691 resultados para 1045


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Vegeu el resum a l'inici del document del fitxer adjunt.

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This study aimed to quantitatively describe and compare whole-body fat oxidation kinetics in cycling and running using a sinusoidal mathematical model (SIN). Thirteen moderately trained individuals (7 men and 6 women) performed two graded exercise tests, with 3-min stages and 1 km h(-1) (or 20 W) increment, on a treadmill and on a cycle ergometer. Fat oxidation rates were determined using indirect calorimetry and plotted as a function of exercise intensity. The SIN model, which includes three independent variables (dilatation, symmetry and translation) that account for main quantitative characteristics of kinetics, provided a mathematical description of fat oxidation kinetics and allowed for determination of the intensity (Fat(max)) that elicits maximal fat oxidation (MFO). While the mean fat oxidation kinetics in cycling formed a symmetric parabolic curve, the mean kinetics during running was characterized by a greater dilatation (i.e., widening of the curve, P < 0.001) and a rightward asymmetry (i.e., shift of the peak of the curve to higher intensities, P = 0.01). Fat(max) was significantly higher in running compared with cycling (P < 0.001), whereas MFO was not significantly different between modes of exercise (P = 0.36). This study showed that the whole-body fat oxidation kinetics during running was characterized by a greater dilatation and a rightward asymmetry compared with cycling. The greater dilatation may be mainly related to the larger muscle mass involved in running while the rightward asymmetry may be induced by the specific type of muscle contraction.

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Eusocial societies are traditionally characterized by a reproductive division of labor, an overlap of generations, and cooperative care of the breeders' young. Eusociality was once thought to occur only in termites, ants, and some bee and wasp species, but striking evolutionary convergences have recently become apparent between the societies of these insects and those of cooperatively breeding birds and mammals. These parallels have blurred distinctions between cooperative breeding and eusociality, leading to calls for either drastically restricting or expanding wage of these terms. We favor the latter approach. Cooperative breeding and eusociality are not discrete phenomena, but rather form a continuum of fundamentally similar social systems whose main differences lie in the distribution of lifetime reproductive success among group members. Therefore we propose to array vertebrate and invertebrate cooperative breeders along a common axis, representing a standardized measure of reproductive variance, and to drop such (loaded) terms as ''primitive'' and ''advanced'' eusociality. The terminology we propose unites all occurrences of alloparental helping of kin under a single theoretical umbrella (e.g., Hamilton's rule). Thus, cooperatively breeding vertebrates can be regarded as eusocial, just as eusocial inverbrates are cooperative breeders. We believe this integrated approach will foster potentially revealing cross-taxon comparisons, which are essential to understanding social evolution in birds, mammals, and in sects.

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Aquest treball de final de carrera vol fer una anàlisi de les necessitats de publicació de continguts i serveis a Internet d'un club d'escacs. Pel que fa a la implementació, l'objectiu es desenvolupar un portal web base, amb una tecnologia que permeti que el client pugui implementar la totalitat de les funcionalitats previstes en un futur.

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La reutilización de las aguas residuales es una parte esencial del uso sostenible del agua. Sin embargo, las actuales plantas de tratamiento no están preparadas para tratar determinados compuestos como los llamados “contaminantes emergentes”. Los hábitos de consumo actuales estan generando una serie de residuos o microcontaminantes que hace tan solo unos años no existian. Entre esas nuevas sustancias aparecen los PPCP’s (Pharmaceuticals & Personal Care Products) que son un amplio grupo de compuestos químicos utilizados en veterinaria, prácticas agrícolas, salut humana y cosmetología. El mayor problema que presentan estas substancias en la actualidad es el parcial desconocimiento sobre sus efectos, la ausencia de reglamentaciones que determinen las concentraciones máximas admisibles en los cauces de vertido, la reducción en procesos de depuración convencionales, así como los tratamientos específicos aplicables a su eliminación. Los objetivos del presente proyecto són: estudiar las tipologías de PPCP’s y sus influencias para la salud humana y el medio ambiente, estudiar los diferentes sistemas de tratamiento de aguas existentes en plantas depuradoras y evaluar su eficiencia en la depuración de PPCP

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Boletín semanal para profesionales sanitarios de la Secretaría General de Salud Pública y Participación Social de la Consejería de Salud

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Memory CD4 T cell responses are functionally and phenotypically heterogeneous. In the present study, memory CD4 T cell responses were analyzed in different models of Ag-specific immune responses differing on Ag exposure and/or persistence. Ag-specific CD4 T cell responses for tetanus toxoid, HSV, EBV, CMV, and HIV-1 were compared. Three distinct patterns of T cell response were observed. A dominant single IL-2 CD4 T cell response was associated with the model in which the Ag can be cleared. Polyfunctional (single IL-2 plus IL-2/IFN-gamma plus single IFN-gamma) CD4 T cell responses were associated with Ag persistence and low Ag levels. A dominant single IFN-gamma CD4 T cell response was associated with the model of Ag persistence and high Ag levels. The results obtained supported the hypothesis that the different patterns observed were substantially influenced by different conditions of Ag exposure and persistence.

