881 resultados para Local Field Potentials


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Tsunamis occur quite frequently following large magnitude earthquakes along the Chilean coast. Most of these earthquakes occur along the Peru-Chile Trench, one of the most seismically active subduction zones of the world. This study aims to understand better the characteristics of the tsunamis triggered along the Peru-Chile Trench. We investigate the tsunamis induced by the Mw8.3 Illapel, the Mw8.2 Iquique and the Mw8.8 Maule Chilean earthquakes that happened on September 16th, 2015, April 1st, 2014 and February 27th, 2010, respectively. The study involves the relation between the co-seismic deformation and the tsunami generation, the near-field tsunami propagation, and the spectral analysis of the recorded tsunami signals in the near-field. We compare the tsunami characteristics to highlight the possible similarities between the three events and, therefore, attempt to distinguish the specific characteristics of the tsunamis occurring along the Peru-Chile Trench. We find that these three earthquakes present faults with important extensions beneath the continent which result in the generation of tsunamis with short wavelengths, relative to the fault widths involved, and with reduced initial potential energy. In addition, the presence of the Chilean continental margin, that includes the shelf of shallow bathymetry and the continental slope, constrains the tsunami propagation and the coastal impact. All these factors contribute to a concentrated local impact but can, on the other hand, reduce the far-field tsunami effects from earthquakes along Peru-Chile Trench.

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Neural field models of firing rate activity have had a major impact in helping to develop an understanding of the dynamics seen in brain slice preparations. These models typically take the form of integro-differential equations. Their non-local nature has led to the development of a set of analytical and numerical tools for the study of waves, bumps and patterns, based around natural extensions of those used for local differential equation models. In this paper we present a review of such techniques and show how recent advances have opened the way for future studies of neural fields in both one and two dimensions that can incorporate realistic forms of axo-dendritic interactions and the slow intrinsic currents that underlie bursting behaviour in single neurons.

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Several environmental stressors can impact the physiology and survival of fishes. Fish experience natural fluctuations in temperature and dissolved oxygen, but variations in these parameters due to anthropogenic sources are typically greater in magnitude and duration. Changes in temperature and oxygen of anthropogenic origins may therefore have larger negative impacts on fish than those occurring during natural events. Physiological parameters are sensitive indicators of the impacts of stressors by providing insight into the manner in which fish are disturbed by the stressor. Fish may display cumulative physiological responses to successive stressors, but the concept of synergy among multiple thermal stressors is poorly understood. Further, some fish species can be subjected to competitive angling events, which expose fish to an array of additional stressors that can increase mortality. The impacts of these events may change over seasons as fish display seasonal changes in behavior and physiology. Latitudinal origin may also affect the physiological response and mortality of fish exposed to common environmental stressors as individual populations are adapted to local environmental conditions. This thesis focuses on addressing these potential impacts on physiological parameters and mortality of largemouth bass (Micropterus salmoides) and provides implications for management and conservation. Largemouth bass were relatively robust to abrupt changes in temperature and oxygen, but were perturbed from physiological homeostasis during large (12°C) temperature shocks and low (< 4 mg O2/L) levels of dissolved oxygen. Cumulative physiological impacts of multiple cold shocks were only slightly greater than the disturbances sustained during a single cold shock, suggesting largemouth bass are able to tolerate successive thermal stressors. Largemouth bass exhibited seasonal changes in physiological parameters but the responses of fish to angling tournaments were relatively similar across seasons when compared with seasonal controls. Mortality was low during angling tournaments held during four seasons and no apparent seasonal trends were observed. Lastly, largemouth bass from two latitudinally separated populations exhibited differences in their physiological responses to acute cold stressors and overwinter mortality, characterized by greater mortality and physiological disturbances of southern fish than northern fish. Knowledge gained from this study can be used to make management and conservation decisions regarding a host of environmental factors and provides insight into the mechanisms by which fish species can persist over large latitudinal ranges.

