829 resultados para Environmental and sustainable performance
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The presence of cognitive impairment is a frequent complaint among elderly individuals in the general population. This study aimed to investigate the relationship between aging-related regional gray matter (rGM) volume changes and cognitive performance in healthy elderly adults. Morphometric magnetic resonance imaging (MRI) measures were acquired in a community-based sample of 170 cognitively-preserved subjects (66 to 75 years). This sample was drawn from the "Sao Paulo Ageing and Health" study, an epidemiological study aimed at investigating the prevalence and risk factors for Alzheimer's disease in a low income region of the city of Sao Paulo. All subjects underwent cognitive testing using a cross-culturally battery validated by the Research Group on Dementia 10/66 as well as the SKT (applied on the day of MRI scanning). Blood genotyping was performed to determine the frequency of the three apolipoprotein E allele variants (APOE epsilon 2/epsilon 3/epsilon 4) in the sample. Voxelwise linear correlation analyses between rGM volumes and cognitive test scores were performed using voxel-based morphometry, including chronological age as covariate. There were significant direct correlations between worse overall cognitive performance and rGM reductions in the right orbitofrontal cortex and parahippocampal gyrus, and also between verbal fluency scores and bilateral parahippocampal gyral volume (p < 0.05, familywise-error corrected for multiple comparisons using small volume correction). When analyses were repeated adding the presence of the APOE epsilon 4 allele as confounding covariate or excluding a minority of APOE epsilon 2 carriers, all findings retained significance. These results indicate that rGM volumes are relevant biomarkers of cognitive deficits in healthy aging individuals, most notably involving temporolimbic regions and the orbitofrontal cortex.
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We aimed to investigate the role of betaine supplementation on muscle phosphorylcreatine (PCr) content and strength performance in untrained subjects. Additionally, we compared the ergogenic and physiological responses to betaine versus creatine supplementation. Finally, we also tested the possible additive effects of creatine and betaine supplementation. This was a double-blind, randomized, placebo-controlled study. Subjects were assigned to receive betaine (BET; 2 g/day), creatine (CR; 20 g/day), betaine plus creatine (BET + CR; 2 + 20 g/day, respectively) or placebo (PL). At baseline and after 10 days of supplementation, we assessed muscle strength and power, muscle PCr content, and body composition. The CR and BET + CR groups presented greater increase in muscle PCr content than PL ( = 0.004 and = 0.006, respectively). PCr content was comparable between BET versus PL ( = 0.78) and CR versus BET + CR ( = 0.99). CR and BET + CR presented greater muscle power output than PL in the squat exercise following supplementation ( = 0.003 and = 0.041, respectively). Similarly, bench press average power was significantly greater for the CR-supplemented groups. CR and BET + CR groups also showed significant pre- to post-test increase in 1-RM squat and bench press (CR: = 0.027 and < 0.0001; BET + CR: = 0.03 and < 0.0001 for upper- and lower-body assessments, respectively) No significant differences for 1-RM strength and power were observed between BET versus PL and CR versus BET + CR. Body composition did not differ between the groups. In conclusion, we reported that betaine supplementation does not augment muscle PCr content. Furthermore, we showed that betaine supplementation combined or not with creatine supplementation does not affect strength and power performance in untrained subjects.
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We examined the effects of listening to music on attentional focus, rating of perceived exertion (RPE), pacing strategy and performance during a simulated 5-km running race. 15 participants performed 2 controlled trials to establish their best baseline time, followed by 2 counterbalanced experimental trials during which they listened to music during the first (M-start) or the last (M-finish) 1.5 km. The mean running velocity during the first 1.5 km was significantly higher in M-start than in the fastest control condition (p < 0.05), but there was no difference in velocity between conditions during the last 1.5 km (p > 0.05). The faster first 1.5 m in M-start was accompanied by a reduction in associative thoughts compared with the fastest control condition. There were no significant differences in RPE between conditions (p > 0.05). These results suggest that listening to music at the beginning of a trial may draw the attentional focus away from internal sensations of fatigue to thoughts about the external environment. However, along with the reduction in associative thoughts and the increase in running velocity while listening to music, the RPE increased linearly and similarly under all conditions, suggesting that the change in velocity throughout the race may be to maintain the same rate of RPE increase.
