10 resultados para Béla Székely

em Université de Lausanne, Switzerland


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With the aid of the cobalt labelling technique, frog spinal cord motor neuron dendrites of the subpial dendritic plexus have been identified in serial electron micrographs. Computer reconstructions of various lengths (2.5-9.8 micron) of dendritic segments showed the contours of these dendrites to be highly irregular, and to present many thorn-like projections 0.4-1.8 micron long. Number, size and distribution of synaptic contacts were also determined. Almost half of the synapses occurred at the origins of the thorns and these synapses had the largest contact areas. Only 8 out of 54 synapses analysed were found on thorns and these were the smallest. For the total length of reconstructed dendrites there was, on average, one synapse per 1.2 micron, while 4.4% of the total dendritic surface was covered with synaptic contacts. The functional significance of these distal dendrites and their capacity to influence the soma membrane potential is discussed.

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OBJECTIVE: Delirium is highly prevalent in general hospitals but remains underrecognized and undertreated despite its association with increased morbidity, mortality, and health services utilization. To enhance its management, we developed guidelines covering all aspects, from risk factor identification to preventive, diagnostic, and therapeutic interventions in adult patients. METHODS: Guidelines, systematic reviews, randomized controlled trials (RCT), and cohort studies were systematically searched and evaluated. Based on a synthesis of retrieved high-quality documents, recommendation items were submitted to a multidisciplinary expert panel. Experts scored the appropriateness of recommendation items, using an evidence-based, explicit, multidisciplinary panel approach. Each recommendation was graded according to this process' results. RESULTS: Rated recommendations were mostly supported by a low level of evidence (1.3% RCT and systematic reviews, 14.3% nonrandomized trials vs. 84.4% observational studies or expert opinions). Nevertheless, 71.1% of recommendations were considered appropriate by the experts. Prevention of delirium and its nonpharmacological management should be fostered. Haloperidol remains the first-choice drug, whereas the role of atypical antipsychotics is still uncertain. CONCLUSIONS: While many topics addressed in these guidelines have not yet been adequately studied, an explicit panel and evidence-based approach allowed the proposal of comprehensive recommendations for the prevention and management of delirium in general hospitals.

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In some fishes, water chemistry or temperature affects sex determination or creates sex-specific selection pressures. The resulting population sex ratios are hard to predict from laboratory studies if the environmental triggers interact with other factors, whereas in field studies, singular observations of unusual sex ratios may be particularly prone to selective reporting. Long-term monitoring largely avoids these problems. We studied a population of grayling (Thymallus thymallus) in Lake Thun, Switzerland, that has been monitored since 1948. Samples of spawning fish have been caught about 3 times/week around spawning season, and water temperature at the spawning site has been continuously recorded since 1970. We used scale samples collected in different years to determine the average age of spawners (for life-stage specific analyses) and to identify the cohort born in 2003 (an extraordinarily warm year). Recent tissue samples were genotyped on microsatellite markers to test for genetic bottlenecks in the past and to estimate the genetically effective population size (N(e) ). Operational sex ratios changed from approximately 65% males before 1993 to approximately 85% males from 1993 to 2011. Sex ratios correlated with the water temperatures the fish experienced in their first year of life. Sex ratios were best explained by the average temperature juvenile fish experienced during their first summer. Grayling abundance is declining, but we found no evidence of a strong genetic bottleneck that would explain the apparent lack of evolutionary response to the unequal sex ratio. Results of other studies show no evidence of endocrine disruptors in the study area. Our findings suggest temperature affects population sex ratio and thereby contributes to population decline. Persistencia de Proporción de Sexos Desigual en una Población de Tímalos (Salmonidae) y el Posible Papel del Incremento de la Temperatura.