7 resultados para Visual Recognition

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Perceiving a possible predator may promote physiological changes to support prey 'fight or flight'. In this case, an increase in ventilatory frequency (VF) may be expected, because this is a way to improve oxygen uptake for escape tasks. Therefore, changes in VF may be used as a behavioral tool to evaluate visual recognition of a predator threat. Thus, we tested the effects of predator visual exposure on VF in the fish Nile tilapia, Oreochromis niloticus. For this, we measured tilapia VF before and after the presentation of three stimuli: an aquarium with a harmless fish or a predator or water (control). Nile tilapia VF increased significantly in the group visually exposed to a predator compared with the other two, which were similar to each other. Hence, we conclude that Nile tilapia may recognize an allopatric predator; consequently VF is an effective tool to indicate visual recognition of predator threat in fish. (C) 2002 Elsevier B.V. B.V. All rights reserved.

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Norms for three visual memory tasks, including Corsi's block tapping test and the BEM 144 complex figures and visual recognition, were developed for neuropsychological assessment in Brazilian children. The tasks were measured in 127 children ages 7 to 10 years from rural and urban areas of the States of São Paulo and Minas Gerais. Analysis indicated age-related but not sex-related differences. A cross-cultural effect was observed in relation to copying and recall of Complex pictures. Different performances between rural and urban children were noted. © Perceptual and Motor Skills 2005.

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OBJECTIVE: As a result of overall growing population's life expectancy, it has become increasingly important to ensure not only that the elderly have greater longevity but also happiness and life satisfaction. The objective of the study was to describe factors associated with life satisfaction among elderly people.METHODS: Three hundred and sixty-five older persons, selected by means of random stratified proportional sampling, were interviewed in 2003. The instrument used was a combination of Flanagan and Nahas questionnaires and WHOQOL-100. There were added questions concerning physical activity extracted from International Physical Activity Questionnaire, questions regarding reported morbidity and emotional assessment, sociodemographic condition and an open question. The level of life satisfaction was measured using a scale from one to seven by means of visual recognition. Hierarchical logistic regression analysis was performed including life satisfaction as a dependent variable and those included the final questionnaire, in blocks, as independent variables.RESULTS: Most elderly were generally rather satisfied with life as well as with specific aspects. The level of life satisfaction was associated with: comfort at home (OR=11.82; 95% Cl: 3.27; 42.63); appraising leisure as quality of life (OR=3.82; 95% Cl: 2.28; 6.39); waking up feeling well in the morning (OR=2.80; 95% Cl: 1.47; 5.36); not reporting loneliness (OR=2.68; 95% Cl: 1.54; 4.65); having three or more daily meals (OR=2.63; 95% Cl: 1.75; 5.90) and not reporting Diabetes Mellitus (OR-2.63; 95% Cl: 1.3 1; 5.27).CONCLUSIONS: Most elderly in the study were satisfied with life and their satisfaction was associated with situations related to being well and not being diabetic.

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Pós-graduação em Alimentos e Nutrição - FCFAR

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Ornamental fish may be severely affected by a stressful environment. Stressors impair the immune response, reproduction and growth rate; thus, the identification of possible stressors will aid to improve the overall quality of ornamental fish. The aim of this study was to determine whole-body cortisol of adult zebrafish, Danio rerio, following visual or direct contact with a predator species. Zebrafish were distributed in three groups: the first group, which consisted of zebrafish reared completely isolated of the predator, was considered the negative control; the second group, in which the predator, Parachromis managuensis was stocked together with zebrafish, was considered the positive control; the third group consisted of zebrafish stocked in a glass aquarium, with direct visual contact with the predator. The mean whole-body cortisol concentration in zebrafish from the negative control was 6.78 +/- 1.12 ng g(-1), a concentration statistically lower than that found in zebrafish having visual contact with the predator (9.26 +/- 0.88 ng g(-1)) which, in turn, was statistically lower than the mean whole-body cortisol of the positive control group (12.35 +/- 1.59 ng g(-1)). The higher whole-body cortisol concentration found in fish from the positive control can be attributed to the detection, by the zebrafish, of relevant risk situations that may involve a combination of chemical, olfactory and visual cues. One of the functions of elevated cortisol is to mobilize energy from body resources to cope with stress. The elevation of whole-body cortisol in fish subjected to visual contact with the predator involves only the visual cue in the recognition of predation risk. We hypothesized that the zebrafish could recognize predator characteristics in P managuensis, such as length, shape, color and behavior. Nonetheless, the elevation of whole-body cortisol in zebrafish suggested that the visual contact of the predator may elicit a stress response in prey fish. This assertion has a strong practical application concerning the species distribution in ornamental fish markets in which prey species should not be allowed to see predator species. Minimizing visual contact between prey and predator fish may improve the quality, viability and welfare of small fish in ornamental fish markets. (c) 2007 Elsevier B.V. All rights reserved.

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An intelligent system that emulates human decision behaviour based on visual data acquisition is proposed. The approach is useful in applications where images are used to supply information to specialists who will choose suitable actions. An artificial neural classifier aids a fuzzy decision support system to deal with uncertainty and imprecision present in available information. Advantages of both techniques are exploited complementarily. As an example, this method was applied in automatic focus checking and adjustment in video monitor manufacturing. Copyright © 2005 IFAC.

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Pós-graduação em Engenharia Mecânica - FEG