71 research outputs found
Studies into the in vivo interactions between human immunodeficiency virus and human herpes virus 8
In HIV-coinfected people unaffected by Kaposi sarcoma (KS), circulating HHV-8 DMA and anti-HHV-8 antibodies are detected particularly frequently and at high levels. Studies were conducted to determine whether HHV-8 hyperactivity in such individuals could be the consequence of immunosuppression-associated reactivation, transactivation by HIV or the propensity of the host to multiple HHV-8 Infection. HHV-8 subgenomic DMA was amplified by PCR from peripheral blood of HIV-infected patients, health care workers and patients who had undergone bone marrow transplantation (BMT), and from oral lesional tissues of patients with AIDS-associated KS. Clones derived from amplicons originating from DMA fragments in open reading frame (ORF) 26 and ORF K1 were Isolated. For each ORF, intra-specimen nucleotide sequence differences were determined. The extent of HHV-8 variation in clones derived from blood of HIV-positive patients was significantly higher than In blood from health care workers or post-BMT patients or in AIDS-KS lesional tissue. Among the clones derived from the latter three categories of specimens, sequence variations were not significantly different. To Investigate if HIV plays a role in inducing HHV-8 hyperactivity, the frequency of circulating HHV-8 DMA, HIV load, anti-HHV-8 antibody level and CD4+ T cell counts was studied before and after therapy with protease inhibitors. While there was an increase in the CD4+ T cell counts and a decrease in HHV-8 DMA, no significant differences in the other variables were observed. The findings of this study suggest that HIV-infected individuals tend to be multiply-infected with HHV-8, that each AIDS-KS lesion is associated with infection by a single HHV-8 variant or a small group of related variants, and that HIV may Influence, or be associated with the replication of HHV-8
Shodhan houses and Thiago de Mello : approximations and differences between works by two masters of modern architecture
Em seu livro “Lucio Costa”, Guilherme Wisnik trata da obra desse importante arquiteto brasileiro, figura-chave na implantação da arquitetura moderna no Brasil. O mote do presente trabalho é uma afirmação de Wisnik que põe em confronto duas casas de mestres da arquitetura moderna: Casa Thiago de Mello, de Lucio Costa, e Casa Shodhan, de Le Corbusier: Moderno de primeira hora, Lucio (...) opera com o agenciamento combinatório de vazios em cubos perspécticos – poética similar à de Le Corbusier, nítida no projeto da Villa Shodhan (1951-54), e que em Lucio Costa alcança expressão lapidar na residência Thiago de Mello (1978), na Amazônia, onde as aberturas e varandas, externas e internas, vazam o cubo por todos os lados, desconstruindo-o. (WISNIK, 2001, p. 39) A Casa Shodhan faz parte de um conjunto de obras que Le Corbusier projeta para Ahmedabad, importante polo industrial da Índia. Nela, emprega o sistema Dom-Ino de 1914, mas adapta-o ao clima quente através do uso de quebra-sóis e terraços escavados no prisma de base retangular, estrategicamente pensados para promover ventilação e proteção solar. A Casa Thiago de Mello foi projetada por Lucio Costa para o conhecido poeta brasileiro, que em 1978 resolve morar novamente em sua terra natal, a cidade de Barreirinha, no Amazonas. A estrutura é de madeira, com vedação em alvenaria de tijolos e cobertura em telhas cerâmicas. Para melhor adaptação ao clima quente e úmido, Lucio propõe uma série de varandas, criteriosamente distribuídas dentro do prisma de base retangular. O objetivo deste trabalho é investigar mais profundamente as relações entre as casas Shodhan e Thiago de Mello através da análise arquitetônica de cada uma, especialmente quanto a sítio, estrutura formal, estrutura de suporte, técnicas construtivas e composição arquitetônica. Mediante tal análise pretende-se desvelar com rigor as analogias e diferenças entre ambas as obras.In his book entitled “Lucio Costa”, Guilherme Wisnik explores the work of the famous Brazilian architect and key figure in Brazilian modernism. The motto of the present article is a statement by Wisnik in the aforementioned book that contrasts two houses of masters of modern architecture, Lucio Costa’s Thiago de Mello house, and Le Corbusier’s Shodhan house: A typical modernist, Lucio (…) operates with the combination of empty spaces inside cubes put in perspective – in a poetics similar to that of Le Corbusier, as it can be seen in the Villa Shodhan project (1951-54), and in which