771 resultados para Donald E. Lundberg
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Following the new tendency of interdisciplinarity of modern science, a new field called neuroengineering has come to light in the last decades. After 2000, scientific journals and conferences all around the world have been created on this theme. The present work comprises three different subareas related to neuroengineering and electrical engineering: neural stimulation; theoretical and computational neuroscience; and neuronal signal processing; as well as biomedical engineering. The research can be divided in three parts: (i) A new method of neuronal photostimulation was developed based on the use of caged compounds. Using the inhibitory neurotransmitter GABA caged by a ruthenium complex it was possible to block neuronal population activity using a laser pulse. The obtained results were evaluated by Wavelet analysis and tested by non-parametric statistics. (ii) A mathematical method was created to identify neuronal assemblies. Neuronal assemblies were proposed as the basis of learning by Donald Hebb remain the most accepted theory for neuronal representation of external stimuli. Using the Marcenko-Pastur law of eigenvalue distribution it was possible to detect neuronal assemblies and to compute their activity with high temporal resolution. The application of the method in real electrophysiological data revealed that neurons from the neocortex and hippocampus can be part of the same assembly, and that neurons can participate in multiple assemblies. (iii) A new method of automatic classification of heart beats was developed, which does not rely on a data base for training and is not specialized in specific pathologies. The method is based on Wavelet decomposition and normality measures of random variables. Throughout, the results presented in the three fields of knowledge represent qualification in neural and biomedical engineering
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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This study aims to understand as the children who show expressive behaviors of antisocial trends at Núcleo de Ação Social da Praia do Meio in Natal-RN city, linked to Secretaria Municipal do Trabalho e Assistência Social-SEMIT, which experience the relation with the social educator in role of caregiver. This matter was investigated within an interpretation and approach qualitative view of the social phenomena, using the Thematic Analysis technique of drawings and stories which express the relation with the caregiver gotten in sessions of playful interactions between child and researcher in order to understand the child experiences with the social educator. The used theoretical referential is by D. W. Winnicott who associates the social trend to a failure of environment in child holding. The subjects expressed the need of a firm and protective environment and they look for this in NASPM educators. Moreover, they show as solitude and vulnerability take part their lives due to the lack of emotional holding on family that favors the involvement with violent groups. But, it is worth pointing out that the children value the Nucleus environment when has offered them a safe holding which can be positive the established linking with it. Such conclusion points out to the possibility, recognized theoretically, that exists from these children to resume the way of healthy development
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In the work reported here we present theoretical and numerical results about a Risk Model with Interest Rate and Proportional Reinsurance based on the article Inequalities for the ruin probability in a controlled discrete-time risk process by Ros ario Romera and Maikol Diasparra (see [5]). Recursive and integral equations as well as upper bounds for the Ruin Probability are given considering three di erent approaches, namely, classical Lundberg inequality, Inductive approach and Martingale approach. Density estimation techniques (non-parametrics) are used to derive upper bounds for the Ruin Probability and the algorithms used in the simulation are presented
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OBJECTIVE: To describe the clinical presentation of hydatidiform molar pregnancy in women under the age of 20 years. In addition, we sought to understand if this adolescent population manifests differences in clinical factors compared to an adult population that may affect outcome.STUDY DESIGN: We used a database from the New England Trophoblastic Disease Center to analyze clinical data from all women followed for molar pregnancy between 1970 and 2009 with complete follow-up information. This population was stratified by age and clinical parameters including presenting signs, molar histology and development of gestational trophoblastic neoplasia (GTN). Univariable and multivariable logistic regression was employed to discern clinical factors that associated with adolescent age. The Partners Human Research Committee approved this study.RESULTS: We identified 1,494 women diagnosed with hydatidiform mole (HM), of which 220 (14.7%) were adolescents defined as age <20 years. The most common presenting clinical signs were vaginal bleeding and an enlarged uterus compared to dates. Median gestational age at diagnosis was 13.4 weeks, not different from that in the adult population. Similarly, no difference in presenting human chorionic gonadotropin was observed between the adult and adolescent populations. Adolescents presented with a significant overrepresentation of