126 research outputs found

    Lower Devonian rhynchonellid brachiopods from the Ougarta area (western Sahara, Algeria)

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    The description and study of rhynchonellid brachiopods recently collected from the Lower Devonian of the Ougarta area in western Algerian Sahara permitted the revision of previously described and/or listed taxa, mainly from Morocco. Palaeobiogeographically, the nine identified taxa share many similarities with the rhynchonellid fauna of the Ibarmaghian Domain. Five of the nine identified taxa belong to three genera of the Family Nucinulidae Sartenaer, 2004. Three of these are new taxa, namely Nucinulus orbignyanus crassicostus subsp. nov., Cuninulus ougartaensis sp. nov. and Palinulus saharaensis sp. nov. The our remaining taxa are assigned (one of them questionably) to the genera Lanceomyonia, Stenorhynchia and Glossinulus of the families Hebetoechiidae, Trigonirhynchiidae, and Glossinotoechiidae, respectively.Peer reviewe

    Les sites remarquables

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    Persistence of Protective Immunity to Malaria Induced by DNA Priming and Poxvirus Boosting: Characterization of Effector and Memory CD8+-T-Cell Populations

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    The persistence of immunity to malaria induced in mice by a heterologous DNA priming and poxvirus boosting regimen was characterized. Mice were immunized by priming with DNA vaccine plasmids encoding the Plasmodium yoelii circumsporozoite protein (PyCSP) and murine granulocyte-macrophage colony-stimulating factor and boosting with recombinant vaccinia encoding PyCSP. BALB/c mice immunized with either high-dose (100 µg of p PyCSP plus 30 µg of pGM-CSF) or low-dose (1 µg of p PyCSP plus 1 µg of pGM-CSF DNA) priming were protected against challenge with 50 P. yoelii sporozoites. Protection 2 weeks after immunization was 70 to 100%, persisted at this level for at least 20 weeks, and declined to 30 to 40% by 28 weeks. Eight of eight mice protected at 20 weeks were still protected when rechallenged at 40 weeks. The antigen (Ag)-specific effector CD8+-T-cell population present 2 weeks after boosting had ex vivo Ag-specific cytolytic activity, expressed both gamma interferon (IFN-{gamma}) and tumor necrosis factor alpha, and constituted 12 to 20% of splenic CD8+ T cells. In contrast, the memory CD8+-Ag-specific-cell population at 28 weeks lacked cytolytic activity and constituted only 6% of splenic CD8+ T cells, but at the single-cell level it produced significantly higher levels of IFN-{gamma} than the effectors. High levels of Ag- or parasite-specific antibodies present 2 weeks after boosting had declined three- to sevenfold by 28 weeks. Low-dose priming was similarly immunogenic and as protective as high-dose priming against a 50-, but not a 250-, sporozoite challenge. These results demonstrate that a heterologous priming and boosting vaccination can provide lasting protection against malaria in this model system

    Evidence of decline of malaria in the general hospital of Libreville, Gabon from 2000 to 2008

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    BACKGROUND: Substantial decline in malaria transmission, morbidity and mortality has been reported in several countries where new malaria control strategies have been implemented. In Gabon, the national malaria policy changed in 2003, according to the WHO recommendations. The trend in malaria morbidity was evaluated among febrile children before and after their implementation in Libreville, the capital city of Gabon. METHODS: From August 2000 to December 2008, febrile paediatric outpatients and inpatients, under 11 years of age, were screened for malaria by microscopic examination at the Malaria Clinical Research Unit (MCRU) located in the largest public hospital in Gabon. Climatic data were also collected. RESULTS: In total, 28,092 febrile children were examined; those under five years always represented more than 70%. The proportion of malaria-positive slides was 45% in 2000, and declined to 15% in 2008. The median age of children with a positive blood smear increased from 24(15-48) to 41(21-72) months over the study period (p < 0.01). Rainfall patterns had no impact on the decline observed throughout the study period. CONCLUSION: The decrease of malaria prevalence among febrile children during the last nine years is observed following the introduction of new strategies of malaria cases management, and may announce epidemiological changes. Moreover, preventive measures must be extended to children older than five years

