23 resultados para Performance and performativity


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Physical exercise triggers coordinated physiological responses to meet the augmented metabolic demand of contracting muscles. To provide adequate responses, the brain must receive sensory information about the physiological status of peripheral tissues and organs, such as changes in osmolality, temperature and pH. Most of the receptors involved in these afferent pathways express ion channels, including transient receptor potential (TRP) channels, which are usually activated by more than one type of stimulus and are therefore considered polymodal receptors. Among these TRP channels, the TRPV1 channel (transient receptor potential vanilloid type 1 or capsaicin receptor) has well-documented functions in the modulation of pain sensation and thermoregulatory responses. However, the TRPV1 channel is also expressed in non-neural tissues, suggesting that this channel may perform a broad range of functions. In this review, we first present a brief overview of the available tools for studying the physiological roles of the TRPV1 channel. Then, we present the relationship between the TRPV1 channel and spontaneous locomotor activity, physical performance, and modulation of several physiological responses, including water and electrolyte balance, muscle hypertrophy, and metabolic, cardiovascular, gastrointestinal, and inflammatory responses. Altogether, the data presented herein indicate that the TPRV1 channel modulates many physiological functions other than nociception and thermoregulation. In addition, these data open new possibilities for investigating the role of this channel in the acute effects induced by a single bout of physical exercise and in the chronic effects induced by physical training.

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The aim of this article was to describe the attention functioning of twenty-two truck drivers and its relationship with amphetamine use. Those drivers who reported using amphetamines in the twelve months previous to the interview had the best performance in a test evaluating sustained attention functioning. Although amphetamine use may initially seem advantageous to the drivers, it may actually impair safe driving. The findings suggest the importance of monitoring the laws regarding amphetamine use in this country.

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The objective of this work was to analyze the agronomic performance and chromosomal stability of transgenic homozygous progenies of soybean [Glycine max (L.) Merrill.], and to confirm the resistance of these plants against Anticarsia gemmatalis. Eleven progenies expressing cry1Ac, hpt and gusA genes were evaluated for agronomic characteristics in relation to the nontransformed parent IAS 5 cultivar. Cytogenetical analysis was carried out on transgenic and nontransgenic plants. Two out of the 11 transgenic progenies were also evaluated, in vitro and in vivo, for resistance to A. gemmatalis. Two negative controls were used in resistance bioassays: a transgenic homozygous line, containing only the gusA reporter gene, and nontransgenic 'IAS 5' plants. The presence of cry1Ac transgene affected neither the development nor the yield of plants. Cytogenetical analysis showed that transgenic plants presented normal karyotype. In detached-leaf bioassay, cry1Ac plants exhibited complete efficacy against A. gemmatalis, whereas negative controls were significantly damaged. Whole-plant feeding assay confirmed a very high protection of cry1Ac against velvetbean caterpillar, while nontransgenic 'IAS 5' plants and homozygous gusA line exhibited 56.5 and 71.5% defoliation, respectively. The presence of cry1Ac transgene doesn't affect the majority of agronomic traits (including yield) of soybean and grants high protection against A. gemmatalis.

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Abstract Objective: To compare the diagnostic performance of the three-dimensional turbo spin-echo (3D TSE) magnetic resonance imaging (MRI) technique with the performance of the standard two-dimensional turbo spin-echo (2D TSE) protocol at 1.5 T, in the detection of meniscal and ligament tears. Materials and Methods: Thirty-eight patients were imaged twice, first with a standard multiplanar 2D TSE MR technique, and then with a 3D TSE technique, both in the same 1.5 T MRI scanner. The patients underwent knee arthroscopy within the first three days after the MRI. Using arthroscopy as the reference standard, we determined the diagnostic performance and agreement. Results: For detecting anterior cruciate ligament tears, the 3D TSE and routine 2D TSE techniques showed similar values for sensitivity (93% and 93%, respectively) and specificity (80% and 85%, respectively). For detecting medial meniscal tears, the two techniques also had similar sensitivity (85% and 83%, respectively) and specificity (68% and 71%, respectively). In addition, for detecting lateral meniscal tears, the two techniques had similar sensitivity (58% and 54%, respectively) and specificity (82% and 92%, respectively). There was a substantial to almost perfect intraobserver and interobserver agreement when comparing the readings for both techniques. Conclusion: The 3D TSE technique has a diagnostic performance similar to that of the routine 2D TSE protocol for detecting meniscal and anterior cruciate ligament tears at 1.5 T, with the advantage of faster acquisition.

