130 research outputs found

    Social context of disclosing HIV test results in Tanzania

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    This study sought to understand how individuals reveal their HIV test results to others and the ways in which social relations affect the disclosure process. The data were collected through open-ended interviews administered in Swahili to informants who had just been tested for HIV and to those who were living with HIV in Dar es Salaam and Iringa regions. Analysis shows that social relations influence the decisions individuals make about disclosure. Most people preferred to reveal their HIV status to close family members. Most also mentioned the fear of being rejected and discriminated against as major reasons for not disclosing their test results to others

    Adenoviral-Mediated Endothelial Precursor Cell Delivery of Soluble CD115 Suppresses Human Prostate Cancer Xenograft Growth in Mice

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    Prostate cancer tumor growth and neovascularization is promoted by an interplay between migratory tumor stromal cells such as specialized tumor-associated macrophages (TAMs) and circulating endothelial precursor cells (CEPs). As vehicles for tumor therapy, human CEPs are relatively easy to isolate from peripheral blood, are able to proliferate long-term in vitro, are amenable to viral manipulation, and preferentially home to regions of ischemia found in growing tumors. We show here that human peripheral blood CEPs expanded ex vivo migrate to prostate cancer cells in vitro and efficiently home to human prostate tumor xenografts in vivo. Infection of precursors ex vivo with an adenovirus constructed to secrete a soluble form of the colony-stimulating factor-1 receptor CD115 that inhibits macrophage viability and migration in vitro significantly decreases the number of TAMs in xenografts (p < .05), reduces proliferation (p < .01) and vascular density (p < .03), and suppresses the growth of xenografts (p < .03). These data show for the first time that targeting stromal cell processes with cellular therapy has the potential to retard prostate tumor growth

    Born to learn: The inspiration, progress, and future of evolved plastic artificial neural networks

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    Biological plastic neural networks are systems of extraordinary computational capabilities shaped by evolution, development, and lifetime learning. The interplay of these elements leads to the emergence of adaptive behavior and intelligence. Inspired by such intricate natural phenomena, Evolved Plastic Artificial Neural Networks (EPANNs) use simulated evolution in-silico to breed plastic neural networks with a large variety of dynamics, architectures, and plasticity rules: these artificial systems are composed of inputs, outputs, and plastic components that change in response to experiences in an environment. These systems may autonomously discover novel adaptive algorithms, and lead to hypotheses on the emergence of biological adaptation. EPANNs have seen considerable progress over the last two decades. Current scientific and technological advances in artificial neural networks are now setting the conditions for radically new approaches and results. In particular, the limitations of hand-designed networks could be overcome by more flexible and innovative solutions. This paper brings together a variety of inspiring ideas that define the field of EPANNs. The main methods and results are reviewed. Finally, new opportunities and developments are presented

    A voz dos bandos: colectivos de justiça e ritos da palavra portuguesa em Timor Leste colonial

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    Este artigo examina as relações entre o discurso da justiça e a prática do ritual nos bandos do governo colonial português em Timor Leste, entre a segunda metade do século XIX e as primeiras décadas do século XX. Os bandos consistiam em ordens e instruções de comando emanadas pelo governador português em Díli, e comunicadas de forma cerimonial por oficiais às populações dos diversos reinos timorenses dispersos pelo país. Bandos eram um instrumento por excelência de governação colonial dos assuntos indígenas, servindo para arbitrar conflitos, punir transgressões e, em geral, instituir realidades no mundo timorense. Contudo, esta instituição assumiu igualmente uma singular expressão nos usos timorenses, servindo bandos para comunicar também as ordens de autoridades tradicionais, os liurais. O artigo acompanha as variações coloniais e indígenas que os bandos adquiriram em Timor Leste, conceptualizando-os enquanto colectivos de justiça. Ao considerar assim os bandos como colectivos – formações heterogéneas em que elementos linguísticos e não linguísticos se combinam na produção de efeitos de poder sobre as populações – o artigo propõe uma via conceptual alternativa às perspectivas linguísticas e literárias de análise do discurso colonial

    Speciation in little: the role of range and body size in the diversification of Malagasy mantellid frogs