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Résumé : L'épargne et le crédit sont reconnus comme deux éléments clés du développement économique. Or, jusqu'à ce que les membres défavorisés d'une communauté aient accès aux ressources et services financiers, ils seront toujours privés de la participation au processus du développement et des bénéfices qui pourraient s'en suivre. La recherche indique que les services des prêts offerts par les institutions officielles ne parviennent que rarement aux plus pauvres de la société, qui sont obligés par conséquent de dépendre des intermédiaires informels comme les groupes d'épargne et les usuriers. Diverses organisations sur place comme les coopératives ont essayé de répondre aux besoins du développement des communautés défavorisées. Dans ce contexte, nous ferons d'abord le bilan historique et international des coopératives d'épargne et de crédit (i.e. les caisses populaires). Ensuite, nous analyserons quatre autres tentatives récentes qui eurent pour but de créer de nouvelles formes d'institutions financières, de les développer de telle sorte qu'elles offrent un degré d'accès raisonnable, sinon privilégié, aux ménages de revenu inférieur. L'analyse de ces cas-ci (venant du Zimbabwe, de l'Inde, du Ghana, et du Bangladesh) permettra d'identifier leurs caractéristiques communes et divergentes. À partir des résultats de cette analyse, un projet pilote au Zimbabwe fut initié pour élaborer une stratégie appropriée qui faciliterait le développement d'un réseau de caisses rurales. L'analyse théorique, la mise en pratique du projet, ainsi que les conclusions subséquentes soulignent l'importance de la participation directe des communautés à l'élaboration des organisations populaires. Il est évident que ces méthodes sont de loin plus efficaces que celles basées sur des politiques et des structures uniformes et compréhensives.||Abstract : Savings and credit are recognized as key elements of economic development, but until such time as disadvantaged members of the community have access to financial resources and services, they are obstructed from participating fully in the development process. Experience has shown that formal institutional credit bas rarely reached the poorer sectors of society, who have had to rely on informal intermediaries such as savings groups and money-lenders. Local organizations such as co-operatives have attempted to respond to the development needs of disadvantaged communities, and the historical and international record of savings and credit co-operatives (i.e. credit unions) is examined in this context. Four recent initiatives to design and develop new forms of financial institutions that give fair if not favoured access to low-income housebolds are also identified. These cases (from Zimbabwe, India, Bangladesh, and Ghana) are examined in an effort to identify common and divergent characteristics. Following from this analysis, a pilot project in Zimbabwe was initiated in an effort to elaborate an appropriate strategy for development of a network of rural savings and credit organization. The theoretical analysis, field exercise and subsequent reflections highlight the need for participatory methods of organizational design and development, rather than any all-encompassing structural or policy guidelines.

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The general goal of this study was to analyze the relations between the agents’ social capital and joint actions developed by the Cluster of wine produced at the high altitudes of Santa Catarina. This group is made up of 43 agents: one governing agent, 26 support agents and 16 winemakers. This descriptive and exploratory study uses data from qualitative and quantitative approaches. During the exploratory phase, a documental analysis was carried out, as well as semi-structured interviews. The data collection tool used to gather information concerning the social capital and joint actions was the semi-structured questionnaire, and this data gathering was conducted through field research using a structured interview with the selected agents from November 16 to November 26, 2015. The results of this study show a good social capital, which reflects on the joint actions done by the agents. Among the variables of social capital, trust shows a great level among the Cluster agents, followed by good levels concerning commitment and involvement, information share, rules and sanctions, horizontality and authority and improvement. As a result, it has created a nice level of involvement and effectiveness of joint actions, highlighting events organization, joint participation at fairs and events, marketing campaigns, development of products and processes, and human resources improvement. There is a small group of agents who show a strong social capital and a proper environment to expand this capital throughout the network. However, the evaluation concerning reciprocity and density represents only one third of the possibilities of this group, and it happens especially because of the geographical distance between the agents who are part of the Cluster. The main limitation of this study was the trouble trying to map the whole agent group before applying the questionnaires and identifying the responsible people in each of the support agents to inform everything correctly. It is suggested that these questionnaires be carried out with other Clusters as well as in the future in order to have a temporal assessment of this study.

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One of the most significant research topics in computer vision is object detection. Most of the reported object detection results localise the detected object within a bounding box, but do not explicitly label the edge contours of the object. Since object contours provide a fundamental diagnostic of object shape, some researchers have initiated work on linear contour feature representations for object detection and localisation. However, linear contour feature-based localisation is highly dependent on the performance of linear contour detection within natural images, and this can be perturbed significantly by a cluttered background. In addition, the conventional approach to achieving rotation-invariant features is to rotate the feature receptive field to align with the local dominant orientation before computing the feature representation. Grid resampling after rotation adds extra computational cost and increases the total time consumption for computing the feature descriptor. Though it is not an expensive process if using current computers, it is appreciated that if each step of the implementation is faster to compute especially when the number of local features is increasing and the application is implemented on resource limited ”smart devices”, such as mobile phones, in real-time. Motivated by the above issues, a 2D object localisation system is proposed in this thesis that matches features of edge contour points, which is an alternative method that takes advantage of the shape information for object localisation. This is inspired by edge contour points comprising the basic components of shape contours. In addition, edge point detection is usually simpler to achieve than linear edge contour detection. Therefore, the proposed localization system could avoid the need for linear contour detection and reduce the pathological disruption from the image background. Moreover, since natural images usually comprise many more edge contour points than interest points (i.e. corner points), we also propose new methods to generate rotation-invariant local feature descriptors without pre-rotating the feature receptive field to improve the computational efficiency of the whole system. In detail, the 2D object localisation system is achieved by matching edge contour points features in a constrained search area based on the initial pose-estimate produced by a prior object detection process. The local feature descriptor obtains rotation invariance by making use of rotational symmetry of the hexagonal structure. Therefore, a set of local feature descriptors is proposed based on the hierarchically hexagonal grouping structure. Ultimately, the 2D object localisation system achieves a very promising performance based on matching the proposed features of edge contour points with the mean correct labelling rate of the edge contour points 0.8654 and the mean false labelling rate 0.0314 applied on the data from Amsterdam Library of Object Images (ALOI). Furthermore, the proposed descriptors are evaluated by comparing to the state-of-the-art descriptors and achieve competitive performances in terms of pose estimate with around half-pixel pose error.

