. Thiselton Dyer

1879-01-01

31

GREEN FLUORESCENT PROTEIN-LABELED STRAINS OF XYLELLA FASTIDIOSA COLONIZE CITRUS, GRAPEVINES AND PERIWINKLE.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Grapevines, sweet orange and periwinkle are three natural symptomatic host plants of Xylella fastidiosa. Our previous studies showed that X. fastidiosa strains from citrus could also induced disease symptoms in grapevines and periwinkle. In our post-genomic research program, defined gfp-marked strai...

32

Total plate count and coliform levels in Nigerian periwinkles from fresh and brackish water  

Microsoft Academic Search

Three species of freshly harvested Nigerian periwinkles — Tympanotonus fuscatus T. fuscatus var radula (both of brackish water habitat) and Pachymelinia bryonensis (a fresh water species) — were evaluated for bacteriological quality using aerobic plate counts and coliform counts. Results showed that all the periwinkles contained unacceptable levels of bacteria with P. bryonensis carrying up to 8.90 ± 1.93 mean

E. O. Ekanem; B. N. Otti

1997-01-01

33

A small cohort of Island Southeast Asian women founded Madagascar  

PubMed Central

The settlement of Madagascar is one of the most unusual, and least understood, episodes in human prehistory. Madagascar was one of the last landmasses to be reached by people, and despite the island's location just off the east coast of Africa, evidence from genetics, language and culture all attests that it was settled jointly by Africans, and more surprisingly, Indonesians. Nevertheless, extremely little is known about the settlement process itself. Here, we report broad geographical screening of Malagasy and Indonesian genetic variation, from which we infer a statistically robust coalescent model of the island's initial settlement. Maximum-likelihood estimates favour a scenario in which Madagascar was settled approximately 1200 years ago by a very small group of women (approx. 30), most of Indonesian descent (approx. 93%). This highly restricted founding population raises the possibility that Madagascar was settled not as a large-scale planned colonization event from Indonesia, but rather through a small, perhaps even unintended, transoceanic crossing.

Cox, Murray P.; Nelson, Michael G.; Tumonggor, Meryanne K.; Ricaut, Francois-X.; Sudoyo, Herawati

2012-01-01

34

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

NASA Astrophysics Data System (ADS)

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.

Buschbaum, C.; Reise, K.

35

Growth of the salt marsh periwinkle Littoraria irrorata on fungal and cordgrass diets  

Microsoft Academic Search

The growth of the salt marsh periwinkleLittoraria irrorata (collected from Sapelo Island, Georgia in 1991, initial shell length 6.2 to 11.5 mm) on various diets was measured. Growth was highest on a diet of standing-dead leaves ofSpartina alterniflora. Periwinkles provided with marsh sediment, yellow-green, sterile, or bacteria-colonized leaves lost organic mass. Fungal-colonized leaves and pure mycelia of fungi common on

F. Bärlocher; S. Y. Newell

1994-01-01

36

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

Microsoft Academic Search

Shell size distribution patterns of marine gastropod populations may vary considerably across different environments. We investigated\\u000a 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\\u000a Bight). On the sedimentary shore, periwinkle density (917 ± 722 individuals m?2) was about three

Nina Eschweiler; Markus Molis; Christian Buschbaum

2009-01-01

37

[Latrodectism in Madagascar].  

PubMed

Data concerning lactrodectism in Madagascar is scarce. Two spider species of the Latrodectus genus are found on the Grand Isle: the black widow Latrodectus mactans mena vody and the brown widow Latrodectus geometricus. From March 1991 through July 1992, 10 cases of envenomation by these spiders were treated in the Intensive Care Unit of Antananarivo Hospital. Symptomatology was remarkable with regard to severity (one fatality due to cardiovascular failure, one gangrene of the foot) as well as clinical manifestations (immediate local pain, kidney dysfunction, arterial hypertension). In two cases, the spider was captured and identified. Both were female brown widows (Latrodectus geometricus), which might explain the differences observed in comparison with the classic features of latrodectism that have been established from American and European black widow bites. Since antivenom was unavailable, only symptomatic treatment was administered, including intravenous calcium that proved effective for pain relief. PMID:7934777

Ramialiharisoa, A; de Haro, L; Jouglard, J; Goyffon, M

1994-01-01

38

Market Structures, Socioeconomics, and Tobacco Usage Patterns in Madagascar.  

PubMed

INTRODUCTION: The isolated island nation of Madagascar has substantial prevalence of both smoking and smokeless tobacco use, although not of dual use. Madagascar's tobacco market, much like its historical and cultural underpinnings, appears to have both Asian and African influences. Additionally, it has a unique market structure that plays an important role in influencing patterns of tobacco use. This study analyzes the determinants of smoking and smokeless tobacco use in Madagascar. METHODS: This study uses the 2008 Madagascar Demographic and Health Survey to analyze both smoking tobacco and smokeless tobacco use, stratified by gender. Multivariate log binomial models were used to evaluate the relationship between tobacco use and age, residence (urban/rural), province, marital status, and education. RESULTS: Our analysis indicates that two distinctly different groups of people use two distinctly different tobacco products. Smoking is almost exclusively used by men and does not appear to be related to socioeconomic status. Conversely, smokeless tobacco is consumed by large proportions of both men and women, who are less educated and live in rural areas of the country. This disparate pattern in consumption is a reflection of the different market structures for smokeless tobacco (a cottage industry) and smoking tobacco (a near monopoly). CONCLUSIONS: Distinct market-based, geographic, and socioeconomic disparities in tobacco use are explored in order to begin the classification of Madagascar's tobacco epidemic as more African, more Asian, or as a distinctly different environment. PMID:23703733

Blecher, Evan; Liber, Alex C; Chaussard, Martine; Fedewa, Stacey

2013-05-23

39

From herkogamy to cleistogamy--development of cleistogamy in periwinkle.  

PubMed

Periwinkle (Catharanthus roseus [L.] G. Don), an important medicinal plant, is an allogamous species in which the stigma is below the anthers. The receptive portion is at the base of the stigmatic head and thus automatic intra-flower self-pollination is excluded. The structure of the flower is of typical reverse herkogamy and pollination occurs through nectar-seeking insects. A few self-pollinating strains are also reported in which self-pollination is brought about by an increase in length of the style or of the ovary. Self-pollination is governed by allelic duplicate genes recessive to allogamy. An induced monogenic recessive mutant (EMS 17-1) with caducous closed corolla (corolla abscising before anthesis), isolated from variety, Dhawal, was crossed with two self-pollinating strains to study the possibility of obtaining cleistogamous recombinants combining closed corolla and self-pollination traits. Cleistogamous plants were obtained in which development of fruits and seeds occurred without opening of the corolla. Closed corolla and self-pollination were found to be independently inherited. A dominant gene in the parent in which self-pollination occurred due to an increase in length of the ovary, appeared to completely or partially inhibit expression of the gene for closed corolla in homozygous or heterozygous condition, respectively. The genetic basis of development of cleistogamy is described. Cleistogamy in periwinkle would facilitate in ensuring genetic purity, pollen containment, and seed production even in the absence of pollinators. This appears to be the first report on the development of cleistogamous plants in an allogamous species. PMID:23077233

Kulkarni, Raghavendra N; Baskaran, Kuppusamy

2012-10-16

40

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

NASA Astrophysics Data System (ADS)

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.

de Wit, Maarten J.

41

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)

Lake 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.

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

2006-11-01

42

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...

43

Logistical teamwork tames Madagascar wildcats  

SciTech Connect

Amoco Production Company's exploration program in western Madagascar's Sakalaya coastal plain exemplifies the unique logistical challenges both operator and drilling contractor must undergo to reach the few remaining onshore frontier areas. Sakalava is characterized by deep rivers, flood prone tributaries, and a lone 40 km hard-surface road. Problems caused by a lack of port facilities and oil field services are complicated by thousands of square miles of unimproved wooded plains. Rainwater from the nearby mountains of central Madagascar frequently floods rivers in the Sakalava coastal plain leaving impassable marshes in their wake. Prior to this project, about 45 wells had been drilled in Madagascar. Most recently, state oil company Omnis contracted Bawden Drilling International Inc. to drill nine wells for its heavy oil project on the Tsimioro oil prospect. Bawden provided both logistical and drilling services for that program.

Twa, W.

1986-03-01

44

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

Microsoft Academic Search

Lake 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

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

2006-01-01

45

Effect of cytokinin on alkaloid accumulation in periwinkle callus cultures transformed with a light-inducible ipt gene  

Microsoft Academic Search

The effect of cytokinins on accumulation of indole alkaloids in periwinkle callus cultures was investigated. Firstly, it was found that exogenously-applied cytokinin increased the ajmalicine and serpentine content of untransformed callus culture obtained from cotyledons. Secondly, periwinkle cotyledons were transformed with the isopentenyl transferase (ipt) gene under the control of a light-inducible promoter and two transformed callus lines were used

Frédérique Garnier; Sabine Carpin; Philippe Label; Joel Crèche; Marc Rideau; Saïd Hamdi

1996-01-01

46

Large scale population structure and gene flow in the planktonic developing periwinkle, Littorina striata, in Macaronesia (Mollusca: Gastropoda)  

Microsoft Academic Search

Allozymes were used to investigate the genetic structure of 42 populations of the planktonic developing, Macaronesian periwinkle Littorina striata, throughout its entire geographic range (Azores, Madeira, Canary Islands and Cape Verde Islands). This periwinkle is presumed to have a high dispersal and gene flow potential, because it has a planktonic development. It is therefore expected to show little population genetic

Hans De Wolf; Ron Verhagen; Thierry Backeljau

2000-01-01

47

Ecological and Economic Analysis of Watershed Protection in Eastern Madagascar  

Microsoft Academic Search

Watershed protection is one of the many goods and services provided by the world's fast disappearing tropical forests. Among the variety of watershed protection benefits, flood damage alleviation is crucial, particularly in upland watersheds. This study is a rare attempt to estimate flooding alleviation benefits, resulting from the protection of upland forests in Eastern Madagascar. A three stage model is

Randall A. Kramer; Daniel D. Richter; Subhrendu Pattanayak; Narendra P. Sharma

1997-01-01

48

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

PubMed

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

Valluri, Jagan V

2009-01-01

49

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

ERIC Educational Resources Information Center

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.…

Georges, Claude

1993-01-01

50

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

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

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

1999-04-01

51

Seizing an opportunity in Madagascar  

NSDL National Science Digital Library

Approximately 50 percent of plant and over 70 percent of vertebrate species are crammed into biodiversity "hotspots" that make up only 2.3 percent of Earth's land surface. Madagascar is one of these hotspots, and its government is planning to triple the amount of the protected land where the plants and animals can live without interference from humans.

American Association for the Advancement of Science (AAAS;)

2008-04-10

52

The culture history of Madagascar  

Microsoft Academic Search

Madagascar's culture is a unique fusion of elements drawn from the western, northern, and eastern shores of the Indian Ocean, and its past has fascinated many scholars, yet systematic archaeological research is relatively recent on the island. The oldest traces of visitors are from the first century AD. Coastal settlements, with clear evidence of ties to the western Indian Ocean

Robert E. Dewar; Henry T. Wright

1993-01-01

53

Relationships and traders in Madagascar  

Microsoft Academic Search

This article documents the role that personal relationships play in economic exchange. Original survey data show that agricultural traders in Madagascar perceive relationships as the most important factor for success in their business. Evidence details the extent to which relationships are used to serve a variety of purposes such as: the circulation of information about prices and market conditions; the

Marcel Fafchamps; Bart Minten

1999-01-01

54

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

NASA Astrophysics Data System (ADS)

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.

Eschweiler, Nina; Molis, Markus; Buschbaum, Christian

2009-06-01

55

Adaptive and non-adaptive variation in two species of rough periwinkle (Littorina) on British shores  

Microsoft Academic Search

Rough periwinkles are notoriously variable in shell characters. There are many reports of substantial local variation on single shores which not only make identification difficult but also may be difficult to understand in terms of likely selective pressures. We show that despite local variation in southern Britain there is evidence of a broader scale of change which is likely to

J. Grahame; P. J. Mill; A. C. Brown

1990-01-01

56

An anomalous form of mycoplasma-like bodies in periwinkle infected with the sandal spike agent  

Microsoft Academic Search

An anomalous form of mycoplasma-like bodies was found in ‘necrotic’ cells in the sieve elements of periwinkle stem after infection with the sandal spike disease agent. These bodies, 50–160 nm in diameter, were strongly osmiophilic and bounded by a unit membrane. It is suggested that these anomalous bodies represent a naturally degenerated form of the mycoplasma-like bodies.

C. Hiruki; Jeanne Dijkstra

1973-01-01

57

Mitochondrial DNA CoI haplotype variation in sibling species of rough periwinkles  

Microsoft Academic Search

Three sibling species of rough periwinkles are currently recognized: Littorina arcana, L. compressa and L. saxatilis. Certain forms of L. saxatilis are also argued by some to deserve species status, such as the barnacle-dwelling ‘L. neglecta’ and the lagoonal ‘L. tenebrosa’. Relationships between these taxa, and between and within representative populations, are investigated using sequence analysis and restriction fragment length

C S Wilding; J Grahame; P J Mill

2000-01-01

58

Biochemical Differences Between Trail Mucus and Adhesive Mucus From Marsh Periwinkle Snails  

Microsoft Academic Search

The composition of the adhesive form of marsh periwinkle mucus was compared to the trail mucus used during locomotion. The trail mucus consists primarily of large, carbohydrate-rich molecules with some relatively small proteins. In contrast, the adhesive mucus has 2.7 times as much protein with no significant difference in carbohy- drate concentration. The resulting gel has roughly equal amounts of

ANDREW M. SMITH; MARTHA C. MORIN

2002-01-01

59

Observations on the tidal activity rhythm of the periwinkle Littorina nigrolineata (Gray)  

Microsoft Academic Search

The spontaneous activity pattern of the periwinkle L. nigrolineata has been studied by direct observation in the field and under controlled conditions in the laboratory. In the laboratory the animals are induced to crawl by both immersion and exposure under simulated tidal conditions, and the increased activity following emersion has been confirmed by field observations. Animals kept submerged under constant

Saran Petpiroon; Elfed Morgan

1983-01-01

60

TOP-DOWN CONTROL OF SPARTINA ALTERNIFLORA PRODUCTION BY PERIWINKLE GRAZING IN A VIRGINIA SALT MARSH  

Microsoft Academic Search

Top-down forces, such as grazing and predation, have long been thought to be unimportant in controlling plant growth in salt marshes. Instead, bottom-up forces, such as porewater ammonium and oxygen availability, are thought to be the primary regulating factors. In the field, we observed the periwinkle, Littoraria irrorata, grazing on live salt- marsh cordgrass, Spartina alterniflora. To examine the relative

Brian R. Silliman; Jay C. Zieman

2001-01-01

61

Transgenic periwinkle tissues overproducing cytokinins do not accumulate enhanced levels of indole alkaloids  

Microsoft Academic Search

Cytokinins play a critical role in several aspects of plant growth, metabolism and development. We previously reported that adding cytokinins to the culture medium of a suspension-cultured cell line of periwinkle increased the accumulation of indole alkaloids, and our aim was to compare the effect of exogenously-applied cytokinins with that of elevated levels of endogenous cytokinins on indole alkaloid production.

Frédérique Garnier; Philippe Label; Didier Hallard; Jean-Claude Chrnieux I; Marc Rideau I; Saïd Hamdi

1996-01-01

62

Applications of Ecological Niche Modeling for Species Delimitation: A Review and Empirical Evaluation Using Day Geckos (Phelsuma) from Madagascar  

Microsoft Academic Search

Although the systematic utility of ecological niche modeling is generally well known (e.g., concerning the recog- nition and discovery of areas of endemism for biogeographic analyses), there has been little discussion of applications concerning species delimitation, and to date, no empirical evaluation has been conducted. However, ecological niche mod- eling can provide compelling evidence for allopatry between populations, and can

CHRISTOPHER J. RAXWORTHY; COLLEEN M. INGRAM; Nirhy Rabibisoa; RICHARD G. PEARSON

2007-01-01

63

A NEW SPECIES OF PROBOLOMYRMEX FROM MADAGASCAR  

Microsoft Academic Search

The worker and queen of Probolomyrmex tani (sp. nov.) from Madagascar are described. This is the first record of the genus from the Malagasy region. P. tani is widespread throughout western Madagascar but rare in collections. Collection data indicate that this species nests and forages in soil or litter in a range of habitats from montane forest to dry spiny

Brian L. Fisher

64

Gem corundum deposits of Madagascar: A review  

Microsoft Academic Search

Madagascar is one of the most important gem-producing countries in the world, including ruby and sapphires. Gem corundum deposits formed at different stages in the geological evolution of the island and in contrasting environments. Four main settings are identified: (1) Gem corundum formed in the Precambrian basement within the Neoproterozoic terranes of southern Madagascar, and in the volcano-sedimentary series of

Amos Fety Michel Rakotondrazafy; Gaston Giuliani; Daniel Ohnenstetter; Anthony E. Fallick; Saholy Rakotosamizanany; Alfred Andriamamonjy; Théogène Ralantoarison; Madison Razanatseheno; Yohann Offant; Virginie Garnier; Henri Maluski; Christian Dunaigre; Dietmar Schwarz; Voahangy Ratrimo

2008-01-01

65

Madagascar satellite data: an inversion test case  

Microsoft Academic Search

The Madagascar satellite data set provides images of a spreading ridge off the coast of Madagascar. This data set has two regions: the southern half is densely sampled and the northern half is sparsely sampled. This data set is an excellent test case for inversion methods. It presents several challenges that geophysicists face in generating seismic maps in general. The

Jesse Lomask

2002-01-01

66

Deforestation in the Madagascar Highlands – Established `truth' and scientific uncertainty  

Microsoft Academic Search

The Madagascar central highlands with their red soils and erosion gullies are often held up as a frightening example of the\\u000a consequences of deforestation. They are also used as a model of how the entire island will look if so-called `forest unfriendly\\u000a activities' of local people continue. This insight is based on a narrative that describes the highlands as totally

Jorgen Klein; Hogskoleni Hedmark LUH

2002-01-01

67

Exploring the Association Between People and Deforestation in Madagascar  

Microsoft Academic Search

\\u000a An island widely recognized for remarkably high biological diversity, Madagascar continues to experience considerable deforestation.\\u000a This study explores possible causes of forest loss between 1990 and 2000. Applying a multivariate probit model, the study\\u000a considers a range of human geographic, physical geographic, and infrastructure data to identify likely reasons for deforestation\\u000a during the final decade of the twentieth century. Results

L. J. Gorenflo; Catherine Corson; Kenneth M. Chomitz; Grady Harper; Miroslav Honzák; Berk Özler

68

[Resistances and initiatives in Madagascar].  

PubMed

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

Georges, C

1993-03-01

69

Dipoles of the South East Madagascar Current  

NASA Astrophysics Data System (ADS)

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.

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

2013-02-01

70

Chemical Composition and Pharmacological Activity of Alkaloids from the Common Periwinkle Cultured in Georgia  

Microsoft Academic Search

periwinkle to the field of the Experimental Center of Medicinal Plants (Shiraki, East Kakhetia) was successful, leading to an increase in the alkaloid content. The total alkaloid yield reached up to 1 and 0.8%, in which the vincamine content amounted to 0.06 and 0.04%, in the blooming and fruitage stages, respectively. The purpose of this study was to refine the

V. Yu. Vachnadze; É. Z. Dzhakeli; Z. V. Robakidze; G. V. Chkhikvadze; M. M. Mudzhiri; G. V. Abuladze; N. A. Chuchulashvili

2001-01-01

71

A geographically-based study of shell shape in small rough periwinkles  

Microsoft Academic Search

A study using principal component analysis and discriminant analysis was carried out on shell shape variation in 3093 specimens\\u000a of rough periwinkles, 2500 of which were below 5.5 mm in columella length, from around the North Atlantic. Using a combination\\u000a of colour plus sculpture, and life history trait, the snails were classified by inspection and examination into Littorina nigrolineata, L.

K. J. Caley; J. Grahame; Peter J. Mill

1995-01-01

72

Uptake and depuration of 131I by the edible periwinkle Littorina littorea: uptake from seawater  

Microsoft Academic Search

Uptake and depuration experiments for the edible periwinkle Littorina littorea have been performed using 131I-labelled seawater. Throughout the experimental phase the winkles were fed on unlabelled Chondrus crispus. 131I concentrations in winkles during uptake followed linear first-order kinetics with an uptake half-time of 11 days, whereas for depuration a triphasic sequence with biological half-lives of 4, 23 and 56 days

J. Vives i Batlle; R. C. Wilson; P. McDonald; T. G. Parker

2004-01-01

73

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

Microsoft Academic Search

On sedimentary tidal flats in the Wadden Sea near the Island of Sylt, the periwinkleLittorina 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 (?2). Green algae covering>10% of sediment surface appeared in

U. Wilhelmsen; K. Reise

1994-01-01

74

Dispersion of the salt-marsh periwinkle Littoraria irrorata : Effects of water level, size, and season  

Microsoft Academic Search

This paper documents horizontal and vertical dispersion patterns of a Texas population of the saltmarsh periwinkle, Littoraria irrorata, over a 15-month period. The study was conducted within a tidal marsh on the Anahuac National Wildlife Refuge in Galveston\\u000a Bay. Two mark-recapture experiments demonstrated that L. irrorata rarely move more than 2 m from their release point over long periods of

Caryn C. Vaughn; Frank M. Fisher

1992-01-01

75

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

Microsoft Academic Search

.   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

Bettina Saier

2000-01-01

76

Country Commercial Guide: Madagascar, Fiscal Year 2000.  

National Technical Information Service (NTIS)

This Country Commercial Guide (CCG) offers a comprehensive look at Madagascar's commercial environment, using economic, political and market analyses. The CCG's were established by recommendation of the Trade Promotion Coordinating Committee (TPCC), a mul...

1999-01-01

77

Atmospheric Effects of Biomass Burning in Madagascar.  

National Technical Information Service (NTIS)

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 s...

A. C. Aikin W. R. Hoegy J. R. Ziemke A. Thorpe

2000-01-01

78

Madagascar basalts: tracking oceanic and continental sources  

Microsoft Academic Search

Extensive Upper Cretaceous volcanism in southern Madagascar was fed in part by mantle sources resembling those expressed today in the Indian Ocean at Marion and Prince Edward islands and on the central Southwest Indian Ridge. In addition, very low ?Nd(T) (to -17.4), high (87Sr\\/86Sr)T (to 0.72126) tholeiites in southwestern Madagascar were variably but highly contaminated by ancient continental material broadly

J. Mahoney; C. Nicollet; C. Dupuy

1991-01-01

79

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

USGS Publications Warehouse

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.

De Waele, B.; Thomas, R. 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

80

NESTING BIOLOGY AND DIET OF THE MADAGASCAR HARRIER (CIRCUS MA CROSCELES) IN AMBOHITANTELY SPECIAL RESERVE, MADAGASCAR  

Microsoft Academic Search

ABSTP, ACT.--We studied Madagascar Harriers (Circus macrosceles) in the central high plateau at Ambo- hitantely Special Reserve, Madagascar during the 1997 and 1998 breeding seasons. We located 11 nests and documented eight nesting attempts during the two seasons. All nests were placed on vegetation within marshes (N = 9) and averaged 43 cm above water level. Breeding commenced in late

LILY-ARISON RENE DE ROLAND; JEANNENEY RABEARIVONY; IGNACE RANDRIAMANGA; RUSSELL THORSTROM

81

The impact of agricultural shocks on households growth performance in rural Madagascar  

Microsoft Academic Search

(english) This paper tests if agricultural and climatic shocks have persistent impacts on consumption growth in 7 rural areas from Madagascar. The empirical framework is inspired by a standard Solow growth model. Shocks are introduced directly in the reduced form model as controls for factor productivity and investment level. This model is estimated on a panel of 6175 households observed

Anne-Claire Thomas

2009-01-01

82

FOOD HABITS OF THE MADAGASCAR LONG-EARED OWL ASIO MADAGASCARIENSIS IN TWO HABITATS IN SOUTHERN MADAGASCAR  

Microsoft Academic Search

Goodman, S. M., Langrand, O. & Raxworthy, C. J. 1993. Food habits of the Madagascar Long-eared Owl Asio madagascariensis in two habitats in southern Madagascar. Ostrich 64:79-85.Food remains recovered from regurgitated pellets of the Madagascar Long-eared Owl Asio madagascariensis were collected at two sites on Madagascar with different habitats and weather regimes. The localities are Beza Mahafaly, a sub-arid thorn

Steven M. Goodman; Olivier Langrand; Christopher J. Raxworthy

1993-01-01

83

Urban household food security, Madagascar.  

PubMed

This article discusses the success of the Madagascar Food Security and Nutrition project in decreasing malnutrition and monitoring child health. Success has occurred in the following realms: effective collaboration between government and nongovernmental organizations (NGOs), capacity building through investment in training of community workers, increased quality of services provided by community nutrition workers, community involvement, government commitment, and a flexible program design. NGOs were able to respond to community concerns by adding program inputs without losing the focus on core nutrition interventions. Community workers were selected from a group of mothers. Women were trained to monitor the growth of all children under age 5. Children who were severely malnourished were identified and referred to rehabilitation centers for treatment lasting up to 3 weeks. The program offered support and nutrition education for mothers of sick children. One drawback of the treatment program was the inability of mothers to stay for long periods of time during the duration of treatment. The program offers distribution of iodine capsules as part of a long-term salt iodization program that is supported by UNICEF and the World Bank. The program also offers microcredit. Since 1993, 28,000 children under age 5 have been weighed each month. These children came from two provinces and belonged to 300,000 families. The monitored children were 66% of the total number of children aged under 5 years. Malnutrition rates decreased from 46% to 37%. PMID:12293185

Balachander, J

1997-12-01

84

Evolution in the hypervariable environment of Madagascar.  

PubMed

We show that the diverse ecoregions of Madagascar share one distinctive climatic feature: unpredictable intra- or interannual precipitation compared with other regions with comparable rainfall. Climatic unpredictability is associated with unpredictable patterns of fruiting and flowering. It is argued that these features have shaped the evolution of distinctive characteristics in the mammalian fauna of the island. Endemic Herpestidae and Tenrecidae and members of five endemic primate families differ from closely related species elsewhere, exhibiting extremes of "fastness" and "slowness" in their life histories. Climatic features may also account for the dearth of frugivorous birds and mammals in Madagascar, and for the evolutionary prevalence of species with large body mass. PMID:17698810

Dewar, Robert E; Richard, Alison F

2007-08-13

85

Evolution in the hypervariable environment of Madagascar  

PubMed Central

We show that the diverse ecoregions of Madagascar share one distinctive climatic feature: unpredictable intra- or interannual precipitation compared with other regions with comparable rainfall. Climatic unpredictability is associated with unpredictable patterns of fruiting and flowering. It is argued that these features have shaped the evolution of distinctive characteristics in the mammalian fauna of the island. Endemic Herpestidae and Tenrecidae and members of five endemic primate families differ from closely related species elsewhere, exhibiting extremes of “fastness” and “slowness” in their life histories. Climatic features may also account for the dearth of frugivorous birds and mammals in Madagascar, and for the evolutionary prevalence of species with large body mass.

Dewar, Robert E.; Richard, Alison F.

2007-01-01

86

Rainforest Pharmacopeia in Madagascar Provides High Value for Current Local and Prospective Global Uses  

Microsoft Academic Search

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

Christopher D. Golden; B. J. Rodolph Rasolofoniaina; E. J. Gasta Anjaranirina; Lilien Nicolas; Laurent Ravaoliny; Claire Kremen

2012-01-01

87

Geological evolution of the Neoproterozoic Bemarivo Belt, northern Madagascar  

USGS Publications Warehouse

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).

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

2009-01-01

88

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

NASA Astrophysics Data System (ADS)

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.

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

2013-05-01

89

The effect of trail?following on the locomotion of the marsh periwinkle Littorina irrorata (mesogastropoda: Littorinidae)  

Microsoft Academic Search

The marsh periwinkle, Littorina irrorata, like many gastropods, can detect conspecific mucous trails and often follows them with polarity. Although trail?following is a common component of L. irrorata's behavioral repertoire, the adaptive significance of this behavior is not evident. This study examined some of the biomechanical and energetic advantages of tracking in L. irrorata.Mean crawling speeds of L. irrorata on

Richard A. Tankersley

1989-01-01

90

Integrated laboratory and field assessments of heavy metals accumulation in edible periwinkle, Tympanotonus fuscatus var radula (L.)  

Microsoft Academic Search

Laboratory and field bioaccumulation experiments were employed in assessing the impact of metal-laden effluents on the tissue concentrations of heavy metals in edible periwinkle, Tympanotonus fuscatus, in Lagos Lagoon. The field experiments showed that Zn and Pb accumulated in T. fuscatus collected from impacted stations were found to be about 10 times higher than the concentrations detected in control animals.

A. A Otitoloju; K. N Don-Pedro

2004-01-01

91

Increasing the content of leaf and root alkaloids of high alkaloid content mutants of periwinkle through nitrogen fertilization  

Microsoft Academic Search

In industrial plants such as medicinal plants, the content of the economically important metabolite is more important than the yield of the plant part containing the metabolite, as it determines the cost of extraction of the metabolite. Two high alkaloid content mutants of periwinkle (Catharanthus roseus, a medicinal plant yielding anti-cancer and anti-hypertension alkaloids) were developed through induced mutagenesis. Since

Y. Sreevalli; R. N. Kulkarni; K. Baskaran; R. S. Chandrashekara

2004-01-01

92

Effect of phytoplasmal infection on concentration and translocation of carbohydrates and amino acids in periwinkle and tobacco  

Microsoft Academic Search

Source and sink tissue of Catharanthus roseus (periwinkle) infected with the grapevine yellows (GY), apple proliferation (AP), or ash yellows (ASHY) phytoplasma and of Nicotiana tabacum (tobacco) infected with the AP phytoplasma, were examined for concentrations of glucose, fructose, sucrose, starch and total amino acids. Phytoplasmal infection caused growth inhibition and severe yellowing in both plants, the GY phytoplasma being

P LEPKA; M STITT; E MOLL; E SEEMÜLLER

1999-01-01

93

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

NASA Astrophysics Data System (ADS)

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.

Wilhelmsen, U.; Reise, K.

1994-06-01

94

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

NASA Astrophysics Data System (ADS)

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.