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PEM fuel cells seem to be the most affordable and commercially viable hydrogen-based cells, the biggest challenge being to obtain CO-free H-2 (<100 ppm) as the fuel. In this study, the use of CuO-CeO2 catalysts in preferential oxidation of CO to obtain CO-free H-2 (PROX reaction) was investigated. Ce1-xCuxO2 catalysts, with x (mol%) = 0, 0.01, 0.03, 0.05 and 0.10, were synthesized in one-step by the polymeric precursor method, to obtain a very fine dispersion and strong metal-support interaction, to favor active copper species and a preference for the PROX reaction. The results obtained from catalyzed reactions and characterization of the catalysts by XRD, Rietveld refinement, BET surface area, UV-Vis and TPR, suggest that this one-step synthesis method gives rise to catalysts with copper species selective for the PROX reaction, which reaches a maximum rate on Ce0.97Cu0.03O2 catalyst. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
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ZnO and doped M:ZnO (M = V, Fe and Co) nanostructures were synthesized by microwave hydrothermal synthesis using a low temperature route without addition of any surfactant. The transition metal ions were successfully doped in small amount (3% mol) into ZnO structure. Analysis by X-ray diffraction reveals the formation of ZnO with the hexagonal (wurtzite-type) crystal structure for all the samples. The as-obtained samples showed a similar flower-like morphology except for Fe:ZnO samples, which presented a plate-like morphology. The photocatalytic performance for Rhodamine B (RhB) degradation confirmed that the photoactivity of M:ZnO nanostructures decreased for all dopants in structure, according to their eletronegativity. Photoluminescence spectroscopy was employed to correlate M:ZnO structure with its photocatalytical properties. It was suggested that transition metal ions in ZnO lattice introduce defects that act as trapping or recombination centers for photogenerated electrons and holes, making it impossible for them reach the surface and promote the photocatalytical process.
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Locomotor capacity is often considered an excellent measure of whole animal performance because it requires the integrated functioning of many morphological, physiological (and biochemical) traits. However, because studies tend to focus on either structural or functional suits of traits, we know little on whether and how morphological and physiological traits coevolve to produce adequate locomotor capacities. Hence, we investigate the evolutionary relationships between morphological and physiological parameters related to exercise physiology, using tropidurine lizards as a model. We employ a phylogenetic principal component analysis (PCA) to identify variable clusters (factors) related to morphology, energetic metabolism and muscle metabolism, and then analyze the relationships between these clusters and measures of locomotor performance, using two models (star and hierarchical phylogenies). Our data indicate that sprint performance is enhanced by simultaneous evolutionary tendencies affecting relative limb and tail size and physiological traits. Specifically, the high absolute sprint speeds exhibited by tropidurines from the sand dunes are explained by longer limbs, feet and tails and an increased proportion of glycolytic fibers in the leg muscle, contrasting with their lower capacity for overall oxidative metabolism [principal component (PC1)]. However, when sprint speeds are corrected for body size, performance correlates with a cluster (PC3) composed by moderate loads for activity metabolic rate and body size. The simultaneous measurement of morphological and physiological parameters is a powerful tool for exploring patterns of coadaptation and proposing morphophysiological associations that are not directly predictable from theory. This approach may trigger novel directions for investigating the evolution of form and function, particularly in the context of organismal performance.
