880 resultados para Impulse Facilities
LEARNING IMPULSE CONTROL IN A NOVEL ANIMAL MODEL: SYNAPTIC, CELLULAR, AND PHARMACOLOGICAL SUBSTRATES
Resumo:
Impulse control, an executive process that restrains inappropriate actions, is impaired in numerous psychiatric conditions. This thesis reports three experiments that utilized a novel animal model of impulse control, the response inhibition (RI) task, to examine the substrates that underlie learning this task. In the first experiment, rats were trained to withhold responding on the RI task, and then euthanized for electrophysiological testing. Training in the RI task increased the AMPA/NMDA ratio at the synapses of pyramidal neurons in the prelimbic, but not infralimbic, region of the medial prefrontal cortex. This enhancement paralleled performance as subjects underwent acquisition and extinction of the inhibitory response. AMPA/NMDA was elevated only in neurons that project to the ventral striatum. Thus, this experiment identified a synaptic correlate of impulse control. In the second experiment, a separate group of rats were trained in the RI task prior to electrophysiological testing. Training in the RI task produced a decrease in membrane excitability in prelimbic, but not infralimbic, neurons as measured by maximal spiking evoked in response to increasing current injection. Importantly, this decrease was strongly correlated with successful inhibition in the task. Fortuitously, subjects trained in an operant control condition showed elevated infralimbic, but not prelimbic, excitability, which was produced by learning an anticipatory signal that predicted imminent reward availability. These experiments revealed two cellular correlates of performance, corresponding to learning two different associations under distinct task conditions. In the final experiment, rats were trained on the RI task under three conditions: Short (4-s), long (60-s), or unpredictable (1-s to 60-s) premature phases. These conditions produced distinct errors on the RI task. Interestingly, amphetamine increased premature responding in the short and long conditions, but decreased premature responding in the unpredictable condition. This dissociation may arise from interactions between amphetamine and underlying cognitive processes, such as attention, timing, and conditioned avoidance. In summary, this thesis showed that learning to inhibit a response produces distinct synaptic, cellular, and pharmacological changes. It is hoped that these advances will provide a starting point for future therapeutic interventions of disorders of impulse control.
Resumo:
The development of cultural policy analysis by social science has been produced a theorization about cultural policy models from sociology and political science. This analysis shows the influence of the national model of cultural policy on the forms of governance and management of cultural facilities. However, in this paper we will defend that currently the local model of cultural policy decisively influences the model of cultural institutions. This is explained by the growing importance of culture in local development strategies. In order to demonstrate this we will analyze the case of the Barcelona Model of local development and cultural policy, that is characterized for the level of local government leadership, multilevel governance, the use of culture in urban planning processes and a tendency to use public-private partnership in public management. This Model influences the genesis and development of the cultural facilities and it produces a singular and relatively successful model.
Resumo:
The ways of incorporating newcoming students into schools and colleges have been at the center of debate in most OECD countries in recent years. In Spain, the set of measures developed for the reception of immigrant pupils in different Autonomous Communities has also been the subject of specific research, pointing out the similarities and contradictions between pedagogic discourses and school practices. This article takes into account these considerations and presents the reflections from the results of research on the Educational Welcome Facilities (and specifically the EBE) conducted during the school years 2008-2010. This device was created in Catalonia to attend newcomers before enrolling them in the school. It was a pilot project which took place in Vic and Reus for two consecutive years. The research of the EBE has enabled us to explain the relationship between educational assessment that schools made about this facility and reception processes that schools were implementing. The conclusions that emerge from this analysis allowed us to establish relationships between educational host practices of the seven centers analyzed with three different conceptual and educational frameworks of reception.
Resumo:
Solid low-level radioactive waste (LLW) is currently being disposed at a number of facilities in the United Kingdom (UK). The safety of these facilities relies to some extent on the use of engineered barriers, such as a cap, to isolate the waste and protect the environment. Generally, the material used as the barrier layer within such a cap should be of low permeability and it should retain this property over long timescales (beyond a few decades normally required for facilities containing non-radioactive wastes). The objective of this research is to determine the mineralogy of selected geological deposits from the UK and Ireland as part of a larger project to examine their suitability as a capping material, particularly on LLW sites. Mineral transformations, as a result of future climate change, may impact on the long-term performance of the cap and even the disposal facility. X-ray diffraction (XRD) was carried-out on the sand, silt and clay fractions of the London Clay, Belfast Upper Boulder Clay, Irish Glacial Till, Belfast Sleech, and Ampthill Clay geological deposits. Minerals were present that could pose both positive and negative effects on the long-term performance of the cap. Smectite, which has a high shrink swell potential, may produce cracks in London Clay, Belfast Upper Boulder Clay and Ampthill Clay capping material during dry, hotter periods as a possible consequence of future climate change; thus, resulting in higher permeability. Ampthill Clay and Belfast Sleech had elevated amounts of organic matter (OM) at 5.93% and 5.88%, respectively, which may also contribute to cracking. Over time, this OM may decompose and result in increased permeability. Gypsum (CaSO4) in the silt and sand fractions of Ampthill Clay may reduce the impact of erosion during wetter periods if it is incorporated into the upper portion of the cap. There are potential negative effects from the acidity created by the weathering of pyrite (FeS2) present in the silt and sand fractions of Belfast Sleech and Ampthill Clay that could impede the growth of grasses used to stabilize the surface of the capping material if this material is used as part of the vegetative soil layer. Additionally, acidic waters generated from pyrite weathering could negatively impact the lower lying capping layers and the disposal facility in general. However, the calcium carbonate (CaCO3) present in the silt and sand fractions of these deposits, and dolomite (CaMg(CO3)2) in Belfast Sleech, may counter act the acidity.
Resumo:
Total cross sections for electron capture are calculated for collisions of fast protons and a-particles with atomic hydrogen. The distorted-wave impulse approximation is applied over the energy range 10-1500 keV/u. State-selective results are given for the 1s, 2s and 2p levels. Both the post and prior forms of the model are calculated and compared with results from other theories and experimental measurements. In general the model performs very well in comparison with experiment over this energy range though discrepancies arise at lower energies.
STUDY OF X-RAY LASER SCHEMES USING NEW EXPERIMENTAL FACILITIES AT THE RUTHERFORD-APPLETON-LABORATORY
Resumo:
Aims. This paper is a report of a study examining the association between ownership type and perceived team climate among older people care staff. In addition, we examined whether work stress factors (time pressure, resident-related stress, role conflicts and role ambiguity) mediated or moderated the above mentioned association. Background. There has been a trend towards contracting out in older people care facilities in Finland and the number of private for-profit firms has increased. Studies suggest that there may be differences in employee well-being and quality of care according to the ownership type of older people care. Methods. Cross-sectional survey data was collected during the autumn of 2007 from 1084 Finnish female older people care staff aged 1869 years were used. Team Climate Inventory was used to measure team climate. Ownership type was divided into four categories: for-profit sheltered homes, not-for-profit sheltered homes, public sheltered homes and not-for-profit nursing homes. Analyses of covariance were used to examine the associations. Results. Team climate dimensions participative safety, vision and support for innovation were higher in not-for-profit organizations (both sheltered homes and nursing homes) compared to for-profit sheltered homes and public sheltered homes. Stress factors did not account for these associations but acted as moderators in a way that in terms of task orientation and participative safety employees working in for-profit organizations seemed to be slightly more sensitive to work-related stress than others. Conclusion. Our results suggest that for-profit organizations and public organizations may have difficulties in maintaining their team climate. In consequence, these organizations should focus more effort on improving their team climate.