Saier, Bettina

2000-11-01

95

Challenges of forest governance in Madagascar  

Microsoft Academic Search

There has been a huge surge in interest in the preservation of Madagascar's forests in the past two decades, but despite the investment of hundreds of millions of dollars, the goal remains elusive. Recent legislation has given the government the authority to enter into contractual arrangements with communities for the management of the country's public forests, so it has become

WILLIAM J MCCONNELL; SEAN P SWEENEY

2005-01-01

96

Human Dimensions of Madagascar's Marine Protected Areas  

Microsoft Academic Search

We conducted a socio-economic assessment in thirteen communities within or adjacent to Madagascar's Marine Protected Areas (MPAs); Nosy Atafana MPA in the Mananara Nord biosphere reserve; Tampolo, Tanjona, and Masoala MPAs in the Masoala National Park, and the recently designated Sahamalaza MPA. Socio-economic information was gathered using several techniques, including household surveys, resource user key informant interviews, community leader key

JOSHUA CINNER; MARIANA FUENTES

97

Welfare dynamics in rural Kenya and Madagascar  

Microsoft Academic Search

This paper presents comparative qualitative and quantitative evidence from rural Kenya and Madagascar in an attempt to untangle the causality behind persistent poverty. We find striking differences in welfare dynamics depending on whether one uses total income, including stochastic terms and inevitable measurement error, or the predictable, structural component of income based on a household's asset holdings. Our results suggest

Christopher B. Barrett; Paswel Phiri Marenya; John Mcpeak; Bart Minten; Festus Murithi; Willis Oluoch-Kosura; Jean Claude Randrianarisoa; Jhon Rasambainarivo; Justine Wangila

2006-01-01

98

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

PubMed Central

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.

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

2008-01-01

99

Imperfect Isolation: Factors and Filters Shaping Madagascar's Extant Vertebrate Fauna  

PubMed Central

Analyses of phylogenetic topology and estimates of divergence timing have facilitated a reconstruction of Madagascar’s colonization events by vertebrate animals, but that information alone does not reveal the major factors shaping the island’s biogeographic history. Here, we examine profiles of Malagasy vertebrate clades through time within the context of the island’s paleogeographical evolution to determine how particular events influenced the arrival of the island’s extant groups. First we compare vertebrate profiles on Madagascar before and after selected events; then we compare tetrapod profiles on Madagascar to contemporary tetrapod compositions globally. We show that changes from the Mesozoic to the Cenozoic in the proportions of Madagascar’s tetrapod clades (particularly its increase in the representation of birds and mammals) are tied to changes in their relative proportions elsewhere on the globe. Differences in the representation of vertebrate classes from the Mesozoic to the Cenozoic reflect the effects of extinction (i.e., the non-random susceptibility of the different vertebrate clades to purported catastrophic global events 65 million years ago), and new evolutionary opportunities for a subset of vertebrates with the relatively high potential for transoceanic dispersal potential. In comparison, changes in vertebrate class representation during the Cenozoic are minor. Despite the fact that the island’s isolation has resulted in high vertebrate endemism and a unique and taxonomically imbalanced extant vertebrate assemblage (both hailed as testimony to its long isolation), that isolation was never complete. Indeed, Madagascar’s extant tetrapod fauna owes more to colonization during the Cenozoic than to earlier arrivals. Madagascar’s unusual vertebrate assemblage needs to be understood with reference to the basal character of clades originating prior to the K-T extinction, as well as to the differential transoceanic dispersal advantage of other, more recently arriving clades. Thus, the composition of Madagascar’s endemic vertebrate assemblage itself provides evidence of the island's paleogeographic history.

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

2013-01-01

100

Hémoparasites des oiseaux sauvages à Madagascar  

Microsoft Academic Search

RESUME : Cette étude évalue la prévalence et la densité des hémoparasites chez 387 oiseaux appartenant à 43 espèces,et collectés sur 6 sites répartis dans différents milieux bio-climatiques de Madagascar. 139 (35,9%) se sont révélés porteurs d'au moins un hémoparasite avec par ordre de fréquence Plasmodium et\\/ou Haemoproteus (19,9% des 387 oiseaux), microfilaires (13,7%), Leucocytozoon (11,1%) et Trypanosoma (1,0%). Pour

Raharimanga V; Soula F; Raherilalao MJ; Goodman SM; Tall A; Randrianarivelojosia M; Raharimalala L; Duchemin JB; Ariey F; Robert V

101

Ethnomedicine in the Maroantsetra Region of Madagascar  

Microsoft Academic Search

Ethnomedicinal information was collected from the Betsimisaraka—the inhabitants of the Maroantsetra Region in the northeastern\\u000a part of Madagascar—during a recent expedition to the region. In spite of the inhabitants’ rich knowledge of and willingness\\u000a to discuss medicinal uses of plants, from both disturbed areas and undisturbed primary rainforests, it was found that much\\u000a ethnomedicinal information has not been documented. There

Nat Quansah

1988-01-01

102

Pathways of rural development in Madagascar  

Microsoft Academic Search

This paper is based on community-level data from 188 villages in rural Madagascar. The survey that was conducted in 1997 made extensive use of long-term recall questions ascertaining changes during the past 10 years in rice yields, wages, population, soil fertility, and other pertinent variables of rural development. We find that—on average for all villages—the yields of irrigated rice, the

Manfred Zeller; Cécile Lapenu; Bart Minten; Eliane Ralison; Désiré Randrianaivo; Claude Randrianarisoa

2000-01-01

103

A chronology for late prehistoric Madagascar  

Microsoft Academic Search

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

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

2004-01-01

104

Uptake and depuration of 131I by the edible periwinkle Littorina littorea: uptake from labelled seaweed (Chondrus crispus).  

PubMed

Uptake and depuration experiments of (131)I from labelled seaweed (Chondrus crispus) by the edible periwinkle Littorina littorea have been performed. Radioiodine concentrations in winkles during uptake followed first-order kinetics with an uptake half-time of 1 day, and a calculated equilibrium concentration (C(infinity)) of 21 000 Bq kg(-1) resulting in a transfer factor of 0.07 with respect to the labelled seaweed used as food. For depuration, a biphasic sequence with biological half-lives of 1 and 24 days was determined. The results suggest that in general, iodine turnover in periwinkles is slower than observed for other molluscs (monophasic biological half-lives in the order of 2-3 days). Both environmental media, food and seawater, can be significant sources of radioiodine for the winkle. PMID:15725502

Wilson, R C; Vives i Batlle, J; McDonald, P; Parker, T G

2004-12-08

105

HSP90 homologue from Madagascar periwinkle (Catharanthus roseus): cDNA sequence, regulation of protein expression and location in the endoplasmic reticulum  

Microsoft Academic Search

We describe cDNAs for a HSP90 homologue from Catharanthus roseus and studies on the regulation of expression. The largest cDNA (2670 bp) coded for a protein of 817 amino acids with a calculated size of 93 491 Da and a pI of 4.61. It contained a eucaryotic secretory signal, the endoplasmic reticulum (ER) targeting and retention signal (Lys-Asp-Glu-Leu), and the

Gudrun Schröder; Markus Beck; Johannes Eichel; Hans-Peter Vetter; Joachim Schröder

1993-01-01

106

Uptake and depuration of 131I by the edible periwinkle Littorina littorea: uptake from labelled seaweed ( Chondrus crispus)  

Microsoft Academic Search

Uptake and depuration experiments of 131I from labelled seaweed (Chondrus crispus) by the edible periwinkle Littorina littorea have been performed. Radioiodine concentrations in winkles during uptake followed first-order kinetics with an uptake half-time of 1 day, and a calculated equilibrium concentration (C?) of 21?000Bqkg?1 resulting in a transfer factor of 0.07 with respect to the labelled seaweed used as food.

R. C. Wilson; J. Vives i Batlle; P. McDonald; T. G. Parker

2005-01-01

107

Large-scale patterns of shell variation in Littorina striata , a planktonic developing periwinkle from Macaronesia (Mollusca: Prosobranchia)  

Microsoft Academic Search

Littorina striata King and Broderip, 1832 is a strictly Macaronesian, intertidal periwinkle with planktonic development. The species displays\\u000a a high degree of shell variation involving size and sculpture (nodulose vs smooth shells). The present work provides a preliminary\\u000a account of some aspects of this shell variation on wave-exposed shores over the entire geographical range of the species.\\u000a Based on morphological

H. De Wolf; T. Backeljau; S. Van Dongen; R. Verhagen

1998-01-01

108

Zonal jets in the Madagascar plankton bloom  

NASA Astrophysics Data System (ADS)

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.

Huhn, F.; von Kameke, A.; Pérez-Muñuzuri, V.; Olascoaga, M. J.; Beronavera, F. B.

2012-04-01

109

Development of Environmental Education Programs for Protected Areas in Madagascar  

Microsoft Academic Search

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 staff. The multi-year qualitative research methods included individual and focus

Alison Ormsby

2008-01-01

110

Evidence of early butchery of giant lemurs in Madagascar  

Microsoft Academic Search

We report here definitive evidence of butchery, most probably associated with hunting, of giant extinct lemurs by early human settlers in Madagascar. Specimens of Palaeopropithecus ingens and Pachylemur insignis from two sites in southwestern Madagascar, Taolambiby and Tsirave, show classic signs of butchering. We compared these to the bones (also from Taolambiby) of butchered Propithecus verreauxi, a lemur still living

Ventura R. Perez; Laurie R. Godfrey; Malgosia Nowak-Kemp; David A. Burney; Jonah Ratsimbazafy; Natalia Vasey

2005-01-01

111

Development of Environmental Education Programs for Protected Areas in Madagascar  

ERIC Educational Resources Information Center

|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…

Ormsby, Alison

2007-01-01

112

Finding the Connections between Paleoecology, Ethnobotany, and Conservation in Madagascar  

Microsoft Academic Search

Studying Madagascar's late prehistoric past can add a useful dimension to ethnobotany research, as it has to conservation efforts. These studies provide evidence that people first arrived about two millennia ago. The plants they brought to Madagascar are predominantly south Asian in origin, including coconut, banana, rice, and hemp, pointing to their probable Indonesian origins. Lat- er plant additions, such

David A. Burney

113

Development of climatic zones and passive solar design in Madagascar  

Microsoft Academic Search

Climate classification is extremely useful to design buildings for thermal comfort purposes. This paper presents the first work for a climate classification of Madagascar Island. This classification is based on the meteorological data measured in different cities of this country. Three major climatic zones are identified. Psychometric charts for the six urban areas of Madagascar are proposed, and suited passive

O. Rakoto-Joseph; F. Garde; M. David; L. Adelard; Z. A. Randriamanantany

2009-01-01

114

An Abelisauroid Theropod Dinosaur from the Turonian of Madagascar  

PubMed Central

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.

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

2013-01-01

115

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

ERIC Educational Resources Information Center

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…

Hugon, Philippe

116

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

ERIC Educational Resources Information Center

|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…

Hugon, Philippe

117

Healing words: becoming a spirit-host in Madagascar.  

PubMed

In discussion of healing processes in sub-Saharan Africa, emphasis is characteristically placed on the role of performance. Yet in spirit mediumship, speech is also an important element in therapeutic practices. In Madagascar, the spirits (tromba) are often of exotic origins (frequently in time as well as space) and the language used is likewise exotic. A complex of techniques of enchantment is employed: amongst them, music, changes of dress, the burning of perfumes and incense, rum, putting matches in the mouth, or the use of herbal medicines. Sometimes artefacts, such as - in the case discussed - a large model ship, are employed. Although the setting is shrine-like, the techniques are at once both dynamic and eclectic, collapsing time and space into a single embodied moment when the spirit speaks through the vehicle of the medium. Such 'spirit-speech' is itself empowered and empowering, cathartic and curative. PMID:21810039

Mack, John

2011-08-01

118

Endemism and evolutionary history in conflict over Madagascar’s freshwater conservation priorities  

Microsoft Academic Search

Regional-scale biodiversity indicators provide important criteria for the selection of protected areas in conservation, but their application is often hindered by a lack of taxonomic knowledge. Moreover, different indicators include different types of information, sometimes leading to divergent conservation priorities. Madagascar tops the world list of biodiversity hotspots and much conservation effort has been directed toward its threatened plants and

B. Isambert; J. Bergsten; M. T. Monaghan; H. Andriamizehy; T. Ranarilalatiana; M. Ratsimbazafy; J. R. Andriniainimanana; A. P. Vogler

2011-01-01

119

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

PubMed

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

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

2012-07-01

120

Taxi driver training in Madagascar: the first step in developing a functioning prehospital emergency care system  

Microsoft Academic Search

BackgroundPrehospital care in developing countries is severely lacking. Few countries can afford the relatively expensive formalised Western model of a prehospital emergency medical system. The WHO has highlighted the development of layperson first responder programmes as the most basic step in the development of a functioning prehospital system.AimTo describe the first training programme of its kind, run in Mahajanga, Madagascar.

Heike Geduld; Lee Wallis

2010-01-01

121

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

Microsoft Academic Search

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

Thomas Wesener; Michael J. Raupach; Petra Sierwald

2010-01-01

122

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

NASA Astrophysics Data System (ADS)

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.

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

2012-04-01

123

The amino acid and stable isotope biogeochemistry of elephant bird (Aepyornis) eggshells from southern Madagascar  

NASA Astrophysics Data System (ADS)

A diverse suite of animals became extinct on Madagascar during the Late Holocene. As observed on landmasses elsewhere, the extinction process broadly coincided with the arrival of people. Our research on the amino acid racemisation and the carbon and oxygen isotope biogeochemistry of elephant bird (Aepyornis) eggshells from southern Madagascar refines models that attempt to explain the extinction process. A correlation between the extent of isoleucine epimerisation (aIle/Ile) and radiocarbon age of eggshells allows aIle/Ile to serve as a proxy for eggshell age. The aIle/Ile values indicate the majority (87%) of eggshells in this study are Holocene, with the remainder representing Pleistocene Aepyornis populations, and that further amino acid analyses would help to constrain the timing of Aepyornis extinction. Carbon isotope ratios in the organic and calcite fractions of eggshells indicate that Aepyornis primarily browsed C3 vegetation. Oxygen isotope values are more negative and less variable than in eggshells of ostriches living in semi-arid environments, suggesting that Aepyornis populations relied upon groundwater-fed coastal wetlands for their drinking water. The isotope results require that the changing abundances of C3 vegetation and groundwater-fed watering points be considered in models that aim to understand the extinction of Aepyornis in southern Madagascar.

Clarke, Simon J.; Miller, Gifford H.; Fogel, Marilyn L.; Chivas, Allan R.; Murray-Wallace, Colin V.

2006-09-01

124

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

PubMed Central

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

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

1984-01-01

125

The Madagascar Bloom: A serendipitous study  

NASA Astrophysics Data System (ADS)

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.

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

2013-01-01

126

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

NASA Astrophysics Data System (ADS)

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}?3[{{Fe}}_{1.99}^{3 + } {{Mn}}_{0.01}^{3 + }]?2(Si2.95Al0.03 {{Fe}}_{0.02}^{3 + })?3O12, 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 ?2 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.

Antao, Sytle M.; Klincker, Allison M.

2013-05-01

127

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

PubMed

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

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

2013-04-12

128

Audit of USAID/Madagascar's Biologically Diverse Forest Ecosystem Conservation Program.  

National Technical Information Service (NTIS)

Madagascar has one of the most amazing biodiversities in the world. Tens of millions of years of isolation from the African mainland have resulted in a large number of species that are endemic to Madagascar. The first human encounter with Madagascar's bio...

2008-01-01

129

Evaluating ring-tailed lemurs (Lemur catta) from southwestern Madagascar for a genetic population bottleneck.  

PubMed

In light of historical and recent anthropogenic influences on Malagasy primate populations, in this study ring-tailed lemur (Lemur catta) samples from two sites in southwestern Madagascar, Beza Mahafaly Special Reserve (BMSR) and Tsimanampetsotsa National Park (TNP), were evaluated for the genetic signature of a population bottleneck. A total of 45 individuals (20 from BMSR and 25 from TNP) were genotyped at seven microsatellite loci. Three methods were used to evaluate these populations for evidence of a historical bottleneck: M-ratio, mode-shift, and heterozygosity excess tests. Three mutation models were used for heterozygosity excess tests: the stepwise mutation model (SMM), two-phase model (TPM), and infinite allele model (IAM). M-ratio estimations indicated a potential bottleneck in both populations under some conditions. Although mode-shift tests did not strongly indicate a population bottleneck in the recent historical past when samples from all individuals were included, a female-only analysis indicated a potential bottleneck in TNP. Heterozygosity excess was indicated under two of the three mutation models (IAM and TPM), with TNP showing stronger evidence of heterozygosity excess than BMSR. Taken together, these results suggest that a bottleneck may have occurred among L. catta in southwestern Madagascar in the recent past. Given knowledge of how current major stochastic climatic events and human-induced change can negatively impact extant lemur populations, it is reasonable that comparable events in the historical past could have caused a population bottleneck. This evaluation additionally functions to highlight the continuing environmental and anthropogenic challenges faced by lemurs in southwestern Madagascar. PMID:22052208

Parga, Joyce A; Sauther, Michelle L; Cuozzo, Frank P; Jacky, Ibrahim Antho Youssouf; Lawler, Richard R

2011-11-03

130

Insatiable demands: Income, energy and environmental policy in Madagascar  

SciTech Connect

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.

Shaw, C.L.

1993-01-01

131

Age progressive volcanism in the Comores Archipelago and Northern Madagascar  

NASA Astrophysics Data System (ADS)

The Comores islands and Tertiary volcanic province of Northern Madagascar form a sub-linear trend of alkalic shield volvanoes across the northern Mozambique Channel. Potassium-argon dating of shield building lavas confirms an eastward increase in age of volcanism along the chain, consistent with a hotspot origin for the lineament. The rate of migration of the Somali Plate over the mantle source is approximately 45 mm/yr. This new geochronology for the Comores island chain is used to model the absolute motion of the Somali Plate for the last 10 million years. A systematic departure of the Somali Plate absolute motion from the African Plate absolute motion during this period represents a component of relative motion across the East African Rift at the rate of .330 deg/m.y., about an Euler pole located at 63.6 deg. S,2.3. deg. E. The geometry of older portions of the Comores and Reunion trends indicates that there was no significant relative motion between the African and Somali Plates prior to about 10 m.y. ago. Sequential reconstructions from 200-0 m.y. are presented.

Emerick, C. M.

132

Deforestation and apparent extinctions of endemic forest beetles in Madagascar.  

PubMed

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

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

2007-06-22

133

Cretaceous may hold promise in Majunga basin, Madagascar  

SciTech Connect

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.

Lalaharisaina, J.V. (Office des Mines Nationales et des Industries Stategiques, Antananarivo (Madagascar)); Ferrand, N.J. (Oil and Gas Consultants, Palaiseau (France))

1994-08-01

134

Dental caries among urban schoolchildren in Madagascar.  

PubMed

An epidemiological survey of prevalence and severity of dental caries was carried out in an urban population of children in Madagascar. The study population comprised 1257 children in the age groups 4-5 yr to 14-15 yr equally distributed by sex. The children were examined according to the recording system for the Danish Child Dental Services. The caries experience in the primary dentition as well as in the permanent dentition was high. For example, among 6-yr-olds a mean number of 11.8 defs and 5.2 deft was observed and 82% of the children were affected by caries in primary teeth. In particular, primary molars in the mandibular and incisors in the maxilla were affected and approximal caries was frequent. Among 12-yr-olds mean DMFS was 4.0 and DMFT 2.4 and 75% of the children had caries in permanent teeth. In permanent teeth caries was located predominantly to mandibular molars and occlusal surfaces. In both dentitions almost all decay was untreated, indicating lack of dental treatment available due to the shortage of dental manpower. The establishment of a child dental service system is a matter of urgency. Dental health education and primary health care should be organized. PMID:3163963

Petersen, P E; Steengaard, M

1988-06-01

135

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

NASA Astrophysics Data System (ADS)

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).

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

2006-12-01

136

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

SciTech Connect

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.

Kilmer, D.S.; Duncan, I.J. (Washington Univ., St. Louis, MO (USA))

1990-05-01

137

A chronology for late prehistoric Madagascar.  

PubMed

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

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

138

RELATIONSHIPS OF STREAM INVERTEBRATE COMMUNITIES TO DEFORESTATION IN EASTERN MADAGASCAR  

Microsoft Academic Search

Madagascar has been recently identified as a global hotspot for freshwater biodiversity. Loss of most of its eastern rain forest, combined with a high incidence of micro-endemism and specialization to forest stream habitats, has likely led to extinction of many of the island's stream insect species. We compared habitat and macroinvertebrate community structure in three streams draining protected rain forest

Jonathan P. Benstead; Michael M. Douglas; Catherine M. Pringle

2003-01-01

139

Listen To The Radio ! Media and Corruption: Evidence from Madagascar  

Microsoft Academic Search

This paper investigates the role of the media in reducing corruption. We analyze data on personal capture of public education expenditures by local officials in Madagascar. We find that corruption can be successfully constrained through a combination of media programs and monitoring. More transparent funding mechanisms and access to mass media reduce capture. However, the impact of the media is

Nathalie Francken; Bart Minten; Johan F. M. Swinnen

140

A Late Cretaceous (Maastrichtian) avifauna from the Maevarano Formation, Madagascar  

Microsoft Academic Search

Recent field efforts in the Mahajanga Basin of northwestern Madagascar have recovered a diverse Late Cretaceous terrestrial and freshwater vertebrate fauna, including a growing diversity of avialans. Previous work on associated bird skeletons resulted in the description of two named avialans (Rahonavis, Vorona). Other materials, including two synsacra and numerous appendicular elements, represent at least five additional taxa of basal

Patrick M. Oconnor; Catherine A. Forster

2010-01-01

141

Multiple Miocene Melastomataceae dispersal between Madagascar, Africa and India  

Microsoft Academic Search

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 hypoth- esized to have arrived by trans-oceanic dispersal. An alternative hypothesis posits that the ancestors of Madagascan,

Susanne S. Renner

2004-01-01

142

Bayesian mapping of pulmonary tuberculosis in Antananarivo, Madagascar  

Microsoft Academic Search

BACKGROUND: Tuberculosis (TB), an infectious disease caused by the Mycobacterium tuberculosis is endemic in Madagascar. The capital, Antananarivo is the most seriously affected area. TB had a non-random spatial distribution in this setting, with clustering in the poorer areas. The aim of this study was to explore this pattern further by a Bayesian approach, and to measure the associations between

Rindra V Randremanana; Vincent Richard; Fanjasoa Rakotomanana; Philippe Sabatier; Dominique J Bicout

2010-01-01

143

Ecotourism, Poverty and Resources Management in Ranomafana, Madagascar  

Microsoft Academic Search

This paper explores how the protection of natural resources is managed in Madagascar in order to understand how and why tourism development is part of the strategy to safeguard these resources. Based on a heterodox political economy approach and using documentary analysis as well as exploratory interviews, this paper focuses on the specific case of Ranomafana National Park showing how

Bruno Sarrasin

2012-01-01

144

Isle of Fire Political Ecology of Landscape Burning in Madagascar  

Microsoft Academic Search

Long considered both best friend and worst enemy to humankind, fire is at once creative and destructive. On the endangered tropical island of Madagascar, these two faces of fire have fueled a century-long conflict between rural farmers and island leaders. Based on detailed fieldwork in Malagasy villages and a thorough archival investigation, Isle of Fire offers a detailed analysis of

Christian A. Kull

145

Food Marketing Liberalization and Trader Entry: Evidence from Madagascar  

Microsoft Academic Search

Food marketing liberalization was expected to induce massive trader entry and competitive markets in Africa. Despite evidence of trader entry, enterprise expansion remains difficult and many claim market power persists, though perhaps in different hands. This paper confronts this puzzle of substantial market entry that might not foster competition. Data from Madagascar reveal distinct groups within rural food marketing channels,

Christopher B. Barrett

1997-01-01

146

Satellite imagery, human ecology, anthropology, and deforestation in Madagascar  

Microsoft Academic Search

Satellite images were used to determine rates of deforestation over the past 35 years and to identify current deforestation hotspots in the eastern rainforests and in the dry endemic forests of southern Madagascar. The analysis of population trends, topography, and coincident ethnographic research points to a number of different factors influencing deforestation in these regions. Each of these factors generates

Robert W. Sussman; Glen M. Green; Linda K. Sussman

1994-01-01

147

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

ERIC Educational Resources Information Center

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…

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

2011-01-01

148

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

ERIC Educational Resources Information Center

|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…

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

2011-01-01

149

[On the road to hope with street children in Madagascar].  

PubMed

On a four-month humanitarian mission to Madagascar, two young child care nurses were able to use their nursing skills, listening skills and their imagination to help orphaned children. They were able to discover the island's social and cultural reality. Here they look back at this experience of deep poverty which also included moments of sharing and hope. PMID:22919804

Legrand, Solenne; Pichon, Caroline

150

High plant diversity of lowland rainforest vestiges in eastern Madagascar  

Microsoft Academic Search

Based on cartography, floristic inventory and vegetation analysis in the north and south of the Eastern Domain of Madagascar we identified three original tropical rainforest types which are among the world's most biodiverse known sites for plants: the littoral forest on sand, the lowland forest on gneiss and the lowland forest on basalt. Floristic and structural comparisons were conducted on

Nicolas Dumetz

1999-01-01

151

Spillovers from Globalization on Land Use: Evidence from Madagascar  

Microsoft Academic Search

The effect of globalization on the environment and natural resource use in developing countries is hotly debated. We contribute to this debate through the analysis of primary data collected with small contract farmers in Madagascar that produce vegetables for export to Europe. Strong spillover effects of these trade opportunities on land use exist. Using a matched plot sampling design, the

Bart Minten; Lalaina Randrianarison; Johan F. M. Swinnen

2006-01-01

152

Evaluation of the joint-action toxicity of binary mixtures of heavy metals against the mangrove periwinkle Tympanotonus fuscatus var radula (L.)  

Microsoft Academic Search

The joint-action toxicity of binary mixtures of heavy metal compounds prepared in predefined ratios of 4:1, 3:2, 1:1, 2:3, and 1:4 (wt\\/wt) of Zn:Cu, Zn:Cd, and Cd:Cu, respectively, and tested against the mangrove periwinkle Tympanotonus fuscatus were carried out in laboratory bioassays. The interactions between binary mixtures showed significant departures from the action of the individual constituent metals when acting

Adebayo Akeem Otitoloju

2002-01-01

153

Predator-induced alarm responses in the common periwinkle, Littorina littorea: dependence on season, light conditions, and chemical labelling of predators  

Microsoft Academic Search

Chemically mediated alarm reactions of the common periwinkle, Littorina littorea (L.), were studied in laboratory experiments during two consecutive summers, and one intermediate autumn season. Responses\\u000a to chemical stimuli were detected as crawl-out responses, i.e. movements of snails out of the water. Snails were exposed to\\u000a extracts of injured conspecifics, extracts of the mussel Modiolus modiolus (L.), and water conditioned

H. P. Jacobsen; O. B. Stabell

1999-01-01

154

Phylogeography and Molecular Epidemiology of Yersinia pestis in Madagascar  

PubMed Central

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.

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

155

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

NASA Astrophysics Data System (ADS)

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 >60°C 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 ˜90-100°C. 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.

Giese, JöRg; Seward, Diane; Schreurs, Guido

2012-04-01

156

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

PubMed

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 12months (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 58.9Bq/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?Sv/y to human beings. PMID:23871576

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

2013-07-17

157

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

ERIC Educational Resources Information Center

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…

Tshiangale, Mupemba Wa

158

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

ERIC Educational Resources Information Center

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,…

Tshiangale, Mupemba Wa

159

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

PubMed Central

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.

Ganzhorn, Jorg 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

160

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

NASA Astrophysics Data System (ADS)

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.

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

2012-04-01

161

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

NASA Astrophysics Data System (ADS)

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.

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

2006-02-01

162

A bizarre predatory dinosaur from the Late Cretaceous of Madagascar.  

PubMed

Here we report the discovery of a small-bodied (approximately 1.8 m) predatory dinosaur from the Late Cretaceous (Maastrichtian) of Madagascar. Masiakasaurus knopfleri, gen. et sp. nov., represented by several skull elements and much of the postcranial skeleton, is unique in being the only known theropod with a highly procumbent and distinctly heterodont lower dentition. Such a derived dental morphology is otherwise unknown among dinosaurs. Numerous skeletal characteristics indicate that Masiakasaurus is a member of Abelisauroidea, an enigmatic clade of Gondwanan theropods. Previously, small-bodied abelisauroids were known only from Argentina. The occurrence of Masiakasaurus on Madagascar suggests that small-bodied abelisauroids, like their larger-bodied counterparts, were more cosmopolitan, radiating throughout much of Gondwana and paralleling the diversification of small coelurosaur theropods in Laurasia. PMID:11206544

Sampson, S D; Carrano, M T; Forster, C A

2001-01-25

163

An old adaptive radiation of forest dung beetles in Madagascar.  

PubMed

Adaptive radiations of mammals have contributed to the exceptionally high levels of biodiversity and endemism in Madagascar. Here we examine the evolutionary history of the endemic dung beetle tribe Helictopleurini (Scarabaeidae) and its relationship to the widely distributed Oniticellini and Onthophagini. Helictopleurini species are dependent on mammals for their resources. We date the single origin of the tribe at 37 to 23 MY ago, indicating overseas colonization of Madagascar. The main radiation occurred concurrently with the main radiations of lemurs. The ancestors of Helictopleurini are inferred to have been coprophagous species inhabiting open habitats. Subsequent evolution has involved a shift into forests, changes in resource use to a more generalized diet, and changes in body size. Four species of the extant 65 species have shifted to use the dung of the recently introduced cattle in open habitats, allowing these species to greatly expand their geographical ranges. PMID:18424187

Wirta, Helena; Orsini, Luisa; Hanski, Ilkka

2008-03-15

164

AVHRR-LAC estimates of forest area in Madagascar, 1990  

Microsoft Academic Search

Three AVHRR-LAC data sets acquired in September 1990 and January 1991 were used to map the forest resources of Madagascar. The island was partitioned into four strata to include: (1) the western hardwoods, (2) the central grasslands, (3) the eastern rainforest, and (4) spiny forest. Each stratum was classified separately using AVHRR-LAC data in conjunction with 1984-1988 Landsat-MSS photoproducts. The

R. Nelson; N. Horning

1993-01-01

165

Strain pattern and late Precambrian deformation history in southern Madagascar  

Microsoft Academic Search

This paper examines the thermo-mechanical evolution of the lower crust, in Precambrian times, with an example from southern Madagascar. The finite strain pattern is derived from the study of satellite images complemented by field structural analysis. The finite geometry reflects the superposition of two distinct finite strain patterns, D1 and D2. The geodynamic significance of the D1 event remains unclear.

Jean-Emmanuel Martelat; Jean-Marc Lardeaux; Christian Nicollet; Raymond Rakotondrazafy

2000-01-01

166

Madagascar corals reveal Pacific multidecadal modulation of rainfall since 1708  

NASA Astrophysics Data System (ADS)

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 Niño 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.

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

167

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

Microsoft Academic Search

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)

Jörg Giese; Diane Seward; Guido Schreurs

2010-01-01

168

Survey of Giardia and Cryptosporidium in lemurs from the Ranomafana National Park, Madagascar.  