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An object's motion relative to an observer can confer ethologically meaningful information. Approaching or looming stimuli can signal threats/collisions to be avoided or prey to be confronted, whereas receding stimuli can signal successful escape or failed pursuit. Using movement detection and subjective ratings, we investigated the multisensory integration of looming and receding auditory and visual information by humans. While prior research has demonstrated a perceptual bias for unisensory and more recently multisensory looming stimuli, none has investigated whether there is integration of looming signals between modalities. Our findings reveal selective integration of multisensory looming stimuli. Performance was significantly enhanced for looming stimuli over all other multisensory conditions. Contrasts with static multisensory conditions indicate that only multisensory looming stimuli resulted in facilitation beyond that induced by the sheer presence of auditory-visual stimuli. Controlling for variation in physical energy replicated the advantage for multisensory looming stimuli. Finally, only looming stimuli exhibited a negative linear relationship between enhancement indices for detection speed and for subjective ratings. Maximal detection speed was attained when motion perception was already robust under unisensory conditions. The preferential integration of multisensory looming stimuli highlights that complex ethologically salient stimuli likely require synergistic cooperation between existing principles of multisensory integration. A new conceptualization of the neurophysiologic mechanisms mediating real-world multisensory perceptions and action is therefore supported.

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The genes encoding alpha- and beta-tubulins have been widely sampled in most major fungal phyla and they are useful tools for fungal phylogeny. Here, we report the first isolation of alpha-tubulin sequences from arbuscular mycorrhizal fungi (AMF). In parallel, AMF beta-tubulins were sampled and analysed to identify the presence of paralogs of this gene. The AMF alpha-tubulin amino acid phylogeny was congruent with the results previously reported for AMF beta-tubulins and showed that AMF tubulins group together at a basal position in the fungal clade and showed high sequence similarities with members of the Chytridiomycota. This is in contrast with phylogenies for other regions of the AMF genome. The amount and nature of substitutions are consistent with an ancient divergence of both orthologs and paralogs of AMF tubulins. At the amino acid level, however, AMF tubulins have hardly evolved from those of the chytrids. This is remarkable given that these two groups are ancient and the monophyletic Glomeromycota probably diverged from basal fungal ancestors at least 500 million years ago. The specific primers we designed for the AMF tubulins, together with the high molecular variation we found among the AMF species we analysed, make AMF tubulin sequences potentially useful for AMF identification purposes.

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IMPORTANCE: The discontinuation of randomized clinical trials (RCTs) raises ethical concerns and often wastes scarce research resources. The epidemiology of discontinued RCTs, however, remains unclear. OBJECTIVES: To determine the prevalence, characteristics, and publication history of discontinued RCTs and to investigate factors associated with RCT discontinuation due to poor recruitment and with nonpublication. DESIGN AND SETTING: Retrospective cohort of RCTs based on archived protocols approved by 6 research ethics committees in Switzerland, Germany, and Canada between 2000 and 2003. We recorded trial characteristics and planned recruitment from included protocols. Last follow-up of RCTs was April 27, 2013. MAIN OUTCOMES AND MEASURES: Completion status, reported reasons for discontinuation, and publication status of RCTs as determined by correspondence with the research ethics committees, literature searches, and investigator surveys. RESULTS: After a median follow-up of 11.6 years (range, 8.8-12.6 years), 253 of 1017 included RCTs were discontinued (24.9% [95% CI, 22.3%-27.6%]). Only 96 of 253 discontinuations (37.9% [95% CI, 32.0%-44.3%]) were reported to ethics committees. The most frequent reason for discontinuation was poor recruitment (101/1017; 9.9% [95% CI, 8.2%-12.0%]). In multivariable analysis, industry sponsorship vs investigator sponsorship (8.4% vs 26.5%; odds ratio [OR], 0.25 [95% CI, 0.15-0.43]; P < .001) and a larger planned sample size in increments of 100 (-0.7%; OR, 0.96 [95% CI, 0.92-1.00]; P = .04) were associated with lower rates of discontinuation due to poor recruitment. Discontinued trials were more likely to remain unpublished than completed trials (55.1% vs 33.6%; OR, 3.19 [95% CI, 2.29-4.43]; P < .001). CONCLUSIONS AND RELEVANCE: In this sample of trials based on RCT protocols from 6 research ethics committees, discontinuation was common, with poor recruitment being the most frequently reported reason. Greater efforts are needed to ensure the reporting of trial discontinuation to research ethics committees and the publication of results of discontinued trials.

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AIMS: To review the concept of binge drinking as a measure of risky single occasion drinking (RSOD), to illustrate its differential impact on selected health outcomes and to identify research gaps. METHODS: Narrative literature review with focus on conceptual and methodological differences, trajectories of RSOD and effects of RSOD on fetal outcomes, coronary heart disease (CHD) and injuries. RESULTS: Effects ascribed commonly to RSOD may often be the effects of an undifferentiated mixture of risky single occasions and regular heavy volume drinking, constituted by frequent, successive RSOD. This leads to the problem that additional risks due to RSOD are mis-specified and remain unidentified or underestimated in some cases, such as for injuries or CHD, but are probably overstated for some chronic consequences or for effects of maternal drinking on newborns. CONCLUSION: A stronger focus should be placed upon methods that can differentiate the effects of RSOD from those due to frequent occasions of heavy drinking that result in heavy volume drinking.

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Aims To review the concept of binge drinking as a measure of risky single occasion drinking (RSOD), to illustrate its differential impact on selected health outcomes and to identify research gaps.Methods Narrative literature review with focus on conceptual and methodological differences, trajectories of RSOD and effects of RSOD on fetal outcomes, coronary heart disease (CHD) and injuries.Results Effects ascribed commonly to RSOD may often be the effects of an undifferentiated mixture of risky single occasions and regular heavy volume drinking, constituted by frequent, successive RSOD. This leads to the problem that additional risks due to RSOD are mis-specified and remain unidentified or underestimated in some cases, such as for injuries or CHD, but are probably overstated for some chronic consequences or for effects of maternal drinking on newborns.Conclusion A stronger focus should be placed upon methods that can differentiate the effects of RSOD from those due to frequent occasions of heavy drinking that result in heavy volume drinking.