Towards the Modeling of Neuronal Firing by Gaussian Processes

This paper focuses on the outline of some computational methods for the approximate solution of the integral equations for the neuronal firing probability density and an algorithm for the generation of sample-paths in order to construct histograms estimating the firing densities. Our results originate from the study of non-Markov stationary Gaussian neuronal models with the aim to determine the neuron's firing probability density function. A parallel algorithm has been implemented in order to simulate large numbers of sample paths of Gaussian processes characterized by damped oscillatory covariances in the presence of time dependent boundaries. The analysis based on the simulation procedure provides an alternative research tool when closed-form results or analytic evaluation of the neuronal firing densities are not available.Comment: 10 pages, 3 figures, to be published in Scientiae Mathematicae Japonica

Regulamentações envolvendo agentes microbianos de controle no Brasil.

A importância do controle biológico de organismos nocivos no Brasil tem crescido consideravelmente nas ultimas duas décadas. Um número grande de projetos conduzidos no pais tem resultado em reduções significativas de varias pragas, através da introdução ou manejo de agentes nativos de controle biológico. Um desenvolvimento cada vez maior do controle biológico e esperado diante das demandas internacionais, para o uso de meios mais naturais de produção da agricultura, e pela implementação das normas ISO 14.000. Pesquisa, produção, comercialização uso, importacao e registro de pesticidas em geral são regulamentados no Brasil pela Lei Federal numero 7802, de julho de 1989 e pelo Decreto Presidencial numero 98816, de janeiro de 1990. Uma regulamentação específica para o registro comercial de produtos contendo agentes microbianos de controle, considerando suas características diferentes das partículas químicas, não existe oficialmente no Brasil. Recentemente, foi elaborada uma proposta oficial para os Órgaos de Registros (NARDO et al., 1995), levando em consideração as características intrínsecas dos microrganismos, assim como requisitos para sua avaliação sobre componentes do meio ambiente e da saúde humana, baseada em regulamentações exóticas para fins de controle biológico, o Brasil tem uma serie de regras de intercambio internacional. Permissão para introdução e exploração são necessárias, entretanto não existe nenhuma menção sobre a exportação de agentes microbianos coletados no pais. Atualmente todas essas regulamentações estão sofrendo revisões e adaptações. O Laboratório de Quarentena "Costa Lima",, situado em Jaguariúna, SP, junto ao Centro Nacional De Pesquisa de Monitoramento e Avaliação de Impacto Ambiental (EMBRAPA/CNPMA), e o unido credenciado no país para auxiliar o Ministério da Agricultura e do Abastecimento, quanto as solicitações para a incrementação deste método de controle. Também no âmbito regional dos países do Cone Sul, o Brasil tem participado na elaboração de regulamentações relacionadas com o controle biológico através do COSAVE (COMITÊ DE SANIDADE VEGETAL DO CONE SUL) criado em 1992, com a finalidade de elaborar e harmonizar regulamentações fitossanitárias para os países da região: Argentina, Brasil

Sistem Informasi Geografis dalam Pemetaan Lahan Gambut di Kabupaten Musi Banyuasin

Conservation of nature is a central issue at this time, this is caused by the increasing number of natural damages that occur because of human ignorance to keep the nature of the world remains a friendly place for our lives. One of the important factor of nature conservation is the sustainability of peatlands which is capable of storing carbon gases that serve to withstand the rate of earth temperature rise. One of the efforts undertaken to maintain the sustainability of peatlands is the availability of the lastest and comprehensive data and information about peatland conditions that can be accessed by stakeholders that related to peatland conditions. For that reason, we need a Geographic Information System that is designed and built using the Classic Life Cycle Model approach and supported by ArcGIS software, UML Model and PHP programming language. Geographic information system provides peatland mapping information such as: location of peatlands, peatland categories, peatlands category that already managed and peatland category not yet managed

Pulmonary tuberculosis followed by sarcoidosis in an HIV-infected patient: a case report and a simplified diagnostic flowchart for diagnosis and treatment of sarcoidosis