PubMed

We detected Cryptosporidium sp. by direct immunofluorescence in fecal samples from greater bamboo lemurs (Prolemur simus) and eastern rufous mouse lemurs (Microcebus rufus) inhabiting the Ranomafana National Park, Madagascar. This is the first report of an occurrence of these potentially zoonotic parasites in free-ranging lemurs in the rain forest of Madagascar. PMID:23778635

Rasambainarivo, Fidisoa T; Gillespie, Thomas R; Wright, Patricia C; Arsenault, Julie; Villeneuve, Alain; Lair, Stéphane

2013-07-01

169

Sustainable livelihoods and forest resources in Madagascar: a multi-scale analysis using remote sensing  

Microsoft Academic Search

Madagascar, as much of sub-Saharan Africa, suffers from highly variable and unpredictable climate, and human societies, as well as the natural ecosystems upon which they depend, have evolved and adapted to cope with this to some degree since humans populated the island some 2000 years BP. In Madagascar, humans are an integral component of most landscapes and, thus, may be

Terence P. Dawson; J. Carter Ingram

2008-01-01

170

Antimicrobial resistance among uropathogens that cause community-acquired urinary tract infections in Antananarivo, Madagascar  

Microsoft Academic Search

Background: Urinary tract pathogens obtained from patients in Madagascar are becoming increasingly resistant to commonly used antibiotics that are readily available at a low price. This poses a real problem for the treatment of community-acquired urinary tract infections (UTIs) in Madagascar. Objectives: To obtain data on the pathogens responsible for community-acquired UTIs in Antananarivo and on their susceptibility patterns to

Frederique Randrianirina; Jean-Louis Soares; Jean-Francois Carod; Vincent Thonnier; Antoine Talarmin

171

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

ERIC Educational Resources Information Center

|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…

Wagler, Ron

2009-01-01

172

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

Microsoft Academic Search

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

G. M. Green; R. W. Sussman

1990-01-01

173

Integrated coastal management at the regional level: lessons from Toliary, Madagascar  

Microsoft Academic Search

Within the framework of the National Environment Action Plan in Madagascar, an integrated coastal management (ICM) program was launched in 1997. In accordance with international guidelines, the integration effort on the coastal zone concerns the local, regional, and national levels. The field study we conducted in Madagascar in 1999 and 2000 showed that the results achieved by this program vary

Raphaël Billé; Laurent Mermet

2002-01-01

174

Taxonomic Revision of Mouse Lemurs (Microcebus) in the Western Portions of Madagascar  

Microsoft Academic Search

The genus Microcebus (mouse lemurs) are the smallest extant primates. Until recently, they were considered to comprise two different species: Microcebus murinus, confined largely to dry forests on the western portion of Madagascar, and M. rufus, occurring in humid forest formations of eastern Madagascar. Specimens and recent field observations document rufous individuals in the west. However, the current taxonomy is

Rodin M. Rasolooarison; Steven M. Goodman; Jörg U. Ganzhorn

2000-01-01

175

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

SciTech Connect

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.

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

1992-06-01

176

The importance of littoral forest remnants for indigenous bird conservation in southeastern Madagascar  

Microsoft Academic Search

The littoral forests of Madagascar are relatively unexplored ecosystems that are considered seriously threatened by deforestation and habitat fragmentation. We set out to describe the bird communities inhabiting the littoral forest remnants in three different sub-regions of southeastern Madagascar to determine the national importance of these forests for bird conservation. In total, 77 bird species were found inhabiting 14 littoral

James E. M. Watson; Robert J. Whittaker; Terence P. Dawson

2005-01-01

177

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

SciTech Connect

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.

Reyes, N.E.

1993-01-01

178

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

PubMed

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

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

2012-07-31

179

Molecular Analysis and Heterologous Expression of an Inducible Cytochrome P-450 Protein from Periwinkle (Catharanthus roseus L.) 1  

PubMed Central

We screened cDNA libraries from periwinkle (Catharanthus roseus) cell cultures induced for indole alkaloid synthesis and selected clones for induced cytochrome P-450 (P-450) proteins by differential hybridization, size of the hybridizing mRNA, and presence of amino acid motifs conserved in many P-450 families. Four cDNAs satisfying these criteria were analyzed in detail. They were grouped in two classes (pCros1, pCros2) that represented two closely related genes of a new P-450 family designated CYP72. Antiserum against a cDNA fusion protein overexpressed in Escherichia coli recognized in C. roseus a protein band of 56 kD. Quantification of western blots showed that it represented 1.5 ± 0.5 and 6 ± 1 ?g/mg of protein in the membranes from noninduced and induced cells, respectively, and analysis of the total P-450 content suggested that the cDNA-encoded protein was one of the dominant P-450 proteins. The pathway to indole alkaloids contains two known P-450 enzymes, geraniol-10-hydroxylase (GE10H) and nerol-10-hydroxylase (NE10H). The induction kinetics of the cloned P-450 protein and of GE10H activity were similar, but those of NE10H were different. Western blots with membranes from other plants suggested that P-450 CYP72 is specific for C. roseus and other plants with GE10H activity. A tentative assignment of CYP72 as GE10H is discussed. The cDNA was recloned for expression in Saccharomyces cerevisiae, and the presence of the protein was demonstrated by western blots. Assays for GE10H failed to detect enzyme activity, and the same negative result was obtained for NE10H and other P-450 enzymes that are present in C. roseus. Images Figure 5 Figure 7

Vetter, Hans-Peter; Mangold, Ursula; Schroder, Gudrun; Marner, Franz-Josef; Werck-Reichhart, Danielle; Schroder, Joachim

1992-01-01

180

Les aspergillomes pulmonaires: ? propos de 37 cas ? Madagascar  

PubMed Central

L'aspergillome pulmonaire est une colonisation par Aspergillus d'une cavité pulmonaire préformée. Nos objectifs étaient de définir le profil épidémio-clinique et thérapeutique des aspergillomes pulmonaires et essayer de dégager les facteurs favorisants de cette affection à Madagascar. Nous avons réalisés une étude prospective, descriptive, analytique durant 59 mois sur les aspergillomes pulmonaires à Antananarivo Madagascar. Etaient inclus dans cette étude les malades ayant un diagnostic d'aspergillome pulmonaire. Trente-sept (37) cas d'aspergillome pulmonaire étaient recensés parmi les 8 392 patients hospitalisés dans le service de Pneumologie (0,44%). Il s'agit de 29 hommes (78,38%) et 8 femmes (21,61%), d’âge moyen de 43 ans. Les facteurs prédisposant étaient dominés par la tuberculose pulmonaire (89,19%). Le délai moyen d'apparition de l'aspergillome chez les malades ayant un antécédent de tuberculose pulmonaire à bacilloscopie positive (TPM+) était de 8 ans et 6 mois avec un délai extrême de un mois à 23 ans. L'hémoptysie était le mode de révélation le plus fréquent (91,89%). Le traitement était médical chez 27 patients (72,97%) et médico-chirurgical chez 10 patients (27,03%). Vingt sept patients étaient perdus de vue (72,97%), et pour les 10 patients suivis (27,02%), 70% avaient une évolution favorable avec disparition des signes, et 30% présentaient des hémoptysies récidivantes. Le taux de mortalité postopératoire était de 4% et 50% des patients avaient des complications postopératoires. La surveillance des lésions séquellaires de tuberculose pulmonaire qui constituent les facteurs favorisants prédominant d'aspergillome pulmonaire à Madagascar nécessite une attention particulière. La prise en charge de la tuberculose doit être précoce et adaptée surtout dans les pays à forte prévalence tuberculeuse.

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

2011-01-01

181

Age-specific seroprevalence of hepatitis A in Antananarivo (Madagascar)  

PubMed Central

Background Hepatitis A virus (HAV) is an enteric, viral, infectious disease endemic in many developing countries such as Madagascar. Infection is often subclinical or asymptomatic in children; however, symptomatic acute infections become more common with increasing age. In some developing countries, improvements in living conditions have led to changes in the epidemiological pattern of HAV infection. There are very few reports on the prevalence of HAV in Madagascar. This study was to determine the seroprevalence of hepatitis A virus antibodies in relation to age in the city of Antananarivo, Madagascar. Methods Serum samples collected in 2004 during a cross-sectional survey of individuals aged between two and 24 years from Antananarivo were tested for anti-HAV antibody using a commercial enzyme immunoassay kit. Subjects were investigated using a standardized social and medical history questionnaire. Results 926 subjects were enrolled including 406 males and 520 females. There were 251 children under 10 years old and 675 subjects between 10 and 24 years old. Of the 926 serum samples tested, 854 (92.2%) were positive for anti-HAV antibodies. The number of seropositive samples was similar for males and females. The overall seroprevalence was 83.7% (210/251) for children under 10 years old and 95.5% (644/675) for subjects aged between 10 and 24 years (p < 0.001). Conclusion Despite improvements in sanitary conditions and hygiene over the last few years, the prevalence of HAV in Antananarivo is high. Only children under five years old remain susceptible to HAV infection. Immunization against HAV is not needed at the present time in the Madagascan population, but should be recommended for travellers.

Raharimanga, Vaomalala; Carod, Jean-Francois; Ramarokoto, Charles-Emile; Chretien, Jean-Baptiste; Rakotomanana, Fanjasoa; Talarmin, Antoine; Richard, Vincent

2008-01-01

182

The value of small size: loss of forest patches and ecological thresholds in southern Madagascar.  

PubMed

Many services generated by forest ecosystems provide essential support for human well-being. However, the vulnerability of these services to environmental change such as forest fragmentation are still poorly understood. We present spatial modeling of the generation of ecosystem services in a human-dominated landscape where forest habitat patches, protected by local taboos, are located in a matrix of cultivated land in southern Madagascar. Two ecosystem services dependent on the forest habitats were addressed: (1) crop pollination services by wild and semidomesticated bees (Apoidea), essential for local crop production of, for example, beans, and (2) seed dispersal services based on the presence of ring-tailed lemurs (Lemur catta). We studied the vulnerability of these ecosystem services to a plausible scenario of successive destruction of the smallest habitat patches. Our results indicate that, in spite of the fragmented nature of the landscape, the fraction of the landscape presently covered by both crop pollination and seed dispersal services is surprisingly high. It seems that the taboo system, though indirectly and unintentionally, contributes to upholding the generation of these services by protecting the forest patches. Both services are, however, predicted to be very vulnerable to the successive removal of small patches. For crop pollination, the rate of decrease in cover was significant even when only the smallest habitat patches were removed. The capacity for seed dispersal across the landscape displayed several thresholds with habitat patch removal. Our results suggest that, in order to maintain capacity for seed dispersal across the landscape and crop pollination cover in southern Androy, the geographical location of the remaining forest patches is more crucial than their size. We argue that in heavily fragmented production landscapes, small forest patches should increasingly be viewed as essential for maintaining ecosystem services, such as agricultural production, and also should be considered in the ongoing process of tripling the area of protected habitats in Madagascar. PMID:16711035

Bodin, Orjan; Tengö, Maria; Norman, Anna; Lundberg, Jakob; Elmqvist, Thomas

2006-04-01

183

A new species of Pandanaceae from northern Madagascar, Pandanus ankaranensis.  

PubMed

A new species, Pandanus ankaranensis Callm. & Laivao (Pandanaceae), is described from the karst region of Ankarana in northern Madagascar. It resembles P. grallatus B. C. Stone, another member of Pandanus sect. Mammillares H. St. John occurring in the area. The new taxon can be distinguished by its larger and wider leaves that are persistent on the branches, the stipe often lying on the rocks where plants grow, and its larger syncarps. Pandanus ankaranensis is classified as Vulnerable based on the IUCN Red List criteria. PMID:21698065

Callmander, Martin W; Laivao, Michel O; Randrianaivo, Richard

2010-09-01

184

A new species of Pandanaceae from northern Madagascar, Pandanus ankaranensis  

PubMed Central

A new species, Pandanus ankaranensis Callm. & Laivao (Pandanaceae), is described from the karst region of Ankarana in northern Madagascar. It resembles P. grallatus B. C. Stone, another member of Pandanus sect. Mammillares H. St. John occurring in the area. The new taxon can be distinguished by its larger and wider leaves that are persistent on the branches, the stipe often lying on the rocks where plants grow, and its larger syncarps. Pandanus ankaranensis is classified as Vulnerable based on the IUCN Red List criteria.

Callmander, Martin W.; Laivao, Michel O.; Randrianaivo, Richard

2011-01-01

185

Euphane triterpenoids of Cassipourea lanceolata from the Madagascar rainforest*  

PubMed Central

Fractionation of an ethanol extract of a Madagascar collection of the leaves and fruit of Cassipourea lanceolata Tul. led to the isolation of three euphane triterpenoids 1–3. The 1H and 13C NMR spectra of all compounds were fully assigned using a combination of 2D NMR experiments, including COSY, TOCSY, HSQC (HMQC), HMBC and ROESY sequences. The three compounds showed weak antiproliferative activities against the A2780 human ovarian cancer cell line, with IC50 values of 25, 25 and 32 ?M, respectively.

Hou, Yanpeng; Cao, Shugeng; Brodie, Peggy J.; Miller, James S.; Birkinshaw, Chris; Andrianjafy, Mamisoa N.; Andriantsiferana, Rabodo; Rasamison, Vincent E.; TenDyke, Karen; Shen, Yongchun; Suh, Edward M.; Kingston, David G.I.

2010-01-01

186

Cytotoxic Xanthones from Psorospermum molluscum from the Madagascar Rain Forest  

PubMed Central

Two new cytotoxic xanthones were isolated from extracts of the Madagascar rain forest plant Psorospermum cf. molluscum using bioassay guided fractionation with the Escherichia coli SOS chromotest. The structures of the new dihydrofuranoxanthones, designated 3?,4?-deoxy-4?-chloropsoroxanthin-(3?,5?-diol) (1) and psoroxanthin (4), were determined on the basis of 2D-NMR, MS and UV spectroscopic data, and are structurally related to the psorospermins, a known class of plant antitumor agents. A new hydroxyprenylated xanthone (5) is also described. Xanthones (1) and (4) showed selective in vitro cytotoxicity against ABAE cells (bovine endothelial cell line).

Leet, John E.; Liu, Xiaohong; Drexler, Dieter M.; Cantone, Joseph L.; Huang, Stella; Mamber, Stephen W.; Fairchild, Craig R.; Hussain, Raouf; Newman, David J.; Kingston, David G. I.

2010-01-01

187

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

USGS Publications Warehouse

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.

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

188

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

PubMed Central

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.

2012-01-01

189

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

PubMed Central

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.

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

2011-01-01

190

Mountain refugia play a role in soil arthropod speciation on Madagascar: a case study of the endemic giant fire-millipede genus Aphistogoniulus.  

PubMed

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. rubrodorsalisn. sp. and A. jeekelin. 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. rubrodorsalisn. 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

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

2011-12-06

191

Growth, distribution and poverty in Madagascar  

Microsoft Academic Search

This paper presents an applied microsimulation model built on household data with explicit treatment of heterogeneity of skills, labor preferences and opportunities, and consumption preferences at the individual and\\/or household level, while allowing for an endogenous determination of relative prices between sectors. The model is primarily focused on labor markets and labor allocation at the household level, but consumption behavior

Denis Cogneau; Anne-Sophie Robilliard

2000-01-01

192

[ Current situation of the development of acupuncture and moxibustion in Madagascar].  

PubMed

The development of acupuncture and moxibustion therapy in Madagascar is introduced briefly in this paper. Acupuncture and moxibustion therapy was introduced to Madagascar in 1975 by China Medical Aid Team. China Medical Aid Team had established acupuncture and moxibustion department in four hospitals, with 10 to 20 treatment beds. Taking Vatomandry Hospital and Sambava Hospital as the examples to introduce the general situation and the current questions in acupuncture-moxibustion department of comprehensive hospitals in Madagascar, so as to explore the future development potential of acupuncture-moxibustion therapy in the country. PMID:22493930

Wang, Yi

2012-02-01

193

Organizational analysis of maternal mortality reduction programs in Madagascar.  

PubMed

Little is known about the organizational factors involved in policy creation and programs implementation aimed at reducing maternal mortality in Madagascar. A qualitative case study was performed to investigate organizational factors influencing the health system's capacity to elaborate and implement maternal mortality reduction programs. Semi-structured interviews were conducted with 53 participants. A conceptual framework based on Gamson's coalition theory and Hinings and Greenwood's archetypes concept was used. Three major conclusions emerge: the Ministry of Health is a poor leader in the development of national strategies, due to its dependency on external financial resources and expertise, and because of poor transmission of key information from the field; at a meso level (regions and districts), the capacity to adapt programs is highly dependent on the collaboration with NGOs; at the micro level, there are few incentives provided to field workers to participate in a collective effort and little attempt to exploit complementarities between scare resources. The Madagascar health system should consider the need for improvement in data analysis capacity, and implementing behavior-changing tools suitable for stimulating providers who work inside and outside the health care system, to participate to a coordinated collective effort. PMID:21796678

Harimanana, Aina; Barennes, Hubert; Reinharz, Daniel

2010-12-10

194

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

PubMed

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

Swierczewski, Dariusz; Stroi?ski, Adam

2013-07-30

195

[Technology of the production of antigens against soil-borne diseases in Madagascar].  

PubMed

There are two important soilborne diseases in Madagascar: Anthrax and Blackleg. The history of vaccine production is described, which is especially marked by the success since the introduction of biofermenter technology. PMID:8593157

Fatou-Rakotobe; Rajaonarison, J J

1996-01-01

196

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

PubMed Central

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.

Swierczewski, Dariusz; Stroinski, Adam

2013-01-01

197

[Trematode distribution in Littorina saxatilis populations can support the reproductive potential of the host: "toilers" and "idlers" among female periwinkles].  

PubMed

Co-evolution between parasites and their hosts can involve adaptations on the individual and population levels likely to be especially prominent in the systems where parasites have a direct strong impact on the hosts fitness, as is the case with castrating trematodes and their gastropod hosts. We studied populations of the rough periwinkles Littorina saxatilis in the White Sea infested by castrating trematodes to determine whether spatial and temporal variations in the trematode prevalence affect the demographic structure of the host population. Sex, age, reproductive status and infestation of L. saxatilis from 19 populations with different trematode burdens (from < 1 % to 30-50%); in two of these 19 populations (RI and KLN) a long-term monitoring over the period of 15-20 years was also performed. These analyses showed that (1) the average age of gravid females did not correlate with the trematode prevalence of the population, (2) the ratio was skewed towards females, (3) the trematode prevalence in females tended to be higher than in males, (4) the proportion of the non-infested gravid females of the younger ages classes (2-4 years) did not correlate with trematode prevalence of the population. The proportion of young non-infested females that were not reproducing ("idlers") decreased significantly with increasing infestation prevalence when compared among different populations of L. saxatilis, but remained relatively stable within two heavily infested populations RI and KLN despite the year-to-year fluctuations of the infestation prevalence. Thus, a demographic mechanism to compensate for the parasite pressure in L. saxatilis populations may involve the maintenance of a relatively constant proportion of uninfected gravid female ("toilers") at the expense of uninfected, but not reproducing females of fertile age ("idlers"); the latter can be viewed a reproductive reserve of the population tapped into under the conditions of high infestation prevalence. This mechanism, in combination with the previously described elevated individual fecundity of females in heavily infested populations, may compensate for the parasite-induced decrease in the reproductive potential of the host population and ensure the stability of the host-parasite system. PMID:23458020

Granovich, A I; Iagunova, E B; Sokolova, I M

198

Breeding biology, diet and vocalization of the Helmet Vanga, Euryceros prevostii, on the Masoala Peninsula, Madagascar  

Microsoft Academic Search

La Morco, G. & Thorstrom, R. 2000. Breeding biology, diet and vocalization of the Helmet Vanga Euryceros prevostii on the Masoala Peninsula, Madagascar. Ostrich 71 (3&4): 400-403. The endemic Helmet Vanga, Euryceros prevostii, was studied from October to December 1997, with incidental observations from October to December 1993-1997, on the Masoala Peninsula, northeastern Madagascar. Three types of vocalizations of this

Giuseppe Marca; Russell Thorstrom

2000-01-01

199

Evidence of Invasive Felis silvestris Predation on Propithecus verreauxi at Beza Mahafaly Special Reserve, Madagascar  

Microsoft Academic Search

Increasing evidence supports the idea that endemic avian and mammalian predators have profoundly impacted primate populations\\u000a in Madagascar (Goodman, S. M. Predation on lemurs. In S. M. Goodman, & J. P. Benstead (Eds.), The natural history of Madagascar (pp. 1221–1228). Chicago: University of Chicago Press, (2003).). The role in regulating lemur populations of the 3 introduced\\u000a mammalian carnivorans —small Indian

Diane K. Brockman; Laurie R. Godfrey; Luke J. Dollar; Joelisoa Ratsirarson

2008-01-01

200

Structure of the eastern margin of the East African Orogen in central Madagascar  

Microsoft Academic Search

The island of Madagascar straddles the poorly understood eastern margin of the East African Orogen, which is characterised by a high-grade gneissic basement that was structurally and thermally reworked during the Neoproterozoic collision of the Dharwar craton of India with the Congo\\/Tanzania\\/Bangweulu craton of Africa. An east-west traverse across the eastern margin of the Antananarivo block of central Madagascar and

Alan S Collins; Ian C. W Fitzsimons; Bregje Hulscher; Théodore Razakamanana

2003-01-01

201

Oxygen isotope systematics of gem corundum deposits in Madagascar: relevance for their geological origin  

Microsoft Academic Search

The oxygen isotopic composition of gem corundum was measured from 22 deposits and occurrences in Madagascar to provide a gemstone\\u000a geological identification and characterization. Primary corundum deposits in Madagascar are hosted in magmatic (syenite and\\u000a alkali basalt) and metamorphic rocks (gneiss, cordieritite, mafic and ultramafic rocks, marble, and calc-silicate rocks).\\u000a In both domains the circulation of fluids, especially along shear

Gaston Giuliani; Anthony Fallick; Michel Rakotondrazafy; Daniel Ohnenstetter; Alfred Andriamamonjy; Théogène Ralantoarison; Saholy Rakotosamizanany; Marie Razanatseheno; Yohann Offant; Virginie Garnier; Christian Dunaigre; Dietmar Schwarz; Alain Mercier; Voahangy Ratrimo; Bruno Ralison

2007-01-01

202

An economic analysis of deforestation in Madagascar in the 1990s  

Microsoft Academic Search

Madagascar is well-known among conservationists for both its unique forest ecosystems and its alarmingly high rates of deforestation. This paper studies the factors driving deforestation in Madagascar using a nation-wide data set of commune-level variables. The analysis suggests that higher population and fertility rates were associated with higher deforestation in the moist forest region in the 1990s. Deforestation was lower

Christine Moser

2008-01-01

203

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

Microsoft Academic Search

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

JEFF A. JOHNSON; RUTH E. TINGA; MELANIE CULVER; FRANK HAILER

2009-01-01

204

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

PubMed

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

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

2012-03-19

205

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

NASA Astrophysics Data System (ADS)

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.

Coffin, Millard F.; Rabinowitz, Philip D.

1987-08-01

206

Ecological divergence and speciation between lemur (Eulemur) sister species in Madagascar.  

PubMed

Understanding ecological niche evolution over evolutionary timescales is crucial to elucidating the biogeographic history of organisms. Here, we used, for the first time, climate-based ecological niche models (ENMs) to test hypotheses about ecological divergence and speciation processes between sister species pairs of lemurs (genus Eulemur) in Madagascar. We produced ENMs for eight species, all of which had significant validation support. Among the four sister species pairs, we found nonequivalent niches between sisters, varying degrees of niche overlap in ecological and geographic space, and support for multiple divergence processes. Specifically, three sister-pair comparisons supported the null model that niches are no more divergent than the available background region. These findings are consistent with an allopatric speciation model, and for two sister pairs (E. collaris-E. cinereiceps and E. rufus-E. rufifrons), a riverine barrier has been previously proposed for driving allopatric speciation. However, for the fourth sister pair E. flavifrons-E. macaco, we found support for significant niche divergence, and consistent with their parapatric distribution on an ecotone and the lack of obvious geographic barriers, these findings most strongly support a parapatric model of speciation. These analyses thus suggest that various speciation processes have led to diversification among closely related Eulemur species. PMID:23865477

Blair, M E; Sterling, E J; Dusch, M; Raxworthy, C J; Pearson, R G

2013-07-19

207

Antiproliferative cardenolides from Pentopetia androsaemifolia from the Madagascar rain forest†  

PubMed Central

Plant natural products have historically been very important to drug discovery and development, particularly in the anticancer field. This is illustrated by a discussion of the structures and activities of camptothecin and its analogues, paclitaxel (Taxol®), the vinca alkaloids vinblastine and vincristine, and podophyllotoxin and its analogues. A description of the isolation of one new and three known cardenolides from the Madagascar plant Pentopetia androsaemifolia is then provided as an example of this approach to drug discovery. The paper concludes with a brief discussion of betulinic acid, an old compound which is being developed into an anticancer and anti-HIV agent, and ipomoeassin F, an interesting antiproliferative compound isolated from a plant collected in Suriname.

Adou, Eba; Miller, James S; Ratovoson, Fidisoa; Birkinshaw, Chris; Andriantsiferana, Rabodo; Rasamison, Vincent E; Kingston, David G I

2010-01-01

208

Three parallel radiations of Canthonini dung beetles in Madagascar.  

PubMed

Madagascar has an exceptionally large fauna of more than 250 species of endemic dung beetles. Based on molecular phylogenies, the species descend from eight independent overseas colonisations, of which four have given rise to big radiations. Here, we analyse the tribe Canthonini with three parallel radiations following the respective colonisations at 64-44 Mya (Arachnodes-Epilissus, 101 species), 30-19 Mya (Epactoides, 37 species), and 24-15 Mya (Apotolamprus-Nanos, 61 species). All three radiations have taken place in forests, but there are also substantial differences between them. The oldest radiation exhibits the greatest ecological diversification, including monophyletic groups of primate and cattle dung specialists and multiple shifts to arboreal foraging. Analysis of pairs of sister species suggests allopatric speciation in the oldest and the youngest, apparently non-adaptive, radiations, whereas in Epactoides closely related species have diverged ecologically and have largely overlapping geographical ranges, suggestive of adaptive radiation in parapatry or regional sympatry. PMID:20732432

Wirta, Helena; Viljanen, Heidi; Orsini, Luisa; Montreuil, Olivier; Hanski, Ilkka

2010-08-21

209

Migration, isolation and hybridization in island crop populations: the case of Madagascar rice.  

PubMed

Understanding how crop species spread and are introduced to new areas provides insights into the nature of species range expansions. The domesticated species Oryza sativa or Asian rice is one of the key domesticated crop species in the world. The island of Madagascar off the coast of East Africa was one of the last major Old World areas of introduction of rice after the domestication of this crop species and before extensive historical global trade in this crop. Asian rice was introduced in Madagascar from India, the Malay Peninsula and Indonesia approximately 800-1400 years ago. Studies of domestication traits characteristic of the two independently domesticated Asian rice subspecies, indica and tropical japonica, suggest two major waves of migrations into Madagascar. A population genetic analysis of rice in Madagascar using sequence data from 53 gene fragments provided insights into the dynamics of island founder events during the expansion of a crop species' geographic range and introduction to novel agro-ecological environments. We observed a significant decrease in genetic diversity in rice from Madagascar when compared to those in Asia, likely the result of a bottleneck on the island. We also found a high frequency of a unique indica type in Madagascar that shows clear population differentiation from most of the sampled Asian landraces, as well as differential exchange of alleles between Asia and Madagascar populations of the tropical japonica subspecies. Finally, despite partial reproductive isolation between japonica and indica, there was evidence of indica/japonica recombination resulting from their hybridization on the island. PMID:20964753

Mather, Kristie A; Molina, Jeanmaire; Flowers, Jonathan M; Rubinstein, Samara; Rauh, Brad L; Lawton-Rauh, Amy; Caicedo, Ana L; McNally, Kenneth L; Purugganan, Michael D

2010-10-21

210

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

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

211

Shifting continents, not behaviours: independent colonization of solitary and subsocial Anelosimus spider lineages on Madagascar (Araneae, Theridiidae)  

Microsoft Academic Search

Agnarsson, I., Kuntner, M., Coddington, J. A. & Blackledge, T. A. (2009). Shifting continents, not behaviours: independent colonization of solitary and subsocial Anelosimus spider lineages on Madagascar (Araneae, Theridiidae). — Zoologica Scripta, **, ***-***. Madagascar is a biodiversity hotspot, thought to be colonized mostly via Cenozoic dis- persal from Africa, followed by endemic radiation of multiple lineages. Anelosimus spiders are

INGI AGNARSSON; J ONATHAN ATJAZKUNTNER; A. CODDINGTON; T ODD A. BLACKLEDGE

2009-01-01

212

ASSESSING FLAVIVIRUS, LENTIVIRUS, AND HERPESVIRUS EXPOSURE IN FREE-RANGING RING-TAILED LEMURS IN SOUTHWESTERN MADAGASCAR  

Microsoft Academic Search

The ring-tailed lemur (Lemur catta) is an endangered species found in southwestern Madagascar, and understanding infectious disease susceptibility is an essential step towards the preservation of wild and captive lemur populations. Lemurs are primates that are widely dispersed throughout the island of Madagascar and may serve as hosts or reservoirs for zoonotic infections. The aim of this study was to

Kerry Sondgeroth; Brad Blitvich; Carol Blair; Julie Terwee; Randall Junge; Michelle Sauther; Sue VandeWoude

213

Export Processing Zones in Madagascar: the impact of the dismantling of clothing quotas on employment and labour standards  

Microsoft Academic Search

(english) The success of Export Processing Zones (EPZs) or the Zone Franche in Madagascar is, with the exception of Mauritius, an isolated and unrecognized case in Africa. The Zone Franche has had a highly significant macroeconomic impact in terms of exports and jobs. Madagascar became the number two clothing exporter in sub-Saharan Africa. At its peek in 2004, the Zone

Jean-Pierre Cling; Mireille Razafindrakoto; François Roubaud

2007-01-01

214

Seismic reflection profiling and basement topography in the Somali Basin: possible fracture zones between Madagascar and Africa  

Microsoft Academic Search

Continuous seismic profiling in the western Somali Basin reveals basement topography aligned approximately north to south. We interpret three buried ridges, approximately 50 km apart, approximately parallel to the Davie Ridge in the Mozambique Channel, as fracture zones along which Madagascar moved away from Africa. These data therefore support the northern paleopositions of Madagascar suggested by du Toit [1937] and

Elizabeth T. Bunce; Peter Molnar

1977-01-01

215

Poverty Reduction and Millennium Development Goals: Recognizing Population, Health, and Environment Linkages in Rural Madagascar  

PubMed Central

The Millennium Development Goals (MDGs), committed to by all 191 United Nations member states, are rooted in the concept of sustainable development. Although 2007 (midway) reports indicated that programs are under way, unfortunately many countries are unlikely to reach their goals by 2015 due to high levels of poverty. Madagascar is one such example, although some gains are being made. Attempts of this island nation to achieve its MDGs, expressed most recently in the form of a Madagascar Action Plan, are notable in their emphasis on (1) conserving the country's natural resource base, (2) the effect of demographic trends on development, and (3) the importance of health as a prerequisite for development. Leadership in the country's struggle for economic growth comes from the president of the Republic, in part, through his “Madagascar Naturally” vision as well as his commitment to universal access to family planning, among other health and development interventions. However, for resource-limited countries, such as Madagascar, to get or stay “on track” to achieving the MDGs will require support from many sides. “Madagascar cannot do it alone and should not do it alone.” This position is inherent in the eighth MDG: “Develop a global partnership for development.” Apparently, it takes a village after all – a global one.

