Using Neural Networks to Simulate the Alzheimer's Disease

Making use of biologically plausible artificial neural networks that implement Grossberg’s presynaptic learning rule, we simulate the possible effects of calcium dysregulation in the neuron’s activation function, to represent the most accepted model of Alzheimer's Disease: the calcium dysregulation hypothesis. According to Cudmore and Turrigiano calcium dysregulation alters the shifting dynamic of the neuron’s activation function (intrinsic plasticity). We propose that this alteration might affect the stability of synaptic weights in which memories are stored. The results of the simulation supported the theoretical hypothesis, implying that the emergence of Alzheimer's disease's symptoms such as memory loss and learning problems might be correlated to intrinsic neuronal plasticity impairment due to calcium dysregulation

Intrapopulation genetic structure in Cryptocarya moschata Nees (Lauraceae)

Through the analysis of six enzyme systems (ACP, ALP, CAT, GOT, PPO and PO), with 18 polymorphic loci, allele frequencies of 24 alleles were calculated for 141 adult individuals of a natural population of Cryptocarya moschata (Brazilian nutmeg), from Carlos Botelho State Park (24º03'21 S, 47º59'36 W), São Miguel Arcanjo, SP, Brazil, which were sampled in an area ca. 647 ha. The spatial genetic structure was investigated by the spatial autocorrelation method, using Moran's I coefficients estimated for 10 distance classes. Additionally, for the same distance classes, coefficients r were calculated through a multivariate analysis. Both approaches were qualitatively similar, poiting out that 15 correlograms from Moran's I coefficients were significant at 95% probability level. The total correlogram from r coefficients indicated that there was a significant spatial structure for the distance class of 0 to 150 m. By subdividing this class into 10 m intervals, positive spatial autocorrelation was detected in the majority of classes, suggesting that clusters of C. moschata trees, which were shorter than 50 m apart, were constituted of individuals with greater genetic similarity and were probably related. However, the greatest genetic similarity occurred among individuals being 105 m apart, which could be related to the kind of seed dispersal promoted by Brachyteles arachnoides (Primates - Cebidae). Results showed that for an adequate sampling, aiming to detect genetic diversity, the collection of individuals separated by a distance of 750 m, or more, from each other, would be advisable.Pela análise de seis sistemas enzimáticos (ACP, ALP, CAT, GOT, PPO e PO), com 18 locos polimórficos, foram calculadas as freqüências alélicas de 24 alelos referentes a 141 indivíduos adultos de uma população natural de Cryptocarya moschata (noz-moscada-do-Brasil) do Parque Estadual Carlos Botelho (24º03'21 S, 47º59'36 W), São Miguel Arcanjo, SP, amostrados em uma área de cerca de 647 ha. A estrutura genética espacial foi investigada através do método de autocorrelação espacial, utilizando-se coeficientes I de Moran estimados para 10 classes de distância. Adicionalmente, para as mesmas classes de distância, estimaram-se os coeficientes r através de uma análise multivariada. Ambas as abordagens mostraram-se similares qualitativamente, sendo que 15 correlogramas de coeficientes I foram significativos ao nível de 95% de probabilidade. O correlograma total gerado pelos coeficientes r indicou estruturação espacial significativa para a classe de distância de 0 a 150 m. Pela subdivisão desta classe em intervalos de 10 m, detectou-se autocorrelação espacial positiva na maioria das classes, indicando que os agrupamentos de árvores de C. moschata, que se encontram separadas a distâncias menores que 50 m, são constituídos por indivíduos semelhantes geneticamente e provavelmente aparentados. Contudo, a maior similaridade genética ocorreu entre indivíduos distanciados em torno de 105 m, podendo estar associada à dispersão de sementes promovida por Brachyteles arachnoides (Primates - Cebidae). Pela análise dos resultados, conclui-se que para uma amostragem adequada, visando a detecção de diversidade genética, a coleta de indivíduos distanciados acima de 750 m seria recomendável.475487Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

The effect of laser pan-retinal photocoagulation with or without intravitreal bevacizumab injections on the OCT-measured macular choroidal thickness of eyes with proliferative diabetic retinopathy