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FAPESP/BIOTA
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INTRODUCTION: Schizophrenia is a chronic mental disorder associated with impairment in social functioning. The most widely used scale to measure social functioning is the GAF (Global Assessment of Functioning), but it has the disadvantage of measuring at the same time symptoms and functioning, as described in its anchors. OBJECTIVES:Translation and cultural adaptation of the PSP, proposing a final version in Portuguese for use in Brazil. METHODS: We performed five steps: 1) translation; 2) back translation; 3) formal assessment of semantic equivalence; 4) debriefing; 5) analysis by experts. Interrater reliability (Intraclass correlation, ICC) between two raters was also measured. RESULTS: The final version was applied by two independent investigators in 18 adults with schizophrenia (DSM-IV-TR). The interrater reliability (ICC) was 0.812 (p < 0.001). CONCLUSION: The translation and adaptation of the PSP had an adequate level of semantic equivalence between the Portuguese version and the original English version. There were no difficulties related to understanding the content expressed in the translated texts and terms. Its application was easy and it showed a good interrater reliability. The PSP is a valid instrument for the measurement of personal and social functioning in schizophrenia.
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We present the synthesis of a copolymer structure, poly(9,9′-n-di-hexyl-2,7-fluorene-alt-2,5- bithiophene), referred to herein as LaPPS43, and its physico-chemical characterization. Thin films of this polymer mixed with phenyl-C61-butyric acid methyl ester (PCBM) were used as the active layer in photovoltaic devices using the ITO/PEDOT:PSS/LaPPS43: PCBM/Ca/Al bulk heterojunction structure. The devices of different active layer thicknesses were electrically studied using J-V curves and the Photo-Celiv technique. The obtained results show that LaPPS43 combined with PCBM is a promising system for photovoltaic devices. Device performance is discussed in terms of the mean drift distance x for charge carriers. Photophysical data showed that the excitonic species are all localized in the aggregated forms. The mechanism of exciton formation and dissociation is also discussed.
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Diploma de Estudios Avanzados y Tesis de Máster
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Clusters have increasingly become an essential part of policy discourses at all levels, EU, national, regional, dealing with regional development, competitiveness, innovation, entrepreneurship, SMEs. These impressive efforts in promoting the concept of clusters on the policy-making arena have been accompanied by much less academic and scientific research work investigating the actual economic performance of firms in clusters, the design and execution of cluster policies and going beyond singular case studies to a more methodologically integrated and comparative approach to the study of clusters and their real-world impact. The theoretical background is far from being consolidated and there is a variety of methodologies and approaches for studying and interpreting this phenomenon while at the same time little comparability among studies on actual cluster performances. The conceptual framework of clustering suggests that they affect performance but theory makes little prediction as to the ultimate distribution of the value being created by clusters. This thesis takes the case of Eastern European countries for two reasons. One is that clusters, as coopetitive environments, are a new phenomenon as the previous centrally-based system did not allow for such types of firm organizations. The other is that, as new EU member states, they have been subject to the increased popularization of the cluster policy approach by the European Commission, especially in the framework of the National Reform Programmes related to the Lisbon objectives. The originality of the work lays in the fact that starting from an overview of theoretical contributions on clustering, it offers a comparative empirical study of clusters in transition countries. There have been very few examples in the literature that attempt to examine cluster performance in a comparative cross-country perspective. It adds to this an analysis of cluster policies and their implementation or lack of such as a way to analyse the way the cluster concept has been introduced to transition economies. Our findings show that the implementation of cluster policies does vary across countries with some countries which have embraced it more than others. The specific modes of implementation, however, are very similar, based mostly on soft measures such as funding for cluster initiatives, usually directed towards the creation of cluster management structures or cluster facilitators. They are essentially founded on a common assumption that the added values of clusters is in the creation of linkages among firms, human capital, skills and knowledge at the local level, most often perceived as the regional level. Often times geographical proximity is not a necessary element in the application process and cluster application are very similar to network membership. Cluster mapping is rarely a factor in the selection of cluster initiatives for funding and the relative question about critical mass and expected outcomes is not considered. In fact, monitoring and evaluation are not elements of the cluster policy cycle which have received a lot of attention. Bulgaria and the Czech Republic are the countries which have implemented cluster policies most decisively, Hungary and Poland have made significant efforts, while Slovakia and Romania have only sporadically and not systematically used cluster initiatives. When examining whether, in fact, firms located within regional clusters perform better and are more efficient than similar firms outside clusters, we do find positive results across countries and across sectors. The only country with negative impact from being located in a cluster is the Czech Republic.
