6 resultados para pre-stress

em CiencIPCA - Instituto Politécnico do Cávado e do Ave, Portugal


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Exposure to a novel environment triggers the response of several brain areas that regulate emotional behaviors. Here, we studied theta oscillations within the hippocampus (HPC)-amygdala (AMY)-medial prefrontal cortex (mPFC) network in exploration of a novel environment and subsequent familiarization through repeated exposures to that same environment; in addition, we assessed how concomitant stress exposure could disrupt this activity and impair both behavioral processes. Local field potentials were simultaneously recorded from dorsal and ventral hippocampus (dHPC and vHPC respectively), basolateral amygdala (BLA) and mPFC in freely behaving rats while they were exposed to a novel environment, then repeatedly re-exposed over the course of 3 weeks to that same environment and, finally, on re-exposure to a novel unfamiliar environment. A longitudinal analysis of theta activity within this circuit revealed a reduction of vHPC and BLA theta power and vHPC-BLA theta coherence through familiarization which was correlated with a return to normal exploratory behavior in control rats. In contrast, a persistent over-activation of the same brain regions was observed in stressed rats that displayed impairments in novel exploration and familiarization processes. Importantly, we show that stress also affected intra-hippocampal synchrony and heightened the coherence between vHPC and BLA. In summary, we demonstrate that modulatory theta activity in the aforementioned circuit, namely in the vHPC and BLA, is correlated with the expression of anxiety in novelty-induced exploration and familiarization in both normal and pathological conditions.

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Residents tend to have high expectations regarding the benefits of hosting a mega- event, in particular the creation of new infrastructure, growth in GDP and employ- ment, image enhancement and the spin-offs of attracting tourists and fostering sustainable growth of the cultural supply (Jeong and Faulkner 1996; Deccio and Baloglu 2002; Gursoy and Kendall 2006; Getz 2008; Langen and Garcia 2009; Ritchie et al. 2009; Gursoy et al. 2011; Palonen 2011). Nevertheless, they normally recognise that some costs will be incurred (Kim and Petrick 2005; Kim et al. 2006; Ritchie et al. 2009; Gursoy et al. 2011; Lee et al. 2013). So, it was not surprising that the nomination of Guimaraes, a small city in the northwest of Portugal, as one of the two European Capitals of Culture in 2012 (2012 ECOC), had raised great expectations in the local community vis- a-vis its socio-economic and cultural benefits. Our research was designed to examine the Guimar~aes residents’ perceptions of the impacts of hosting the 2012 ECOC, approached at two different times: before and after the event, to try and capture the evolution of the residents’ assessment of its impacts. From the empirical literature, we know that residents’ perceived impacts tend to change as time goes by (Kim et al. 2006; Ritchie et al. 2009; Gursoy et al. 2011; Lee et al. 2013). The data were gathered via two surveys applied to Guimaraes residents, one in 2011, before the event, and the other afterwards, in 2013. The Guimaraes residents’ assessment was thought to be essential to get an accurate appraisal of the impact of the mega-event as they were a main part of the hosting process. 2012 ECOC impacts were mainly felt by local people who, in most cases, will go on feeling them in the short and long term. The research was thought to be socially pertinent as the opinions collected through the surveys can help to prevent repeating mistakes when similar mega- events are organised in the future, and to increase the positive impacts derived from hosting them. When we talk about the social pertinence of the empirical results, we want to stress that the expertise acquired can be useful to any host city or country.

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Pectus excavatum is the most common congenital deformity of the anterior chest wall, in which an abnormal formation of the rib cage gives the chest a caved-in or sunken appearance. Today, the surgical correction of this deformity is carried out in children and adults through Nuss technic, which consists in the placement of a prosthetic bar under the sternum and over the ribs. Although this technique has been shown to be safe and reliable, not all patients have achieved adequate cosmetic outcome. This often leads to psychological problems and social stress, before and after the surgical correction. This paper targets this particular problem by presenting a method to predict the patient surgical outcome based on pre-surgical imagiologic information and chest skin dynamic modulation. The proposed approach uses the patient pre-surgical thoracic CT scan and anatomical-surgical references to perform a 3D segmentation of the left ribs, right ribs, sternum and skin. The technique encompasses three steps: a) approximation of the cartilages, between the ribs and the sternum, trough b-spline interpolation; b) a volumetric mass spring model that connects two layers - inner skin layer based on the outer pleura contour and the outer surface skin; and c) displacement of the sternum according to the prosthetic bar position. A dynamic model of the skin around the chest wall region was generated, capable of simulating the effect of the movement of the prosthetic bar along the sternum. The results were compared and validated with patient postsurgical skin surface acquired with Polhemus FastSCAN system

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Chronic stress impairs cognitive function, namely on tasks that rely on the integrity of cortico-limbic networks. To unravel the functional impact of progressive stress in cortico-limbic networks we measured neural activity and spectral coherences between the ventral hippocampus (vHIP) and the medial prefrontal cortex (mPFC) in rats subjected to short term stress (STS) and chronic unpredictable stress (CUS). CUS exposure consistently disrupted the spectral coherence between both areas for a wide range of frequencies, whereas STS exposure failed to trigger such effect. The chronic stress-induced coherence decrease correlated inversely with the vHIP power spectrum, but not with the mPFC power spectrum, which supports the view that hippocampal dysfunction is the primary event after stress exposure. Importantly, we additionally show that the variations in vHIP-to-mPFC coherence and power spectrum in the vHIP correlated with stress-induced behavioral deficits in a spatial reference memory task. Altogether, these findings result in an innovative readout to measure, and follow, the functional events that underlie the stress-induced reference memory impairments.

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Residents tend to have high expectations about the benefits of hosting a mega‐event. So, it was not surprising that the nomination of Guimarães, Portugal, as the 2012 European Capital of Culture (2012 ECOC) had raised great expectations in the local community towards its socio‐economic and cultural benefits. The present research was designed to examine the Guimarães residents’ perceptions on the impacts of hosting the 2012 ECOC approached in two different time schedules, the pre‐ and the post‐event, trying to capture the evolution of the residents` evaluation of its impacts. For getting the data, two surveys were applied to Guimarães` residents, one in the pre‐event phase, in 2011, and another in the post‐event phase, in 2013. This approach is uncommonly applied to Portugal data and it is even the first time it was done to a Portuguese European Capital of Culture. After a factor analysis, the results of t‐tests indicate that there were significant differences (p<0.05) between the samples from the pre‐ and post‐2012 ECOC on two positive impact factors (Community’ benefits and Residents’ benefits) and one negative impact factor (Economic, social and environmental costs). Respondents also showed a negative perception of the impacts in all dimensions, except Changes in habits of Guimarães residents.

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The nomination of Guimarães, a small city located in the northwest of Portugal, as European capital of culture (ECOC) in 2012 raised great expectations in the local community towards its socio-economic and cultural benefits. As noted by various authors, namely Kim and Petrick (2005), Kim, Gursoy and Lee (2006) and Gursoy, Chi, Ai and Chen (2011), residents tend to have high expectations about the benefits of hosting a mega-event, although they tend to recognize that some costs will result from it. Therefore, the present research was designed to examine the Guimarães residents’ perceptions on the impacts of the 2012 European capital of culture (2012 ECOC) on the city and the municipality of Guimarães before and after the mega-event and the differences found between the two time periods.