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An inactive vent field comprised of dead chimneys was discovered on the ultrafast East Pacific Rise (EPR) at 18°S during the research campaign NAUDUR with the R/V Le Nadir in December 1993. One of these chimneys was sampled, studied and found to be largely composed of silica-mineralized bacterial-like filaments. The filaments are inferred to be the result of microbial activity leading to silica (± Fe-oxyhydroxide) precipitation. The chimney grew from the most external layer (precipitated 226 ± 4 yr. B.P.) towards the central chimney conduit. Hydrothermal activity ceased 154 ± 13 yr. B.P. and the chimney conduit was completely sealed. Mixing between an end-member hydrothermal fluid and seawater explains the Sr–Nd isotopic composition of the chimney. Seawater was the major source of Sr to the chimney, whereas the dominant Nd source was the local mid-ocean ridge basalt (MORB) leached by the hydrothermal fluids. The mixing scenarios point to a dynamic hydrothermal system with fluctuating fluid compositions. The proportion of seawater within the venting fluid responsible for the precipitation of the silica chimney layers varied between 94 and 85%. Pb-isotope data indicates that all of the Pb in the chimney was derived from the underlying MORB. The precipitation temperatures of the chimney layers varied between 55 and 71 °C, and were a function of the seawater/end-member hydrothermal fluid mixing ratio. δ30Si correlates with the temperature of precipitation implying that temperature is one of the major controls of the Si-isotope composition of the chimney. Concentrations of elements across the chimney wall were a function of this mixing ratio and the composition of the end-member hydrothermal fluid. The inward growth of the chimney wall and accompanying decrease in wall permeability resulted in an inward decrease in the seawater/hydrothermal fluid mixing ratio, which in turn exerted a control on the concentrations of the elements supplied mainly by the hydrothermal fluids. The silica chimney is significantly enriched in U, likely a result of bacterial concentration of U from the seawater-dominated vent fluid. The chimney is poor in rare earth elements (REE). It inherited its REE distribution patterns from the parent end-member hydrothermal fluids. The dilution of the hydrothermal fluid with over 85% seawater could not obliterate the particular REE features (positive Eu anomaly) of the hydrothermal fluids.

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In this paper we consider a class of scalar integral equations with a form of space-dependent delay. These non-local models arise naturally when modelling neural tissue with active axons and passive dendrites. Such systems are known to support a dynamic (oscillatory) Turing instability of the homogeneous steady state. In this paper we develop a weakly nonlinear analysis of the travelling and standing waves that form beyond the point of instability. The appropriate amplitude equations are found to be the coupled mean-field Ginzburg-Landau equations describing a Turing-Hopf bifurcation with modulation group velocity of O(1). Importantly we are able to obtain the coefficients of terms in the amplitude equations in terms of integral transforms of the spatio-temporal kernels defining the neural field equation of interest. Indeed our results cover not only models with axonal or dendritic delays but those which are described by a more general distribution of delayed spatio-temporal interactions. We illustrate the predictive power of this form of analysis with comparison against direct numerical simulations, paying particular attention to the competition between standing and travelling waves and the onset of Benjamin-Feir instabilities.

