908 resultados para Mating preference


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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Heart failure (HF) is a complex syndrome that involves changes in behavioral, neural and endocrine regulatory systems. Dietary salt restriction along with pharmacotherapy is considered an essential component in the effective management of symptomatic HF patients. However, it is well recognized that HF patients typically have great difficulty in restricting sodium intake. We hypothesized that under HF altered activity in systems that normally function to regulate body fluid and cardiovascular homeostasis could produce an increased preference for the taste of salt. Therefore, this study was conducted to evaluate the perceived palatability (defined as salt preference) of food with different concentrations of added salt in compensated chronically medicated HF patients and comparable control subjects. Healthy volunteers (n = 25) and medicated, clinically stable HF patients (n = 38, NYHA functional class II or III) were interviewed and given an evaluation to assess their preferences for different amounts of saltiness. Three salt concentrations (0.58, 0.82, and 1.16 g/100 g) of bean soup were presented to the subjects. Salt preference for each concentration was quantified using an adjective scale (unpleasant, fair or delicious). Healthy volunteers preferred the soup with medium salt concentration (p = 0.042), HF patients disliked the low concentration (p < 0.001) and preferred the high concentration of salted bean soup (p < 0.001). When compared to healthy volunteers, HF patients demonstrated a significantly greater preference for the soup with a high salt concentration (p = 0.038). It is concluded that medicated, compensated patients under chronic treatment for HF have an increased preference for salt. (C) 2011 Elsevier Ltd. All rights reserved,

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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We studied the colour preference of isolated Nile tilapia (Oreochromis niloticus) and whether previous residence or body size can affect environmental colour choice. In the first phase, a cylindrical tank was divided into five differently coloured compartments (yellow, blue, green, white and red), a single fish was introduced into the tank and the frequency at which this fish visited each compartment was recorded over a 2-day study period. An increasingly larger fish (approx +2 cm in length each time) was then added into the tank on each of days 3, 5 and 7 (=four fish in the tank by day 7), and the frequency at which each fish visited the different compartments of the tank was observed twice a day to obtain visit frequency data on the differently sized fishes. This experiment was replicated six times. In the first phase, the solitary fish established residence inside the yellow compartment on the first and second days. Following the introduction of a larger fish, the smaller fish was displaced from the occupied compartment. Nile tilapia possibly shows this preference for yellow as a function of its visual spectral sensitivity and/or the spectral characteristics of its natural environment. Moreover, body size is an important factor in determining hierarchical dominance and territorial defence, and dominant fish chose the preferred environmental colour compartment as their territory.

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Selection favors females that attend to reliable information about male genetic quality and fitness. Male nutritional condition can be a significant sign of mate quality since poor nutrition can be related to reduced sperm quality, low sperm quantity, sexually transmitted diseases, and parasites. We tested whether female Nile tilapia, Oreochromis niloticus, preferred the chemical cues of males that were well fed with high-protein diet over those fed with low-protein diet. Females do not only discriminate between males but also show a preference for well-fed males, discriminating between the odors with respect to nutritional state, suggesting that they were responding to a food-specific chemical cue. It is therefore likely that nutritional condition is related to the production of pheromones in males. Our results suggest that information about male nutritional state can be conveyed in chemical cues and that females attend to these cues during mate choice.

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This study tested the preference of pintado catfish females (Pseudoplatystoma coruscans) for associating with well-fed or food-deprived males in simultaneous choice tests. Females were tested under three different treatments in which: (1) females could choose on the basis of multiple cues from the well-fed or food-deprived males (visual plus chemical); (2) only chemical cues were presented; (3) only visual cues were presented. Females chose well-fed males when chemical cues were presented (either visual + chemical or only chemical cues). When only visual cues were presented, females spent an equal amount of time in the choice apparatus compartments. Chemical signals, either directly through control of pheromone production, or indirectly by excreted metabolites, are likely to be an important source of information about nutritional condition in mating choice.