Gaffikin, Lynne; Ashley, Jeffrey; Blumenthal, Paul D.

2007-01-01

216

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

NASA Astrophysics Data System (ADS)

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.

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

2012-03-01

217

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

NASA Astrophysics Data System (ADS)

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.

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

2012-08-01

218

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

PubMed

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

Ingram, J Carter; Dawson, Terence P

2005-01-15

219

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

NASA Astrophysics Data System (ADS)

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 ˜25°S 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.

Huhn, F.; von Kameke, A.; Pérez-Muñuzuri, V.; Olascoaga, M. J.; Beron-Vera, F. J.

2012-03-01

220

Trans-oceanic and endemic origins of the small minnow mayflies (Ephemeroptera, Baetidae) of Madagascar.  

PubMed

We investigated the relative importance of dispersal and vicariance in forming the Madagascar insect fauna, sequencing approximately 2300bp from three rRNA gene regions to investigate the phylogeny of Afrotropical small minnow mayflies (Ephemeroptera: Baetidae). Six lineages contained trans-oceanic sister taxa, and variation in genetic divergence between sister taxa revealed relationships that range from very recent dispersal to ancient vicariance. Dispersal was most recent and frequent in species that spend the larval stage in standing water, adding to evidence that these evolutionarily unstable habitats may select for ecological traits that increase dispersal in insects. Ancestral state likelihood analysis suggested at least one Afrotropical lineage had its origin in Madagascar, demonstrating that unidirectional dispersal from a continental source may be too simplistic. We conclude that the Malagasy mayfly fauna should be considered in a biogeographical context that extends beyond Madagascar itself, encompassing trans-oceanic dispersal within multiple lineages. PMID:16096096

Monaghan, Michael T; Gattolliat, Jean-Luc; Sartori, Michel; Elouard, Jean-Marc; James, Helen; Derleth, Pascale; Glaizot, Olivier; de Moor, Ferdy; Vogler, Alfried P

2005-09-01

221

Immunological characteristics of malaria antibodies in two regions of Madagascar.  

PubMed

Antibodies directed against antigens of the asexual blood stages of Plasmodium falciparum were studied in the plasma of 29 individuals infected with P. falciparum and living in two areas of Madagascar. These plasma samples were investigated by four immunological methods: indirect fluorescence, immunoprecipitation of radiolabeled P. falciparum polypeptides, inhibition of the in vitro growth of P. falciparum, and double diffusion in a gelose plate. A multifactorial correspondence analysis of the results obtained for each sample revealed that the nature of several of the antibodies varied according to the age and place of residence of the subjects. In comparison with plasma samples from older individuals, specimens from young children had a higher immunofluorescence titer, immunoprecipitated several additional peptides (90, 110, and 118 kilodaltons), revealed more precipitation lines in the Ouchterlony plate technique, and did not inhibit the in vitro growth of P. falciparum to the same extent. Furthermore, as opposed to plasma samples from individuals living in the high central plateau, plasma samples from individuals living on the east coast of the island inhibited the penetration of erythrocytes by merozoites of one of the two studied P. falciparum strains and preferentially immunoprecipitated low-, rather than high-, molecular-weight peptides. PMID:3108313

Deloron, P; Jaureguiberry, G; Gaudebout, C; Le Bras, J; Savel, J; Pocidalo, J J

1987-05-01

222

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

PubMed

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

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

2009-01-01

223

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

USGS Publications Warehouse

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.

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

2009-01-01

224

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

NSDL National Science Digital Library

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 students how to properly care for animals, and are very cool looking! This article describes an inquiry-based MHC activity and further questions for your students to explore. The activity and questions address basic concepts of nutrition.

Wagler, Ron

2009-03-01

225

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

PubMed Central

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.

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

2011-01-01

226

Small effect of fragmentation on the genetic diversity of Dalbergia monticola, an endangered tree species of the eastern forest of Madagascar, detected by chloroplast and nuclear microsatellites  

PubMed Central

Background and Aims The oriental forest ecosystem in Madagascar has been seriously impacted by fragmentation. The pattern of genetic diversity was analysed on a tree species, Dalbergia monticola, which plays an important economic role in Madagascar and is one of the many endangered tree species in the eastern forest. Methods Leaves from 546 individuals belonging to 18 small populations affected by different levels of fragmentation were genotyped using eight nuclear (nuc) and three chloroplast (cp) microsatellite markers. Key Results For nuclear microsatellites, allelic richness (R) and heterozygosity (He,nuc) differed between types of forest: R = 7·36 and R = 9·55, He,nuc = 0·64 and He,nuc = 0·80 in fragmented and non-fragmented forest, respectively, but the differences were not significant. Only the mean number of alleles (Na,nuc) and the fixation index FIS differed significantly: Na,nuc = 9·41 and Na,nuc = 13·18, FIS = 0·06 and FIS = 0·15 in fragmented and non-fragmented forests, respectively. For chloroplast microsatellites, estimated genetic diversity was higher in non-fragmented forest, but the difference was not significant. No recent bottleneck effect was detected for either population. Overall differentiation was low for nuclear microsatellites (FST,nuc = 0·08) and moderate for chloroplast microsatellites (FST,cp = 0·49). A clear relationship was observed between genetic and geographic distance (r = 0·42 P < 0·01 and r = 0·42 P = 0·03 for nuclear and chloroplast microsatellites, respectively), suggesting a pattern of isolation by distance. Analysis of population structure using the neighbor-joining method or Bayesian models separated southern populations from central and northern populations with nuclear microsatellites, and grouped the population according to regions with chloroplast microsatellites, but did not separate the fragmented populations. Conclusions Residual diversity and genetic structure of populations of D. monticola in Madagascar suggest a limited impact of fragmentation on molecular genetic parameters.

Andrianoelina, O.; Favreau, B.; Ramamonjisoa, L.; Bouvet, J.-M.

2009-01-01

227

Field Survey of the 2004 Indonesian Tsunami in Madagascar  

NASA Astrophysics Data System (ADS)

We present a report from the work of the International Tsunami Survey Team in Madagascar in the aftermath of the 2004 Sumatra tsunami. During an 11-day campaign, the team surveyed approximately 950 km of coastlines along the Eastern shore of the island, building a database of 52 standardized measurements of flow-depth, run-up and inundation, obtained primarily from eyewitness reports. Maximum heights were found typically on the order of 2 to 4 meters, with an absolute maximum of 5.4 m at the Southernmost tip of the island. In general, the largest values are reported at the extremities of the surveyed area, in the vicinity of Tolagnaro in the South (in a region where one fatality was reported), and of Sambava in the North. By contrast, the central area, in the vicinity of Toamasina, features lower amplitudes, with the tsunami not being observed along a segment of at least 100 km of coastline, around Vatomandry and Manahoro. A most remarkable effect of the tsunami took place in the port of Toamasina, where a 50-m commercial ship broke its moorings and wandered for several hours in the port, carried by powerful eddy currents. This situation is similar to the case of a large container ship in Salalah, Oman (Raad et al., 2005), but the incident in Toamasina occurred around 16:00 GMT, several hours after the arrival of the waves of maximum amplitude. It warrants a reassessment of the evaluation of potential hazards and of mitigation and evacuation procedures for port infrastructures.

Okal, E. A.; Fritz, H. M.; Raveloson, R.; Joelson, G.; Pancoskova, P.; Rambolamanana, G.

2005-12-01

228

The genetic population structure of the gray mouse lemur ( Microcebus murinus), a basal primate from Madagascar  

Microsoft Academic Search

The genetic structure of a population is closely connected to fundamental evolutionary processes and aspects of social behavior. Information on genetic structure is therefore instrumental for the interpretation of social behavior and evolutionary reconstructions of social systems. Gray mouse lemurs (Microcebus murinus) are basal primates endemic to Madagascar whose social organization is characterized by solitary foraging at night and communal

Barbara Wimmer; Diethard Tautz; Peter M. Kappeler

2002-01-01

229

Craniofacial morphology of Simosuchus clarki (Crocodyliformes: Notosuchia) from the Late Cretaceous of Madagascar  

Microsoft Academic Search

Simosuchus clarki is a small, pug-nosed notosuchian crocodyliform from the Late Cretaceous of Madagascar. Originally described on the basis of a single specimen including a remarkably complete and well-preserved skull and lower jaw, S. clarki is now known from five additional specimens that preserve portions of the craniofacial skeleton. Collectively, these six specimens represent all elements of the head skeleton

Nathan J. Kley; Joseph J. W. Sertich; Alan H. Turner; David W. Krause; Patrick M. OConnor; Justin A. Georgi

2010-01-01

230

Long-term changes in dominance ranks among ring-tailed lemurs at Berenty Reserve, Madagascar  

Microsoft Academic Search

A study was conducted between 1989 and 2001 to monitor changes in the dominance ranks among adult ring-tailed lemurs (Lemur catta) at Berenty Reserve, Madagascar. Adult females were observed to be dominant over adult males. Their rank fluctuated greatly. However, in some troops, female rank orders were fairly stable over a period of several years. In general, male ranks were

Naoki Koyama; Shinichiro Ichino; Masayuki Nakamichi; Yukio Takahata

2005-01-01

231

A framework for understanding community resident perceptions of Masoala National Park, Madagascar  

Microsoft Academic Search

SUMMARY Protected areas (PAs) represent a central strategy in biodiversity conservation worldwide. Yet many PAs are weakened by people-PA conflicts resulting from the separation of natural resource protection from human considerations. Research at Masoala National Park in Madagascar focused on the following questions: (1) What are the factors that influence residents' perceptions of the Park and restrictions on use of

ALISON ORMSBY; BETH A. KAPLIN

2005-01-01

232

Coordination issues in policy implementation networks: An illustration from Madagascar's Environmental Action Plan  

Microsoft Academic Search

Policy implementation brings together multiple agencies and groups to work in concert to achieve a set of objectives. Making these joint arrangements function effectively depends upon multiactor linkages and coordination. Drawing upon the Interorganizational and policy network literature, this article discusses these issues and applies them to National Environmental Action Plans (NEAPs). The article looks specifically at Madagascar, examining the

Derick W. Brinkerhoff

1996-01-01

233

Phylogenetic relationships of Trachylepis skink species from Madagascar and the Seychelles (Squamata: Scincidae).  

PubMed

Lizards of the genus Trachylepis are a species-rich group of skinks mainly inhabiting Africa, Madagascar, and several other islands in the western Indian Ocean. All except one probably introduced species of Madagascan Trachylepis are endemic. Two species groups have been distinguished on the basis of subocular scale shape but their phylogenetic relationships remained unclear. We inferred a multilocus phylogeny of the Madagascan Trachylepis species, based on a concatenated dataset of 3261 bp from 3 mitochondrial and 4 nuclear genes with a dense Madagascan taxon sampling and find high support for the monophyly of the endemic Madagascan Trachylepis. The two species groups in Madagascar are highly supported as clades. The highland species T. boettgeri is nested in the T. aureopunctata species group of mainly arid-adapted species, suggesting a colonization of highland swamps by ancestors inhabiting dry western Madagascar. The Seychellois species were sister to the T. maculilabris/T. comorensis clade, suggesting their origin directly out of Africa as with Seychellois chameleons. In Madagascar, a high intraspecific molecular variation was confirmed for T. gravenhorstii, T. elegans, and T. vato, indicating a need for taxonomic revision. PMID:23435267

Lima, Alexandra; James Harris, D; Rocha, Sara; Miralles, Aurélien; Glaw, Frank; Vences, Miguel

2013-02-19

234

Transoceanic and endemic origins of the small minnow mayflies (Ephemeroptera, Baetidae) of Madagascar  

Microsoft Academic Search

We investigated the relative importance of dispersal and vicariance in forming the Madagascar insect fauna, sequencing approximately 2300 bp from three rRNA gene regions to investigate the phylogeny of Afrotropical small minnow mayflies (Ephemeroptera: Baetidae). Six lineages contained trans-oceanic sister taxa, and variation in genetic divergence between sister taxa revealed relationships that range from very recent dispersal to ancient vicariance.

Michael T. Monaghan; Jean-Luc Gattolliat; Michel Sartori; Jean-Marc Elouard; Helen James; Pascale Derleth; Olivier Glaizot; Ferdy de Moor; Alfried P. Vogler

2005-01-01

235

Permian to tertiary faunas and paleogeography: Somalia, Kenya Tanzania, Mozambique, Madagascar, South Africa  

Microsoft Academic Search

Permian to Tertiary faunas along the eastern margin of Africa, and on Madagascar, are presented, described, and discussed. Presentation of the faunas is made in four charts: Permo-Triassic, Jurassic, Cretaceous, and Tertiary. A correlation chart provides tentative time-rock units. Paleogeography northeast and east of Africa is derived from the writer's analysis of marine invertebrate fauna, and is delineated in sketches

Maurice Kamen-Kaye

1978-01-01

236

Understanding Mortality and the Life of the Ancestors in Rural Madagascar  

ERIC Educational Resources Information Center

|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…

Astuti, Rita; Harris, Paul L.

2008-01-01

237

Sea Surface Temperature and Seawater Oxygen Isotope Variability Recorded in a Madagascar Coral Record  

Microsoft Academic Search

Within KIHZ a coral from the lagoon of Ifaty off southwest Madagascar in the Mozambique Channel was examined. Based on temporal variability of skeletal oxygen isotopes annual mean sea surface temperatures are reconstructed for the period from 1658 to 1995. Sr\\/Ca ratios were measured for selected windows with monthly resolution (1973 to 1995, 1863 to 1910, 1784 to 1809, 1688

J. Zinke; W. Dullo; A. Eisenhauer

2002-01-01

238

Sea Surface Temperature and Seawater Oxygen Isotope Variability Recorded in a Madagascar Coral Record  

Microsoft Academic Search

We analysed a 336 year coral oxygen isotope record off southwest Madagascar in the Mozambique Channel. Based on temporal variability of skeletal oxygen isotopes annual mean sea surface temperatures are reconstructed for the period from 1659 to 1995. Sr\\/Ca ratios were measured for selected windows with monthly resolution (1973 to 1995, 1863 to 1910, 1784 to 1809, 1688 to 1710)

J. Zinke; W. Chr Dullo; A. Eisenhauer

2003-01-01

239

Observations of the southern East Madagascar Current and undercurrent and countercurrent system  

Microsoft Academic Search

In April 2001 four hydrographic sections perpendicular to the southern East Madagascar Current were surveyed as part of the Agulhas Current Sources Experiment. Observations with a vessel mounted and a lowered ADCP produced information on the current field while temperature, salinity, oxygen and nutrient data obtained with a CTD-Rosette system, gave information on the water mass structure of the currents

J. J. Nauw; H. M. van Aken; A. Webb; J. R. E. Lutjeharms; W. P. M. de Ruijter

2008-01-01

240

Breakup of Pangaea and Isolation of Relict Mammals in Australia, South America, and Madagascar  

Microsoft Academic Search

The composition of aboriginal land mammal faunas in Australia and New Guinea (prototherians and metatherians), South America (metatherians and eutherians) and Madagascar (eutherians only) is reconsidered in light of continental drift reconstructions of Mesozoic-Tertiary world paleogeography. It is proposed that these three faunas represent successively detached samples of the evolving world mammal fauna as it existed when each of these

Jack Fooden

1972-01-01

241

The Impact of Media and Monotoring on Corruptin in Decentralized Public Programs: Evidence from Madagascar  

Microsoft Academic Search

Local capture of public expenditures is an important problem for service delivery and poverty reduction in developing countries. Standard anticorruption institutions may not be effective, as these tend often to be corrupt themselves. This paper analyses the impact of monitoring and information distribution through the mass media on local capture of public expenditures on education in Madagascar in 2002-2003. We

Nathalie Francken; Bart Minten; Johan F. M. Swinnen

2005-01-01

242

Romancing Dahalo: The Social Environment of Cattle Theft in Ihorombe, Madagascar  

Microsoft Academic Search

In 1990 a woman named Nancy, a Peace Corps worker in southern Madagascar, received a marriage proposal from a man she did not know. It was Easter Monday, a national holiday for the Malagasy, and the man had been drinking; his proposal included a dowry of a very substantial number of cattle, an animal of tremendous cultural and material wealth

John McNair

2008-01-01

243

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

Microsoft Academic Search

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

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

2002-01-01

244

Deforestation and cultivation effects on characteristics of oxisols in the highlands of Madagascar  

Microsoft Academic Search

Soils of tropical forests are often inherently nutrient poor, although the extents of extremely infertile tropical forest soils are not as large as previous estimates may suggest. This paper presents findings from a study of change in soil quality in relation to deforestation and land use change in the highlands of Madagascar. A synthesis of some of the available research

Tor-Gunnar Vågen; Masy-A. A. Andrianorofanomezana; Salmata Andrianorofanomezana

2006-01-01

245

Site-and watershed-level assessment of nutrient dynamics under shifting cultivation in eastern Madagascar  

Microsoft Academic Search

Nutrient depletion is an important limiting factor for agricultural sustainability in shifting cultivation systems. This paper presents a case study examining nutrient dynamics for a hillrice-fallow system located on the eastern escarpment of Madagascar. A nutrient assessment was carried out, measuring total C, N, P, K, Ca and Mg concentrations in phytomass, ashes and harvests and total C and N,

J Brand; J. L Pfund

1998-01-01

246

Une nouvelle famille est nécessaire pour des microscorpions humicoles de madagascar et d'afrique  

Microsoft Academic Search

The sub-family Microcharminae is raised to the rank of family as Microcharmidae so as to contain humicolous microscorpions of Madagascar and Africa belonging to the genera Microcharmus and Akentrobuthus. Phylogenetic considerations are proposed in relation to the morphological characters but also in association with their adaptation to the humicolous environment of the soil.

Wilson R. Lourenço

1998-01-01

247

Developing sustainable cropping systems with minimal inputs in Madagascar: direct seeding on plant cover with \\  

Microsoft Academic Search

In the Hautes-Terres region of Madagascar, population pressure is accelerating thé conversion of hilly areas with fragile and relatively infertile soils into cropland. As fertilizers are limited, crop yields remain low and erosion is destroying rice fields. Instead of clearing areas fallowed with Aristida sp. by burning, ibis biomass can be kept for use as mulch and for \\

R. MICHELLON; L. SEGUY

248

The significance of human induced and natural erosion features (lavakas) on the central highlands of Madagascar  

Microsoft Academic Search

Massive hill slope erosion in Madagascar is represented by the widespread gullies called 'lavaka'. Lavakas may be result of natural processes that involves a combination of continuous tectonic uplift that maintains a high angle of repose, ground water sapping at the soil - saprolite interface, and subsequent collapse of the soil surface due to low grade seismic activity in the

Michael S. Zavada; Yeqiao Wang

249

Soil–vegetation patterns in secondary slash and burn successions in Central Menabe, Madagascar  

Microsoft Academic Search

Slash and burn agriculture is a traditional and predominant land use practice in Madagascar and its relevance in the context of forest preservation is significant. At the end of a cycle of culture, the fields become mostly weed covered and the soil fertility starts to drop. As a consequence, these fields are abandoned (they are called “monka”) and the farmers,

Olga Raharimalala; Alexandre Buttler; Clémence Dirac Ramohavelo; Samuel Razanaka; Jean-Pierre Sorg; Jean-Michel Gobat

2010-01-01

250

Interpreting some outstanding features of the flora and vegetation of Madagascar  

Microsoft Academic Search

Six features are covered. (1) The high endemism, which is not discussed in detail, is all-pervasive, and has resulted from the isolation of Madagascar from Africa some 125 million years ago and their present separation by 430 km. (2) The great richness in plant species (especially relative to Africa), seen particularly in the families of woody species in the wetter

Peter J. Grubb

2003-01-01

251

Vetiver Victorious: The Systematic Use of Vetiver to Save Madagascar's FCE Railway  

Microsoft Academic Search

In 2000, two cyclones hit the island nation of Madagascar in a two-week period. The devastation to infrastructur es was enormous. Among the worst hit was the FCE train line in the southeastern part of the country that suffered more than 280 landslides. The line was closed for three months, causing severe hardship to the more than 100 000 people

Diti Hengchaovanich; Karen Schoonmaker Freudenberger

252

A Eucheuma (Solieriaceae, rhodophyta) cultivation test on the south-west coast of Madagascar  

Microsoft Academic Search

Well established populations of Eucheuma denticulatum and E. striatum exist on the coral reef of the south west coast of Madagascar but natural beds are not dense enough to support high harvest pressure. A cultivation test was conducted on a 250 m2 module using the monoline method with 1560 seedlings of both species for over one year (weighings at 15

Jean Mollion; Jean-Paul Braud

1993-01-01

253

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

ERIC Educational Resources Information Center

|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…

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

2013-01-01

254

Farmers' Welfare and Changing Food Prices: Nonparametric Evidence from Rice in Madagascar  

Microsoft Academic Search

This paper uses nonparametric density estimation and kernel smoothing techniques to examine the instantaneous distributional implications of rice price changes in Madagascar. While many farmers do not participate in product markets as either buyers or sellers, and net sales or marketable surplus are fairly small for many others, the roughly one-third of rice farmers who fall below the poverty line

Christopher B. Barrett; Paul A. Dorosh

1996-01-01

255

Patterns of amphibian and reptile diversity at Berara Forest (Sahamalaza Peninsula), NW Madagascar  

Microsoft Academic Search

Amphibians and reptiles were surveyed at Berara, a forest on the Sahamalaza Peninsula, NW Madagascar. Visual methods and pitfalls were used, leading to the discovery of 12 amphibian and 30 reptile species. The herpetofaunal community appeared as a mosaic of dry forest species and species from the more humid Sambirano Domain. The comparatively low amphibian diversity may be correlated with

Franco Andreone; Miguel Vences; Jasmin Emile Randrianirina

2001-01-01

256

Population and Territory Stability of the Lemur catta at Berenty, Madagascar  

Microsoft Academic Search

Several Lemur catta troops at Berenty, Madagascar have been censused repeatedly since 1963. In 1972, the entire reserve was censused. A recensus in 1975 showed that although some minor changes have occurred in the number of animals in individual troops, the population of the reserve as a whole, the core areas of the lemurs’ territories, and their home range boundaries

Anne S. Mertl-Míllhollen; Herbert L. Gustafson; Norman Budnitz; Kathryn Dainis; Alison Jolly

1979-01-01

257

Understanding Mortality and the Life of the Ancestors in Rural Madagascar  

ERIC Educational Resources Information Center

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…

Astuti, Rita; Harris, Paul L.

2008-01-01

258

DNA barcoding for effective biodiversity assessment of a hyperdiverse arthropod group: the ants of Madagascar  

Microsoft Academic Search

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

M. Alex Smith; Brian L. Fisher; Paul D. N. Hebert

2005-01-01

259

Reconciling fossils and molecules: Cenozoic divergence of cichlid fishes and the biogeography of Madagascar  

Microsoft Academic Search

Aim The biogeographical origins of the extant vertebrates endemic to Madagascar are largely unsolved, but have often been related to vicariance in the context of fragmentation of the supercontinent Gondwana in the Mesozoic. Such hypotheses are especially appealing in the case of cichlid fishes, which show phylogenetic relationships reflecting the temporal successions of the breakup of Gondwana. We used molecular

M. Vences; J. Freyhof; R. Sonnenberg; J. Kosuch; M. Veith

2001-01-01

260

Determinants of credit rationing: A study of informal lenders and formal credit groups in Madagascar  

Microsoft Academic Search

Previous research on the determinants of credit rationing exclusively focused on thebehavior of formal lenders who contract directly with an individual borrower. Based on ahousehold survey in Madagascar, this paper presents an analysis of credit rationing behaviorby informal lenders and by members of community-based groups that allocate formal grouploans among themselves. The results show that group members obtain and use

Manfred Zeller

1994-01-01

261

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

USGS Publications Warehouse

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.

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

2009-01-01

262

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

ERIC Educational Resources Information Center

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…

Korhonen, Kaisa; Lappalainen, Anu

2004-01-01

263

Has Vicariance or Dispersal Been the Predominant Biogeographic Force in Madagascar? Only Time Will Tell  

Microsoft Academic Search

Madagascar is one of the world's hottest biodiversity hot spots due to its diverse, endemic, and highly threatened biota. This biota shows a distinct signature of evolution in isolation, both in the high levels of diversity within lineages and in the imbalance of lineages that are represented. For example, chameleon diversity is the highest of any place on Earth, yet

Anne D. Yoder; Michael D. Nowak

2006-01-01

264

Multivariate analysis of management and biosecurity practices in smallholder pig farms in Madagascar  

Microsoft Academic Search

A cross-sectional study was carried out in 2005 and 2006 in three geographical areas of Madagascar to investigate and differentiate swine farm management and biosecurity practices in smallholder farming communities. Questionnaire data from a total of 709 pig farms were analysed using multiple factor analysis (MFA) and hierarchical cluster analysis (HCA). Variables describing management and biosecurity practices were organised into

S. Costard; V. Porphyre; S. Messad; S. Rakotondrahanta; H. Vidon; F. Roger; D. U. Pfeiffer

2009-01-01

265

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

PubMed Central

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 populations—separated by only 248 km—is 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.

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

266

Aligning Conservation Priorities Across Taxa in Madagascar with High-Resolution Planning Tools  

Microsoft Academic Search

Globally, priority areas for biodiversity are relatively well known, yet few detailed plans exist to direct conservation action within them, despite urgent need. Madagascar, like other globally recognized biodiversity hot spots, has complex spatial patterns of endemism that differ among taxonomic groups, creating challenges for the selection of within-country priorities. We show, in an analysis of wide taxonomic and geographic

C. Kremen; A. Cameron; A. Moilanen; S. J. Phillips; C. D. Thomas; H. Beentje; J. Dransfield; B. L. Fisher; F. Glaw; T. C. Good; G. J. Harper; R. J. Hijmans; D. C. Lees; E. Louis; R. A. Nussbaum; C. J. Raxworthy; A. Razafimpahanana; G. E. Schatz; M. Vences; D. R. Vieites; P. C. Wright; M. L. Zjhra

2008-01-01

267

Helping Women Help Themselves: Sex Work, Health, and Development in Mahajanga, Madagascar  

Microsoft Academic Search

Poverty is an inescapable reality in Madagascar, a force that permeates the lives of many Malagasy people. Approximately 75 % of the population lives below the poverty line, defined as one United States dollar per person per day . This poverty proves to be particularly cruel to women who are often illiterate, unmarried, and have children to support. In cases

Rachel Pryzby

2007-01-01

268

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

Microsoft Academic Search

BackgroundThe 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

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

2009-01-01

269

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

ERIC Educational Resources Information Center

|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…

Wagler, Ron

2010-01-01

270

Diets of Two Lemur Species in Different Microhabitats in Beza Mahafaly Special Reserve, Madagascar  

Microsoft Academic Search

Studies of primate diets usually focus on differences that distinguish species or populations. However, variation in diet can occur at a more local level of groups within a population, especially in a non-homogeneous habitat. I compared dietary variation in food composition and toughness across groups of 2 lemur species in Beza Mahafaly special reserve, Madagascar. Beza Mahafaly contains an 80-ha

Nayuta Yamashita

2002-01-01

271

Unreported fishing, hungry people and political turmoil: the recipe for a food security crisis in Madagascar?  

Microsoft Academic Search

Madagascar, the world's fourth largest island, is one of the world's poorest developing countries, and its people depend heavily on marine resources for subsistence and income. Exports of these resources and foreign fishing access agreements are also important, at least from a large-scale economic perspective. In recent years, concerns have been voiced amongst local fishers and industry groups regarding the

Frédéric Le Manach; Charlotte Gough; Alasdair Harris; Frances Humber; Sarah Harper; Dirk Zeller

2012-01-01

272

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

NASA Astrophysics Data System (ADS)

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 Niño 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.

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

273

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

NASA Astrophysics Data System (ADS)

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.

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

2012-04-01

274

Rainforest pharmacopeia in Madagascar provides high value for current local and prospective global uses.  

PubMed

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. PMID:22848447

Golden, Christopher D; Rasolofoniaina, B J Rodolph; Anjaranirina, E J Gasta; Nicolas, Lilien; Ravaoliny, Laurent; Kremen, Claire

2012-07-27

275

Diversification into Man-Made Fiber Apparel Exports: A Strategic Option for Madagascar to Maximize Post-2004 Preferential Tariff Margins.  

National Technical Information Service (NTIS)

For more than 30 years, exports of textiles and apparel between developed and developing countries have been tightly regulated by quotas. Shielded from competition by quotas, many countries like Madagascar have built substantial export sectors for these p...

2004-01-01

276

Population Growth, Shifting Cultivation, and Unsustainable Agricultural Development. A Case Study in Madagascar. Africa Technical Department Series.  

National Technical Information Service (NTIS)

The study of a microregion in Madagascar illustrates important linkages and synergies between population growth, unsustainable agriculture, and natural resource decline. Further, the study shows that agricultural development has been hampered by the lack ...

A. Keck N. P. Sharma G. Feder

1994-01-01

277

Geological evolution of the Antongil Craton, NE Madagascar  

USGS Publications Warehouse

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.

Schofield, D. I.; Thomas, R. 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

278

Protected area surface extension in Madagascar: Do endemism and threatened species remain useful criteria for site selection ?  

Microsoft Academic Search

The 'hotspot approach' considers that endemism and threat- ened species are key factors in protected area designation. Three wetland and forest sites have been proposed to be included into Madagascar's system of protected areas (SAPM - Système des Aires Protégées de Madagascar). These sites are Manambolomaty (14,701 ha) and Mandrozo (15,145 ha) in the west and Bemanevika (37,041 ha) in

Jeanneney Rabearivony; Russell Thorstrom; Gilbert Razafimanjato I; Daniel Rakotondravony; Achille P. Raselimanana; Michel Rakotoson I

2010-01-01

279

Revision of the genera Hovadelium Ardoin and Mimolaena Ardoin (Coleoptera, Tenebrionidae, Laenini) from Madagascar, with remarks on tribal assignment1  

PubMed Central

Abstract The genera Hovadelium Ardoin, 1961 and Mimolaena Ardoin, 1961, endemic in Madagascar, are revised and assigned to the tribe Laenini Seidlitz, 1896 (subfamily Lagriinae Latreille, 1825). New species: Hovadelium ardoini sp. n., Hovadelium bremeri sp. n. and Mimolaena janaki sp. n. An identification key is compiled for all taxa. Distribution of Hovadelium (5 species) and Mimolaena (3 species) is mapped. The congeners might be indicator species for the highly endangered mature forests in Madagascar.

Schawaller, Wolfgang

2013-01-01

280

Revision of the genera Hovadelium Ardoin and Mimolaena Ardoin (Coleoptera, Tenebrionidae, Laenini) from Madagascar, with remarks on tribal assignment.  