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Associated Partners in the Work Package 5: National Health Institute Doutor Ricardo Jorge (INSA), Portugal (Luciana Costa)

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The purpose of the thesis is to examine the relationship between tourism and the local culture expressed in culinary experiences offered in the traditional, nostalgic-themed markets that have arisen as popular attractions in the 21 st century. Central to the thesis is an examination of how the traditional cultural values are articulated in the production, promotion and consumption of culinary experiences in order to understand the value of culture when embedded in the process of commodification, as well as to understand influential socio-cultural factors. The thesis investigates the potential of traditional markets to promote food as the main attraction in the market. Field studies were conducted from December 2012–March 2014 in eight traditional markets in the central region of Thailand. Based on the ethnographic approach in studying the narratives in the markets, a variety of methods were implemented in the process of data collection. Besides observational analysis of the venue, semi-structured interviews and the self-administered questionnaires were used to collect data from actors who engage in food experiences, including management team members, food traders and visitors. Data was also collected from interviews with officers working for Tourism Authority of Thailand (TAT).  Keys findings of the thesis reveal that the cultural expressions of food experience in each market is an outcome of both the interactions of worldviews expressed by actors involved in the traditional market and the socio-cultural condition of Thailand. The relationships between stakeholders’ attitudes towards food experiences and the commercial potentials and limitations of food were analysed. The analysis of the cultural value of culinary experiences demonstrates that the existing academic discussions of the authenticity of tourism are insightful in explaining the character of food experiences offered in this tourism scenario. Most importantly, authenticity in tourism experiences, being a desirable element in culinary experiences, is a reflection of the how the pre-modern aspect of Thai society is embraced in a contemporary context. In addition, the commodification of culinary culture generates multidimensional consequences on the value of traditional culture and local lives. Moreover, the performance of culinary experiences can be viewed from the perspective of how Thai society interacts with globalization. The thesis also points out that it is possible to compare the situation of the traditional markets with the marketing positioning of food in Thai tourism marketing policy.

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This socio-legal thesis has explored the factors responsible for explaining whether and how redress mechanisms control bureaucratic decision-making. The research considered the three principal institutions of administrative justice: courts, tribunals, and ombudsman schemes. The field setting was the local authority education area and the thesis examined bureaucratic decision-making about admissions to school, home-to-school transport, and Special Educational Needs (SEN). The thesis adopted a qualitative approach, using interviews and documentary research, within a multiple embedded case study design. The intellectual foundations of the research were inter-disciplinary, cutting across law, socio-legal studies, public administration, organization studies, and social policy. The thesis drew on these scholarly fields to explore the nature of bureaucratic decision-making, the extent to which it can be controlled and the way that learning occurs in bureaucracies and, finally, the extent to which redress mechanisms might exercise control. The concept of control was studied across all its dimensions – in relation both to ex post control in specific cases and the more challenging notion of ex ante or structuring control. The aim of the thesis was not to measure the prevalence of bureaucratic control by redress mechanisms, but to understand the factors that might explain its presence or absence in a particular area. The findings of the research have allowed for a number of analytical refinements and extensions to be made to existing theoretical and empirical understandings. 14 factors, along with 87 supporting propositions, have been set out with the aim of making empirically derived suggestions which can be followed up in future research. In terms of the thesis’ contribution to existing knowledge, its comparative focus and its emphasis on the broad notion of control offered the potential for new insights to be developed. Overall, the thesis claims to have made three contributions to the conceptual framework for understanding the exercise of control by redress mechanisms: it emphasizes the importance of ‘feedback’ in relation to the nature of the cases referred to redress mechanisms; it calls attention to the structure of bureaucratic decision-making as well as its normative character; and it discusses how the operational modes of redress mechanisms relate to their control functions.

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Este trabajo pretende ser una reflexión sobre cómo dos profesiones que, a pesar de compartir una base común, en el mundo académico aparecen a menudo separadas por determidas competencias bien definidas y divergentes entre sí. No obstante, ambas pueden converger en la figura del llamado traductor e intérprete jurado. Esta realidad es absolutamente tangible en la provincia de Málaga, donde nuestro mercado local cuenta con una amplia presencia de extranjeros que no tiene demasiados problemas para comunicarse en ciertos contextos, pero sí cuando hay trámites legales o administrativos, en los que interviene el traductor jurado, que cumple las funciones simultáneas de traductor e intérprete. Por último, el trabajo finaliza con una revisión de qué respuesta damos a nivel local a esta heterogeneidad.

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Bupivacaine (BVC; S75-R25, NovaBupilocal anesthetic. Sodium alginate is a water-soluble linear polysaccharide. The present study reports the development of alginate/bis(2-ethylhexyl) sulfosuccinate (AOT) and alginate/chitosan nanoparticle formulations containing BVC (0.5%). The amounts of BVC associated in the alginate/AOT and alginate/chitosan nanoparticles were 87 +/- 1.5 and 76 +/- 0.9%, respectively. The average diameters and zeta potentials of the nanoparticles were measured for 30 days, and the results demonstrated the good stability of these particles in solution. The in vitro release kinetics showed a different behavior for the release profile of BVC in solution, compared with BVC-loaded alginate nanoparticles. In vitro and in vivo assays showed that alginate-chitosan BVC (BVC(ALG-CHIT)) and alginate-AOT BVC (BVC(ALG-AOT)) presented low cytotoxicity in 3T3-fibroblasts, enhanced the intensity, and prolonged the duration of motor and sensory blockades in a sciatic nerve blockade model.