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This study aims at providing a theoretical framework encompassing the two approaches towards entrepreneurial opportunity (opportunity discovery and opportunity creation) by outlining a trajectory from firm creation to capability development, to firm performance in the short term (firm survival) and the medium/long term (growth rate). A set of empirically testable hypotheses is proposed and tested by performing qualitative analyses on interviews on a small sample of entrepreneurs and event history analysis on a large sample of firms founded in the United States in 2004.
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Within this PhD thesis several methods were developed and validated which can find applicationare suitable for environmental sample and material science and should be applicable for monitoring of particular radionuclides and the analysis of the chemical composition of construction materials in the frame of ESS project. The study demonstrated that ICP-MS is a powerful analytical technique for ultrasensitive determination of 129I, 90Sr and lanthanides in both artificial and environmental samples such as water and soil. In particular ICP-MS with collision cell allows measuring extremely low isotope ratios of iodine. It was demonstrated that isotope ratios of 129I/127I as low as 10-7 can be measured with an accuracy and precision suitable for distinguishing sample origins. ICP-MS with collision cell, in particular in combination with cool plasma conditions, reduces the influence of isobaric interferences on m/z = 90 and is therefore well-suited for 90Sr analysis in water samples. However, the applied ICP-CC-QMS in this work is limited for the measurement of 90Sr due to the tailing of 88Sr+ and in particular Daly detector noise. Hyphenation of capillary electrophoresis with ICP-MS was shown to resolve atomic ions of all lanthanides and polyatomic interferences. The elimination of polyatomic and isobaric ICP-MS interferences was accomplished without compromising the sensitivity by the use of a high resolution mode as available on ICP-SFMS. Combination of laser ablation with ICP-MS allowed direct micro and local uranium isotope ratio measurements at the ultratrace concentrations on the surface of biological samples. In particular, the application of a cooled laser ablation chamber improves the precision and accuracy of uranium isotopic ratios measurements in comparison to the non-cooled laser ablation chamber by up to one order of magnitude. In order to reduce the quantification problem, a mono gas on-line solution-based calibration was built based on the insertion of a microflow nebulizer DS-5 directly into the laser ablation chamber. A micro local method to determine the lateral element distribution on NiCrAlY-based alloy and coating after oxidation in air was tested and validated. Calibration procedures involving external calibration, quantification by relative sensitivity coefficients (RSCs) and solution-based calibration were investigated. The analytical method was validated by comparison of the LA-ICP-MS results with data acquired by EDX.
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This thesis is a collection of essays related to the topic of innovation in the service sector. The choice of this structure is functional to the purpose of single out some of the relevant issues and try to tackle them, revising first the state of the literature and then proposing a way forward. Three relevant issues has been therefore selected: (i) the definition of innovation in the service sector and the connected question of measurement of innovation; (ii) the issue of productivity in services; (iii) the classification of innovative firms in the service sector. Facing the first issue, chapter II shows how the initial width of the original Schumpeterian definition of innovation has been narrowed and then passed to the service sector form the manufacturing one in a reduce technological form. Chapter III tackle the issue of productivity in services, discussing the difficulties for measuring productivity in a context where the output is often immaterial. We reconstruct the dispute on the Baumol’s cost disease argument and propose two different ways to go forward in the research on productivity in services: redefining the output along the line of a characteristic approach; and redefining the inputs, particularly analysing which kind of input it’s worth saving. Chapter IV derives an integrated taxonomy of innovative service and manufacturing firms, using data coming from the 2008 CIS survey for Italy. This taxonomy is based on the enlarged definition of “innovative firm” deriving from the Schumpeterian definition of innovation and classify firms using a cluster analysis techniques. The result is the emergence of a four cluster solution, where firms are differentiated by the breadth of the innovation activities in which they are involved. Chapter 5 reports some of the main conclusions of each singular previous chapter and the points worth of further research in the future.