    Microcephaly with or without chorioretinopathy, lymphoedema, or mental retardation (MCLMR): review of phenotype associated with KIF11 mutations

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    Microcephaly with or without chorioretinopathy, lymphoedema, or mental retardation (MCLMR) (MIM No.152950) is a rare autosomal dominant condition for which a causative gene has recently been identified. Mutations in the kinesin family member 11 (KIF11) gene have now been described in 16 families worldwide. This is a review of the condition based on the clinical features of 37 individuals from 22 families. This report includes nine previously unreported families and additional information for some of those reported previously. The condition arose de novo in 8/20 families (40%). The parental results were not available for two probands. The mutations were varied and include missense, nonsense, frameshift, and splice site and are distributed evenly throughout the KIF11 gene. In our cohort, 86% had microcephaly, 78% had an ocular abnormality consistent with the diagnosis, 46% had lymphoedema, 73% had mild-moderate learning difficulties, 8% had epilepsy, and 8% had a cardiac anomaly. We identified three individuals with KIF11 mutations but no clinical features of MCLMR demonstrating reduced penetrance. The variable expression of the phenotype and the presence of mildly affected individuals indicates that the prevalence may be higher than expected, and we would therefore recommend a low threshold for genetic testing

    \u27Struggling with Language\u27 : Indigenous movements for Linguistic Security and the Politics of Local Community

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    In this article, I explore the relationship between linguistic diversity and political power. Specifically, I outline some of the ways that linguistic diversity has served as a barrier to the centralization of power, thus constraining, for example, the political practice of empire-formation. A brief historical example of this dynamic is presented in the case of Spanish colonialism of the 16th-century. The article proceeds then to demonstrate how linguistic diversity remains tied to struggles against forms of domination. I argue that in contemporary indigenous movements for linguistic security, the languages themselves are not merely conceived of as the object of the political struggle, but also as the means to preserve a space for local action and deliberation – a ‘politics of local community’. I show that linguistic diversity and the devolution of political power to the local level are in a mutually reinforcing relationship. Finally, I consider the implications of this thesis for liberal theorizing on language rights, arguing that such theory cannot fully come to terms with this political-strategic dimension of language struggles

    Vaccination with Plasmodium knowlesi AMA1 Formulated in the Novel Adjuvant Co-Vaccine HTâ„¢ Protects against Blood-Stage Challenge in Rhesus Macaques

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    Plasmodium falciparum apical membrane antigen 1 (PfAMA1) is a leading blood stage vaccine candidate. Plasmodium knowlesi AMA1 (PkAMA1) was produced and purified using similar methodology as for clinical grade PfAMA1 yielding a pure, conformational intact protein. Combined with the adjuvant CoVaccine HT™, PkAMA1 was found to be highly immunogenic in rabbits and the efficacy of the PkAMA1 was subsequently tested in a rhesus macaque blood-stage challenge model. Six rhesus monkeys were vaccinated with PkAMA1 and a control group of 6 were vaccinated with PfAMA1. A total of 50 µg AMA1 was administered intramuscularly three times at 4 week intervals. One of six rhesus monkeys vaccinated with PkAMA1 was able to control parasitaemia, upon blood stage challenge with P. knowlesi H-strain. Four out of the remaining five showed a delay in parasite onset that correlated with functional antibody titres. In the PfAMA1 vaccinated control group, five out of six animals had to be treated with antimalarials 8 days after challenge; one animal did not become patent during the challenge period. Following a rest period, animals were boosted and challenged again. Four of the six rhesus monkeys vaccinated with PkAMA1 were able to control the parasitaemia, one had a delayed onset of parasitaemia and one animal was not protected, while all control animals required treatment. To confirm that the control of parasitaemia was AMA1-related, animals were allowed to recover, boosted and re-challenged with P. knowlesi Nuri strain. All control animals had to be treated with antimalarials by day 8, while five out of six PkAMA1 vaccinated animals were able to control parasitaemia. This study shows that: i) Yeast-expressed PkAMA1 can protect against blood stage challenge; ii) Functional antibody levels as measured by GIA correlated inversely with the day of onset and iii) GIA IC50 values correlated with estimated in vivo growth rates
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