PubMed

The genera Hovadelium Ardoin, 1961 and Mimolaena Ardoin, 1961, endemic in Madagascar, are revised and assigned to the tribe Laenini Seidlitz, 1896 (subfamily Lagriinae Latreille, 1825). New species: Hovadelium ardoini sp. n., Hovadelium bremeri sp. n. and Mimolaena janaki sp. n. An identification key is compiled for all taxa. Distribution of Hovadelium (5 species) and Mimolaena (3 species) is mapped. The congeners might be indicator species for the highly endangered mature forests in Madagascar. PMID:24039536

Schawaller, Wolfgang

2013-08-26

281

Anti-Predator Strategies in a Diurnal Prosimian, the Ring-Tailed Lemur ( Lemur catta ), at the Beza Mahafaly Special Reserve, Madagascar  

Microsoft Academic Search

With the dramatic increase in research on Madagascar’s lemurs during the past few decades, it is now feasible to both document\\u000a anti-predator behavior and to test predictions regarding the effect of predation pressure on the behavioral ecology of lemurs.\\u000a In 1994 Goodman raised much interest by his suggestion that, in the absence of large, extant predators on Madagascar, anti-predator\\u000a behaviors

Lisa Gould; Michelle L. Sauther

282

Breakup history of central Madagascar: a combined remote sensing &fission track approach  

NASA Astrophysics Data System (ADS)

After collision and amalgamation of East- and West-Gondwana during Late Neoproterozoic times Madagascar had a central position in Gondwana. Following Pan-African ductile deformation, Madagascar underwent a long period of extensional tectonism, associated with basin formation, major faulting, volcanism, exhumation and passive margin formation. We used a combined remote sensing and fission track (FT) approach to obtain more detailed structural indications for the breakup history in Madagascar. Because of insufficient infrastructure and outcrop data in Madagascar, satellite image interpretation is a very useful tool to complete data obtained from field observations and geochronological methods. A set of six Landsat 5 and 7 satellite images, covering most parts of central Madagascar, was used to identify ductile and brittle structures. After image processing, specific regions were selected for detailed investigation. The dominant ductile Pan-African structures in this region are the N-S striking Angavo shear zone and the merely E-W striking Virgation zone. In the western and central part of the island the detailed lineament mapping revealed a reactivation of Pan-African structures with directions N and NW. In contrast, the brittle structures around the Angavo shear zone show clear defined NW and NE directions corresponding to the dominant orientations in the Mascarene basin and are most probably related to the Madagascar-India breakup. 54 FT samples were collected and studied along three W-E cross sections running from the basement/basin contact towards the eastern coast. Titanite FT ages range between 483 ± 33 and 266 ± 13 Ma. Apatite FT ages varies between 460 ± 21 and 79 ± 5 Ma. The oldest titanite FT ages occur in the centre of the island. The titanite FT ages from the western paleo margin are mostly ˜70 Ma older than the apatite FT ages, indicating moderate cooling during the opening of the Karoo basins in this area. The titanite FT ages from the eastern coast are about ˜340 Ma and are significantly older than the apatite FT ages (˜80 Ma), indicating that the breakup related Marion hot spot had probably only a minor thermal (at least <300^oC) effect on the study area. Remote sensing and FT data from samples around the Angavo shear zone suggest a new structural imprint during the Cretaceous breakup. The structural data from the eastern coast with two clearly defined directions argue also for a minor structural influence of the Marion hot spot. Thus, the Cretaceous apatite FT ages are most probably related to flexural denudation during the breakup process.

Kastowski, M.; Emmel, B.; Jacobs, J.

2003-04-01

283

Breakup of pangaea and isolation of relict mammals in australia, South america, and madagascar.  

PubMed

The composition of aboriginal land mammal faunas in Australia and New Guinea (prototherians and metatherians), South America (metatherians and eutherians) and Madagascar (eutherians only) is reconsidered in light of continental drift reconstructions of Mesozoic-Tertiary world paleogeography It is proposed that these three faunas represent successively detached samples of the evolving world mammal fauna as it existed when each of these land masses became faunally isolated from the rest of the world as a result of the progressive fragmentation of Pangaea. Isolation of aboriginal prototherians and metatherians in Australia and New Guinea may date from the Upper JurassicLower Cretaceous; isolation of aboriginal metatherians and eutherians in South America may date from the Middle Cretaceous-Upper Cretaceous; isolation of aboriginal eutherians in Madagascar may date from the Paleocene-Eocene. PMID:17781064

Fooden, J

1972-02-25

284

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

SciTech Connect

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.

Green, G.M.; Sussman, R.W. (Washington Univ., St. Louis, MO (USA))

1990-04-13

285

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

PubMed

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

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

2010-06-02

286

Social interactions and aggression among male Madagascar hissing cockroaches ( Gromphadorhina portentosa ) in groups (Dictyoptera: Blaberidae)  

Microsoft Academic Search

We studied agonistic interactions among male Madagascar hissing cockroaches,Gromphadorhina portentosa, in groups of five (low-density) or 10 (high-density) males. Consistent with previous studies of male pairs, we observed aggression (Abdomen Flick, Abdomen Push, Butt, Lunge), submission (Crouch, Retreat), and noncontact behavior (Abdominal Extension, Abdomen Thrash, Agonistic Hiss, Stilt). Males at both densities performed all acts. However, males in the high-density

Deborah C. Clark; Allen J. Moore

1994-01-01

287

A ten-year summary of reproductive parameters for ring-tailed lemurs at berenty, madagascar  

Microsoft Academic Search

From 1989 to 1998, 204 live births were recorded for ring-tailed lemurs (Lemur catta) at Berenty, Madagascar. Excluding unknown birth dates, the peak month of birth was September, with 82.0% (146\\/178) occurring\\u000a during this period. The offspring sex ratio (1?1.19) was not significantly different from 1?1, and there was no association\\u000a with the mother's age. The first births occurred at

Naoki Koyama; Masayuki Nakamichi; Ryo Oda; Naomi Miyamoto; Shinichiro Ichino; Yukio Takahata

2001-01-01

288

Daytime deliveries observed for the ring-tailed lemurs of the berenty reserve, Madagascar  

Microsoft Academic Search

In the Berenty Reserve, Southern Madagascar, of the 16 deliveries recorded for ring-tailed lemurs from 1995 and 1997, 10 cases\\u000a occurred during daytime hours (07:00 – 16:59). Four mothers lost contact with their troop members during parturition, but\\u000a were able to rejoin them after about one hour. No attack from the individuals of the neighboring groups or predators on the

Yukio Takahata; Naoki Koyama; Naomi Miyamoto; Megumi Okamoto

2001-01-01

289

Mating behavior of ring-tailed lemurs ( Lemur catta ) at Berenty, Madagascar  

Microsoft Academic Search

The mating behavior of ring-tailed lemurs at Berenty, Madagascar, was observed in April 1982. Although Troop A included five\\u000a adult females, only two were observed to mate. The mating period covered two consecutive days, April 24 and 25. Each female\\u000a was receptive for about 4 hr. Data from 47 copulations, of which 38 were with ejaculation, suggest that to be

Naoki Koyama

1988-01-01

290

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

PubMed

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

Godfrey, Laurie R; Irwin, Mitchell T

2007-09-07

291

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

NASA Astrophysics Data System (ADS)

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.

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

2010-12-01

292

Origin of the high variability of water mineral content in the bedrock aquifers of Southern Madagascar  

Microsoft Academic Search

This study assesses the causes of the high spatial variability of the mineral content of groundwater in crystalline bedrock of Southern Madagascar. Although many kilometres from the coast and at a mean altitude of 400m a.s.l, wells drilled in this area produce water with electrical conductivities in the range of 300–30,000?Scm?1 with a high spatial variability. Chemical and isotopic data

V. Rabemanana; S. Violette; G. de Marsily; H. Robain; B. Deffontaines; P. Andrieux; M. Bensimon; A. Parriaux

2005-01-01

293

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

Microsoft Academic Search

The Ianapera emerald deposit is located in the Neoproterozoic Vohibory Block of southern Madagascar. The local geology consists\\u000a of intercalated migmatitic gneissic units and calcareous metasedimentary rocks, containing boudinaged metamorphosed mafic\\/ultramafic\\u000a lenses, all intruded by pegmatite veins. These units occur near the hinge of the tightly folded Ianapera antiform, within\\u000a a few kilometers of the Ampanihy shear zone. Emerald mineralization

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

2009-01-01

294

Breeding biology of Coquerel’s Coua ( Coua coquereli ) in Western Madagascar  

Microsoft Academic Search

The breeding biology of the endemic Coquerel’s Coua (Coua coquereli), a non-parasitic cuckoo species for which few ecological data are available, was studied in the dry deciduous forest of\\u000a western Madagascar. Nestling C. coquereli remain in the nest for only a short time after hatching. At approximately 9 days old and still unable to fly, they were observed\\u000a to leave the

Philippe Chouteau; Miguel Pedrono

2009-01-01

295

Export Processing Zone Expansion in Madagascar: What are the Labour Market and Gender Impacts?  

Microsoft Academic Search

This paper analyses part of the controversy over export processing zones (EPZs)--the labour market and gender impacts--using unique time-series labour force survey data from an African setting: urban Madagascar, in which the EPZ (or Zone Franche) grew very rapidly during the 1990s. Employment in the Zone Franche exhibits some basic patterns seen elsewhere in export processing industries of the developing

Peter Glick; François Roubaud

2006-01-01

296

A Molecular Phylogeny of Four Endangered Madagascar Tortoises Based on MtDNA Sequences  

Microsoft Academic Search

Four of the five tortoise species in Madagascar,Pyxis arachnoides, P. planicauda, Geochelone radiata,andG. yniphora,are endemic and on the verge of extinction. Their phylogenetic relationships remain controversial and unresolved. Here we address the phylogeny of this group using DNA sequences for the 12S and 16S rDNA and cytbgenes in mitochondrial DNA. As outgroups we used two species ofGeochelone, pardalis(mainland Africa) andnigra(Galápagos),

Adalgisa Caccone; George Amato; Oliver C. Gratry; John Behler; Jeffrey R. Powell

1999-01-01

297

[Phlebotomine sandflies from Madagascar (Diptera: Psychodidae). V--description of Sergentomyia majungaensis n. sp].  

PubMed

Sergentomyia majungaensis, a new species of Phlebotomine sandfly, is described from Madagascar. The female is characterised by an unusual antennal formula (1/IV-V to VII; 2/VI to VIII-XV) and smooth and narrow spermathecae, with a common duct, whose shape is intermediate between Sergentomyia and Parrotomyia subgenera. The male has the same antennal formula than Grassomyia (1/IV-XV) but no hairs on the mesanepistern and a longer third antennal segment. PMID:17933299

Depaquit, J; Léger, N; Robert, V

2007-09-01

298

Agroecological Implications of the System of Rice Intensification (SRI) in Madagascar  

Microsoft Academic Search

A system of plant, soil, water and nutrient management for irrigated rice developed in Madagascar has been yielding 5, 10, even 15?t?ha-1 on farmers' fields where previous yields averaged around 2?t?ha-1. This is achieved using whatever variety of rice the farmer is already using and without having to utilize chemical fertilizer or other purchased inputs. This system, known as SRI,

Norman Uphoff

1999-01-01

299

Cycles of Activity, Group Composition, and Diet of Lemur mongoz mongoz Linnaeus 1766 in Madagascar  

Microsoft Academic Search

A preliminary study of the ecology and behavior of Lemur mongoz mongoz was carried out in the northwest of Madagascar. The animals were observed for approximately 250 h in July till August, 1973, and for 50 h in June, 1974. L.m.mongoz has been reported to be diurnal and to live in groups of 6–8 individuals. However, we found the animals

Robert W. Sussman; Ian Tattersall

1976-01-01

300

Liberalization and Food Price Distributions: ARCH-M Evidence From Madagascar  

Microsoft Academic Search

There is no well-articulated theory of how stochastic food prices respond to economic liberalization measures, a surprising oversight in the vast literature on market-oriented reforms. This paper presents reduced form estimates of the effects of liberalization measures on food commodity prices in Madagascar using autoregressive conditional heteroskedastic in mean (ARCH-M) methods. The data indicate that the short-term effects of liberalization

Christopher B. Barrett

1997-01-01

301

Troop Continuity and Troop Spacing in Propithecus verreauxi and Lemur catta at Berenty (Madagascar)  

Microsoft Academic Search

Sifaka troops (Propithecus verreauxi) at Berenty, Madagascar, seem stable numerically, geographically, and in pacing behavior. Recognizeable individuals preserved their 1963–1964 ranges in 1970, in a classical mosaic of defended territories. Lemur catta had twice as many troops of half the mean size in 1970, and had changed from spatial exclusivity to time-plan spacing, both within and between troops, with inter-troop

Alison Jolly

1972-01-01

302

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

USGS Publications Warehouse

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.

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

2011-01-01

303

The impact of selective logging on forest structure and tenrec populations in western Madagascar  

Microsoft Academic Search

Cette étude met en évidence quelques effets de l'exploitation séléctive de la forêt sur la structure de la végétation et les conséquences pour deux espèces de tenrecs dans une forêt sèche à l'ouest de Madagascar. Dans un domaine limité, l'exploitation de bois de moins de 10 m3 par ha change considérablement la structure de la forêt. Mais si on considère

J. U. Ganzhorn; A. W. Ganzhorn; J.-P. Abraham; L. Andriamanarivo; A. Ramananjatovo

1990-01-01

304

Rotavirus genotypes in children in the community with diarrhea in Madagascar.  

PubMed

In the context of the possible introduction of a preventive vaccine against rotaviruses in Madagascar, the G and P genotypes distribution of the rotaviruses circulating in the children in Madagascar was studied, and the presence of emerging genotypes and unusual strains were assessed. From February 2008 to May 2009, 1,679 stools specimens were collected from children ?5 years old with diarrhea. ELISA was used for antigen detection, and molecular amplification of VP7 and VP4 gene fragments was used for genotyping. Rotavirus antigen was detected in 104 samples (6.2%). Partial sequences of VP7 and VP4 genes were obtained from 81 and 80 antigen-positive stools, respectively. The most frequent G and P types combinations detected were G9P[8] (n?=?51; 64.6%), followed by G1P[8] (n?=?15; 18.9%), and G1P[6] (n?=?8; 10.1%). A few unusual G-P combinations, such as G4P[6] (n?=?3; 3.8%), G9P[6] (n?=?1; 1.3%), and G3P[9] reassortant feline human virus (n?=?1; 1.3%) were identified. Both VP4 and VP7 sequences in one of the three G4P[6] isolates were closely related to those in porcine strains, and one was a reassortant human porcine virus. These findings give an overview of the strains circulating in Madagascar and should help public health authorities to define a vaccine strategy. PMID:23797859

Razafindratsimandresy, Richter; Heraud, Jean-Michel; Ramarokoto, Charles Emile; Rabemanantsoa, Sendraharimanana; Randremanana, Rindra; Andriamamonjy, Nelson Seta; Richard, Vincent; Reynes, Jean Marc

2013-06-24

305

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

PubMed

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

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

2010-05-01

306

Vertical transmission as the key to the colonization of Madagascar by fungus-growing termites?  

PubMed Central

The mutualism between fungus-growing termites (Macrotermitinae) and their mutualistic fungi (Termitomyces) began in Africa. The fungus-growing termites have secondarily colonized Madagascar and only a subset of the genera found in Africa is found on this isolated island. Successful long-distance colonization may have been severely constrained by the obligate interaction of the termites with fungal symbionts and the need to acquire these symbionts secondarily from the environment for most species (horizontal symbiont transmission). Consistent with this hypothesis, we show that all extant species of fungus-growing termites of Madagascar are the result of a single colonization event of termites belonging to one of the only two groups with vertical symbiont transmission, and we date this event at approximately 13 Mya (Middle/Upper Miocene). Vertical symbiont transmission may therefore have facilitated long-distance dispersal since both partners disperse together. In contrast to their termite hosts, the fungal symbionts have colonized Madagascar multiple times, suggesting that the presence of fungus-growing termites may have facilitated secondary colonizations of the symbiont. Our findings indicate that the absence of the right symbionts in a new environment can prevent long-distance dispersal of symbioses relying on horizontal symbiont acquisition.

Nobre, T.; Eggleton, P.; Aanen, D. K.

2010-01-01

307

Population dynamics, infestation and host selection of Vexilla vexillum, an ectoparasitic muricid of echinoids, in Madagascar.  

PubMed

The symbiotic interaction, population and infestation dynamics of the muricid Vexilla vexillum (Gmelin, 1791) on 2 echinoid species, Tripneustes gratilla (Linnaeus, 1785) and Echinometra mathaei (Blainville, 1825), was investigated on the barrier reef off Toliara (Madagascar). V. vexillum is an ectoparasitic muricid which was exclusively found in association with sea urchins, on which it moves freely and browses over the integument. Host recovery from damage caused by muricid grazing was dependent on lesion size. Small lesions regenerated while larger ones were subjected to secondary infections, which led to host death. A 27 mo survey (2000 to 2003) of the muricid's population dynamics revealed annual recruitment episodes during the mid-summer season (December to January). Patterns of recruitment peaks were apparently linked to its reproductive cycle. Demographic parameters including growth and mortality rates of the muricid were estimated from analysis of size-frequency distributions. Growth was described by the von Bertalanffy function. The model predicts that V. vexillum is a fast-growing species in which asymptotic shell length (L infinity = 1.024 cm) is reached 6 to 7 mo after recruitment. The growth rate constant K, and shell length at settlement L0, were estimated from the model. Estimated mortality rate was 55% yr(-1); V. vexillum has a short lifespan. The observed high growth rate together with the high mortality rate suggest that V. vexillum is a semelparous species. A field survey of the infestation dynamics of V. vexillum was performed during 3 consecutive years, with seasonal variation in parasite prevalence on both echinoid host species. Although both T. gratilla and E. mathaei were infested, a preference towards T. gratilla was noted. This was attributed to T. gratilla's test morphology (which allows better accessibility for grazing), to the muricid's higher recognition capacity of T. gratilla (as determined by olfactory experiments) and to the high recruitment predictability of that particular host. This study provides novel information on the biology of V. vexillum, an echinoid epidermal grazer, and its relationship with 2 ecologically and economically important echinoid species. PMID:15609879

Vaïtilingon, Devarajen; Eeckhaut, Igor; Fourgon, Didier; Jangoux, Michel

2004-11-01

308

The re-stocking of captive-bred ruffed lemurs (Varecia variegata variegata) into the Betampona Reserve, Madagascar: methodology and recommendations  

Microsoft Academic Search

Since November 1997 the Madagascar Fauna Group has released 13 captive-bred black and white ruffed lemurs (Varecia variegata variegata) into the Betampona Reserve in eastern Madagascar. The release programme has three major aims: (1) to assess the ability of captive-bred V. v. variegata to adapt to life in their natural habitat; (2) to investigate the contribution that such a release

Adam Britt; Charles Welch; Andrea Katz; Bernard Iambana; Ingrid Porton; Randall Junge; Graham Crawford; Cathy Williams; David Haring

2004-01-01

309

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

PubMed Central

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.

2013-01-01

310

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

NASA Astrophysics Data System (ADS)

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.

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

2009-10-01

311

Predicting the impacts of climate change on the distribution of threatened forest-restricted birds in Madagascar.  

PubMed

The greatest common threat to birds in Madagascar has historically been from anthropogenic deforestation. During recent decades, global climate change is now also regarded as a significant threat to biodiversity. This study uses Maximum Entropy species distribution modeling to explore how potential climate change could affect the distribution of 17 threatened forest endemic bird species, using a range of climate variables from the Hadley Center's HadCM3 climate change model, for IPCC scenario B2a, for 2050. We explore the importance of forest cover as a modeling variable and we test the use of pseudo-presences drawn from extent of occurrence distributions. Inclusion of the forest cover variable improves the models and models derived from real-presence data with forest layer are better predictors than those from pseudo-presence data. Using real-presence data, we analyzed the impacts of climate change on the distribution of nine species. We could not predict the impact of climate change on eight species because of low numbers of occurrences. All nine species were predicted to experience reductions in their total range areas, and their maximum modeled probabilities of occurrence. In general, species range and altitudinal contractions follow the reductive trend of the Maximum presence probability. Only two species (Tyto soumagnei and Newtonia fanovanae) are expected to expand their altitude range. These results indicate that future availability of suitable habitat at different elevations is likely to be critical for species persistence through climate change. Five species (Eutriorchis astur, Neodrepanis hypoxantha, Mesitornis unicolor, Euryceros prevostii, and Oriola bernieri) are probably the most vulnerable to climate change. Four of them (E. astur, M. unicolor, E. prevostii, and O. bernieri) were found vulnerable to the forest fragmentation during previous research. Combination of these two threats in the future could negatively affect these species in a drastic way. Climate change is expected to act differently on each species and it is important to incorporate complex ecological variables into species distribution models. PMID:23610622

Andriamasimanana, Rado H; Cameron, Alison

2013-02-15

312

Predicting the impacts of climate change on the distribution of threatened forest-restricted birds in Madagascar  

PubMed Central

The greatest common threat to birds in Madagascar has historically been from anthropogenic deforestation. During recent decades, global climate change is now also regarded as a significant threat to biodiversity. This study uses Maximum Entropy species distribution modeling to explore how potential climate change could affect the distribution of 17 threatened forest endemic bird species, using a range of climate variables from the Hadley Center's HadCM3 climate change model, for IPCC scenario B2a, for 2050. We explore the importance of forest cover as a modeling variable and we test the use of pseudo-presences drawn from extent of occurrence distributions. Inclusion of the forest cover variable improves the models and models derived from real-presence data with forest layer are better predictors than those from pseudo-presence data. Using real-presence data, we analyzed the impacts of climate change on the distribution of nine species. We could not predict the impact of climate change on eight species because of low numbers of occurrences. All nine species were predicted to experience reductions in their total range areas, and their maximum modeled probabilities of occurrence. In general, species range and altitudinal contractions follow the reductive trend of the Maximum presence probability. Only two species (Tyto soumagnei and Newtonia fanovanae) are expected to expand their altitude range. These results indicate that future availability of suitable habitat at different elevations is likely to be critical for species persistence through climate change. Five species (Eutriorchis astur, Neodrepanis hypoxantha, Mesitornis unicolor, Euryceros prevostii, and Oriola bernieri) are probably the most vulnerable to climate change. Four of them (E. astur, M. unicolor, E. prevostii, and O. bernieri) were found vulnerable to the forest fragmentation during previous research. Combination of these two threats in the future could negatively affect these species in a drastic way. Climate change is expected to act differently on each species and it is important to incorporate complex ecological variables into species distribution models.

Andriamasimanana, Rado H; Cameron, Alison

2013-01-01

313

Comparison of the Jurassic and Cretaceous sedimentary cycles of Somalia and Madagascar: implications for the Gondwana breakup  

NASA Astrophysics Data System (ADS)

The Jurassic and Cretaceous sedimentary history of northern Somalia and the Morondava Basin of south-western Madagascar have been studied. Both regions display an independent facial development; however, a comparison of the sequential evolution of the Mesozoic sedimentary successions in these two presently widely separated areas reveals a surprisingly high level of similarity, which probably reflects major events during the disintegration of Eastern Gondwana during the Jurassic and Cretaceous. Although in Jurassic times the onset of transgressions and regressions in both areas compares well with eustatic development, major deviations in combination with the tectonic activities of different degrees are observed in the Early and Late Cretaceous synchronously in both regions. Transgressions are observed in Toarcian, Bajocian (not dated in northern Somalia), Callovian, Valanginian (Madagascar only), Aptian and Campanian times. Tectonism is noted before the Aptian and Campanian transgressions in northern Somalia and the Morondava Basin of south-western Madagascar.

Luger, Peter; Gröschke, M.; Bussmann, M.; Dina, A.; Mette, W.; Uhmann, A.; Kallenbach, H.

1994-12-01

314

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

PubMed Central

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.

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

315

[Haemophilus influenzae, the second cause of bacterial meningitis in children in Madagascar].  

PubMed

The Haemophilus influenzae b is one of the main germs causing bacterial meningitis in children in countries where the vaccine anti-Haemophilus influenzae b is not widely used. In Madagascar, no epidemiological study on this germ has been carried out. The objective of this research is to assess the role of Haemophilus influenzae meningitis in Antananarivo and to determine its epidemiological aspects and evolution. A multicentric study coordinated by the Institut Pasteur de Madagascar included all children less than 15 years old with infectious syndromes associated to a syndrome of meningial irritation and/or convulsion and/or coma. These children were admitted in the pediatric service of the three main hospitals in Antananarivo from June 1998 and June 2000. A lumbar puncture was performed on each child; the cerebrospinal fluid was set aside for cytobacterial and biochemical controls completed with an antimicrobial sensitivity testing and a soluble antigens research. Out of 160 case studies, the Haemophilus influenzae b arrives at the second place among the agents causing bacterial meningitis in children. This type of bacteria is the source of 32% of meningitis after the Streptococcus pneumoniae (34%). It affects 96% of children less than two years old, with a maximal frequency before the age of one year. The lethality rate is 28.6% and the neurological sequelae were observed in 31.4% of patients. Haemophilus influenzae is sensitive to the third generation cephalosporins but shows high resistance to chloramphenicol (42%), amoxicillin (29%) and gentamicin (22%). The relatively high frequency as well as the high lethality rate caused by the Haemophilus influenzae b meningitis, affecting selectively the children under two years old, bring in the need to introduce the anti-Haemophilus influenzae b vaccine in the national vaccination program in Madagascar. This vaccine has proved to be efficient in many countries where it has been used. Furthermore, in the probabilistic treatment of bacterial meningitis in children, the third generation cephalosporins should be used in the first place. PMID:15255350

Razafindralambo, M; Ravelomanana, N; Randriamiharisoa, F A; Migliani, R; Clouzeau, J; Raobijaona, H; Rasamoelisoa, J; Pfister, P

2004-05-01

316

[Prevalence of tobacco use and associated factors among teenage students in Madagascar].  

PubMed

The available data on the prevalence of tobacco use among teenagers in Madagascar are very limited. The aim of this study was to analyze tobacco-use behaviors among teenage pupils aged 12 to 18 living in urban and suburban areas of Madagascar and to identify the associated risk factors. A cross-sectional descriptive study was conducted as part of this research. Probabilistic multistage sampling was used to obtain a representative sample. Data were collected using an anonymous self-reported questionnaire and computer analyzed using SPSS 16. Correlation and logistic regression were used to analyze the risk factors. The results show that approximately one third of the 711 pupils (36.3%) included in the sample reported that they had tried tobacco. Among them, 25.2% were regular users. Nearly 10% had started smoking before the age of 14. Male adolescents were found to smoke twice as much as their female counterparts. The study found that the key factors associated with tobacco use include: male gender (Exp(B)=3,769(95%IC 2,579-5,509), urbanization (Exp(B) = 3,679, 95% IC 2,138-6,332), age, peer influence, a sense of insecurity at school, and the impact of the mass media (films, television). The study found that the family environment did not have a significant impact on tobacco use. To conclude, the prevalence of smoking among teenage pupils in Madagascar is a significant issue. This paper argues that it is important to understand the associated risk factors in order to develop a prevention program aimed at reversing the tobacco epidemic in schools. PMID:22370020

Befinoana, M; Razanamihaja, Noeline

317

Analysis of patterns of bushmeat consumption reveals extensive exploitation of protected species in eastern Madagascar.  

PubMed

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

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

2011-12-14

318

[Resistance of Plasmodium falciparum to antimalarial drugs: impact on malaria pre-elimination in Madagascar].  

PubMed

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

Andriantsoanirina, V; Ménard, D; Tuséo, L; Ratsimbasoa, A; Durand, R

2011-06-01

319

The GLOBE/Madagascar Malaria Project: Creating Student/Educator/Scientist Partnerships With Regional Impact  

NASA Astrophysics Data System (ADS)

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.

Brooks, D.; Boger, R.; Rafalimanana, A.

2006-05-01

320

Phlebotomine sand flies from Madagascar (Diptera: Psychodidae). VIII--Phlebotomus (Anaphlebotomus) vincenti n. sp.  

PubMed

A new species of Phlebotomine sand fly (Diptera: Psychodidae) is described from Mikea Forest in the southwest of Madagascar: Phlebotomus vincenti n. sp. It is temporarily classified in the subgenus Anaphlebotomus according to its spermathecal organization, similar to those of P. berentiensis, P. fertei and P. vaomalalae, previously classified in the subgenus Anaphlebotomus referring to on male genitalia morphology. An original trumpet-like dilatation on the distal part of the spermathecal ducts individualizes P. vincenti n. sp. from the other Malagasy species. Moreover, the second internal transcribed spacer (ITS2) sequences strongly individualises P. vincenti n. sp. from the other Malagasy Phlebotomus. PMID:23934316

Randrianambinintsoa, F J; Depaquit, J

2013-08-09

321

The primates of the Baly Bay area, north-western Madagascar.  

PubMed

Primate surveys were conducted in isolated primary west Malagasy decidous forest blocks around Baly Bay, north-western Madagascar. Eight species of primate were found, including Microcebus c.f. myoxinus, Hapalemur griseus occidentalis and Phaner furcifer. Two species were found only in Namoroka Strict Nature Reserve, which may mean that other forest blocks in the area have experienced primate extinctions. The record of M. c.f. myoxinus came from mangrove, the first confirmed record of a lemur from this habitat. The pelage of female Eulemur fulvus rufus was atypical. PMID:9885334

Hawkins, A F; Durbin, J C; Reid, D B

1998-01-01

322

Antiproliferative Cardenolides of an Elaeodendron sp. from the Madagascar Rain Forest  

PubMed Central

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.

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

323

Geology, petrology and isotope geochemistry of massif-type anorthosites from southwest Madagascar  

Microsoft Academic Search

Four massif-type anorthosite bodies 25–100?km2 in area occur within high-pressure granulite facies supracrustal gneisses in southwestern Madagascar. Two of these bodies\\u000a (Ankafotia and Saririaky) appear to have been pulled apart by 40?km in a ductile shear zone, but structural features such\\u000a as sub-vertical stretching lineations indicate an origin by intense west-directed flattening and pure shear. Country rocks\\u000a (Graphite Series) include

Lewis D. Ashwal; Michael A. Hamilton; Vincent P. I. Morel; Roger A. Rambeloson

1998-01-01

324

Descriptions and biological notes on three unusual mantellid tadpoles (Amphibia: Anura: Mantellidae) from southeastern Madagascar  

USGS Publications Warehouse

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.

Altig, R.; McDiarmid, R.W.

2006-01-01

325

A new threatened species of Pandanaceae from northwestern Madagascar, Pandanus sermolliana.  

