755 resultados para behavioural expectation


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Three hundred and twenty pigs were reared from birth to slaughter at 21 weeks in either barren or enriched environments. The barren environments were defined as intensive housing (slatted floors and minimum recommended space allowances) and the enriched environments incorporated extra space including an area which contained peat and straw in a rack. Behavioural observations showed that environmental enrichment reduced time spent inactive and rime spent involved in harmful social and aggressive behaviour (P

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Tagging animals is frequently employed in ecological studies to monitor individual behaviour, for example postrelease survival and dispersal of captive-bred animals used in conservation programmes. While the majority of studies focus on the efficacy of tags in facilitating the relocation and identification of individuals, few assess the direct effects of tagging in biasing animal behaviour. We used an experimental approach with a control to differentiate the effects of handling and tagging captive-bred juvenile freshwater pearl mussels, Margaritifera margaritifera, prior to release into the wild. Marking individuals with passive integrated transponder (PIT) tags significantly decreased their burrowing rate and, therefore, increased the time taken to burrow into the substrate. This effect was contributed to, in part, by the detrimental impacts of handling, which also significantly affected activity, burrowing ability and the time taken for each individual to emerge and start probing the substrate. Disturbance during handling and tagging may lead to indirect mortality after release by increasing the risk of predation or dislodgement during flooding, thereby potentially compromising any conservation strategy contingent on population supplementation or reintroduction. This is the first study to demonstrate that handling and PIT tagging has a detrimental impact on invertebrate behaviour. Moreover, our results provide useful information that will inform freshwater bivalve conservation strategies.

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Introduction: Although there is evidence for distinct behavioural sub-phenotypes in Alzheimer's disease (AD), their inter-relationships and the effect of clinical variables on their expression have been little investigated.

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Clinically accessible compounds that arrest or reverse the effects of amyloid-ß (Aß) on progressively developing behavioural symptomatology and neuropathology in Alzheimer's disease (AD) have yet to become available. However, a viable strategy may be to target and neutralise soluble Aß oligomers, which have been shown to mediate synaptic dysfunction and to produce cognitive deficits in the intact organism. Inhibiting the aggregation of Aß is therapeutically attractive, as Aß aggregation is a pathological event and pharmacological interventions targeting this are likely to have a non-toxic profile. A behavioural assay, the alternating-lever cyclic-ratio schedule, was used to assess the effect of Aß oligomers and the non-peptide small molecule RS-0406 in male Sprague-Dawley rats. RS-0406 has been shown to inhibit Aß1-42 fibrillogenesis and protect against Aß1-42–induced cytotoxicity in primary hippocampal neurons. In the current study, RS-0406 ameliorated the adverse effects of secreted oligomers of human Aß on behaviour and dose dependently reduced the behavioural effects of Aß oligomers, with the highest dose, 10 µM, maintaining behaviour approximately at control levels. This effect appeared to be central; peripheral confounds having been extensively investigated. This is the first published report on the effects of RS-0406 in vivo and indicates that RS-0406 has potential as a pharmacotherapeutic intervention for behavioural deficits seen in the early stages of AD, and possibly as an intervention in the development of AD neuropathology. Indeed, an analogue of RS-0406 that could be administered peripherally might be a realistic candidate for the clinical treatment of AD.