The diagnosis of sarcoidosis in a patient living with HIV infection is an uncommon event and a challenge for clinicians. Clinical manifestations are variable and fluctuating depending to adherence to ARV therapy and to the level of CD4 count. We analyze here one chronic case in which sarcoidosis appeared clinically two years after pulmonary tuberculosis. The course of the disease was influenced and prolonged by frequent interruptions of antiretroviral therapy. Moreover the diagnosis and the decision to treat have been delayed by the need of exclusion of other pathologies, principally tuberculosis reactivation/reinfection, other mycobacterial diseases, hematologic malignancies. We propose a simplified flowchart for diagnosis and follow up of sarcoidosis, which may also be applied to patients with HIV infection. Diagnosis of latent tuberculosis infection (LTBI) may be difficult in these patients, because the immunological paradox of sarcoidosis. For this reason, following exclusion of active tuberculosis, we advise to submit all sarcoidosis patients to IPT (isoniazid preventive therapy), when immunosuppressive therapy is started

Impact of sidewall etching on the dynamic performance of GaN-on-Si E-mode transistors

Abstract The aim of this paper is to investigate the role of the etching of the sidewalls of p-GaN on the dynamic performance of normally-off GaN HEMTs with p-type gate. We analyze two wafers having identical epitaxy but with different recipes for the sidewall etching, referred to as "Etch A" (non-optimized) and "Etch B" (optimized). We demonstrate the following relevant results: (i) the devices with non-optimized etching (Etch A), when submitted to positive gate bias, show a negative threshold voltage shift and a decrease in Ron, which are ascribed to hole injection under the gate and/or in the access regions; (ii) transient characterization indicates the existence of two trap states, with activation energies of 0.84 eV (CN defects) and 0.30 eV. The latter (with time-constants in the ms range) is indicative of the hole de-trapping process, possibly related to trap states in the AlGaN barrier or at the passivation/AlGaN interface; (iii) by optimizing the p-GaN sidewall etching (for the same epitaxy) it is possible to completely eliminate the threshold voltage shift. This indicates that hole injection mostly takes place along the sidewalls

Avaliação do efeito do Baculovirus anticarsia sobre Podisus nigrispinus (DALLAS, 1851), predador da lagarta da soja Anticarsia gemmatalis (HUBNER, 1818).

Este trabalho tem como objetivo conhecer os efeitos da ingestão de lagartas da soja infectadas com B. anticarsia pelo predador Podisus nigrispinus, avaliando-se os parâmetros biológicos de cada inseto.bitstream/CNPMA/5854/1/baculovirus_anticarsia.pd

Bacterial Faecal Flora in Healthy Women of Different Ages

The composition of the intestinal flora is the result of host physiology, microbial interaction and environmental influences. The possible relationship between faecal flora composition and hormonal modifications in healthy women of different ages was studied. Forty-four normal women were divided into the following groups according to age: group I, 2747 yr; group II, 50-55 yr, 5 yr after menopause. The subjects received no pharmacological treatment. Samples were collected on the 8th and 23rd day of the cycle; two samples were obtained from each postmenopausal woman. Qualitative and quantitative determination of microorganisms was carried out using slightly modified standard methods. In fertile women (group I), the microflora composition was similar for samples collected on the 8th-10th day and during the premenstrual period (23rd day). In postmenopausal women (group III), an increase in fungi, clostridia and aerobic lactobacilli mean concentrations were observed. Escherichia coli mean levels increased and Enterobacteriaceae such as Enterobacter cloacae and Citrobacter freundii were present in 80 per cent of subjects studied. The length of menopause was found to have only a slight influence on flora: the behaviour of the microflora composition in menopausal women in group II may be considered intermediate between groups I and III. This preliminary study demonstrates that there are fluctuations in the composition of the faecal flora in healthy women. The differences observed between premenopausal and postmenopausal women may be a consequence of modifications of the steroid sex hormone pattern.Keywords - Intestinal flora; Age; Premenopausal women; Postmenopausal women; Menopause