Lucio Costa reaches exemplary expression in the Thiago de Mello house (1978), in the Amazon, where windows and balconies, both external and internal, excavate cubes in every surface, deconstructing it. (WISNIK, 2001, p. 39) Shodhan house is part of a group of Le Corbusier works crafted for the Ahmedabad area, an important industrial region in India. He utilizes the “Dom-Ino” system of 1914 in those houses, adapting it however to the hot climate by using sun breakers and excavated terraces in the rectangular base prism, all strategically designed to promote ventilation and sun protection. The Thiago de Mello house was designed by Lucio Costa for the known Brazilian poet of that name, who in 1978 decided to move back to his hometown, Barreirinha, in the Amazonas state. The structure is made out of wood, with brick masonry, and a roof made out of ceramic tiles. Aiming at adjusting the project to the hot humid climate, Lucio designs a series of balconies, carefully distributed inside the rectangular base prism. The goal of this paper is to investigate more deeply the relationship between these two houses, Shodhan and Tiago de Mello. It will do this by undertaking an architectural analysis of each house, taking into account their location, formal structure, support structure, building techniques and architectural composition. This analysis will allow for the rigorous unveiling of the similarities and differences between both architectural works
Characterization of the Spatial Distribution of the Electric Field Strength in Indoor Propagation at 2.45 GHz
Small-scale spatial variations of the electric field strength or “fast fading” are encountered in indoor environments, and are of particular concern for indoor wireless communication applications as well as for electromagnetic compatibility assessment. This thesis is motivated by the problem of electromagnetic interference with a critical-care medical equipment caused by fields radiated by portable electronic devices such as cell phones and tablet computers. Measurement and computer simulation of the electric field strength, in both controlled and real-world scenarios, are explored to estimate parameter values of statistical models for the fast fading in a region of interest inside a building.
First, a method for measuring the dielectric constant of wall construction materials is developed for two reasons: little information available on electrical properties of such materials in the frequency range of interest, 2.4 GHz ISM band, and variations in material properties caused by different manufacturing processes employed by different manufacturers. The proposed technique, referred to as the parallel-path method, falls into the category of free-space methods and is shown to be more sensitive to the dielectric constant than free-space methods based on normal incidence only.
Having determined the dielectric constant of gyproc slabs and of a wooden door, a controlled multipath environment is built inside an anechoic chamber. Two line-of-sight and a non-line-of-sight scenarios, each with about 4000 measurement points, are studied. We apply the Friedman’s goodness-of-fit test at 5% significance level to show that a ray-tracing technique based only on 3D geometrical optics is suitable for estimating the fast fading of the electromagnetic field at 2.45 GHz in a very controlled situation. Then the Anderson-Darling goodness-of-fit test, also at 5% significance level, is applied to show that in the vicinity of a transmitter the Ricean, Normal, Nakagami, and Weibull distributions can be equivalently used to represent the spatial fast fading for both line and non-line-of-sight scenarios. Furthermore, the effects of metal studs are shown to worsen not only point-by-point agreement between measurement and GO simulation, but also the agreement on the statistics of the fast fading in a 65 by 65 cm region.
Another aspect of this thesis is the development of a new method for estimating the parameters of the Ricean probability density function. This new method is compared to the maximum-likelihood method, and is shown to provide accurate estimates with samples containing as few as 36 data points for regions within 2 m from a transmitter, and as few as 9 data points for regions farther away. This is a considerable improvement in term of computation time when compared to estimates based on approximately 4000 points, or even 200 data points. Together with GO simulations, this method reduces the initial and elaborated measurement approach to only a few simulated points and a statistical model.