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In Tropical regions, the animal performance is often affected by climate conditions. This study aimed to evaluate covering materials in individual shelters, normally used to house dairy calves, and its influence on the calves physiology and performance. The design used was completely randomized, with a 2x3 factorial arrangement to compare the averages of 5% through the Tukey's test, i.e., both genders- and three types of covering in the shelters (Z - zinc; AC - asbestos cement; and WPAC - white-painted asbestos cement). Parameters evaluated included daily weight gain (DWG), dry matter intake (DMI), feed conversion (FC), rectal temperature (RT), and respiratory frequency (RF). Results showed significant differences (P < 0.05) among males (1.04kg/day) and females (0.74kg/day) for DWG and interaction between gender and treatment (P < 0.05) for zinc covering (0.562kg/day for females and 1.120kg/day for males). Significant differences were also observed in FI of animals housed under shelters with the covering of zinc (48.35kgDM/day for females and 96.91 kgDM/day for males). There were no significant differences (P > 0.05) in the FC and the RT, and there were significant differences (P < 0.05) for RF in the Z treatments (56.9 mov.min-1), WPAC (62.2 mov.min-1) and FC (70.25 mov.min-1). It was concluded that different covering materials did not affect performance and dry matter intake of dairy calves. However, the animals' physiology of thermoregulation was altered by the different covering materials used in individual shelters.

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There is evidence that brain temperature (Tbrain) provides a more sensitive index than other core body temperatures in determining physical performance. However, no study has addressed whether the association between performance and increases in Tbrain in a temperate environment is dependent upon exercise intensity, and this was the primary aim of the present study. Adult male Wistar rats were subjected to constant exercise at three different speeds (18, 21, and 24 m/min) until the onset of volitional fatigue. Tbrain was continuously measured by a thermistor inserted through a brain guide cannula. Exercise induced a speed-dependent increase in Tbrain, with the fastest speed associated with a higher rate of Tbrain increase. Rats subjected to constant exercise had similar Tbrain values at the time of fatigue, although a pronounced individual variability was observed (38.7-41.7°C). There were negative correlations between the rate of Tbrain increase and performance for all speeds that were studied. These results indicate that performance during constant exercise is negatively associated with the increase in Tbrain, particularly with its rate of increase. We then investigated how an incremental-speed protocol affected the association between the increase in Tbrain and performance. At volitional fatigue, Tbrain was lower during incremental exercise compared with the Tbrain resulting from constant exercise (39.3±0.3 vs 40.3±0.1°C; P<0.05), and no association between the rate of Tbrain increase and performance was observed. These findings suggest that the influence of Tbrain on performance under temperate conditions is dependent on exercise protocol.

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OBJECTIVE: To assess the receptive vocabulary of children aged between two years and six months and five years and eleven months who were attending childcare centers and kindergarten schools. METHODS: An analytical cross-sectional study was carried out in the municipality of Embu, Southeastern Brazil. The Peabody Picture Vocabulary Test and analysis of factors associated with children's performance were applied. The sample consisted of 201 children of both genders, aged between two and six years. Statistical analysis was performed using multivariate analysis and logistic regression model. The dependent variable analyzed was test performance and the independent variables were child's age, mother's level of education and family socio-demographic characteristics. RESULTS: It was observed that 44.3% of the children had performances in the test that were below what would be expected for their age. The factors associated with the best performances in the test were child's age (OR=2.4; 95% CI: 1.6-3.5) and mother's education level (OR= 3.2; 95% CI: 1.3-7.4). CONCLUSIONS: Mother's education level is important for child's language development. Settings such as childcare and kindergarten schools are protective factors for child development in families of low income and education.

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OBJECTIVE To evaluate the validity and reliability of an instrument that evaluates the structure of primary health care units for the treatment of tuberculosis.METHODS This cross-sectional study used simple random sampling and evaluated 1,037 health care professionals from five Brazilian municipalities (Natal, state of Rio Grande do Norte; Cabedelo, state of Paraíba; Foz do Iguaçu, state of Parana; Sao José do Rio Preto, state of Sao Paulo, and Uberaba, state of Minas Gerais) in 2011. Structural indicators were identified and validated, considering different methods of organization of the health care system in the municipalities of different population sizes. Each structure represented the organization of health care services and contained the resources available for the execution of health care services: physical resources (equipment, consumables, and facilities); human resources (number and qualification); and resources for maintenance of the existing infrastructure and technology (deemed as the organization of health care services). The statistical analyses used in the validation process included reliability analysis, exploratory factor analysis, and confirmatory factor analysis.RESULTS The validation process indicated the retention of five factors, with 85.9% of the total variance explained, internal consistency between 0.6460 and 0.7802, and quality of fit of the confirmatory factor analysis of 0.995 using the goodness-of-fit index. The retained factors comprised five structural indicators: professionals involved in the care of tuberculosis patients, training, access to recording instruments, availability of supplies, and coordination of health care services with other levels of care. Availability of supplies had the best performance and the lowest coefficient of variation among the services evaluated. The indicators of assessment of human resources and coordination with other levels of care had satisfactory performance, but the latter showed the highest coefficient of variation. The performance of the indicators “training” and “access to recording instruments” was inferior to that of other indicators.CONCLUSIONS The instrument showed feasibility of application and potential to assess the structure of primary health care units for the treatment of tuberculosis.