OBJECTIVES: To investigate the effect of laser pan-retinal photocoagulation with or without intravitreal bevacizumab injections on macular choroidal thickness parameters in eyes with high-risk proliferative diabetic retinopathy. METHODS: High-risk proliferative diabetic retinopathy patients undergoing laser treatment were prospectively enrolled in this study. One eye was randomly selected for laser treatment combined with bevacizumab injections, study group, whereas the corresponding eye was subjected to laser treatment alone, control group. Spectral-domain optical coherence tomography with enhanced depth imaging was used to measure the macular choroidal thickness prior to and 1 month after treatment. Measurements in both groups were compared. Clinicaltrials.gov: NCT01389505. RESULTS: Nineteen patients (38 eyes) with a mean±standard deviation age of 53.4±9.3 years were evaluated, and choroidal thickness measurements for 15 patients were used for comparison. The greatest measurement before treatment was the subfoveal choroidal thickness (341.68±67.66 μm and 345.79±83.66 μm for the study and control groups, respectively). No significant difference between groups was found in terms of macular choroidal thickness measurements at baseline or after treatment. However, within-group comparisons revealed a significant increase in choroidal thickness parameters in 10 measurements in the study group and in only 5 temporal measurements in the control group when 1-month follow-up measurements were compared to baseline values. CONCLUSIONS: The macular choroidal thickness does not appear to be significantly influenced by laser treatment alone but increases significantly when associated with bevacizumab injections in patients with proliferative diabetic retinopathy and macular edema. Because bevacizumab injections reduce short-term laser pan-retinal photocoagulation-induced macular edema, our findings suggest that the choroid participates in its pathogenesis

Do precocial mammals develop at a faster rate? A comparison of rates of skull development in Sigmodon fulviventer and Mus musculus domesticus

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72993/1/j.1420-9101.2003.00568.x.pd

Cinema: an humanist and pedagogical tool for themes in Health-Education. The experience of CineSocial

Study design: The approach to the research was qualitative. Objective: we used the audiovisual resources (movies) to make teachers, students and health professionals reflect, discuss and updatesocial subjects relevant to health and education. Methodology: The Project was structured as a coursewith five meetings that took place between 2008 August and December. Subjects relevant to PublicHealth and Education were focused (hunger, school violence, teenage pregnancy, health-disease process and teenage drug abuse); for each theme, specialists were invited. The instrument used to acquirethe participant perceptions was a questionnaire with 14 semi-structured questions and at the end ofeach meeting, a report was requested. A Thematic analysis of narrative was conducted with the materialfrom the individual reflection report. Results: The meeting had the presence of 49 participants (undergraduates, public teachers, health professionals, graduates and professors). In the analysis of thenarrative open question material from the individual reflection report, we could identify two sets of categories: the first one identified was the participants' expectancy before beginning the CineSocial project andthe second one identified was the participants' opinions about the course relevance. Discussion andConclusions: The cinema use enabled knowledge flow and experience diffusion; it also corroborated theidea that not only documentaries and fiction films could express the knowledge aimed by Science, butother types of cinema as well. Focusing on cinema was not the priority of this experience, the priority wasfocus on life, society, school, exclusion, current subjects present inside or outside of the school.Modelo do estudo: Abordagem qualitativa de pesquisa Objetivo: foi utilizado recurso audiovisual (filmes)para propiciar reflexões, discussões e atualização de professores, alunos e profissionais da saúde emtemas sociais pertinentes às áreas da saúde e educação. Metodologia: o projeto foi estruturado em formade curso de difusão com cinco encontros, entre agosto e dezembro de 2008. Foram abordados temasrelevantes em Saúde e Educação (fome, violência escolar, gravidez na adolescência, processo saúdedoença e drogas na adolescência) e foram convidados especialistas em cada temática para debate. Oinstrumento utilizado para captar as percepções dos participantes foi um questionário de 14 questõessemi-estruturadas e ao final de cada encontro foi solicitada a entrega de relatório. Foi realizada AnáliseTemática de Narrativa de material proveniente dos relatórios individuais de reflexão. Resultados: osencontros tiveram a presença de 49 participantes (estudantes de graduação, professores da rede municipal de ensino, profissionais da área da saúde, pós-graduandos e docentes do ensino superior). Naanálise do material narrativo advindo das questões abertas dos relatórios individuais de reflexão foipossível levantar dois blocos de categorias, sendo que o primeiro deles destacou as expectativas que osparticipantes tinham antes de iniciar o projeto CineSocial e o segundo bloco levantou a opinião dosparticipantes sobre a relevância do curso. Discussão e Conclusões: o uso do cinema possibilitou acirculação dos conhecimentos, tornou possível a difusão de experiências, corroborou a ideia de quedocumentários assim como filmes de ficção podem exprimir os conhecimentos orientados pela Ciência.Pensar a arte do cinema não foi a prioridade dessa experiência, a prioridade foi pensar a vida, a sociedade, a escola, a saúde, a exclusão social e temas do cotidiano presentes dentro ou fora das escolas