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    <p>Abstract</p> <p>Background</p> <p>The rate and mode of lineage diversification might be shaped by clade-specific traits. In Madagascar, many groups of organisms are characterized by tiny distribution ranges and small body sizes, and this high degree of microendemism and miniaturization parallels a high species diversity in some of these groups. We here investigate the geographic patterns characterizing the radiation of the frog family Mantellidae that is virtually endemic to Madagascar. We integrate a newly reconstructed near-complete species-level timetree of the Mantellidae with georeferenced distribution records and maximum male body size data to infer the influence of these life-history traits on each other and on mantellid diversification.</p> <p>Results</p> <p>We reconstructed a molecular phylogeny based on nuclear and mitochondrial DNA for 257 species and candidate species of the mantellid frog radiation. Based on this phylogeny we identified 53 well-supported pairs of sister species that we used for phylogenetic comparative analyses, along with whole tree-based phylogenetic comparative methods. Sister species within the Mantellidae diverged at 0.2-14.4 million years ago and more recently diverged sister species had geographical range centroids more proximate to each other, independently of their current sympatric or allopatric occurrence. The largest number of sister species pairs had non-overlapping ranges, but several examples of young microendemic sister species occurring in full sympatry suggest the possibility of non-allopatric speciation. Range sizes of species included in the sister species comparisons increased with evolutionary age, as did range size differences between sister species, which rejects peripatric speciation. For the majority of mantellid sister species and the whole mantellid radiation, range and body sizes were associated with each other and small body sizes were linked to higher mitochondrial nucleotide substitution rates and higher clade diversity. In contrast, small range sizes were unexpectedly associated with a slow-down of mitochondrial substitution rates.</p> <p>Conclusions</p> <p>Based on these results we define a testable hypothesis under which small body sizes result in limited dispersal capabilities and low physiological tolerances, causing smaller and more strongly fragmented ranges. This can be thought to facilitate reproductive isolation and thus favor speciation. Contrary to the expectation of the faster speciation of such microendemic phenotype species, we only found small body sizes of mantellid frogs to be linked to higher diversification and substitution rates, but not small range sizes. A joint analysis of various species-rich regional anuran radiations might provide enough species with all combinations of range and body sizes for a more conclusive test of this hypothesis.</p

    Análisis sincrónico de la gobernanza universitaria: una mirada teórica a los años sesenta y setenta

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    Resumen Estudiar las perspectivas en el campo del gobierno de las universidades tiene cada día mayor preeminencia, especialmente si se toma en cuenta la incuestionable necesidad de avanzar hacía organizaciones más eficientes, conectadas con las expectativas que sobre ellas tiene la sociedad. Considerando este escenario, el trabajo se ha planteado como propósito central realizar un análisis de carácter sincrónico del concepto de gobernanza y la constitución de los gobiernos universitarios. Desde el punto de vista metodológico se utilizaron fuentes secundarias: una revisión de papers publicados esencialmente en revistas de habla inglesa. El estudio comprende las décadas del sesenta y el setenta. Se centra en las raíces del concepto de gobernanza universitaria, en la delineación de los actores que participan en sus gobiernos y en las relaciones de poder que fluyen entre ellos.Entre las principales conclusiones, se pueden destacar como el estamento académico desde el principio de las universidades ha ocupado el rol casi plenipotenciario en su respectivo gobierno, producto de esto, en el correr del desarrollo y mientras la complejidad organizacional se incrementaba, es que fue necesario incorporar nuevos actores a los sistemas de gestión; todo lo anterior, teniendo en cuenta que dos elementos han sido fundamentales para la sobrevivencia de este tipo de instituciones, la legitimidad otorgada por la sociedad y los principios de estrategias del ámbito de la gestión

    Diversity dynamics in New Caledonia: towards the end of the museum model?

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    <p>Abstract</p> <p>Background</p> <p>The high diversity of New Caledonia has traditionally been seen as a result of its Gondwanan origin, old age and long isolation under stable climatic conditions (the museum model). Under this scenario, we would expect species diversification to follow a constant rate model. Alternatively, if New Caledonia was completely submerged after its breakup from Gondwana, as geological evidence indicates, we would expect species diversification to show a characteristic slowdown over time according to a diversity-dependent model where species accumulation decreases as space is filled.</p> <p>Results</p> <p>We reanalyze available datasets for New Caledonia and reconstruct the phylogenies using standardized methodologies; we use two ultrametrization alternatives; and we take into account phylogenetic uncertainty as well as incomplete taxon sampling when conducting diversification rate constancy tests. Our results indicate that for 8 of the 9 available phylogenies, there is significant evidence for a diversification slowdown. For the youngest group under investigation, the apparent lack of evidence of a significant slowdown could be because we are still observing the early phase of a logistic growth (i.e. the clade may be too young to exhibit a change in diversification rates).</p> <p>Conclusions</p> <p>Our results are consistent with a diversity-dependent model of diversification in New Caledonia. In opposition to the museum model, our results provide additional evidence that original New Caledonian biodiversity was wiped out during the episode of submersion, providing an open and empty space facilitating evolutionary radiations.</p

    Parent-mediated communication interventions for improving the communication skills of preschool children with non-progressive motor disorders

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    © 2017 The Cochrane Collaboration.This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: To assess the effectiveness of parent-mediated communication interventions in improving the communication skills of preschool children with non-progressive motor disorders. Specifically, this review aims to determine the effectiveness of parent-mediated communication interventions in improving the communication of preschool children with non-progressive motor disorders, when compared to no intervention, and when compared to clinician-mediated interventions

    Thermal Evolution and Magnetic Field Generation in Terrestrial Planets and Satellites

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