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Uma ostomia de eliminação intestinal resulta de um procedimento cirúrgico que consiste na ligação de uma parte do intestino delgado ou grosso, a um orifício externo na cavidade abdominal designado de estoma. O utente portador de uma ostomia de eliminação intestinal, devido à sua situação clínica, manifesta um misto de emoções resultante do enorme impacto físico e emocional devido à doença e ao tratamento. A sua própria vida vai desencadear alterações profundas no seu EU, nos estilos de vida, nas relações familiares e sociais, na sua imagem corporal e na autoestima (Pinto, 2012). Foi objetivo deste estudo analisar a perceção que a pessoa portadora de ostomia de eliminação intestinal, seguida na Unidade Local de Saúde Nordeste (ULSNE), tem sobre a sua qualidade de vida (QV). A investigação enquadra-se no domínio da investigação observacional, optando-se pela realização de um estudo descritivo, analítico e transversal, de abordagem quantitativa. Como instrumento de colheita de dados foi utilizado um formulário com questões relativas às características sociodemográficas, a escala de Graffar e a escala de avaliação da qualidade de vida do utente ostomizado. Aceitaram participar no estudo 105 utentes portadores de eliminação intestinal. O sexo predominante é o masculino (50,5%). A classe etária mais representativa é a dos 65 aos 92 anos (78,1%) e o estado civil predominante antes (67,6%) e depois (55,2%) da cirurgia é o de casado. Quanto à atividade laboral, o abandono do trabalho a tempo inteiro, devido à nova situação clínica, foi referido por 94,3% dos inquiridos. Em relação às habilitações académicas, 46,7% sabe ler e escrever, enquadrando-se na classe social média (57,1%). A consulta de estomaterapia na ULSNE ainda não está implementada, mas os inquiridos consideram que a sua implementação seria pertinente (93,3%), facilitando principalmente a adaptação à nova realidade (40%), a ultrapassar dificuldades (28,6%), a evitar complicações/resolver os problemas (9,5%). A média da QV dos participantes neste estudo é de 279,92, superior à média teórica da escala (215), indicando os inquiridos evidenciam um bom nível de qualidade de vida. O enfermeiro estomaterapeuta é o profissional que melhor pode proporcionar toda a informação e suportes necessários, que permitam ultrapassar os problemas e as limitações sentidas pelo ostomizado e pelas pessoas significativas na sua vida.

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Este trabalho aborda a questão dos atos preparatórios no local do crime, isto é, as medidas cautelares e de polícia que o primeiro interveniente policial que chega ao local deve aplicar. As diligências efetuadas pelo primeiro militar que assume uma ocorrência e que, normalmente, não é especialista na área da Investigação Criminal ou forense, revelam-se de elevada importância para o sucesso da investigação pois repercutem-se ao longo de toda a investigação. Essa abordagem caracteriza-se por não visar uma intervenção investigatória e inspetiva, mas sim de prevenção e proteção do local. O objetivo geral do trabalho consiste numa contribuição para uma exploração mais determinada do local onde foi cometido um crime, através do melhor desempenho possível do primeiro interveniente policial. Os objetivos específicos passam por definir os procedimentos a tomar pelo primeiro interveniente (tendo em conta a sua especialidade, materiais e particularidades da fase da investigação) e definir o que é, para ele, um crime de cenário, identificando as possíveis repercussões de uma má gestão do local do crime para o sucesso da investigação. Utilizamos o método comparativo, estudando os diferentes Manuais de procedimentos (nacionais e internacionais). O quadro de referência é o materialismo histórico pois enfatizamos a dimensão histórica dos processos sociais, a legislação vigente e os problemas atuais para interpretar o nosso estudo. Este trabalho assume contornos exploratório-explicativos. Seguimos um método dedutivo, pois pretende-se chegar a um caso particular da lei geral, ou seja, aos procedimentos específicos do primeiro interveniente policial entre toda a gestão do local do crime. Os resultados mais significativos são a justificação da importância do local do crime para a Investigação Criminal e da complexidade que pode advir para o trabalho do primeiro interveniente. É possível concluir um conjunto padrão de ações que devem ser tomadas (guia prático) e como se pode melhorar a intervenção através de formação e cooperação entre os elementos.