3 resultados para Precision agriculture

em Brock University, Canada


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Most metabolic functions are optimized within a narrow range of body temperatures, which is why thermoregulation is of great importance for the survival and overall fitness of an animal. It has been proposed that lizards will thermoregulate less precisely in low thermal quality environments, where the costs associated with thermoregulation are high; in the case of lizards, whose thermoregulation is mainly behavioural, the primary costs ofthermoregulation are those derived from locomotion. Decreasing thermoregulatory precision in costly situations is a strategy that enhances fitness by allowing lizards to be more flexible to changing environmental conditions. It allows animals to maximize the benefits of maintaining a relatively high body temperature while minimizing energy expenditure. In situations where oxygen concentration is low, the costs of thermoregulation are relatively high (i.e. in relation to the amount of oxygen available for metabolic functions). As a result, it is likely that exposures to hypoxic conditions induce a decrease in the precision of thermoregulation. This study evaluated the effects of hypoxia and low environmental thermal quality, two energetically costly conditions, on the precision and level of thermoregulation in the bearded dragon, Pogona vitticeps, in an electronic temperature-choice shuttle box. Four levels of hypoxia (1O, 7, 5 and 4% 02) were tested. Environmental thermal quality was manipulated by varying the rate of temperature change (oTa) in an electronic temperature-choice shuttle box. Higher oT a's translate into more thermally challenging environments, since under these conditions the animals are forced to move a greater number of times (and hence invest more energy in locomotion) to maintain similar temperatures than at lower oTa's. In addition, lizards were tested in an "extreme temperatures" treatment during which air temperatures of the hot and cold compartments of the shuttle box were maintained at a constant 50 and 15°C respectively. This was considered the most thermally challenging environment. The selected ambient (T a) and internal body temperatures (Tb) of bearded dragons, as well as the thermoregulatory precision (measured by the central 68% ofthe Ta and T b distribution) were evaluated. The thermoregulatory response was similar to both conditions. A significant increase in the size of the Tb range, reflecting a decrease in thermoregulatory precision, and a drop in preferred body temperature of ~2 °C, were observed at both 4% oxygen and at the environment of lowest thermal quality. The present study suggests that in energetically costly situations, such as the ones tested in this study, the bearded dragon reduces energy expenditure by decreasing preferred body temperature and minimizing locomotion, at the expense of precise behavioural thermoregulation. The close similarity of the behavioural thermoregulatory response to two very different stimuli suggests a possible common mechanism and neuronal pathway to the thermoregulatory response.

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This study was done to test the effectiveness of the Precision Fluency Shaping Program in controlling stuttering behaviour in adults. Two sites were chosen, each using the Precision Fluency Shaping Program to treat stuttering. At each clinic, a Speech Patbologist made a random selection of the subjects' pre- and post-therapy video-taped interviews, totalling 20 in all. During the interviews, the clients were asked questions and re~d a short passage to determine the frequency of stuttering in natural conversation and in reading. Perceptions of Stuttering Inventory questionnaires vvere also filled in before and after therapy. Two judges were trained to identify stuttering behaviour, and were given an inter-rater reliability test at selected intervals throughout the study. Protocols",:m.a;d;6 of each interview tape, were scored for (a) stuttering behaviour and (b) words spoken or read. An Analysis of Variance Repeated Measures Test was used to compare before and after scores of conversations, readings, and Perceptions of Stuttering Inventory to determine whether the Precision Fluency Shaping Program controlled stuttering behaviour significantly. A Pearson R Correlation Test was also administered to determine if a relationship existed bet\veen Perceptions of Stuttering Inventory and (i) conversation and (ii) reading scores.

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The Ontario Federation of Agriculture was established in 1936 and is the largest voluntary farm organization in Canada, representing 37,000 farm families. The Federation came about in response to the creation of the Canadian Chamber of Agriculture (later renamed the Canadian Federation of Agriculture) in 1935. The establishment of an Ontario branch was needed to provide a forum through which similar organizations from other provinces could communicate about farm issues that were of interprovincial, national, or international importance. The organization is led by farmers and is based in Guleph, Ontario. Their missionis to enable prosperous and sustainable farms. They accomplish this through lobbying, government and media relations, and community representation.