Finally, this methodology is extended and applied to real-world scenarios such as a long hallway and a conventional laboratory room. The agreement between measurement and GO simulation is not as good as that of the experiment conducted in a shielded anechoic chamber, but it is still reasonable, especially because the interior structures of walls such as metal studs are not modeled by the GO code. As for the statistical models used to describe the electric field strength variation in a region, it is shown that the Ricean, Normal, Nakagami, and the Weibull distributions can be employed. However, for the data collected in this work, the Normal distribution is the one that results in the worst fit to measured data for most of the cases. It is demonstrated that, even though diffracted rays are not taken into account, GO simulation allows for an accurate estimation of the parameters of a statistical model for the fast fading, for both controlled and most real-world scenarios, provided that the site geometry and electrical properties of walls, floor, and ceiling are known
Evidence for the expression of native Mycobacterium tuberculosis phospholipase C: recognition by immune sera and detection of promoter activity
The genome of Mycobacterium tuberculosis H37Rv contains three contiguous genes (plc-a, plc-b and plc-c) which are similar to the Pseudomonas aeruginosa phospholipase C (PLC) genes. Expression of mycobacterial PLC-a and PLC-b in E. coli and M. smegmatis has been reported, whereas expression of the native proteins in M. tuberculosis H37Rv has not been demonstrated. The objective of the present study was to demonstrate that native PLC-a is expressed in M. tuberculosis H37Rv. Sera from mice immunized with recombinant PLC-a expressed in E. coli were used in immunoblots to evaluate PLC-a expression. The immune serum recognized a 49-kDa protein in immunoblots against M. tuberculosis extracts. No bands were visible in M. tuberculosis culture supernatants or extracts from M. avium, M. bovis and M. smegmatis. A 550-bp DNA fragment upstream of plc-a was cloned in the pJEM12 vector and the existence of a functional promoter was evaluated by detection of ß-galactosidase activity. ß-Galactosidase activity was detected in M. smegmatis transformed with recombinant pJEM12 grown in vitro and inside macrophages. The putative promoter was active both in vitro and in vivo, suggesting that expression is constitutive. In conclusion, expression of non-secreted native PLC-a was demonstrated in M. tuberculosis.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Microbiologia, Imunologia e ParasitologiaUNIFESP, EPM, Depto. de Microbiologia, Imunologia e ParasitologiaSciEL
Flexquest : una webquest con aportes de la teoria de la flexibilidad cognitiva (TFC)
En esto trabajo presentamos una estrategia didáctica para la enseñanza de las ciencias, llamada FlexQuest, basada en la incorporación de la Teoría de la Flexibilidad Cognitiva (TFC) en el modelo WebQuest (WQ). La TFC es una teoría que utiliza de la analogía da paisaje como representación del conocimiento y que delimita su aplicación a adquisición de conocimientos de nivel avanzado, en dominios complejos y pocos estructurados. El modelo WQ es una forma de orientar la pesquisa en sala de aula, con recursos de Internet. Pero, diferente de la WQ, la FQ incorpora las ventajas de la abundancia de casos existentes en la Internet, permitiendo a los alumnos la realización de tareas que incentivan la flexibilidad cognitiva, tal como la des-construcción de un nuevo caso y/o la elaboración de una nueva travesía conceptual a partir de los casos des-construidos por el profesor
The Effects of Antimicrobial Mouthwashes on Systemic Disease: What Is the Evidence?
The potential association between antimicrobial mouthwash use and systemic health has gained attention in recent years with reports highlighting how some common systemic conditions are influenced by the use of different types of mouthwashes. In this context, links between mouthwash use and cardiovascular disease, diabetes mellitus, oral cancer, Alzheimer's disease, and preeclampsia have been proposed, albeit with limited levels of evidence. Chlorhexidine mouthwash in particular has been the most widely studied agent while available data on other types of over-the-counter mouthwashes are generally scarce. Furthermore, there is currently no evidence-based recommendations on the appropriate use of mouthwashes during pregnancy. This article will present the current evidence on the association between mouthwash use and the aforementioned conditions with emphasis on the mechanisms that may underlie such an association
Informatizaçao em clínica de marcapasso
Os autores discutem a necessidade atual de se estabelecer um projeto, de característica universal, para a informatizaçao das clínicas de marcapasso (diagnósticos, implantes e avaliaçoes), em funçao da rápida evoluçao tecnológica por que passa a especialidade. Nao há no Brasil um padrao instituído, que possa ser seguido por todos. Os autores apresentam sua experiência pessoal na formaçao de uma equipe mista, com profissionais médicos e da área de informática, que elegeu o Sistema constituído, na sua essência, por tabelas de múltipla escolha, balizando essa conduta: a) na necessidade de manipulaçao de um complexo volume de informaçoes médicas de maneira padronizada, b) na agilidade para atualizaçao do Sistema, composto por componentes independentes, c) na facilidade para realizaçao de pesquisas e, d) na maior economia do método para o armazenamento de grandes volumes de dados
Contribución al estudio de los pteridófitos de la Serra do Urubú, municipio de Maraial, estado de Pernambuco, nordeste de Brasil (Marattiaceae-Vittariaceae)
This paper presents a study of the pteridophytes of six families collected in one of the few remaining fragments of atlantic forest in Pernambuco, NE Brazil. 22 species of 13 genera are recorded most of which live on the ground in shady hollows. The specimens are deposited in the EAN, IPA, UFP and PEUFR herbaria.En el presente trabajo se estudian los pteridófitos de las familias Marattiaceae, Schizaeaceae, Gleicheniaceae, Cyatheaceae, Pteridaceae y Vittariaceae, colectados en uno de los pocos testimonios de selva fragmentada montana, llamada "floresta atlántica", en la Serra do Urubú, Mata do Ageró, municipio de Maraial, estado de Pernambuco, en el NE de Brasil. Se citan, para las seis familias mencionadas, 22 especies incluidas en 13 géneros, las que preferentemente viven como terrícolas en taludes y barrancos sombríos. Los pliegos están depositados en los herbarios EAN, IPA, UFP y PEUFR
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