58 research outputs found

    Genetic Diversity and Population History of a Critically Endangered Primate, the Northern Muriqui (Brachyteles hypoxanthus)

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    Social, ecological, and historical processes affect the genetic structure of primate populations, and therefore have key implications for the conservation of endangered species. The northern muriqui (Brachyteles hypoxanthus) is a critically endangered New World monkey and a flagship species for the conservation of the Atlantic Forest hotspot. Yet, like other neotropical primates, little is known about its population history and the genetic structure of remnant populations. We analyzed the mitochondrial DNA control region of 152 northern muriquis, or 17.6% of the 864 northern muriquis from 8 of the 12 known extant populations and found no evidence of phylogeographic partitions or past population shrinkage/expansion. Bayesian and classic analyses show that this finding may be attributed to the joint contribution of female-biased dispersal, demographic stability, and a relatively large historic population size. Past population stability is consistent with a central Atlantic Forest Pleistocene refuge. In addition, the best scenario supported by an Approximate Bayesian Computation analysis, significant fixation indices (ΦST = 0.49, ΦCT = 0.24), and population-specific haplotypes, coupled with the extirpation of intermediate populations, are indicative of a recent geographic structuring of genetic diversity during the Holocene. Genetic diversity is higher in populations living in larger areas (>2,000 hectares), but it is remarkably low in the species overall (θ = 0.018). Three populations occurring in protected reserves and one fragmented population inhabiting private lands harbor 22 out of 23 haplotypes, most of which are population-exclusive, and therefore represent patchy repositories of the species' genetic diversity. We suggest that these populations be treated as discrete units for conservation management purposes

    Use of the mini-mental state examination in research on the elderly in Brazil: a systematic review

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    The Mini-Mental State Examination (MMSE) is the most widely used cognitive screening test around the world. In Brazil, different MMSE versions and many cut-off points have been used. A systematic review of papers indexed in Scielo was conducted in order to analyze use of the MMSE in Brazilian empirical studies with elderly people. To search for these texts, the complete name of the instrument and its abbreviation were used. A growth trend in the scientific production during the 1998 to 2013 period was observed. Eleven versions of the MMSE were identified and the Bertolucci et al. version was the most cited. Over half of the studies used schooling as the criteria to establish cut-off points. The studies were predominantly conducted using samples recruited from large cities in the Southeastern region and in the community. Despite the growing trend of research with the elderly using the MMSE, the psychometric properties of this scale of measurement have been the subject of little investigation. Despite the widespread use of the MMSE in Brazil, there is a lack of standardization and evidence of validity for this this scale of measurement.O Mini Exame do Estado Mental (MEEM) é o teste de rastreio cognitivo mais utilizado no mundo. No Brasil, diferentes versões e pontos de corte do MEEM têm sido usados. Para analisar seu uso em estudos empíricos brasileiros com idosos, efetuou-se uma revisão sistemática de artigos indexados na SciELO. Foram utilizados o nome completo do instrumento e sua abreviação para recuperar os textos. Observou-se uma tendência de crescimento da produção científica analisada, no período de 1998 a 2013. Foram mencionadas 11 versões do MEEM, destacando-se a de Bertolucci et al. Mais da metade das investigações fizeram uso da escolaridade como critério para estabelecer pontos de corte. Os estudos têm sido realizados predominantemente com amostras recrutadas em grandes cidades da região Sudeste e na comunidade. Não obstante a tendência de crescimento de pesquisas com idosos que utilizam o MEEM, as propriedades psicométricas dessa medida têm sido pouco investigadas. Apesar da ampla utilização do MEEM no Brasil, faltam padronização e evidências de validade para essa medida
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