PubMed

Pandanus sermolliana Callmander & Buerki (Pandanaceae) is described from humid forests in the Galoka mountain chain in northwestern Madagascar. The new species can be easily distinguished from the other members of the genus it most closely resembles, P. insuetus Huynh and P. perrieri Martelli, by several morphological characters including drupes that are incompletely fused, with each of the dome-like carpels separated from the base of the pileus, and stigmas that are sub-vertical or rarely sub-horizontal, slightly spinescent, and raised on an incompletely united base. This distinctive species is rare and is classified as Critically Endangered based on IUCN threat criteria. PMID:21750602

Callmander, Martin W; Buerki, Sven; Wohlhauser, Sebastien

2008-12-16

326

The pig tapeworm Taenia solium, the cause of cysticercosis: Biogeographic (temporal and spacial) origins in Madagascar.  

PubMed

Cysticercosis is a serious public health problem in Madagascar. The prevalence rate of active cysticercosis reached 21% in regions with a high level of livestock farming. Taenia solium of African-American and Asian genotypes are both present on the island. The times of divergence of the 13 specimens studied suggests a very ancient diversification of T. solium. These events are widely thought to be prior to the domestication of pigs, and seem to follow the expansion of Homo in Asia. Multiple human migrations and the diversity of potential intermediate hosts may have led to a complex epidemiological situation on the island. PMID:20093191

Michelet, Lorraine; Carod, Jean-François; Rakontondrazaka, Mahenintsoa; Ma, Laurence; Gay, Frédérick; Dauga, Catherine

2010-01-20

327

Molecular characterization of a new alphasatellite associated with a cassava mosaic geminivirus in Madagascar.  

PubMed

Two complete nucleotide sequences of an alphasatellite isolated from a cassava plant with mosaic disease symptoms in Madagascar are described and analyzed. While the helper begomovirus was identified as an isolate of East African cassava mosaic Kenya virus (EACMKV), its associated alphasatellite was most closely related (80 % nucleotide sequence identity) to cotton leaf curl Gezira alphasatellite. These satellite molecules have typical features of alphasatellites, with a single gene in the virion sense, an A-rich region and a stem-loop structure. According to the proposed species demarcation threshold of alphasatellites (83 % nucleotide identity), they are isolates of a new species for which we propose the name "Cassava mosaic alphasatellite". PMID:23525698

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

2013-03-23

328

Home Sweet Home: How to Build a Madagascar Hissing Cockroach Habitat Out of Recycled Materials  

NSDL National Science Digital Library

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 âwowâ factor. These characteristics make them unique as classroom insects and add to their effectiveness in increasing your studentsâ scientific knowledge. This article provides directions for building a free, eco-friendly, low-maintenance MHC home out of garbage.

Wagler, Ron

2010-04-01

329

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

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…

Rambelo, Michel

330

Overview of the discovery, distribution, and geological context of Simosuchus clarki (Crocodyliformes: Notosuchia) from the Late Cretaceous of Madagascar  

Microsoft Academic Search

Simosuchus clarki is a bizarre, pug-nosed notosuchian crocodyliform known only from the Upper Cretaceous (Maastrichtian) Maevarano Formation in the Mahajanga Basin of northwestern Madagascar. When originally named and described in 2000, S. clarki was based entirely on a single specimen that included a nearly complete skull and lower jaw preserved in articulation with the anterior and mid-trunk portions of the

David W. Krause; Joseph J. W. Sertich; Raymond R. Rogers; Sophia C. Kast; Armand H. Rasoamiaramanana; Gregory A. Buckley

2010-01-01

331

Plasmodium vivax dhfr and dhps mutations in isolates from Madagascar and therapeutic response to sulphadoxine-pyrimethamine  

Microsoft Academic Search

BACKGROUND: Four of five Plasmodium species infecting humans are present in Madagascar. Plasmodium vivax remains the second most prevalent species, but is understudied. No data is available on its susceptibility to sulphadoxine-pyrimethamine, the drug recommended for intermittent preventive treatment during pregnancy. In this study, the prevalence of P. vivax infection and the polymorphisms in the pvdhfr and pvdhps genes were

Céline Barnadas; Magali Tichit; Christiane Bouchier; Arsène Ratsimbasoa; Laurence Randrianasolo; Rogelin Raherinjafy; Martial Jahevitra; Stéphane Picot; Didier Ménard

2008-01-01

332

Well-Being Is a Process of Becoming: Respondent-Led Research with Organic Farmers in Madagascar  

ERIC Educational Resources Information Center

|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…

Farnworth, Cathy Rozel

2009-01-01

333

Social Relationships Among Ring-Tailed Lemurs ( Lemur catta ) in Two Free-Ranging Troops at Berenty Reserve, Madagascar  

Microsoft Academic Search

We observed two free-ranging troops of ring-tailed lemurs at the Berenty Reserve, Madagascar. Kinship affinities in these troops are known only for mothers and their offspring =4 years of age. We attempted to quantify social relationships. Almost all agonistic interactions were dyadic, and triadic agonistic interactions, such as alliances, were very rare. Dominance hierarchies in both sexes in the two

Masayuki Nakamichi; Naoki Koyama

1997-01-01

334

Inverting the impacts: Mining, conservation and sustainability claims near the Rio Tinto\\/QMM ilmenite mine in Southeast Madagascar  

Microsoft Academic Search

This paper traces a genealogy of land access and legitimization strategies culminating in the current convergence of mining and conservation in Southeast Madagascar, contributing to recent debates analyzing the commonalities and interdependencies between seemingly discrete types of land acquisitions. Drawing upon research carried out near the Rio Tinto\\/QMM ilmenite mine in 2009 (January–March), it focuses on how local Malagasy land

Caroline Seagle

2012-01-01

335

Bilan des cancers du col utérin diagnostiqués à l'Institut Pasteur de Madagascar de 1992 à 2002  

Microsoft Academic Search

RESUME : A Madagascar, les données épidémiologiques actualisées concernant le cancer du col utérin ne sont pas disponibles du fait de l'absence de registre du cancer. Le but de ce travail est de réaliser une première évaluation du problème, de compléter les connaissances épidémiologiques, de réfléchir sur les moyens de dépistage précoce des lésions précancéreu- ses, de proposer des mesures

Raharisolo Vololonantenaina CR; Rabarijaona LP; Soares JL; Rasendramino M; Pécarrère JL; Khun H; Huerre M

336

Nonradioactive heteroduplex tracking assay for the detection of minority-variant chloroquine-resistant Plasmodium falciparum in Madagascar  

Microsoft Academic Search

BACKGROUND: Strains of Plasmodium falciparum genetically resistant to chloroquine (CQ) due to the presence of pfcrt 76T appear to have been recently introduced to the island of Madagascar. The prevalence of such resistant genotypes is reported to be low (P. falciparum isolates on the island. Previously, minority variant chloroquine resistant parasites were described in Malawian patients using an isotopic heteroduplex

Jonathan J Juliano; Milijaona Randrianarivelojosia; Benjamin Ramarosandratana; Frédéric Ariey; Victor Mwapasa; Steven R Meshnick

2009-01-01

337

Late Quaternary environmental changes from a pollen and diatom record in the southern tropics (Lake Tritrivakely, Madagascar)  

Microsoft Academic Search

A pollen and diatom study of a 40m-sedimentary sequence from Lake Tritrivakely in the central highlands of Madagascar provides evidence for climatic and environmental changes during the late Pleistocene and the Holocene. The major features of the modern regional climate and vegetation distribution and the hydrological characteristics of the lake basin are first summarized. Lithological units and specific methods used

F Gasse; E Van Campo

2001-01-01

338

Forecasting the distribution of Marmorkrebs, a parthenogenetic crayfish with high invasive potential, in Madagascar, Europe, and North America  

Microsoft Academic Search

The parthenogenetic marbled crayfish, Marmorkrebs, has high potential to become an invasive species because single individuals can establish a population. Marmorkrebs have already been introduced in several countries, have successfully established populations in at least two of them, and are rapidly expanding in one case (Madagascar). To assess the potential ecological threat arising from further Marmorkrebs introductions, we developed four

Teresa Patricia Feria; Zen Faulkes

2011-01-01

339

Group Composition, Home Range Size, and Diet of Three Sympatric Bamboo Lemur Species (Genus Hapalemur ) in Ranomafana National Park, Madagascar  

Microsoft Academic Search

This is the first long-term, simultaneous, comparative study of three bamboo lemur species (Hapalemur griseus, H. aureus, and H. simus) at a site in southeastern-central Madagascar where they occur in sympatry. At Talatakely, Ranomafana National Park, the three Hapalemur spp. share overlapping home ranges. Hapalemur griseus has flexible group sizes, varying from three to nine individuals (n = 6). The

Chia L. Tan

1999-01-01

340

Effects of living mulches or residue amendments on soil microbial properties in direct seeded cropping systems of Madagascar  

Microsoft Academic Search

There is growing recognition for the need to study the impact of agricultural land uses on biological and biochemical properties of soils. In Madagascar, cropping systems based on direct seeding with permanent vegetation cover provide a new means for sustainable agriculture to protect the environment and make the most of natural resources. This study assessed the effects of different direct

Bodovololona Rabary; Saidou Sall; Philippe Letourmy; Olivier Husson; Eliane Ralambofetra; Narcisse Moussa; Jean-Luc Chotte

2008-01-01

341

SIMULATION OF A TYPICAL HOUSE IN THE REGION OF ANTANANARIVO, MADAGASCAR DETERMINATION OF PASSIVE SOLUTIONS USING LOCAL MATERIALS  

Microsoft Academic Search

This paper deals with new proposals for the design of passive solutions adapted to the climate of the highlands of Madagascar. While the strongest population density is located in the central highlands, the problem of thermal comfort in buildings occurs mainly during winter time. Currently, people use raw wood to warm the poorly designed houses. This leads to a large

Harimalala Razanamanampisoa; Zely Arivelo Randriamanantany; François Garde; Harry Boyer

342

Molecular tracing of Bradyrhizobium strains helps to correctly interpret Acacia mangium response to inoculation in a reforestation experiment in Madagascar  

Microsoft Academic Search

A field inoculation experiment using two Bradyrhizobium sp. strains was set up in Madagascar to test the growth response of Acacia mangium and to follow up the survival of inoculant strains using molecular tools. Three months after inoculation, one of the inoculant strains, AUST13c, exhibited a marked growth-promoting effect with a shoot height about 40% higher than that of the

Y. Prin; A. Galiana; C. Le Roux; B. Méléard; V. Razafimaharo; M. Ducousso; G. Chaix

2003-01-01

343

Remote sensing of complex land use change trajectories—a case study from the highlands of Madagascar  

Microsoft Academic Search

Madagascar is often portrayed as a global environmental hotspot with widespread deforestation and environmental degradation. Quantitative and spatially explicit data on ecological change are, however, scarce and current estimates are often based on simplistic representations of deforestation and land use change. Significant uncertainties in current estimates therefore remain. The present study was conducted to assess deforestation and other important complex

Tor-Gunnar Vågen

2006-01-01

344

Remote sensing of complex land use change trajectories—a case study from the highlands of Madagascar  

Microsoft Academic Search

Madagascar is often portrayed as a global environmental hotspot with widespread deforestation and environmental degradation. Quantitative and spatially explicit data on ecological change are, however, scarce and current estimates are often based on simplistic representations of deforestation and land use change. Significant uncertainties in current estimates therefore remain. The present study was conducted to assess deforestation and other important complex

Tor-Gunnar Va

345

A study of the phycocolloids from Gelidium madagascariense and Eucheuma denticulatum (Rhodophyta) collected on the south coasts of Madagascar  

Microsoft Academic Search

Several species of red algae known to contain agar or carrageenan are abundant on the southeast and southwest coasts of Madagascar. The agarophyte Gelidium madagascariense, collected in the Fort Dauphin area, has been exported on a small scale to Japan for several years. FT-IR and GLC analysis show that it contains an agar polymer, of which the methylated fraction contains

J. Mollion; M. Andriantsiferana; M. Sekkal

1990-01-01

346

Setting Up a Bibliographic Database from National Inventory of Scientific and Technical Literature. The CIDST Experience in Madagascar.  

ERIC Educational Resources Information Center

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.…

Andriamparany, Louis Marius; And Others

1991-01-01

347

Molecular Phylogeny and Biogeography of the Native Rodents of Madagascar (Muridae: Nesomyinae): A Test of the Single-Origin Hypothesis  

Microsoft Academic Search

Complete nucleotide sequences from the mitochondrial cytochrome b gene (1143 bp) were used to investigate the phylogenetic relationships among the native rodents of Madagascar. Specifically, this study examines whether the nine genera of nesomyines form a monophyletic group relative to other Old World murids. All nine of the nesomyine genera, including multiple individuals from 15 of the 21 described species,

Sharon A. Jansa; Steven M. Goodman; Priscilla K. Tucker

1999-01-01

348

Well-Being Is a Process of Becoming: Respondent-Led Research with Organic Farmers in Madagascar  

ERIC Educational Resources Information Center

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…

Farnworth, Cathy Rozel

2009-01-01

349

The impacts of logging on the microhabitats used by two species of couas in the western forest of Madagascar  

Microsoft Academic Search

Habitat structure is important to consider in all ecological studies considering the relationships between animals and their environment. Habitat structure can be studied at different scales, from landscape to microhabitat. I studied here the response of two endemic terrestrial birds living in the dry forest of Madagascar. These birds belong to the genus Coua. The study is made at the

Philippe Chouteau

2004-01-01

350

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

Microsoft Academic Search

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

Lao Nathalie Bakoariniaina; Timothy Kusky; Tsilavo Raharimahefa

2006-01-01

351

Conservation priorities for forest-floor invertebrates of the southeastern half of Madagascar: evidence from two land-snail clades  

Microsoft Academic Search

Leaf litter and soil of tropical forests harbour some of Earth's most diverse, most endangered, yet least understood biological communities. How well do east-southeast Madagascar's reserves protect this resource? A preliminary answer is provided by the landsnail genera Cyclophoridae Boucardicus and Charopidae n. gen., as represented by 3680 specimens in 64 species, collected 1990–1993 from 129 stations in 26 transects,

Kenneth C. Emberton

1996-01-01

352

Vast underestimation of Madagascar's biodiversity evidenced by an integrative amphibian inventory  

PubMed Central

Amphibians are in decline worldwide. However, their patterns of diversity, especially in the tropics, are not well understood, mainly because of incomplete information on taxonomy and distribution. We assess morphological, bioacoustic, and genetic variation of Madagascar's amphibians, one of the first near-complete taxon samplings from a biodiversity hotspot. Based on DNA sequences of 2,850 specimens sampled from over 170 localities, our analyses reveal an extreme proportion of amphibian diversity, projecting an almost 2-fold increase in species numbers from the currently described 244 species to a minimum of 373 and up to 465. This diversity is widespread geographically and across most major phylogenetic lineages except in a few previously well-studied genera, and is not restricted to morphologically cryptic clades. We classify the genealogical lineages in confirmed and unconfirmed candidate species or deeply divergent conspecific lineages based on concordance of genetic divergences with other characters. This integrative approach may be widely applicable to improve estimates of organismal diversity. Our results suggest that in Madagascar the spatial pattern of amphibian richness and endemism must be revisited, and current habitat destruction may be affecting more species than previously thought, in amphibians as well as in other animal groups. This case study suggests that worldwide tropical amphibian diversity is probably underestimated at an unprecedented level and stresses the need for integrated taxonomic surveys as a basis for prioritizing conservation efforts within biodiversity hotspots.

Vieites, David R.; Wollenberg, Katharina C.; Andreone, Franco; Kohler, Jorn; Glaw, Frank; Vences, Miguel

2009-01-01

353

Lemur responses to edge effects in the Vohibola III classified forest, Madagascar.  

PubMed

Forest edges are dynamic zones characterized by the penetration (to varying depths and intensities) of conditions from the surrounding environment (matrix) into the forest interior. Although edge effects influence many tropical organisms, they have not been studied directly in primates. Edge effects are particularly relevant to lemurs because of the highly fragmented forest landscapes found in Madagascar. In this study, data are presented regarding how the densities of six lemur species (Avahi laniger, Cheirogaleus major, Eulemur rubriventer, Hapalemur griseus griseus, Microcebus rufus, and Propithecus diadema edwardsi) varied between six 500-m interior transects and six 500-m edge transects in the Vohibola III Classified Forest in SE Madagascar. Diurnal (n = 433) and nocturnal (n = 128) lemur surveys were conducted during June-October 2003 and May-November 2004. A. laniger, E. rubriventer, and H. g. griseus exhibited a neutral edge response (no differences in densities between habitats). M. rufus and P. d. edwardsi had a positive edge response (higher densities in edge habitats), which may be related to edge-related variations in food abundance and quality. Positive edge responses by M. rufus and P. d. edwardsi may ultimately be detrimental due to edge-related anthropogenic factors (e.g., hunting by local people). The negative edge response exhibited by C. major (lower densities in edge habitats) may result from heightened ambient temperatures that inhibit torpor in edge habitats. PMID:16477598

Lehman, Shawn M; Rajaonson, Andry; Day, Sabine

2006-03-01

354

DNA barcoding for effective biodiversity assessment of a hyperdiverse arthropod group: the ants of Madagascar  

PubMed Central

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.

Smith, M. Alex; Fisher, Brian L; Hebert, Paul D.N

2005-01-01

355

Multivariate analysis of management and biosecurity practices in smallholder pig farms in Madagascar  

PubMed Central

A cross-sectional study was carried out in 2005 and 2006 in three geographical areas of Madagascar to investigate and differentiate swine farm management and biosecurity practices in smallholder farming communities. Questionnaire data from a total of 709 pig farms were analysed using multiple factor analysis (MFA) and hierarchical cluster analysis (HCA). Variables describing management and biosecurity practices were organised into five groups: structure of the farm, animal-contacts, person- and vehicle-contacts, feeding, and sanitary aspects. In general, few biosecurity measures were implemented in the pig farms included in the study. Regional differences in management and biosecurity practices emerged from the MFA and were mainly due to, in order of decreasing importance: structure of the farm, sanitary aspects, feeding and animal-contacts and, to a lesser extent, person- and vehicle-contacts. HCA resulted in the differentiation of four distinct types of farms in each of two study areas, Arivonimamo and Marovoay, while no grouping could be identified amongst farms in Ambatondrazaka area. The characterisation of the different types of smallholder pig farms will allow adapting recommendations on husbandry practices and control measures in pig farms of these regions of Madagascar. The development of tailored recommendations is essential for Malagasy smallholders who have limited resources and need to make evidence-based management changes to reduce the risk of contagious diseases in their herds.

Costard, S.; Porphyre, V.; Messad, S.; Rakotondrahanta, S.; Vidon, H.; Roger, F.; Pfeiffer, D.U.

2009-01-01

356

Multiple colonization of Madagascar and Socotra by colubrid snakes: evidence from nuclear and mitochondrial gene phylogenies.  

PubMed Central

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.

Nagy, Zoltan Tamas; Joger, Ulrich; Wink, Michael; Glaw, Frank; Vences, Miguel

2003-01-01

357

In and out of Madagascar: dispersal to peripheral islands, insular speciation and diversification of Indian Ocean daisy trees (Psiadia, Asteraceae).  

PubMed

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

Strijk, Joeri S; Noyes, Richard D; Strasberg, Dominique; Cruaud, Corinne; Gavory, Fredéric; Chase, Mark W; Abbott, Richard J; Thébaud, Christophe

2012-08-10

358

Endemism and diversification in freshwater insects of Madagascar revealed by coalescent and phylogenetic analysis of museum and field collections.  

PubMed

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

Vuataz, Laurent; Sartori, Michel; Gattolliat, Jean-Luc; Monaghan, Michael T

2012-12-20

359

Haemaphysalis (Rhipistoma) Anoplos Sp. N., A Spurless Tick of the Elongata Group (Ixodoidea, Ixodidae) Parasitizing Nesomys Rufus Peters (Rodentia) in Madagascar.  

National Technical Information Service (NTIS)

Three previously described members of the Madagascar Haemaphysalis (Rhipistoma) elongata group have a strong ventral spine on palpal segment 3 and exceptionally long and numerous spines on the coxae and trochanters. These species parasitize spiny insectiv...

H. Hoogstraal G. Uilenberg J. M. Klein

1967-01-01

360

Phanerozoic upper crustal tectono-thermal development of basement rocks from central Madagascar: An integrated fission-track and structural study  

Microsoft Academic Search

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

B. Emmel; J. Jacobs; M. Kastowski; G. Graser

2006-01-01

361

Premier cas d'un sub-fossile d'araignée appartenant au genre Archaea Koch & Berendt (Archaeidae) dans le copal de Madagascar  

NASA Astrophysics Data System (ADS)

The first known case of a sub-fossil of a spider belonging to the genus Archaea from the Madagascan copal. The first known sub-fossil of a spider belonging to the genus Archaea Koch & Berendt is described from the Copal of Madagascar. The new species was found in the Province of Antseranana (Diego-Suarez) in the northern part of the island. It belongs to the family Archaeidae. The genus Archaea is endemic in Madagascar.

Lourenço, Wilson R.

2000-04-01

362

Phanerozoic upper crustal tectono-thermal development of basement rocks from central Madagascar: An integrated fission-track and structural study  

NASA Astrophysics Data System (ADS)

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.

Emmel, B.; Jacobs, J.; Kastowski, M.; Graser, G.

2006-01-01

363

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

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.

Lackner, Tomas; Gomy, Yves

2013-01-01

364

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

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

Lackner, Tomáš; Gomy, Yves

2013-09-20

365

Sensitivity of a semi-arid tropical lake basin to environmental changes (Lake Ihotry basin, South-West of Madagascar)  

NASA Astrophysics Data System (ADS)

The objective of the study is to analyse the sensitivity of water ressources in a large semi-arid catchment, based on few hydro-meteorological and satellite images analysis. The site is located in the south-west of Madagascar. The catchment, which surface is 3000 km^2, is limited in its eastern side by a North-south relief up to 1000m high. The most important part of the catchment is made of a sandy plain, with a very poorly structured hydrographic network. The average annual precipitation varies in the catchment from 600 mm in the plain to 1000 mm in the mountains, with an an average temperature of 25^oC and an annual potential evapotranspiration rate of almost 2000mm. In the plain, surface and subsurface water circulation converges to Lake Ihotry, which has no surface outlet. The lake, very shallow, usually undergoes hudge seasonnal and inter-annual variations in water surface (from 60 to 120 km^2) and in water conductivity (from 7 to 23 mS/cm). In the catchment, no river flow data are available, partly because of the great instability of the hydrographic network. A dynamic model of lake water and salinity balances is used to establish the lake water balance and the temporal variations of water inflows, based on the daily data of precipitation, lake level and pan evaporation obtained during a 3 years field measurement campain. These results provide indirect data for validating a catchment hydrological model. We present the first results of the application of a semi-distributed hydrological modelling approach based on the determination of hydrological response units (HRU). The analysis of four stereoscopic couples of panchromatic SPOT scenes (10m resolution), allows to elaborate a digital elevation model and a vegetation map. The cultivated areas represent more than 20% of the total surface of the catchment, that is more than half of the plain. The delineation of the HRU’s is mainly based on the vegetation map, which seems to be a good integrator of the combined effects of pedology, geology, and topography on hydrological caracteristics. The hydrologic connectivity between the different HRU’s is established using available geological and geomorphological data. The catchment model will be used to study the sensitivity of the hydrological system to environmental changes in the different types of HRU. Special attention will be paid to the impact of irrigated cultivation on water availability and water salinity.

Vallet-Coulomb, C.; Maurin, A.; Gasse, F.; Ferry, L.; Robison, L.

2003-04-01

366

Troop fission in wild ring-tailed lemurs (Lemur catta) at Berenty, Madagascar.  

PubMed

A detailed fission process in a wild ring-tailed lemur (Lemur catta) troop was observed at Berenty Reserve, Madagascar. The troop fission occurred as follows: 1) During the birth season in 2000, two adult females (mother and daughter) were evicted as a result of "targeted aggression" (i.e., intense and persistent aggressive behavior toward particular individuals). 2) Two adult and three immature females in the same kin group as the evicted females spontaneously immigrated into the new group. 3) A male immigrated into the new group 1.5 months later. 4) The new troop successfully established its own home range. This report exemplifies three characteristics of troop fission in ring-tailed lemurs. First, targeted aggression initiated the fission process. Second, the troop females divided along matrilineal lines. Finally, no male played a specific role in the fission process. PMID:16419123

Ichino, Shinichiro

2006-01-01

367

[Premarital sex in Antananarivo (Madagascar): how are students freeing themselves from the norms?].  

PubMed

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

Gastineau, Bénédicte; Binet, Clotilde

2013-06-01

368

Antiproliferative and antiplasmodial dimeric phloroglucinols from Mallotus oppositifolius from the Madagascar Dry Forest (1).  

PubMed

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 1D- 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 ?M, 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 ?M, respectively). PMID:23286240

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

2013-01-03

369

India-Madagascar Conjugate Margins: Spatiospectral Localization of Isostatic Coherence Estimation  

NASA Astrophysics Data System (ADS)

The two-dimensional (2D) nature of the coherence between Bouguer gravity anomalies and bathymetry on the Western Continental margin of India (WCMI) and Eastern Continental margin of Madagascar (ECMM) and their conjugate nature is examined. We estimated the variation of effective elastic thickness (Te) of the lithosphere for the two margins through cross-spectral analysis of gravity and bathymetry data. The results show that Te values at both margins are comparable, despite WCMI having been traversed along strike by a hotspot trace. We also compared Transitional Coherence wavelength (which is equivalent to lithospheric thickness) which are also comparable, varying from 94 km to 127 km for WCMI and 95 km to 102 km for ECMM. These results indicate that these two margins formed by the symmetrical rifting mechanism and also indicate that despite the presence of a hot spot trace along WCMI, the two margins have comparable isostatic compensation mechanism with low Te values.

Nair, R. R.

2009-05-01

370

[Epidemiological survey and sanitary problems in a village in East Central Madagascar].  

PubMed

An evaluation of health problems is done in a village in Eastern Madagascar, where takes place a development programme. 217 inhabitants go through physical examination and lab tests are performed (Blood smear - Thick drop. Emmel test. Stools examination for parasites and enteroviruses). The epidemiologic investigation reveals the prevalences of Malaria (39,4 p. 100) intestinal schistosomiasis (59,9 p. 100) Ascaridiasis (61,3 p. 100) Hookworm (29,9 p. 100) Trichuriasis (19,8 p. 100) and sickle cells anemia (4,80 p. 100). The signs and symptoms are analysed, particularly spleen enlargement which is shown to be due to schistosomiasis. The local transmition pattern of schistosomiasis is investigated and, according to the malacological findings, is thought to be intermittent. The determination of the local hookworm is started. It should be Necator americanus. The sanitary programme to be set is considered regarding the local contexte. PMID:7200761

Cerf, P; Moyroud, J; Coulanges, P

1981-01-01

371

Diagnosis and treatment of a pharyngeal squamous cell carcinoma in a Madagascar ground boa (Boa madagascariensis).  

PubMed

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

Steeil, James C; Schumacher, Juergen; Hecht, Silke; Baine, Katherine; Ramsay, Edward C; Ferguson, Sylvia; Miller, Debra; Lee, Nathan D

2013-03-01

372

Parasitologic analyses of the sifaka (Propithecus verreauxi verreauxi) at Beza Mahafaly, Madagascar.  

PubMed

A cross-sectional parasitologic survey of a population of wild sifaka (Propithecus verreauxi verreauxi) was conducted at the Beza Mahafaly Special Reserve in southwest Madagascar. Ninety fecal samples were collected from thirty 1- to 30-yr-old male and female sifakas, and the formalin-preserved and polyvinyl alcohol-preserved specimens were examined using the zinc sulfate flotation and formalin-ethyl acetate sedimentation techniques. No intestinal parasites were recovered, possibly because the sifakas are arboreal in a dry, riverine habitat and lack human contact. Low rates of parasitic infection may have contributed to the evolution of later age at first reproduction and longer reproductive lifespan, for body mass, in Propithecus compared with other placental mammals. PMID:14582790

Muehlenbein, Michael P; Schwartz, Marion; Richard, Alison

2003-09-01

373

Immune Responses to Plague Infection in Wild Rattus rattus, in Madagascar: A Role in Foci Persistence?  

PubMed Central

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.

Andrianaivoarimanana, Voahangy; Telfer, Sandra; Rajerison, Minoarisoa; Ranjalahy, Michel A.; Andriamiarimanana, Fehivola; Rahaingosoamamitiana, Corinne; Rahalison, Lila; Jambou, Ronan

2012-01-01

374

Anthropophilic mosquitoes and malaria transmission in the eastern foothills of the central highlands of Madagascar.  

PubMed

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

Andrianaivolambo, Lala; Domarle, Olivier; Randrianarivelojosia, Milijaona; Ratovonjato, Jocelyn; Le Goff, Gilbert; Talman, Arthur; Ariey, Frédéric; Robert, Vincent

2010-09-09

375

Forest Management Devolution: Gap Between Technicians' Design and Villagers' Practices in Madagascar  

NASA Astrophysics Data System (ADS)

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.

Rives, Fanny; Carrière, Stéphanie M.; Montagne, Pierre; Aubert, Sigrid; Sibelet, Nicole

2013-10-01

376

A Genome Sequence Resource for the Aye-Aye (Daubentonia madagascariensis), a Nocturnal Lemur from Madagascar  

PubMed Central

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.

Perry, George H.; Reeves, Darryl; Melsted, Pall; Ratan, Aakrosh; Miller, Webb; Michelini, Katelyn; Louis, Edward E.; Pritchard, Jonathan K.; Mason, Christopher E.; Gilad, Yoav

2012-01-01

377

Forest management devolution: gap between technicians' design and villagers' practices in madagascar.  

PubMed

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. PMID:23974902

Rives, Fanny; Carrière, Stéphanie M; Montagne, Pierre; Aubert, Sigrid; Sibelet, Nicole

2013-08-22

378

[Epidemics of acute respiratory infections in Madagascar in 2002: from alert to confirmation].  

PubMed

An epidemiological investigation (Ministry of Health/Institut Pasteur de Madagascar (IPM)) was conducted in July 2002, in two districts of a same province (Fianarantsoa: Fianarantsoa II and Ikongo) considering the high frequency of deaths linked with acute respiratory infection (ARI). Morbidity and mortality data was collected in the Centre de Santé de Base (CSB) which gave the alert (village of Sahafata, district Fianarantsoa II). Analysis of monthly activity reports (MAR) allowed calculation of incidence rates of ARI/pneumonia in Fianarantsoa province. Virological data was based on the analysis of nasopharyngeal samples collected during the investigations. Clinical symptoms and homogeneity of laboratory results are consistent with an origin of these epidemics being related to the circulation of an influenza virus A subtype H3N2. Attack rates were very high. CFR was significantly higher in individuals of less than 1 year and more than 65 years. This data was confirmed by posterior investigations of teams from MoH/WHO. Surprisingly, this large epidemic was due to a known influenza virus that previously circulated in countries of northern hemisphere (the year before) and even in Antananarivo weeks before. Different hypothesis could be proposed to explain such phenomenon: great restriction of exchanges between different geographical zones, nutritional status.... Conclusion: The epidemic episodes of acute respiratory infections in Madagascar in July 2002 were due to an influenza virus A subtype H3N2 without any genotypic or phenotypic features. Various factors, could explain the importance of the epidemic and particular high lethality found in some age groups. This epidemic illustrates the relative incapacity for a developing country, to face and manage a flu epidemic caused by a classical influenza virus. PMID:15678810

Soares, J L; Ratsitorahina, M; Rakoto Andrianarivelo, M; Robinson, R; Rousset, D; Rasoazanamiarana, L N; Rabarijaona, L P; Manuguerra, J C; Migliani, R

2003-01-01

379

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)

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.