complete mole (86% vs. 75%, p < 0.001) compared to adults. Complete mole was associated with a heightened risk of developing GTN (OR 2.6, 95% CI 1.9-3.5), and despite the association of complete mole with young maternal age, univariable analysis showed no difference in the rate of GTN observed between adolescents and adults (24% vs. 30%, p = 0.08). Multivariable analysis controlling for molar histology demonstrated that adolescent age was associated with a decreased risk of GTN (hazard ratio 0.67, 95% CI 0.48 0.93).CONCLUSION: Adolescents account for a substantial proportion of the population with HM. They commonly present with vaginal bleeding. Though this population develops a complete mole with a higher frequency than adults, adolescents appear to have a significantly decreased risk of developing GTN. (J Reprod Med 2012; 57:225-230)
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Statement of problem. Implant overdenture prostheses are prone to acrylic resin fracture because of space limitations around the implant overdenture components.Purpose. The purpose of this study was to evaluate the influence of E-glass fibers and acrylic resin thickness in resisting acrylic resin fracture around a simulated overdenture abutment.Material and methods. A model was developed to simulate the clinical situation of an implant overdenture abutment with varying acrylic resin thickness (1.5 or 3.0 mm) with or without E-glass fiber reinforcement. Forty-eight specimens with an underlying simulated abutment were divided into 4 groups (n=12): 1.5 mm acrylic resin without E-glass fibers identified as thin with no E-glass fiber mesh (TN-N); 1.5 mm acrylic resin with E-glass fibers identified as thin with E-glass fiber mesh (TN-F); 3.0 mm acrylic resin without E-glass fibers identified as thick without E-glass fiber mesh (TK-N); and 3.0 mm acrylic resin with E-glass fibers identified as thick with E-glass fiber mesh (TK-F). All specimens were submitted to a 3-point bending test and fracture loads (N) were analyzed with a 2-way ANOVA and Tukey's post hoc test (alpha=.05).Results. The results revealed significant differences in fracture load among the 4 groups, with significant effects from both thickness (P<.001) and inclusion of the mesh (P<.001). Results demonstrated no interaction between mesh and thickness (P=.690). The TN-N: 39 +/- 5 N; TN-F: 50 +/- 6.9 N; TK-N: 162 +/- 13 N; and TK-F: 193 +/- 21 N groups were all statistically different (P<.001).Conclusions. The fracture load of a processed, acrylic resin implant-supported overdenture can be significantly increased by the addition of E-glass fibers even when using thin acrylic resin sections. on a relative basis, the increase in fracture load was similar when adding E-glass fibers or increasing acrylic resin thickness. (J Prosthet Dent 2011;106:373-377)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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O artigo trata das principais forças em filosofia da educação no Ocidente Moderno e Contemporâneo. Particularmente, destaca a posição do Brasil nos últimos anos, dado que localiza na contribuição de Paulo Freire, junto com o alemão Herbart e com o norte-americano Dewey, a formulação das linhas mestras da pedagogia moderna. O texto também faz menção ao trabalho atual do neopragmatismo, sob o qual nasce a filosofia da educação inspirada nos filósofos norte americanos Richard Rorty e Donald Davidson, que revolucionam atualmente não só a filosofia mas seus campos aplicados, como o direito, a religião, a política e, como não poderia deixar de ser, a educação.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The electron-diffraction pattern for two slits with magnetic flux confined to an inaccessible region between them is calculated. The Aharonov-Bohm effect gives a diffraction pattern that is asymmetric but has a symmetric envelope. In general, both the expected displacement and the kinetic momentum of the electron are nonzero as a consequence of the asymmetry. Nevertheless, Ehrenfests theorems and the conservation of momentum are satisfied. © 1992 The American Physical Society.
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To determine lycopene uptake and tissue distribution in ferrets (Mustela putorius furo) and F344 rats, we supplemented orally 4.6 mg/(kg body wt-d) lycopene in a tomato oleoresin-com oil mixture (experimental groups). After 9 wk of supplementation, the animals were killed and blood and organs were collected. Plasma and tissue carotenoids were extracted and measured using HPLC. Mean concentrations of lycopene (nmol/kg wet tissue) in saponified tissues of ferrets were as follows: liver 933, intestine 73, prostate 12.7 and stomach 9.3. Levels of lycopene (nmol/kg wet tissue) in saponified tissue of rats were as follows: liver 14213, intestine 3125, stomach 78.6, prostate 24 and testis 3.9. When these organs were extracted without saponification, the lycopene levels were lower, except for rat testis. All-translycopene was the predominant isomer found in tomato oleoresin and in the majority of rat tissues, whereas cislycopenes were predominant in rat prostate and plasma. This pattern was reversed in ferrets. The results show the following: 1) lycopene from tomato oleoresin is absorbed and stored primarily in the liver of both animals; 2) saponification generally improves the extraction of lycopene from most tissues of both animals; 3) cis-lycopene and all- translycopene are the predominant isomers in ferret and rat tissues, respectively; and 4) rats absorb lycopene more effectively than ferrets.