130 research outputs found
A General Hippocampal Computational Model Combining Episodic and Spatial Memory in a Spiking Model
Institute for Adaptive and Neural ComputationThe hippocampus, in humans and rats, plays crucial roles in spatial tasks and nonspatial
tasks involving episodic-type memory. This thesis presents a novel computational
model of the hippocampus (CA1, CA3 and dentate gyrus) which creates a framework
where spatial memory and episodic memory are explained together. This general
model follows the approach where the memory function of the rodent hippocampus is
seen as a “memory space” instead of a “spatial memory”.
The innovations of this novel model are centred around the fact that it follows detailed
hippocampal architecture constraints and uses spiking networks to represent all
hippocampal subfields. This hippocampal model does not require stable attractor states
to produce a robust memory system capable of pattern separation and pattern completion.
In this hippocampal theory, information is represented and processed in the form
of activity patterns. That is, instead of assuming firing-rate coding, this model assumes
that information is coded in the activation of specific constellations of neurons. This
coding mechanism, associated with the use of spiking neurons, raises many problems
on how information is transferred, processed and stored in the different hippocampal
subfields. This thesis explores which mechanisms are available in the hippocampus
to achieve such control, and produces a detailed model which is biologically realistic
and capable of explaining how several computational components can work together to
produce the emergent functional properties of the hippocampus. In this hippocampal
theory, precise explanations are given to why mossy fibres are important for storage
but not recall, what is the functional role of the mossy cells (excitatory interneurons)
in the dentate gyrus, why firing fields can be asymmetric with the firing peak closer to
the end of the field, which features are used to produce “place fields”, among others.
An important property of this hippocampal model is that the memory system provided
by the CA3 is a palimpsest memory: after saturation, the number of patterns that can
be recalled is independent of the number of patterns engraved in the recurrent network.
In parallel with the development of the hippocampal computational model, a simulation
environment was created. This simulation environment was tailored for the
needs and assumptions of the hippocampal model and represents an important component
of this thesis
Esquema do modelo territorial: sistema biofísico
A Rede Ecológica Regional (RER) é uma das componentes fundamentais do sistema territorial, na medida em que traduz espacialmente as orientações estratégicas
definidas quanto à Estrutura Regional de Protecção e Valorização Ambiental. Esta rede é compatível com o modelo territorial que se propõe para a região neste trabalho, e tem como objectivo assegurar a sustentabilidade do desenvolvimento da Região, segundo as Opções Estratégicas definidas
Aspectos sociais, econômicos e ambientais de comunidades pesqueiras de uma reserva extrativista marinha na Amazônia paraense
In the Amazon, among the several population groups dedicated to extractivism, those related to artisanal fishing stand out and are representative of the population who lives in line with the rivers and the sea. The objective of this study was to analyze and trace the socio-environmental profile of artisanal fishermen living in three fishing communities in the municipality of Bragança, northeastern Pará state, in the Caeté-Taperaçu Marine Extractive Reserve. To this end, interviews were carried out through questionnaires to 251 families of artisanal fishermen, between men and women, 85 (33.86%) from Vila dos Pescadores, 96 (38.25%) from Vila do Castelo and 70 (27.89 %) from Vila do Taperuçu. The results indicate the age of respondents between 18 and 55 years old, found low schooling, most have their own house, and annual income ranging from R 5,506.56. Access to water is through the distribution network and the provision of urban cleaning services serves almost 50% of communities. The results obtained allowed us to trace a social, economic, and environmental profile of artisanal fishermen from fishing communities in the extractive reserve, which could serve as a basis for the generation of subsidies that involve the implementation of public policies that are directed to artisanal fishermen in the conservation unit in question.En la Amazonía, entre los diversos grupos poblacionales dedicados al extractivismo, se destacan los relacionados con la pesca artesanal y son representativos de la población que vive en la ribera de los ríos y el mar. El estudio tiene como objetivo analizar y rastrear el perfil socioambiental de los pescadores artesanales que residen en tres comunidades pesqueras en el municipio de Bragança, al noreste del estado de Pará, en la Reserva de Extracción Marina Caeté-Taperaçu. Para ello, se realizaron entrevistas a través de cuestionarios a 251 familias de pescadores artesanales, entre hombres y mujeres, siendo 85 (33,86%) de Vila dos Pescadores, 96 (38,25%) de Vila do Castelo y 70 (27,89%) de Vila hacer Taperuçu. Los resultados indican que la edad de los encuestados entre 18 y 55 años, encontró baja escolaridad, la mayoría tiene casa propia e ingresos anuales que oscilan entre R 5.506,56. El acceso al agua es a través de la red de distribución y la prestación de los servicios de limpieza urbana atienden a casi el 50% de las comunidades. Los resultados obtenidos permitieron trazar un perfil social, económico y ambiental de los pescadores artesanales de las comunidades pesqueras de la reserva extractiva, que podría servir de base para la generación de subsidios que impliquen la implementación de políticas públicas que estén dirigidas a los pescadores artesanales en la unidad de conservación en cuestión.Na Amazônia, entre os vários grupos populacionais que se dedicam ao extrativismo, destacam-se os que