1000 resultados para 347-M0067
Resumo:
The processing of biological motion is a critical, everyday task performed with remarkable efficiency by human sensory systems. Interest in this ability has focused to a large extent on biological motion processing in the visual modality (see, for example, Cutting, J. E., Moore, C., & Morrison, R. (1988). Masking the motions of human gait. Perception and Psychophysics, 44(4), 339-347). In naturalistic settings, however, it is often the case that biological motion is defined by input to more than one sensory modality. For this reason, here in a series of experiments we investigate behavioural correlates of multisensory, in particular audiovisual, integration in the processing of biological motion cues. More specifically, using a new psychophysical paradigm we investigate the effect of suprathreshold auditory motion on perceptions of visually defined biological motion. Unlike data from previous studies investigating audiovisual integration in linear motion processing [Meyer, G. F. & Wuerger, S. M. (2001). Cross-modal integration of auditory and visual motion signals. Neuroreport, 12(11), 2557-2560; Wuerger, S. M., Hofbauer, M., & Meyer, G. F. (2003). The integration of auditory and motion signals at threshold. Perception and Psychophysics, 65(8), 1188-1196; Alais, D. & Burr, D. (2004). No direction-specific bimodal facilitation for audiovisual motion detection. Cognitive Brain Research, 19, 185-194], we report the existence of direction-selective effects: relative to control (stationary) auditory conditions, auditory motion in the same direction as the visually defined biological motion target increased its detectability, whereas auditory motion in the opposite direction had the inverse effect. Our data suggest these effects do not arise through general shifts in visuo-spatial attention, but instead are a consequence of motion-sensitive, direction-tuned integration mechanisms that are, if not unique to biological visual motion, at least not common to all types of visual motion. Based on these data and evidence from neurophysiological and neuroimaging studies we discuss the neural mechanisms likely to underlie this effect.
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Background: Imatinib has revolutionized the treatment of chronic myeloid leukemia (CML) and gastrointestinal stromal tumors (GIST). Considering the large inter-individual differences in the function of the systems involved in its disposition, exposure to imatinib can be expected to vary widely among patients. This observational study aimed at describing imatinib pharmacokinetic variability and its relationship with various biological covariates, especially plasma alpha1-acid glycoprotein (AGP), and at exploring the concentration-response relationship in patients. Methods: A population pharmacokinetic model (NONMEM) including 321 plasma samples from 59 patients was built up and used to derive individual post-hoc Bayesian estimates of drug exposure (AUC; area under curve). Associations between AUC and therapeutic response or tolerability were explored by ordered logistic regression. Influence of the target genotype (i.e. KIT mutation profile) on response was also assessed in GIST patients. Results: A one-compartment model with first-order absorption appropriately described the data, with an average oral clearance of 14.3 L/h (CL) and volume of distribution of 347 L (Vd). A large inter-individual variability remained unexplained, both on CL (36%) and Vd (63%), but AGP levels proved to have a marked impact on total imatinib disposition. Moreover, both total and free AUC correlated with the occurrence and number of side effects (e.g. OR 2.9±0.6 for a 2-fold free AUC increase; p<0.001). Furthermore, in GIST patients, higher free AUC predicted a higher probability of therapeutic response (OR 1.9±0.5; p<0.05), notably in patients with tumor harboring an exon 9 mutation or wild-type KIT, known to decrease tumor sensitivity towards imatinib. Conclusion: The large pharmacokinetic variability, associated to the pharmacokinetic-pharmacodynamic relationship uncovered are arguments to further investigate the usefulness of individualizing imatinib prescription based on TDM. For this type of drug, it should ideally take into consideration either circulating AGP concentrations or free drug levels, as well as KIT genotype for GIST.
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Este trabalho apresenta um estudo qualitativo, desenvolvido através de pesquisa exploratória, bibliográfica e de campo, feito a trezentos e noventa e nove empreendedores e empresários da Ilha de Santiago, tendo em consideração o cenário económico actual e a preocupação à volta do sector privado. Procurou-se através de pesquisa junto às empresas activas, e cujo número de pessoas ao seu serviço não ultrapassa vinte, identificar três pontos fundamentais relacionados com os empreendedores: investigar os factores que levaram as pessoas a tornarem-se empreendedores; investigar as características principais do empreendedor de sucesso; identificar as características imprescindíveis para se atingir o sucesso empresarial relacionadas com o conhecimento, competências, atitude e talento, sequenciadas por ordem de importância. Para um melhor entendimento destas questões foi utilizado um referencial teórico que aborda o empreendedorismo. A pesquisa de campo foi realizada através de utilização de questionários – entrevistas às empresas estabelecidas nesta ilha, e o método de recolha de dados foi o de entrevista directa. Os resultados obtidos mostraram que os empreendedores enfatizam a importância dos factores comportamentais no sucesso das pequenas e médias empresas e evidenciaram que os factores mais significativos e limitativos do sucesso dos empreendedores no Município da Praia, ilha de Santiago, se referem ao ambiente interno do negócio. Considerando todos estes factores e de acordo com as pesquisas desenvolvidas e analisadas, este trabalho recolheu informações específicas dos empreendedores de sucesso da ilha de Santiago e que podem ser úteis para os que almejam o sucesso empresarial e para eventuais programas de capacitação e formação empreendedora na ilha. This work presents a qualitative study developed through exploratory, bibliographic and field research to three hundred and ninety nine managers and entrepreneurs from Santiago Island, taking into consideration the present economical scenario and main concerns linked to private sector. Through a research in active enterprises and whose staff number doesn’t exceed twenty, the goal was to identify three main issues related to entrepreneurs: look into the factors that encouraged people to become entrepreneurs; examine the main characteristics of a successful entrepreneur and identify, sequenced by order of importance, the most critical characteristics related to knowledge, skills, attitude and talent, that allow entrepreneurial success achievement. For a better understanding of these questions, a theoretical approach to entrepreneurship was exploited. Field research was carried on through the use of questionnaires in enterprises located in Praia, and the data collection method was direct interviews. Results obtained showed that entrepreneurs emphasize the importance of behavioral factors in the success of small and medium enterprises and they evidenced that the most significant and restrictive factors of entrepreneurs’ success in Santiago Island are related to internal business environment. Considering these factors, and according to research developed and analyzed, the work has collected specific information of successful entrepreneurs in Santiago that can be useful for those, in the island, who seek entrepreneurial success and for eventual capacity building and entrepreneurial training programs.
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The Convention on Biological Diversity (CBD) aims at the conservation of all three levels of biodiversity, that is, ecosystems, species and genes. Genetic diversity represents evolutionary potential and is important for ecosystem functioning. Unfortunately, genetic diversity in natural populations is hardly considered in conservation strategies because it is difficult to measure and has been hypothesised to co-vary with species richness. This means that species richness is taken as a surrogate of genetic diversity in conservation planning, though their relationship has not been properly evaluated. We tested whether the genetic and species levels of biodiversity co-vary, using a large-scale and multi-species approach. We chose the high-mountain flora of the Alps and the Carpathians as study systems and demonstrate that species richness and genetic diversity are not correlated. Species richness thus cannot act as a surrogate for genetic diversity. Our results have important consequences for implementing the CBD when designing conservation strategies.
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Kirje 7.11.1960
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Kirje 7.9.1943