32 research outputs found

    Multi-dimensionality and variability in folk classification of stingless bees (Apidae: Meliponini)

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    Background: Not long ago Eugene Hunn suggested using a combination of cognitive, linguistic, ecological and evolutionary theories in order to account for the dynamic character of ethnoecology in the study of folk classification systems. In this way he intended to question certain homogeneity in folk classifications models and deepen in the analysis and interpretation of variability in folk classifications. This paper studies how a rural culturally mixed population of the Atlantic Forest of Misiones (Argentina) classified honey-producing stingless bees according to the linguistic, cognitive and ecological dimensions of folk classification. We also analyze the socio-ecological meaning of binomialization in naming and the meaning of general local variability in the appointment of stingless bees. Methods: We used three different approaches: the classical approach developed by Brent Berlin which relies heavily on linguistic criteria, the approach developed by Eleonor Rosch which relies on psychological (cognitive) principles of categorization and finally we have captured the ecological dimension of folk classification in local narratives. For the second approximation, we developed ways of measuring the degree of prototypicality based on a total of 107 comparisons of the type "X is similar to Y" identified in personal narratives. Results: Various logical and grouping strategies coexist and were identified as: graded of lateral linkage, hierarchical and functional. Similarity judgments among folk taxa resulted in an implicit logic of classification graded according to taxa's prototypicality. While there is a high agreement on naming stingless bees with monomial names, a considerable number of underrepresented binomial names and lack of names were observed. Two possible explanations about reported local naming variability are presented. Conclusions: We support the multidimensionality of folk classification systems. This confirms the specificity of local classification systems but also reflects the use of grouping strategies and mechanisms commonly observed in other cultural groups, such as the use of similarity judgments between more or less prototypical organisms. Also we support the idea that alternative naming results from a process of fragmentation of knowledge or incomplete transmission of knowledge. These processes lean on the facts that culturally based knowledge, on the one hand, and biologic knowledge of nature on the other, can be acquired through different learning pathways.Fil: Zamudio, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); ArgentinaFil: Hilgert, Norma Ines. Consejo Nacional de Investigaciones Cientiâ­ficas y Tecnicas. Centro Cientifico Tecnologico Nordeste. Instituto de Biologia Subtropical. Instituto de Biologia Subtropical - Nodo Puerto Iguazu; Argentin

    Evolutionary diversity is associated with wood productivity in Amazonian forests

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    Higher levels of taxonomic and evolutionary diversity are expected to maximize ecosystem function, yet their relative importance in driving variation in ecosystem function at large scales in diverse forests is unknown. Using 90 inventory plots across intact, lowland, terra firme, Amazonian forests and a new phylogeny including 526 angiosperm genera, we investigated the association between taxonomic and evolutionary metrics of diversity and two key measures of ecosystem function: aboveground wood productivity and biomass storage. While taxonomic and phylogenetic diversity were not important predictors of variation in biomass, both emerged as independent predictors of wood productivity. Amazon forests that contain greater evolutionary diversity and a higher proportion of rare species have higher productivity. While climatic and edaphic variables are together the strongest predictors of productivity, our results show that the evolutionary diversity of tree species in diverse forest stands also influences productivity. As our models accounted for wood density and tree size, they also suggest that additional, unstudied, evolutionarily correlated traits have significant effects on ecosystem function in tropical forests. Overall, our pan-Amazonian analysis shows that greater phylogenetic diversity translates into higher levels of ecosystem function: tropical forest communities with more distantly related taxa have greater wood productivity

    Carbon uptake by mature Amazon forests has mitigated Amazon nations' carbon emissions

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    BACKGROUND: Several independent lines of evidence suggest that Amazon forests have provided a significant carbon sink service, and also that the Amazon carbon sink in intact, mature forests may now be threatened as a result of different processes. There has however been no work done to quantify non-land-use-change forest carbon fluxes on a national basis within Amazonia, or to place these national fluxes and their possible changes in the context of the major anthropogenic carbon fluxes in the region. Here we present a first attempt to interpret results from ground-based monitoring of mature forest carbon fluxes in a biogeographically, politically, and temporally differentiated way. Specifically, using results from a large long-term network of forest plots, we estimate the Amazon biomass carbon balance over the last three decades for the different regions and nine nations of Amazonia, and evaluate the magnitude and trajectory of these differentiated balances in relation to major national anthropogenic carbon emissions. RESULTS: The sink of carbon into mature forests has been remarkably geographically ubiquitous across Amazonia, being substantial and persistent in each of the five biogeographic regions within Amazonia. Between 1980 and 2010, it has more than mitigated the fossil fuel emissions of every single national economy, except that of Venezuela. For most nations (Bolivia, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname) the sink has probably additionally mitigated all anthropogenic carbon emissions due to Amazon deforestation and other land use change. While the sink has weakened in some regions since 2000, our analysis suggests that Amazon nations which are able to conserve large areas of natural and semi-natural landscape still contribute globally-significant carbon sequestration. CONCLUSIONS: Mature forests across all of Amazonia have contributed significantly to mitigating climate change for decades. Yet Amazon nations have not directly benefited from providing this global scale ecosystem service. We suggest that better monitoring and reporting of the carbon fluxes within mature forests, and understanding the drivers of changes in their balance, must become national, as well as international, priorities

    A systematic review of mental health outcome measures for young people aged 12 to 25 years

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    Victor Horsley's contribution to Jacksonian epileptology

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    To describe Victor Horsley's contribution to John Hughlings Jackson's understanding of the mechanisms involved in the generalization of convulsive epileptic seizures.I reviewed Horsley's writings and other relevant late 19th century medical literature.Horsley's combination of strategically sited surgical lesions and cerebral cortex stimulation studies in experimental animals showed that, contrary to Hughlings Jackson's earlier belief, epileptic activity arising in one cerebral hemisphere had to spread to the contralateral hemisphere before bilateral convulsing could occur.On the basis of well-designed experiments, Horsley made a major contribution to the understanding of epileptic seizure propagation mechanisms

    Vulnerability, life events and depression amongst Moslem Malaysian women: comparing those married and those divorced or separated

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    Introduction: The experiences of married and single mothers were compared in an investigation of psychosocial vulnerability, stress and depression in a community-based study of Moslem mothers in Malaysia. For the first time, a model of vulnerability-provoking agent originally developed by Brown et al. in the UK was tested in a Malaysian context. Methods: A cross-sectional study was carried out in the district of Johor Bahru, Malaysia. Of the 1,200 women approached from membership of community associations, 1,002 (84%) completed the questionnaires. Severe life events Recent Life Events Questionnaire (Brugha and Cragg in Acta Psychiatr Scand 82:77–81, 1990) and psychosocial vulnerability (VDQ) (Moran et al. in Br J Clin Psychol 40:411–427, 2001) were used to measure vulnerability factors. Depression was measured by the General Health Questionnaire (GHQ-30) (Havenaar et al. in Soc Psychiatry Psychiatr Epidemiol 43:209–215, 2008). Results: Single mothers had significantly higher rates of depression than those married (60.5 vs. 39.5%), as well as higher rates of severe life events and Negative Elements in Close Relationships (lack of support and conflict with children). However, married mothers had greater Negative Evaluation of Self. The two vulnerability factors were correlated to each other and to severe life events and social adversity. Logistic regression showed an interaction between severe life events in the material and relationship domains and joint vulnerability for depression outcome. The results are discussed in relation to the low recognition of psychosocial risks for depression in single mothers in Malaysia, as well as lack of appropriate services
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