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Descrevemos o comportamento reprodutivo de Adelosgryllus rubricephalus Mesa & Zefa, 2004. em observações realizadas em laboratório verificamos a seguinte seqüência no comportamento de acasalamento: (1) reconhecimento sexual por antenação; (2) corte, em que o macho volta seu abdômen em direção à fêmea, vibra as antenas médio-lateralmente, treme o corpo ântero-posteriormente e estridula intermitentemente, enquanto a fêmea receptiva toca a ponta do abdômen, os cercos e os fêmures posteriores do macho, com seus palpos ou tarsos anteriores; o macho então fica imóvel por alguns segundos, expõe o espermatóforo e ambos retomam a seqüência comportamental descrita acima; (3) cópula: o macho coloca-se sob a fêmea, com suas tégminas inclinadas para frente, anexa sua genitália à dela e promove a transferência do esperma; a fêmea desce de cima do macho e ocorre brevemente a posição end-to-end durante a separação do casal; (4) pós-cópula: não há comportamento de guarda; o macho retém o espermatóforo e o ingere. Quantificamos o intervalo de tempo das principais etapas do acasalamento e discutimos suas possíveis implicações no comportamento observado.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Objectives: To determine whether chewing side preference (CSP) is correlated to lateralities (handedness, footedness, eyedness and earedness) in primary, mixed and permanent dentitions.Design: Three-hundred subjects were divided into 3 groups: Group 1-100 children 3-5 years old, primary dentition; Group 2-100 children 6-12 years old, mixed dentition; Group 3 - 100 subjects 18-47 years old, permanent dentition. CSP was determined using a method developed by Mc Donnell et al.(9) Subjects were given a piece of gum and the position of the chewing gum was recorded 7 times as right or left. Subjects were classified as 'observed preferred chewing side' (OPCS) when they performed 5/7, 6/7 or 7/7 strokes on the same side. OPCS corresponded to the CSP. Laterality tests were performed for handedness, footedness, eyedness and earedness tasks. The Chi-square (chi(2)) and phi correlation (r) tests were used to investigate significant correlations between CSP and sidedness.Results: There was a significant correlation between chewing and earedness (p = 0.00), although there was weak positive correlation (r = 0.30) for primary dentition. There were significant correlations between chewing and handedness (p = 0.02; r = 0.25) and chewing and footedness (p = 0.02; r = 0.26), however, there were weak positive correlations for mixed dentition; there were significant correlations between chewing and handedness (p = 0.02; r = 0.26); chewing and footedness (p = 0.00; r = 0.33) and chewing and earedness (p = 0.01; r = 0.29); however, there were weak positive correlations for permanent dentition.Conclusion: It may be concluded that CSP can be significantly correlated with: earedness for primary dentition; handedness and footedness for mixed dentition; handedness, footedness and earedness for permanent dentition, but these are weak positive relationships. Future work on larger samples of left- and right-sided individuals is required to validate the findings. (C) 2012 Elsevier Ltd. All rights reserved.

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Samples of water, suspended solids, and bottom sediments from the Madeira River, Rondonia state, Brazil, were physically and chemically analyzed to investigate the actual Hg mobilization in the aquatic environment and compare it with that of other heavy metals and elements in the area. Two dimensionless Hg preference ratios were defined, expressing (1) the ratio of Hg and other elements in the liquid phase divided by the ratio of Hg and other elements in bottom sediments (P(l.phase)) and (2) the ratio of Hg and other elements in the particulate matter divided by the ratio of Hg and other elements in bottom sediments (P(s.solids)). These preference ratios are useful for comparing Hg transport in three different phases (liquid, particulate matter, and bottom sediments). They also were applicable to any analyzed elementin the area studied, because they generated an almost constant value when the maximum calculated was divided by the minimum (P(l.phase) = 2931; P(s.solids) = 84) and because of their sensitivity to the dominance of sorption processes by Fe oxides and hydroxides. Mercury could be transported preferentially to other analyzed elements in the particulate phase only if its concentration reached values at least 10(4)-fold higher than those expected or quantified in the area. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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