Sreejith, C.; Ravindra Kumar, G. R.

2013-01-01

380

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

|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…

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

2007-01-01

381

Sensitivity of a semi-arid tropical lake basin to environmental changes (Lake Ihotry basin, South-West of Madagascar)  

Microsoft Academic Search

The objective of the study is to analyse the sensitivity of water ressources in a large semi-arid catchment, based on few hydro-meteorological and satellite images analysis. The site is located in the south-west of Madagascar. The catchment, which surface is 3000 km^2, is limited in its eastern side by a North-south relief up to 1000m high. The most important part

C. Vallet-Coulomb; A. Maurin; F. Gasse; L. Ferry; L. Robison

2003-01-01

382

Body mass of wild ring-tailed lemurs in Berenty Reserve, Madagascar, with reference to tick infestation: a preliminary analysis  

Microsoft Academic Search

In 1999, we measured the body mass of 101 wild ring-tailed lemurs (Lemur catta) inhabiting the Berenty Reserve, Madagascar. In addition, we counted the number of ticks [Haemaphysalis (Rhipistoma) lemuris Hoogstraal, 1953] infesting their facial skin and external auditory meatuses. For both males and females, the body mass appeared\\u000a to increase until the age of 3 years. With the apparent exception

Naoki Koyama; Mitsuru Aimi; Yoshi Kawamoto; Hirohisa Hirai; Yasuhiro Go; Shinichiro Ichino; Yukio Takahata

2008-01-01

383

Maternal responses to dead and dying infants in wild troops of ring-tailed lemurs at the Berenty Reserve, Madagascar  

Microsoft Academic Search

We describe responses of seven mothers and other troop members to dead and dying infants in several troops of ring-tailed\\u000a lemurs(Lemur catta) at the Berenty Reserve, Madagascar. In contrast to mothers in simian species, ring-tailed lemur mothers rarely carried their\\u000a dying, immobile or dead infants. However, they sniffed, licked, and touched them even after they had died. While the dying

Masayuki Nakamichi; Naoki Koyama; Alison Jolly

1996-01-01

384

Population and social dynamics changes in ring-tailed lemur troops at Berenty, Madagascar between 1989–1999  

Microsoft Academic Search

In the present study, we recorded all births, immigrations, deaths, and emigrations for a population of ring-tailed lemurs\\u000a at Berenty Reserve, Madagascar, between September 1989 and August 1999. In September 1989, three troops (C, B, and T) inhabited\\u000a the study area of 14.2 ha. During the 10-year period, eight troop divisions, six evictions of females, and three troop takeovers\\u000a of

Naoki Koyama; Masayuki Nakamichi; Shinichiro Ichinc; Yukio Takahata

2002-01-01

385

Genetic diversity of Dalbergia monticola (Fabaceae) an endangered tree species in the fragmented oriental forest of Madagascar  

Microsoft Academic Search

There is an urgent need to maintain and restore a broad genetic base for the management of Dalbergia monticola, a very economically important but endangered tree species in Madagascar. Random amplified polymorphism DNAs (RAPDs) and\\u000a chloroplast micro-satellite markers were used to quantify the genetic variation and to analyse the geographic distribution\\u000a of diversity. Ten locations covering most of the natural

Olivarimbola Andrianoelina; Hery Rakotondraoelina; Lolona Ramamonjisoa; Jean Maley; Pascal Danthu; Jean-Marc Bouvet

386

Genetic Diversity of Dalbergia monticola (Fabaceae) an Endangered Tree Species in the Fragmented Oriental Forest of Madagascar  

Microsoft Academic Search

There is an urgent need to maintain and restore a broad genetic base for the management of Dalbergia monticola, a very economically important but endangered tree species in Madagascar. Random amplified polymorphism DNAs (RAPDs) and\\u000a chloroplast microsatellite markers were used to quantify the genetic variation and to analyse the geographic distribution\\u000a of diversity. Ten locations covering most of the natural

Olivarimbola Andrianoelina; Hery Rakotondraoelina; Lolona Ramamonjisoa; Jean Maley; Pascal Danthu; Jean-Marc Bouvet

2006-01-01

387

Top soil radioactivity assessment in a high natural radiation background area: The case of Vinaninkarena, Antsirabe—Madagascar  

Microsoft Academic Search

The village of Vinaninkarena, Antsirabe, Madagascar (47°02?40?E, 19°57?17?S) is located in a high natural radioactivity area. In order to evaluate the natural radionuclide content in soil, sampling was done on-site by the transect method (85 soil samples) and off-site through transects across and beyond the region (up to a range of 100km), to determine the natural radioactivity variation within vs.

Naivo Rabesiranana; Martin Rasolonirina; Franck Terina; Asivelo F. Solonjara; Raoelina Andriambololona

2008-01-01

388

Régime des eaux souterraines en milieu cristallin altéré: un exemple en zone intertropicale humide d'altitude (Madagascar)  

Microsoft Academic Search

Le régime des eaux souterraines en milieu cristallin altéré (zone intertropicale humide d'altitude de Madagascar) est analysé à grande échelle au cours de trois cycles climatiques successifs: (a) par l'étude hydraulique du milieu (tests par pompages et piézométrie en écoulement naturel); et (b) par des données isotopiques (O et H). Le caractère bicouche de l'aquifère est précisé, en particulier par

J. C. GRILLOT

1992-01-01

389

Tropane Aromatic Ester Alkaloids Obtained from a Large-Scale Recollection of Erythroxylum pervillei Stem Bark Collected in Madagascar#  

PubMed Central

Fractionation by pH zone-refining countercurrent chromatography of an extract of the stem bark of Erythroxylum pervillei, obtained on a kilogram scale in southern Madagascar, led to the isolation and characterization of four tropane aromatic ester alkaloids as minor constituents, namely, pervilleines G (5) and H (6), and cis-pervilleines B (7) and F (8). Their structures were determined by spectroscopic data interpretation.

Chin, Young-Won; Jones, William P.; Waybright, Timothy J.; McCloud, Thomas G.; Rasoanaivo, Philippe; Cragg, Gordon M.; Cassady, John M.; Kinghorn, A. Douglas

2008-01-01

390

Metabolism and temperature regulation during daily torpor in the smallest primate, the pygmy mouse lemur ( Microcebus myoxinus ) in Madagascar  

Microsoft Academic Search

Thermoregulation, energetics and patterns of torpor in the pygmy mouse lemur, Microcebus myoxinus, were investigated under natural conditions of photoperiod and temperature in the Kirindy\\/CFPF Forest in western Madagascar.\\u000a M. myoxinus entered torpor spontaneously during the cool dry season. Torpor only occurred on a daily basis and torpor bout duration was\\u000a on average 9.6?h, and ranged from 4.6?h to 19.2?h.

J. Schmid; T. Ruf; G. Heldmaier

2000-01-01

391

Influence of slash-and-burn farming practices on fallow succession and land degradation in the rainforest region of Madagascar  

Microsoft Academic Search

Slash-and-burn agriculture (tavy) is the major cause of upland degradation and deforestation in eastern Madagascar. Upland degradation studies are largely based on floristic loss and have ignored the link to agriculture, the main activity on the uplands. The objectives were to analyze jointly with the Betsimisaraka farmers how slash-and-burn practices influence fallow species succession, and how current fallow\\/cropping regimes influence

Erika Styger; Harivelo M. Rakotondramasy; Max J. Pfeffer; Erick C. M. Fernandes; David M. Bates

2007-01-01

392

Bayesian analysis of combined chloroplast loci, using multiple calibrations, supports the recent arrival of Melastomataceae in Africa and Madagascar  

Microsoft Academic Search

those authors' divergence time estimates. Morley and Dick concluded that Gondwanan vicariance, rather than the more recent long dispersal proposed by Renner et al. explains the presence of the family in Africa and Madagascar. To assess the strength of this conclusion, a Bayesian analysis was conducted on three times the amount of sequence data used before (ndhF, rbcL, rpl16; 3100

SUSANNE S. RENNER

2004-01-01

393

Mineral-magnetic proxies of erosion\\/oxidation cycles in tropical maar-lake sediments (Lake Tritrivakely, Madagascar): paleoenvironmental implications  

Microsoft Academic Search

Mineral-magnetic measurements were performed on the upper 16m of five piston-cored sedimentary sequences from Lake Tritrivakely, Madagascar. AMS 14C dating and correlation of the five magnetic susceptibility records allowed establishment of a composite sedimentary record of the last 46 kyr. Our data suggest that mineral-magnetic changes result from changes in concentration of strongly ferrimagnetic terrigenous minerals and from preservation\\/dissolution cycles

D Williamson; A Jelinowska; C Kissel; P Tucholka; E Gibert; F Gasse; M Massault; M Taieb; E Van Campo; K Wieckowski

1998-01-01

394

Systematics of limbless scincid lizards from northern Madagascar: morphology, phylogenetic relationships and implications for classification (Squamata: Scincidae)  

Microsoft Academic Search

We report on the rediscovery of two limbless scincid species, Paracontias rothschildi Mocquard, 1905 and Paracontias minimus (Mocquard, 1906), after more than a century. The two species were found in syntopy in sandy soils of Forêt d’Orangea, Antsiranana\\u000a Province, northern Madagascar, which probably constitutes the respective type locality and confirms the species’ Malagasy\\u000a origin. Both taxa are redescribed based on

Jörn Köhler; Miguel Vences; Martina Erbacher; Frank Glaw

2010-01-01

395

Détermination du régime des feux en milieu de savane à Madagascar à partir de séries temporelles d'images MODIS  

Microsoft Academic Search

Dans les milieux de savanes, l'identification des surfaces brûlées et leur suivi sont des informations essentielles pour assurer une bonne gestion et conservation de ces écosystèmes. L'approche choisie repose sur l'analyse de séries temporelles d'images de télédétection à moyenne résolution spatiale. Les savanes étudiées sont situées sur le bassin versant de Marovoay au nord-ouest de Madagascar : elles présentent la particularité

Anne Jacquin; Véronique Cheret; David Sheeren; Gérard Balent

2011-01-01

396

Spillovers from high-value agriculture for exports on land use in developing countries: evidence from Madagascar  

Microsoft Academic Search

High-value agriculture for exports is increasingly important in developing countries. In a case study of contract farming for exports of vegetables from Madagascar, strong spillover effects of these trade opportunities on land use are found to exist. Using a matched plot sampling design, the productivity of rice-the main domestically consumed staple-is shown to be two-thirds higher on fields that were

Bart Minten; Lalaina Randrianarison; Johan Swinnen

2007-01-01

397

Petrogenesis of a basanite–tephrite–phonolite volcanic suite in the Bobaomby (Cap d’Ambre) peninsula, northern Madagascar  

Microsoft Academic Search

The Late Cenozoic Bobaomby volcanic field is located in the northernmost Madagascar, in the area north of the Massif d’Ambre. It comprises widely scattered outcrops of lava flows, dykes, scoria cones, tuff rings and plugs, emplaced in the Meso-Cenozoic sedimentary rocks of the Diego Basin. The Bobaomby rocks range in composition from Mg-rich, sodic basanite to phonolite (MgO from 13

L. Melluso; V. Morra; H. Riziky; J. Veloson; M. Lustrino; L. Del Gatto; V. Modeste

2007-01-01

398

Stable isotopes for characterisation of trends in soil carbon following deforestation and land use change in the highlands of Madagascar  

Microsoft Academic Search

The impacts of human land use in the highlands of Madagascar are often equated with land degradation and decreasing soil fertility. The practice most often focused on is deforestation through slash-and-burn cultivation (tavy), and shifting cultivators are often portrayed as being ignorant, poverty-stricken peasants felling trees for fields and food. However, there is uncertainty whether soil degradation is related to

Tor-Gunnar Vågen; Markus G. Walsh; Keith D. Shepherd

2006-01-01

399

Indigenous fruit trees of Madagascar: potential components of agroforestry systems to improve human nutrition and restore biological diversity  

Microsoft Academic Search

Biodiversity in Eastern Madagascar is threatened by slash and burn agriculture, which is resulting in species extinction,\\u000a land and soil degradation and rural impoverishment. An ethnobotanical study was undertaken to determine the domestication\\u000a potential of indigenous fruit tree species as components of agroforestry systems. Four major selection criteria were used:\\u000a nutritional and income needs of the population, diversification of the

E. Styger; J. E. M. Rakotoarimanana; R. Rabevohitra; E. C. M. Fernandes

1999-01-01

400

Recovery of plant species richness and composition after slash-and-burn agriculture in a tropical rainforest in Madagascar  

Microsoft Academic Search

Slash-and-burn agriculture is an important driver of deforestation and ecosystem degradation, with large effects on biodiversity\\u000a and carbon sequestration. This study was conducted in a forest in Madagascar, which consists of fragments of slash-and-burn\\u000a patches, within a matrix of secondary and primary forest. By recording species richness, abundance, and composition of trees,\\u000a shrubs, and herbs in fallows of various age

Kari Klanderud; Hery Zo Hasiniaina Mbolatiana; Manjato Nadiah Vololomboahangy; Marie Agnes Radimbison; Edmond Roger; Ørjan Totland; Charlotte Rajeriarison

2010-01-01

401

Assessing flavivirus, lentivirus, and herpesvirus exposure in free-ranging ring-tailed lemurs in southwestern Madagascar.  

PubMed

The ring-tailed lemur (Lemur catta) is an endangered species found in southwestern Madagascar, and understanding infectious disease susceptibility is an essential step towards the preservation of wild and captive lemur populations. Lemurs are primates that are widely dispersed throughout the island of Madagascar and may serve as hosts or reservoirs for zoonotic infections. The aim of this study was to determine the prevalence of antibodies to West Nile virus (WNV), simian immunodeficiency virus (SIV), and herpes simplex virus type 1 (HSV-1) in a population of free-ranging ring-tailed lemur from the Beza Mahafaly Special Reserve, Madagascar. Samples were collected from 50 animals during field capture studies in June and July 2004 and assayed for presence of viral antibodies during the 12 mo following collection. Forty-seven of the 50 lemurs sampled had antibodies against WNV detectable by epitope-blocking enzyme-linked immunosorbent assay (ELISA). In addition, 50 of 50 samples had titers against WNV ranging from 80 to > or = 1,280 using plaque reduction neutralization test (PRNT(90)). Ten lemurs had antibodies against lentiviral antigens as determined by Western blot analysis. None of the lemurs had antibodies against HSV-1 using ELISA. PMID:17347392

Sondgeroth, Kerry; Blitvich, Brad; Blair, Carol; Terwee, Julie; Junge, Randall; Sauther, Michelle; VandeWoude, Sue

2007-01-01

402

Sedimentological features of lateritic and saprolitic horizons in a mid-slope lavaka, Central Highlands, Madagascar  

NASA Astrophysics Data System (ADS)

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.

Udvardi, B.; Raveloson, A.; Visnovitz, F.; Szabó, Cs.; Kovács, I.; Székely, B.

2012-04-01

403

The Madagascar hissing cockroach as a novel surrogate host for Burkholderia pseudomallei, B. mallei and B. thailandensis  

PubMed Central

Background Burkholderia pseudomallei and Burkholderia mallei are gram-negative pathogens responsible for the diseases melioidosis and glanders, respectively. Both species cause disease in humans and animals and have been designated as category B select agents by the Centers for Disease Control and Prevention (CDC). Burkholderia thailandensis is a closely related bacterium that is generally considered avirulent for humans. While it can cause disease in rodents, the B. thailandensis 50% lethal dose (LD50) is typically???104-fold higher than the B. pseudomallei and B. mallei LD50 in mammalian models of infection. Here we describe an alternative to mammalian hosts in the study of virulence and host-pathogen interactions of these Burkholderia species. Results Madagascar hissing cockroaches (MH cockroaches) possess a number of qualities that make them desirable for use as a surrogate host, including ease of breeding, ease of handling, a competent innate immune system, and the ability to survive at 37°C. MH cockroaches were highly susceptible to infection with B. pseudomallei, B. mallei and B. thailandensis and the LD50 was <10 colony-forming units (cfu) for all three species. In comparison, the LD50 for Escherichia coli in MH cockroaches was >105?cfu. B. pseudomallei, B. mallei, and B. thailandensis cluster 1 type VI secretion system (T6SS-1) mutants were all attenuated in MH cockroaches, which is consistent with previous virulence studies conducted in rodents. B. pseudomallei mutants deficient in the other five T6SS gene clusters, T6SS-2 through T6SS-6, were virulent in both MH cockroaches and hamsters. Hemocytes obtained from MH cockroaches infected with B. pseudomallei harbored numerous intracellular bacteria, suggesting that this facultative intracellular pathogen can survive and replicate inside of MH cockroach phagocytic cells. The hemolymph extracted from these MH cockroaches also contained multinuclear giant cells (MNGCs) with intracellular B. pseudomallei, which indicates that infected hemocytes can fuse while flowing through the insect’s open circulatory system in vivo. Conclusions The results demonstrate that MH cockroaches are an attractive alternative to mammals to study host-pathogen interactions and may allow the identification of new Burkholderia virulence determinants. The importance of T6SS-1 as a virulence factor in MH cockroaches and rodents suggests that the primary role of this secretion system is to target evasion of the innate immune system.

2012-01-01

404

Diurnal resting in brown lemurs in a dry deciduous forest, northwestern Madagascar: implications for seasonal thermoregulation.  

PubMed

Decreased activity has been reported in both nocturnal and diurnal primates during the prolonged dry season in western Madagascar, and this has been interpreted as a reaction to the severe environment, with its food scarcity and/or thermal stress. Several day-active lemurs rest more as trees defoliate, although the reason for this is unclear. To understand the mechanism underpinning the diurnal resting of lemurs in seasonal deciduous forests, I observed common brown lemurs (Eulemur fulvus fulvus) for one year in Ankarafantsika National Park, northwestern Madagascar. In Ankarafantsika, despite high fruit availability during the dry season, brown lemurs are known to engage in diurnal resting. To examine the effects of thermal factors and defoliation on lemur inactivity, I recorded the activity of a troop at 1 min intervals, hourly ambient temperature, daily rainfall, and weather during observations (06:00-18:00). I quantified the amount of leaves biweekly for 680 trees. I tested correlations between percentages of resting time and each factor across hours during the day and across seasons. During the rainy season, resting time did not differ between sunny and cloudy days, and lemurs were active throughout the daytime. At the hourly level during the dry season, lemurs rested exclusively at midday, apparently at peak sunlight intensity rather than at peak ambient temperature. At seasonal level, percentages of total resting time from 08:00 to 16:00 were greater during dry season (81.9%) than during rainy season (62.6%), and percentages increased as ambient temperatures increased. Defoliation was related to seasonal decrease in weekly rainfall, which served as an index of water retained in the forest. Defoliation probably reflected aridification as well as the penetration of sunlight into the forest. Diurnal resting increased as both the amount of leaves and weekly rainfall decreased seasonally. These results suggest that heat stress under dry conditions may promote resting. Diurnal resting may function as behavioral thermoregulation to avoid overheating and to minimize water loss via excessive evaporative respiration. PMID:22388421

Sato, Hiroki

2012-03-03

405

Long-term changes in dominance ranks among ring-tailed lemurs at Berenty Reserve, Madagascar.  

PubMed

A study was conducted between 1989 and 2001 to monitor changes in the dominance ranks among adult ring-tailed lemurs (Lemur catta) at Berenty Reserve, Madagascar. Adult females were observed to be dominant over adult males. Their rank fluctuated greatly. However, in some troops, female rank orders were fairly stable over a period of several years. In general, male ranks were more unstable than female ranks. Most young females aged 3 years occupied the lowest ranks among adult females. However, several were also observed to have attained relatively higher ranks, placing them right beneath their high-ranking mothers; this suggested the existence of "dependent ranks". Mothers were dominant over their daughters. Similarly, older sisters were usually dominant over younger sisters. The mean duration of alpha status for females was 1.95 years, although considerable variation was observed in the duration of the alpha status (1-5 or more years). Most young males aged 3 years initially occupied the lowest ranks in their natal troops, and then they migrated to non-natal troops around the age of 4 years. They ascended in rank between the ages of 4 and 6 years, although there was considerable variation in the acquirement of high rank. The mean duration of alpha status for males was 2.2 years. Larger males were observed to occupy higher ranks. Occasionally, both males and females showed intense aggression (i.e., targeting aggression) towards others. PMID:16142423

Koyama, Naoki; Ichino, Shinichiro; Nakamichi, Masayuki; Takahata, Yukio

2005-09-03

406

Seroprevalence of antibodies against Chikungunya, Dengue, and Rift Valley fever viruses after febrile illness outbreak, Madagascar.  

PubMed

In October 2009, two-3 months after an outbreak of a febrile disease with joint pain on the eastern coast of Madagascar, we assessed serologic markers for chikungunya virus (CHIKV), dengue virus (DENV), and Rift Valley fever virus (RVFV) in 1,244 pregnant women at 6 locations. In 2 eastern coast towns, IgG seroprevalence against CHIKV was 45% and 23%; IgM seroprevalence was 28% and 5%. IgG seroprevalence against DENV was 17% and 11%. No anti-DENV IgM was detected. At 4 locations, 450-1,300 m high, IgG seroprevalence against CHIKV was 0%-3%, suggesting CHIKV had not spread to higher inland-altitudes. Four women had IgG against RVFV, probably antibodies from a 2008 epidemic. Most (78%) women from coastal locations with CHIKV-specific IgG reported joint pain and stiffness; 21% reported no symptoms. CHIKV infection was significantly associated with high bodyweight. The outbreak was an isolated CHIKV epidemic without relevant DENV co-transmission. PMID:23092548

Schwarz, Norbert G; Girmann, Mirko; Randriamampionona, Njary; Bialonski, Alexandra; Maus, Deborah; Krefis, Anne Caroline; Njarasoa, Christine; Rajanalison, Jeanne Fleury; Ramandrisoa, Herly Daniel; Randriarison, Maurice Lucien; May, Jürgen; Schmidt-Chanasit, Jonas; Rakotozandrindrainy, Raphael

2012-11-01

407

Fine-grained debris flows and extraordinary vertebrate burials in the Late Cretaceous of Madagascar  

NASA Astrophysics Data System (ADS)

Vertebrate fossils are remarkably abundant and exceptionally well preserved within the Upper Cretaceous Maevarano Formation of northwestern Madagascar. The vast majority of these fossils, including all of the currently known bone beds, are entombed within deposits of fine-grained cohesive debris flows. These deposits are typically massive and are characterized by very poor sorting and a significant montmorillonite-dominated silt-clay (mud) fraction ranging from 17% to 46% by weight. Deposition is attributed to recurrent exceptional rainfall events that prompted erosion and flooded ancient channel belts with sediment-laden flows. These extraordinary burial events shielded vertebrate remains from destructive surface processes and also afforded protection for soft tissues. Taphonomic attributes of associated bone concentrations suggest that debris flows had limited transport potential and generally entombed subaerially exposed bone assemblages. The remarkable and recurrent association of bone beds and debris-flow deposits likely reflects marked seasonality in this Late Cretaceous terrestrial ecosystem, with prolonged dry spells prompting mortality and subsequent rains setting debris flows in motion.

Rogers, Raymond R.

2005-04-01

408

Aye-aye (Daubentonia madagascariensis) feeding strategies at Ranomafana National Park, Madagascar: an indirect sampling method.  

PubMed

In this research, we focused on aye-aye populations in Ranomafana National Park, Madagascar. From August to December 2008, we tested how aye-aye feeding was influenced by presence/absence of both fruiting and non-fruiting Canarium trees. Deadwood feeding traces were used as a proxy for evidence of Canarium feeding. We enumerated deadwood feeding traces in 20 locations, 10 with Canarium, 10 without. Each location contained two transects (80 m L × 20 m W) for a total area of 5.6 ha. Feeding trace results for Canarium locations compared to non-Canarium locations were not significant (Z = -1.926, p = 0.083); however, feeding trace results were significant when comparing fruiting and non-fruiting Canarium locations (Z = -2.417, p = 0.016). These results highlight the importance of Canarium in the diet of aye-ayes and demonstrate how the distribution of this resource may influence the foraging behavior of aye-ayes. PMID:22627178

Sefczek, Timothy M; Farris, Zach J; Wright, Patricia C

2012-05-22

409

Biomedical evaluation of black lemurs (Eulemur macaco macaco) in Lokobe Reserve, Madagascar.  

PubMed

Complete medical evaluations were performed on 25 wild black lemurs (Eulemur macaco macaco) in Lokobe Reserve, northwestern Madagascar. Each animal received a complete physical examination. Weight, body temperature, heart rate, and respiratory rate were recorded. 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 Toxoplasma gondii and viral serology. Fecal samples were collected for bacterial culture and endoparasite examination. Ectoparasites were collected and identified. Values were compared to established ranges from captive black lemurs in North American zoos. Significant differences exist between captive and wild animals for total white blood cell count, segmented neutrophil count, band neutrophil count, eosinophil count, monocyte count, and basophil count, and for serum biochemistry values of aspartate aminotransferase, alanine aminotransferase, total bilirubin, serum alkaline phosphatase, total protein, creatinine, phosphorus, calcium, sodium, potassium, and creatine phosphokinase. One animal had a positive Toxoplasma titer. Detected endoparasites were identified as Lemuricola and Callistroura. Two ectoparasite mites were identified, one within the Psoroptes genus and one within the Laelapidae family. Enteric bacterial flora included Enterococcus sp., Staphylococcus sp., Escherichia coli, Streptococcus sp., Klebsiella ozaenae and Bacillus cereus. PMID:17469278

Junge, Randall E; Louis, Edward E

2007-03-01

410

Sex differences in scent marking in Propithecus edwardsi of Ranomafana National Park, Madagascar.  

PubMed

In this study we compared the scent-marking rates of females with those of males. Specifically, we examined the ability of season, dominance status, and natal status to explain the frequency of scent marking in female sifakas living wild in Ranomafana National Park, Madagascar, and compared the results with those published for males [Pochron et al., American Journal of Primatology, in press]. We also sought to determine whether vulnerability to infanticide affects marking frequency in adults of either sex, and whether female reproductive status affects female marking behavior. We found that males marked at twice the rate of females, and like males, females in single-female groups marked at the highest rates. Dominant females and non-natal females marked at higher rates than did subordinate females and natal females, a pattern also seen in males. This suggests that scent marks may convey important information about status. Neither females nor males varied their marking frequency with the presence of vulnerable infants. Females did not alter marking frequency with reproductive state, and like males, they marked at higher rates in the period prior to the mating season than they did in the mating season itself. This implies that females may use scent marks more for intrasexual aggression or territoriality than for mate attraction. PMID:15940709

Pochron, Sharon T; Morelli, Toni Lyn; Scirbona, Jessica; Wright, Patricia C

2005-06-01

411

Sea Surface Temperature and Seawater Oxygen Isotope Variability Recorded in a Madagascar Coral Record  

NASA Astrophysics Data System (ADS)

We analysed a 336 year coral oxygen isotope record off southwest Madagascar in the Mozambique Channel. Based on temporal variability of skeletal oxygen isotopes annual mean sea surface temperatures are reconstructed for the period from 1659 to 1995. Sr/Ca ratios were measured for selected windows with monthly resolution (1973 to 1995, 1863 to 1910, 1784 to 1809, 1688 to 1710) to validate the SST reconstructions derived from oxygen isotopes. The coral proxy data were validated against gridded SST data sets. The coral oxygen isotope record is coherent with Kaplan-SST and GISST2.3b on an interdecadal frequency of 17 years, which is the most prominent frequency band observed in this region. The Sr/Ca-SST agree well with SST observations in the validation period (1863 to 1910), whereas the d18O derived SST show largest discrepencies during this time interval. By taking into account the SST values derived from coral Sr/Ca, we were able to reconstruct d18O seawater variability. This indicates that d18O seawater variations contributed significantly to interannual and interdecadal variations in coral d18O. We propose that the local surface-ocean evaporation-precipitation balance and remote forcing by ENSO via South Equatorial Current and/or Indonesian throughflow variability may contribute to observed d18O variability. Our results indicate that coral d18O may be used to reconstruct temporal variations in the fresh water balance within the Indian Ocean on interannual to interdecadal time scales.

Zinke, J.; Dullo, W. Chr; Eisenhauer, A.

2003-04-01

412

Origin of the high variability of water mineral content in the bedrock aquifers of Southern Madagascar  

NASA Astrophysics Data System (ADS)

This study assesses the causes of the high spatial variability of the mineral content of groundwater in crystalline bedrock of Southern Madagascar. Although many kilometres from the coast and at a mean altitude of 400 m a.s.l, wells drilled in this area produce water with electrical conductivities in the range of 300 30,000 ?S cm-1 with a high spatial variability. Chemical and isotopic data are used to identify the processes involved in the groundwater mineralization. It is shown that the chemical composition of the groundwater in this region has its origin in (i) normal silicate and carbonate weathering reactions and (ii) input of marine salts, probably via rainfall recharge, modified by evapo-concentrative processes probably including precipitation and re-dissolution of secondary evaporites in the unsaturated zone. To obtain a better understanding of the spatial salinity distribution, well parameters such as yields, weathered zone thickness, weathered materials and morphological positions (upper slope, mid-slope, lower slope or valley bottom) are scrutinized. A correlation was found between high salinity and low flow, shallow groundwater environments (flat hill tops, valley bottoms, weakly developed and clayey weathered zones) and between low salinity and high flow environments (granular, well-developed weathered zones and situation on valley slopes).

Rabemanana, V.; Violette, S.; de Marsily, G.; Robain, H.; Deffontaines, B.; Andrieux, P.; Bensimon, M.; Parriaux, A.

2005-08-01

413

Sea Surface Temperature and Seawater Oxygen Isotope Variability Recorded in a Madagascar Coral Record  

NASA Astrophysics Data System (ADS)

Within KIHZ a coral from the lagoon of Ifaty off southwest Madagascar in the Mozambique Channel was examined. Based on temporal variability of skeletal oxygen isotopes annual mean sea surface temperatures are reconstructed for the period from 1658 to 1995. Sr/Ca ratios were measured for selected windows with monthly resolution (1973 to 1995, 1863 to 1910, 1784 to 1809, 1688 to 1710) to validate the SST reconstructions derived from oxygen isotopes. The coral proxy data were validated against gridded SST data sets. The Sr/Ca-SST agree well with SST observations in the validation period (1863 to 1910), whereas the d18O derived SST show largest discrepencies during this time interval. By taking into account the SST values derived from coral Sr/Ca, we were able to reconstruct d18O seawater variability. This indicates that d18O seawater variations contributed significantly to interannual and interdecadal variations in coral d18O. We propose that remote forcing by South Equatorial Current and/or Indonesian throughflow variability may contribute to observed d18O variability. The local surface-ocean evaporation-precipitation balance is also of importance. Our results indicate that coral d18O may be used to reconstruct temporal variations in the fresh water balance within the Indian Ocean on interannual to interdecadal time scales.