estão relacionados à pesca praticada de forma artesanal e são representativos da população que habita em consonância aos rios e o mar. O estudo objetiva a caracterização social, econômica e ambiental em três comunidades pertencentes a Reserva Extrativista Marinha Caeté- Taperuçu e, para assim, contribuir para traçar o perfil de pescadores que residem em três comunidades pesqueiras do município de Bragança, nordeste do estado do Pará, na Reserva Extrativista Marinha Caeté-Taperaçu. Foi realizada entrevista através de questionários a 251 famílias de pescadores artesanais entre homens e mulheres, sendo 85 (33,86%) da Vila dos Pescadores, 96 (38,25%) da Vila do Castelo e 70 (27,89%) da Vila do Taperuçu. Os resultados indicam a idade dos entrevistados entre 18 e 55 anos, constatou baixa escolaridade, a maioria possui casa própria e renda anual variando de R5.506,56. O acesso à água se dá pela rede de distribuição e a disponibilização dos serviços de limpeza urbana atendem quase 50% das comunidades. Os resultados obtidos permitiram obter um perfil social, econômico e ambiental dos pescadores artesanais de comunidades pesqueiras na reserva extrativista, podendo contribuir como base para a geração de subsídios que envolvam a implementação de políticas públicas que esteja direcionada a pescadores artesanais na unidade de conservação em questão
Dermatology relevance to graduates from the Universidade Estadual de Campinas Medical School
Some research indicates that physicians do not dominate the expected dermatological content for the proper exercise of the profession. This fact compromises their diagnostic and therapeutic performance, generating unnecessary costs. OBJECTIVE: The aim of this study was to evaluate the relevance of Dermatology and the knowledge acquired in the specialty during the undergraduate course in clinical practice of graduates at the State University of Campinas Medical School (FCM/UNICAMP). METHOD: A questionnaire with 22 closed questions and two open ones was electronically sent to physicians who had graduated more than 10 years ago and others for less than 10 years. In the first group, physicians were trained by the same curriculum and in the second group there were subjects trained by the old and the new curriculum. RESULTS: Of the 126 respondents, 83% had completed a specialization course. Among all, 82% did not study dermatology after graduation. The majority considered that Dermatology has high relevance in clinical practice, regardless of the group. There was a statistically significant difference between non-dermatologist doctors graduated for more than 10 years and those graduated for less than 10 years regarding confidence about lesion diagnosis, diagnostic investigation and treatment of skin diseases. Physicians who have graduated for a longer time feel more insecure in relation to patients with dermatoses. Concerning contributions offered by graduation program completion they prioritized outpatient care, ability to diagnose, knowledge of pathology, research and knowledge of lesions. CONCLUSION: This study has shown that Dermatology is relevant in medical practice and more recent graduates from the FCM/UNICAMP feel less insecure when treating a patient with dermatoses90563163
Síntese de diagnóstico: sistema biofísico
Este trabalho faz uma caracterização da estrutura biofísica e das dinâmicas de ocupação do solo na região de Trás-os-Montes e Alto Douro (TMAD), com base na avaliação global dos valores naturais da região e da sua interacção com as actividades humanas. Orienta-se esta análise tomando como referência o objectivo fundamental de assegurar que, daquela interacção, resulte um equilíbrio que salvaguarde a sustentabilidade ambiental e a conservação da natureza
Assessment of the Body Composition and the Loss of Fat-Free Mass through Bioelectric Impedance Analysis in Patients Who Underwent Open Gastric Bypass
Background. Bariatric surgery is considered an effective option for the management of morbid obesity. The incidence of obesity has been gradually increasing all over the world reaching epidemic proportions in some regions of the world. Obesity can cause a reduction of up to 22% in the life expectancy of morbidly obese patients. Objective. The objective of this paper is to assess the weight loss associated with the first 6 months after bariatric surgery using bioelectric impedance analysis (BIA) for the evaluation of fat mass and fat-free mass. Method. A total of 36 morbidly obese patients were subjected to open gastric bypass surgery. The patients weight was monitored before and after the procedure using the bioelectric impedance analysis. Results. Bariatric surgery resulted in an average percentage of weight loss of 28.6% (40 kg) as determined 6 months after the procedure was performed. Analysis of the different components of body weight indicated an undesirable loss of fat-free mass along with the reduction of total body weight. Conclusion. Open gastric bypass induced a significant loss of total weight and loss of fat-free mass in patients six months after the surgery. The use of bioelectric impedance analysis resulted in an appropriate estimation of the total weight components in individuals subjected to bariatric surgery allowing a more real analysis of the variation of weight after the surgery
Monte Carlo simulations of nuclear de-excitation gamma-ray line spectra from solar flares
Recently, we have demonstrated that the Monte Carlo package FLUKA can be used as an effective tool for simulating nuclear processes which occur in solar flares and that it is capable to provide a self-consistent treatment of all typical components of the γ-ray spectra observed in those events. In this work, we have employed a new simulation strategy that allows to improve statistics and resolution in energy of the generated γ-ray spectra. Using this new strategy, we have calculated spectra of γ-ray nuclear de-excitation lines produced by solar flare primary accelerated ions with typical power-law energy distributions
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