Zinke, J.; Dullo, W.; Eisenhauer, A.

2002-12-01

414

Taboos and forest governance: informal protection of hot spot dry forest in southern Madagascar.  

PubMed

In the dry forest of southern Madagascar, a region of global conservation priority, formally protected areas are nearly totally absent. We illustrate how the continued existence of unique forest habitats in the Androy region is directly dependent on informal institutions, taboos, regulating human behavior. Qualitative interviews to map and analyze the social mechanisms underlying forest protection have been combined with vegetation analyses of species diversity and composition. Of 188 forest patches, 93% were classified as protected, and in Southern Androy all remaining forest patches larger than 5 ha were protected. Eight different types of forests, with a gradient of social fencing from open access to almost complete entry prohibitions, were identified. Transgressions were well enforced with strong sanctions of significant economic as well as religious importance. Analyses of species diversity between protected and unprotected forests were complicated because of size differences and access restrictions. However, since, for example, in southern Androy >90% of the total remaining forest cover is protected through taboos, these informal institutions represent an important, and presently the only, mechanism for conservation of the highly endemic forest species. We conclude that social aspects, such as local beliefs and legitimate sanctioning systems, need to be analyzed and incorporated along with biodiversity studies for successful conservation. PMID:18240685

Tengö, Maria; Johansson, Kristin; Rakotondrasoa, Fanambinantsoa; Lundberg, Jakob; Andriamaherilala, Jean-Aimé; Rakotoarisoa, Jean-Aimé; Elmqvist, Thomas

2007-12-01

415

Multi-gene phylogeny of Madagascar's plated lizards, Zonosaurus and Tracheloptychus (Squamata: Gerrhosauridae).  

PubMed

We analyzed the phylogenetic relationships of the Malagasy plated lizards in the family Gerrhosauridae based on DNA sequence fragments of four mitochondrial and five nuclear genes. Various clades were strongly supported by the concatenated data set and also recovered by separate analyses of mtDNA and nucDNA. In particular, two clades here named the Z. rufipes group (containing Z. bemaraha , Z. brygooi , Z. rufipes , Z. subunicolor , Z. tsingy and an undescribed candidate species from northern Madagascar) and the Z. ornatus group (containing Z. anelanelany , Z. laticaudatus , Z. karsteni , Z. ornatus , Z. quadrilineaus, and Z. trilineatus) were resolved with strong support. A third clade named the Z. madagascariensis group contains Z. madagascariensis with a nested Z. haraldmeieri; the status of that species requires further investigation. Tentatively we also include Z. aeneus in this species group although its phylogenetic relationships were poorly resolved. A fourth clade with less support included Z. boettgeri and Z. maximus. The phylogenetic position of the genus Tracheloptychus remains uncertain: whereas in the species tree it was recovered as the sister group to Zonosaurus, other methods indicated that it was nested within Zonosaurus, albeit alternative topologies were rejected with only marginal statistical support. PMID:23831454

Recknagel, Hans; Elmer, Kathryn R; Noonan, Brice P; Raselimanana, Achille P; Meyer, Axel; Vences, Miguel

2013-07-02

416

[Phlebotomus from Madagascar (Diptera: Psychodidae). III--Description of Phlebotomus (Anaphlebotomus) fontenillei n. sp].  

PubMed

The male of Phlebotomus (Anaphlebotomus) fontenillei n. sp. is described from Namoroka area (Madagascar). Its belongs to the subgenus Anaphlebotomus: style with four spines, coxite without basal process and paramere with two branches. It shares with P. berentiensis an original and exclusive antennal formula: 2/III-XII which distinguishes them from P. fertei. P. fontenillei n. sp. differs mainly from P. berentiensis by about 40 setae in tuft on the ventral face of the coxite, the length of the genital ducts and the position of the spines on the style. Sequence of the second internal transcribed spacer (ITS2) of the ribosomal DNA (rDNA) is very informative: the male of P. fontenillei n. sp. cannot be linked to the female of P. huberti (male unknown) regarding the size of amplified DNA fragment (459 bp versus 600 respectively) and the high degree of variability. There are few differences (10 mutations) between the sequences of P. fontenillei n. sp. and P. berentiensis which are closely related species. PMID:15490749

Depaquit, J; Léger, N; Robert, V

2004-09-01

417

[French language training course: malaria workshop organized by Institut Pasteur de Madagascar].  

PubMed

The Malaria Workshop organized by Institut Pasteur de Madagascar is an original course that applies innovative concepts to training of health professionals involved in malaria control in endemic countries. Course objectives are to enhance the skills needed to fight malaria (transversal competencies, critical approach, and position statement), to reinforce project cycle management proficiency, and to demonstrate how the Internet can be used as a source of documentation to compensate for geographical isolation. The Malaria Workshop is a six-consecutive-week full-day course that has been presented once a year since 2003. Seventy-six researchers, physicians or health ministry officials have already benefited from this training. Teaching methods emphasize andragogy that facilitates a learner/mentor relationship promoting exchange rather than transmission of knowledge and problem-based learning that engages learners to take an active part in gathering information. These methods in combination with the diverse backgrounds and experience of course participants foster a positive dynamic environment for learning that is monitored by weekly progress evaluation. Follow-up surveys have confirmed the positive effect of this training on the professional performance of former participants who become more involved in program development and fund-raising efforts. A professional network is growing and learners are starting to their experience. In this report workshop organizers describe the course's origins and concepts and present the conclusions drawn based on the first five yearly sessions. PMID:18225737

Domarle, O; Randrianarivelojosia, M; Duchemin, J B; Robert, V; Ariey, F; Hommel, M

2007-10-01

418

Geometry and kinematics of the late Proterozoic Angavo Shear Zone, Central Madagascar: Implications for Gondwana Assembly  

NASA Astrophysics Data System (ADS)

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.

Raharimahefa, Tsilavo; Kusky, Timothy M.; Toraman, Erkan; Rasoazanamparany, Christine; Rasaonina, Imboarina

2013-04-01

419

Post-collisional magmatism in the central East African Orogen: The Maevarano Suite of north Madagascar  

USGS Publications Warehouse

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.

Goodenough, K. M.; Thomas, R. 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

420

Polyphase Neoproterozoic orogenesis within the east Africa- Antarctica orogenic belt in central and northern Madagascar  

USGS Publications Warehouse

Our recent geological survey of the basement of central and northern Madagascar allowed us to re-evaluate the evolution of this part of the East Africa-Antarctica Orogen (EAAO). Five crustal domains are recognized, characterized by distinctive lithologies and histories of sedimentation, magmatism, deformation and metamorphism, and separated by tectonic and/or unconformable contacts. Four consist largely of Archaean metamorphic rocks (Antongil, Masora and Antananarivo Cratons, Tsaratanana Complex). The fifth (Bemarivo Belt) comprises Proterozoic meta-igneous rocks. The older rocks were intruded by plutonic suites at c. 1000 Ma, 820-760 Ma, 630-595 Ma and 560-520 Ma. The evolution of the four Archaean domains and their boundaries remains contentious, with two end-member interpretations evaluated: (1) all five crustal domains are separate tectonic elements, juxtaposed along Neoproterozoic sutures and (2) the four Archaean domains are segments of an older Archaean craton, which was sutured against the Bemarivo Belt in the Neoproterozoic. Rodinia fragmented during the early Neoproterozoic with intracratonic rifts that sometimes developed into oceanic basins. Subsequent Mid- Neoproterozoic collision of smaller cratonic blocks was followed by renewed extension and magmatism. The global 'Terminal Pan-African' event (560-490 Ma) finally stitched together the Mid-Neoproterozoic cratons to form Gondwana. ?? The Geological Society of London 2011.

Key, R. M.; Pitfield, P. E. J.; Thomas, R. J.; Goodenough, K. M.; Waele, D.; Schofield, D. I.; Bauer, W.; Horstwood, M. S. A.; Styles, M. T.; Conrad, J.; Encarnacion, J.; Lidke, D. J.; O'connor, E. A.; Potter, C.; Smith, R. A.; Walsh, G. J.; Ralison, A. V.; Randriamananjara, T.; Rafahatelo, J. -M.; Rabarimanana, M.

2011-01-01

421

Gastro-intestinal parasites of red-fronted lemurs in Kirindy Forest, western Madagascar.  

PubMed

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

Clough, Dagmar

2010-04-01

422

Case-Control Study of the Etiology of Infant Diarrheal Disease in 14 Districts in Madagascar  

PubMed Central

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.

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

423

Seroprevalence of malaria in inhabitants of the urban zone of Antananarivo, Madagascar  

PubMed Central

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.

Domarle, Olivier; Razakandrainibe, Romy; Rakotomalala, Emma; Jolivet, Laurence; Randremanana, Rindra Vatosoa; Rakotomanana, Fanjasoa; Ramarokoto, Charles Emile; Soares, Jean-Louis; Ariey, Frederic

2006-01-01

424

Rectal Carriage of Extended-Spectrum Beta-Lactamase-Producing Gram-Negative Bacilli in Community Settings in Madagascar  

Microsoft Academic Search

BackgroundExtended-spectrum ß-lactamase-producing Enterobacteria (ESBL-PE) emerged at the end of the 1980s, causing nosocomial outbreaks and\\/or hyperendemic situations in hospitals and long-term care facilities. In recent years, community-acquired infections due to ESBL-PE have spread worldwide, especially across developing countries including Madagascar.ObjectivesThis study aimed to determine the prevalence and risk factors of intestinal carriage of ESBL-PE in the community of Antananarivo.MethodsNon-hospitalized patients

Perlinot Herindrainy; Frédérique Randrianirina; Rila Ratovoson; Elisoa Ratsima Hariniana; Yves Buisson; Nathalie Genel; Dominique Decré; Guillaume Arlet; Antoine Talarmin; Vincent Richard

2011-01-01

425

Top soil radioactivity assessment in a high natural radiation background area: the case of Vinaninkarena, Antsirabe-Madagascar.  

PubMed

The village of Vinaninkarena, Antsirabe, Madagascar (47 degrees 02'40''E, 19 degrees 57'17''S) is located in a high natural radioactivity area. In order to evaluate the natural radionuclide content in soil, sampling was done on-site by the transect method (85 soil samples) and off-site through transects across and beyond the region (up to a range of 100 km), to determine the natural radioactivity variation within vs. outside the region, and to detect significant differences, taking into account spatial variability. PMID:18502647

Rabesiranana, Naivo; Rasolonirina, Martin; Terina, Franck; Solonjara, Asivelo F; Andriambololona, Raoelina

2008-04-11

426

Cryogenian (˜830 Ma) mafic magmatism and metamorphism in the northern Madurai Block, southern India: A magmatic link between Sri Lanka and Madagascar?  

NASA Astrophysics Data System (ADS)

The northern Madurai Block, southern India, lies directly south of, and partly deformed by, the Palghat-Cauvery Shear Zone System (PCSS) - a potential suture of the Neoproterozoic Mozambique Ocean. The Kadavur gabbro-anorthosite complex lies south of the PCSS, in the northern Madurai Block, and crystallized at 829 ± 14 Ma (LA-ICPMS zircon data) in a supra-subduction zone setting. The complex contains zircon &z.epsiv;Hf(t) values of -12.5 to -8.6 that represent Palaeoproterozoic T(DM) model ages (2.3-2.5 Ga). These broadly agree with a whole rock neodymium T(DM) model age of 2287 Ma. Oxygen isotope ?18O ratios range from 5.82‰ and 6.74‰. The parental magma for the gabbro-anorthosites are interpreted to be derived from a juvenile Neoproterozoic mantle contaminated by Mesoarchaean igneous infra-crustal sources. The gabbro-anorthosites intrude quartzites with dominantly Palaeoproterozoic detrital zircons that contain Neoarchaean and Mesoarchaean hafnium model ages. These quartzite zircons contain metamorphic rims that yield an age of 843 ± 23 Ma demonstrating the autochthonous nature of the gabbro-anorthosite complex. Later felsic magmatism is recorded by the 766 ± 8 Ma crystallisation age of the protolith of a felsic gneiss.Cryogenian magmatism in the Madurai Block is interpreted to form part of an extensive arc magmatic province within the southern East African Orogen that can be traced from central Madagascar, through southern India to the Wanni Complex of Sri Lanka. This province is interpreted to have formed above a south/west dipping subduction system as the Mozambique Ocean was subducted under the Neoproterozoic continent Azania.

Teale, William; Collins, Alan S.; Foden, John; Payne, Justin L.; Plavsa, Diana; Chetty, T. R. K.; Santosh, M.; Fanning, Mark

2011-08-01

427

Petrology of ultramafic xenoliths in Cenozoic alkaline rocks of northern Madagascar (Nosy Be Archipelago)  

NASA Astrophysics Data System (ADS)

Late Miocene basanites of Nosy Be and Nosy Sakatia islands (Nosy Be Archipelago, northern Madagascar) carry spinel-facies anhydrous ultramafic xenoliths (lherzolites, harzburgites and wehrlites). Geothermobarometric estimates indicate that these xenoliths derive from shallow mantle depths of 35-40 km, with those from Nosy Be island showing equilibration T (averages in the range of 945-985 °C) lower than the Nosy Sakatia analogues (averages ranging from 1010 to 1110 °C). One Nosy Sakatia mantle xenolith exhibits relatively fertile lherzolite composition, with trace and major element mineral chemistry consistent with a residual character after low degrees (1-2%) of mafic melt extraction. We interpret this composition as that resembling a depleted mantle (DM)-like lithospheric composition before metasomatic overprints. The other lherzolites and harzburgites display petrochemical characters consistent with variable extent of partial melting (up to 18%), associated with pronounced metasomatic overprints caused by migrating melts, as highlighted by enrichments in highly incompatible trace elements (e.g. light rare earth elements, LREE and Sr), together with the abundant occurrence of wehrlitic lithologies.The variability of petrochemical features points to different styles of metasomatism and metasomatic agents. The estimated composition of the parental melts of wehrlites matches that of host basanites. The combination of this evidence with the petrographic features, characterized by coarse-granular to porphyroclastic textures and by the presence of olivine without kink-banding, suggests that wehrlites are veins or pockets of high pressure cumulates within the mantle peridotite. The same melts also metasomatized via porous-flow percolation some lherzolites and harzburgites. Distinctly, a group of lherzolites and harzburgites was metasomatized by a different alkaline melt having markedly lower incompatible trace element contents.Late infiltration of metasomatic fluids is responsible for the spongy texture of some clinopyroxenes of lherzolites, harzburgites and wehrlites.

Rocco, Ivana; Lustrino, Michele; Zanetti, Alberto; Morra, Vincenzo; Melluso, Leone

2013-01-01

428

Phylogenomics and taxonomy of Lecomtelleae (Poaceae), an isolated panicoid lineage from Madagascar.  

PubMed

Background and Aims An accurate characterization of biodiversity requires analyses of DNA sequences in addition to classical morphological descriptions. New methods based on high-throughput sequencing may allow investigation of specimens with a large set of genetic markers to infer their evolutionary history. In the grass family, the phylogenetic position of the monotypic genus Lecomtella, a rare bamboo-like endemic from Madagascar, has never been appropriately evaluated. Until now its taxonomic treatment has remained controversial, indicating the need for re-evaluation based on a combination of molecular and morphological data. Methods The phylogenetic position of Lecomtella in Poaceae was evaluated based on sequences from the nuclear and plastid genomes generated by next-generation sequencing (NGS). In addition, a detailed morphological description of L. madagascariensis was produced, and its distribution and habit were investigated in order to assess its conservation status. Key Results The complete plastid sequence, a ribosomal DNA unit and fragments of low-copy nuclear genes (phyB and ppc) were obtained. All phylogenetic analyses place Lecomtella as an isolated member of the core panicoids, which last shared a common ancestor with other species >20 million years ago. Although Lecomtella exhibits morphological characters typical of Panicoideae, an unusual combination of traits supports its treatment as a separate group. Conclusions The study showed that NGS can be used to generate abundant phylogenetic information rapidly, opening new avenues for grass phylogenetics. These data clearly showed that Lecomtella forms an isolated lineage, which, in combination with its morphological peculiarities, justifies its treatment as a separate tribe: Lecomtelleae. New descriptions of the tribe, genus and species are presented with a typification, a distribution map and an IUCN conservation assessment. PMID:23985988

Besnard, Guillaume; Christin, Pascal-Antoine; Malé, Pierre-Jean G; Coissac, Eric; Ralimanana, Hélène; Vorontsova, Maria S

2013-08-28

429

A Decade of Plague in Mahajanga, Madagascar: Insights into the Global Maritime Spread of Pandemic Plague  

PubMed Central

ABSTRACT A cluster of human plague cases occurred in the seaport city of Mahajanga, Madagascar, from 1991 to 1999 following 62 years with no evidence of plague, which offered insights into plague pathogen dynamics in an urban environment. We analyzed a set of 44 Mahajanga isolates from this 9-year outbreak, as well as an additional 218 Malagasy isolates from the highland foci. We sequenced the genomes of four Mahajanga strains, performed whole-genome sequence single-nucleotide polymorphism (SNP) discovery on those strains, screened the discovered SNPs, and performed a high-resolution 43-locus multilocus variable-number tandem-repeat analysis of the isolate panel. Twenty-two new SNPs were identified and defined a new phylogenetic lineage among the Malagasy isolates. Phylogeographic analysis suggests that the Mahajanga lineage likely originated in the Ambositra district in the highlands, spread throughout the northern central highlands, and was then introduced into and became transiently established in Mahajanga. Although multiple transfers between the central highlands and Mahajanga occurred, there was a locally differentiating and dominant subpopulation that was primarily responsible for the 1991-to-1999 Mahajanga outbreaks. Phylotemporal analysis of this Mahajanga subpopulation revealed a cycling pattern of diversity generation and loss that occurred during and after each outbreak. This pattern is consistent with severe interseasonal genetic bottlenecks along with large seasonal population expansions. The ultimate extinction of plague pathogens in Mahajanga suggests that, in this environment, the plague pathogen niche is tenuous at best. However, the temporary large pathogen population expansion provides the means for plague pathogens to disperse and become ecologically established in more suitable nonurban environments.

Vogler, Amy J.; Chan, Fabien; Nottingham, Roxanne; Andersen, Genevieve; Drees, Kevin; Beckstrom-Sternberg, Stephen M.; Wagner, David M.; Chanteau, Suzanne; Keim, Paul

2013-01-01

430

Patterns of loss and regeneration of tropical dry forest in Madagascar: the social institutional context.  

PubMed

Loss of tropical forests and changes in land-use/land-cover are of growing concern worldwide. Although knowledge exists about the institutional context in which tropical forest loss is embedded, little is known about the role of social institutions in influencing regeneration of tropical forests. In the present study we used Landsat images from southern Madagascar from three different years (1984, 1993 and 2000) and covering 5500 km(2), and made a time-series analysis of three distinct large-scale patterns: 1) loss of forest cover, 2) increased forest cover, and 3) stable forest cover. Institutional characteristics underlying these three patterns were analyzed, testing the hypothesis that forest cover change is a function of strength and enforcement of local social institutions. The results showed a minor decrease of 7% total forest cover in the study area during the whole period 1984-2000, but an overall net increase of 4% during the period 1993-2000. The highest loss of forest cover occurred in a low human population density area with long distances to markets, while a stable forest cover occurred in the area with highest population density and good market access. Analyses of institutions revealed that loss of forest cover occurred mainly in areas characterized by insecure property rights, while areas with well-defined property rights showed either regenerating or stable forest cover. The results thus corroborate our hypothesis. The large-scale spontaneous regeneration dominated by native endemic species appears to be a result of a combination of changes in precipitation, migration and decreased human population and livestock grazing pressure, but under conditions of maintained and well-defined property rights. Our study emphasizes the large capacity of a semi-arid system to spontaneously regenerate, triggered by decreased pressures, but where existing social institutions mitigate other drivers of deforestation and alternative land-use. PMID:17476324

Elmqvist, Thomas; Pyykönen, Markku; Tengö, Maria; Rakotondrasoa, Fanambinantsoa; Rabakonandrianina, Elisabeth; Radimilahy, Chantal

2007-05-02

431

Co-circulation and evolution of polioviruses and species C enteroviruses in a district of Madagascar.  

PubMed

Between October 2001 and April 2002, five cases of acute flaccid paralysis (AFP) associated with type 2 vaccine-derived polioviruses (VDPVs) were reported in the southern province of the Republic of Madagascar. To determine viral factors that favor the emergence of these pathogenic VDPVs, we analyzed in detail their genomic and phenotypic characteristics and compared them with co-circulating enteroviruses. These VDPVs appeared to belong to two independent recombinant lineages with sequences from the type 2 strain of the oral poliovaccine (OPV) in the 5'-half of the genome and sequences derived from unidentified species C enteroviruses (HEV-C) in the 3'-half. VDPV strains showed characteristics similar to those of wild neurovirulent viruses including neurovirulence in poliovirus-receptor transgenic mice. We looked for other VDPVs and for circulating enteroviruses in 316 stools collected from healthy children living in the small area where most of the AFP cases occurred. We found vaccine PVs, two VDPVs similar to those found in AFP cases, some echoviruses, and above all, many serotypes of coxsackie A viruses belonging to HEV-C, with substantial genetic diversity. Several coxsackie viruses A17 and A13 carried nucleotide sequences closely related to the 2C and the 3D(pol) coding regions of the VDPVs, respectively. There was also evidence of multiple genetic recombination events among the HEV-C resulting in numerous recombinant genotypes. This indicates that co-circulation of HEV-C and OPV strains is associated with evolution by recombination, resulting in unexpectedly extensive viral diversity in small human populations in some tropical regions. This probably contributed to the emergence of recombinant VDPVs. These findings give further insight into viral ecosystems and the evolutionary processes that shape viral biodiversity. PMID:18085822

Rakoto-Andrianarivelo, Mala; Guillot, Sophie; Iber, Jane; Balanant, Jean; Blondel, Bruno; Riquet, Franck; Martin, Javier; Kew, Olen; Randriamanalina, Bakolalao; Razafinimpiasa, Lalatiana; Rousset, Dominique; Delpeyroux, Francis

2007-12-01

432

The ranging behavior of Lemur catta in the region of Cap Sainte-Marie, Madagascar.  

PubMed

Large home ranges and extreme flexibility in ranging behaviors characterize most subarid dwelling haplorhines. However, the most comparable extant strepsirhine, Lemur catta, is characterized as having small home ranges with consistent boundaries. Since ranging studies on this species have been limited to gallery forest habitat, the author's goal is to identify ecological factors that affect range use of L. catta in one of the most resource-limited environments of its distribution. To conduct this study, ranging and behavioral data were collected on two nonoverlapping groups through all-day follows in the semidesert scrub environment of Cap Sainte-Marie (CSM), Madagascar. Data were collected from August 2007 through July 2008. Home range areas and day range lengths were generated using ArcGIS(®) 9.3. Other variables measured were habitat composition, diet richness, daily activity, and microclimate. Home range areas of CSM L. catta were very large relative to those of gallery forest L. catta, and there was great monthly variation. In contrast, day range lengths at CSM were either smaller than or approximated the size of comparative gallery forest groups. Temperature, sunning, and diet richness were associated with day range length for one but not for both groups and appear to be related to energy management needs. Based on these findings, the author suggests that L. catta is capable of extensive behavioral and ranging flexibility in the extremes of its environment. However, physiological constraints impose limitations that can interfere with its ability to adapt to even seemingly minor variations in microclimate and habitat structure within the same site. PMID:23180618

Kelley, Elizabeth A

2012-11-26

433

Successful contracting of prevention services: fighting malnutrition in Senegal and Madagascar.  

PubMed

There are very few documented large-scale successes in nutrition in Africa, and virtually no consideration of contracting for preventive services. This paper describes two successful large-scale community nutrition projects in Africa as examples of what can be done in prevention using the contracting approach in rural as well as urban areas. The two case-studies are the Secaline project in Madagascar, and the Community Nutrition Project in Senegal. The article explains what is meant by 'success' in the context of these two projects, how these results were achieved, and how certain bottlenecks were avoided. Both projects are very similar in the type of service they provide, and in combining private administration with public finance. The article illustrates that contracting out is a feasible option to be seriously considered for organizing certain prevention programmes on a large scale. There are strong indications from these projects of success in terms of reducing malnutrition, replicability and scale, and community involvement. When choosing that option, a government can tap available private local human resources through contracting out, rather than delivering those services by the public sector. However, as was done in both projects studied, consideration needs to be given to using a contract management unit for execution and monitoring, which costs 13-17% of the total project's budget. Rigorous assessments of the cost-effectiveness of contracted services are not available, but improved health outcomes, targeting of the poor, and basic cost data suggest that the programmes may well be relatively cost-effective. Although the contracting approach is not presented as the panacea to solve the malnutrition problem faced by Africa, it can certainly provide an alternative in many countries to increase coverage and quality of services. PMID:10787654

Marek, T; Diallo, I; Ndiaye, B; Rakotosalama, J

1999-12-01

434

The importance of taboos and social norms to conservation in Madagascar.  

PubMed

Informal institutions governing the use of wild species are present in many societies. A system of prohibitions known as fady is central to Malagasy culture. We examined whether fady that relate to the use of natural resources in the eastern rainforests of Madagascar play an important conservation role. Prohibitions ranged from strict taboos in which a species or area was forbidden by the ancestors to social norms that concerned acceptable behavior when harvesting wild species. Strict taboos offered real protection to threatened species, such as the lemur Propithecus edwardsi and the carnivore Cryptoprocta ferox. Taboos also reduced pressure on some economically important endemic species by preventing their sale or limiting the harvest season. Despite their value for conservation, the taboos did not appear to originate from attempts to sustainably manage resources. Nevertheless, social norms, in which the sanction was social disapproval rather than supernatural retribution, encouraged sustainable harvesting practices for tenrecs (Tenrec ecudatus) and pandans (Pandanus spp.). Unfortunately, the social norms concerning methods of harvesting pandans appeared to be breaking down in villages surrounding Ranomafana National Park, and we suggest that the imposition of external conservation rules is weakening traditional management. Informal institutions are important to conservation because they suggest ways of improving cultural understanding and conservation communication. Food taboos influence societal preferences, which affect the wider demand for a species. Most important, where capacity to enforce external conservation rules is limited, informal institutions may provide the only effective regulations. Informal institutions should receive greater attention from conservation biologists so that local people's conservation roles can be acknowledged fairly and so that potential synergies with conservation objectives can be realized. PMID:18616743

Jones, Julia P G; Andriamarovololona, Mijasoa M; Hockley, Neal

2008-07-09

435

Organic matter sources and early diagenetic degradation in a tropical peaty marsh (Tritrivakely, Madagascar). Implications for environmental reconstruction during the Sub-Atlantic  

Microsoft Academic Search

Peat samples from a one metre core and living Cyperaceae, collected in Tritrivakely marsh in Madagascar, were studied to determine the organic matter (OM) composition and extent of OM degradation in this core. The study was carried out combining light microscopy observations, bulk analyses, infra-red spectroscopy, hydrolyses of sugars, oxidation of lignin and pyrolyses. In the surface peat, organic matter

Sonia Bourdon; Fatima Laggoun-Défarge; Jean-Robert Disnar; Ousmane Maman; Bernard Guillet; Sylvie Derenne; Claude Largeau

2000-01-01

436

Population Ecology of the Ring-Tailed Lemur, Lemur catta, and the White Sifaka, Propithecus verreauxi verreauxi, at Berenty, Madagascar, 1981  

Microsoft Academic Search

The diurnal lemurs Propithecus verreauxi verreauxi and Lemur catta at Berenty in southern Madagascar, have been studied for the last 30 years. The August 1981 census indicates that the population size of L. catta remains stable at 150 adults but that P. v. verreauxi troops have become fragmented and scattered and the population is apparently increasing. Eight different vegetation types

C. J. Howarth; J. M. Wilson; A. P. Adamson; M. E. Wilson; M. J. Boase

1986-01-01

437

‘Even with higher education you remain a woman’: a gender perspective on higher education and social change in the Toliara region of Madagascar  

Microsoft Academic Search

This article investigates some issues related to gender and education based on a qualitative, empirical study of women in higher education in the Toliara region of Madagascar. The focus is on how women’s participation in higher education has created changes in gender relations, and how these women have succeeded in achieving higher education. In spite of the interviewed women’s more

Marianne Skjortnes; Heidi Holt Zachariassen

2010-01-01

438

THE EFFECT OF LOCAL ROCK PHOSPHATE FERTILIZER ON YIELD OF MAIZE IN P-DEFICIENT SOILS OF THE CENTRAL PLATEAU OF MADAGASCAR  

Microsoft Academic Search

Orthic Ferralsols of the moist Mid-Altitude Central Plateau of Madagascar are characterized among other things by low pH, low exchangeable bases especially Ca, and high deficiency in P and N. Low and declining fertility from soil nutrient mining without replenishment are responsible for the poor production levels of smallholder farms with limited cash access. Local rock phosphate named Barren hyperphosphate

R. Ramilison

439

Relative infectivity of two Pisolithus spp. strains inoculated to the nitrogen-fixing legume tree Acacia crassicarpa A. Cunn. ex Benth. in a field experiment in Madagascar  

Microsoft Academic Search

A field behaviour trial was set up in Mahela (Madagascar) to evaluate the ecological competence of two ectomycorrhizal fungal strains on Acacia crassicarpa. This fast-growing Australasian species is very well appreciated locally by farmers as multipurpose wood. However, its symbiotic associations with nitrogen fixing bacteria, ectomycorrhizas, and arbuscular mycorrhizas have been poorly studied so far. The inoculated fungal strains used

Marc Ducousso; Antoine Galiana; Gilles Chaix; Yves Prin

2004-01-01

440

Mulch type affects soil biological functioning and crop yield of conservation agriculture systems in a long-term experiment in Madagascar  

Microsoft Academic Search

Conservation agriculture (CA) is rapidly developing in Madagascar but little is known about its effects on local soil functioning. To assess some of those effects, we investigated the effects of three CA systems and two levels of fertilization on soil functioning using nematofauna as indicator. The systems consisted in (i) soybean (Glycine max L.)-maize (Zea mays L.) rotation with mulch

Djibril Djigal; Stéphane Saj; Bodovololona Rabary; Eric Blanchart; Cécile Villenave

441

Developpement, amenagement linguistique et terminologie: Un mythe? L'exemple de la malgachisation (Development, Language Planning, and Terminology: A Myth? The Example of Madagascar).  

ERIC Educational Resources Information Center

The French language provides a context for comparison of the modernization efforts of Quebec and Madagascar, looking at the following issues: the beginning role of the language in the society, political influences, language needs for technology transfer and the introduction of terminology in societies with well-documented and poorly-documented…

Boulanger, Jean-Claude

1989-01-01