Mechanical strength and thermal conductivity of low-porosity gypsum plates

The thermal conductivity and mechanical strength of gypsum and gypsum-cellulose plates made from commercial plaster by a new process have been measured. The gypsum parts made by the new process, 'novogesso', have high mechanical strength and low porosity. The gypsum strength derives from both the high aspect ratio of the gypsum crystals and the strong adhesion among them by nano-flat layers of confined water, which behaves as supercooled water. Another contribution to the strength comes from the nano-flatness of the lateral surfaces of the gypsum single crystals. The bending and compression strengths, σB and σc, of gypsum plates prepared by this new technique can be as high as 30 and 100 MPa, respectively. The way gypsum plates have been assembled as well as their low thermal conductivity allowed for the construction of a low-cost experimental house with thermal and acoustic comfort.FINEPFAPES

Estudo sobre o Campo Bosónico de Higgs

Nós sabemos que a matéria é formada por átomos e há não muito tempo se descobriu que os átomos são compostos de outras partículas menores, como os elétrons, prótons e nêutrons. Mais recentemente ainda, se descobriu que o próton e o nêutron poderiam ser divididos em partículas ainda menores, chamadas de quarks. No decorrer do século passado foi descoberto muitas partículas novas que possuíam propriedades características diferentes entre si. (SAGAN, Carl)

Chaotropic substances and their effects on the mechanical strength of Portland cement-based materials

Portland cement–based materials are present in our everyday life. Over the last two decades, important developments have been made to improve their mechanical strength, mainly through microstructural design. In addition, another promising parameter still remains in the early stages of understanding: that of adhesion. Recently, interdisciplinary researchers have considered the issue of water confinement by the hydrated cementitious surfaces. It could contribute to increase the adhesion and strength in these materials. On the other hand, ionic and non–ionic chaotropic substances might be able to disorder the structure of such special water. The results presented in this paper show important effects of these chaotropic substances on the strength of cementitious materials. They highlight the role of the confined water on the adhesion, when the microstructural parameters are kept constant. More than contributing to the fundamental understanding of adhesion within cement paste, these results provide basic insights on in-situ nanotechnology.FAPESP (02/10492–3)CNPq (151329/2007–9

Long-term ecological research in southern Brazil grasslands: effects of grazing exclusion and deferred grazing on plant and arthropod communities

Grazing exclusion may lead to biodiversity loss and homogenization of naturally heterogeneous and species-rich grassland ecosystems, and these effects may cascade to higher trophic levels and ecosystem properties. Although grazing exclusion has been studied elsewhere, the consequences of alleviating the disturbance regime in grassland ecosystems remain unclear. In this paper, we present results of the first five years of an experiment in native grasslands of southern Brazil. Using a randomized block experimental design, we examined the effects of three grazing treatments on plant and arthropod communities: (i) deferred grazing (i.e., intermittent grazing), (ii) grazing exclusion and (iii) a control under traditional continuous grazing, which were applied to 70 x 70 m experimental plots, in six regionally distributed blocks. We evaluated plant community responses regarding taxonomic and functional diversity (life-forms) in separate spatial components: alpha (1 x 1 m subplots), beta, and gamma (70 x 70 m plots), as well as the cascading effects on arthropod high-taxa. By estimating effect sizes (treatments vs. control) by bootstrap resampling, both deferred grazing and grazing exclusion mostly increased vegetation height, plant biomass and standing dead biomass. The effect of grazing exclusion on plant taxonomic diversity was negative. Conversely, deferred grazing increased plant taxonomic diversity, but both treatments reduced plant functional diversity. Reduced grazing pressure in both treatments promoted the break of dominance by prostrate species, followed by fast homogenization of vegetation structure towards dominance of ligneous and erect species. These changes in the plant community led to increases in high-taxa richness and abundance of vegetation-dwelling arthropod groups under both treatments, but had no detectable effects on epigeic arthropods. Our results indicate that decision-making regarding the conservation of southern Brazil grasslands should include both intensive and alleviated levels of grazing management, but not complete grazing exclusion, to maximize conservation results when considering plant and arthropod communities

Brief Research Report: Expression of PD-1 and CTLA-4 in T Lymphocytes and Their Relationship With the Periparturient Period and the Endometrial Cytology of Dairy Cows During the Postpartum Period

The present study sought to evaluate the expression of PD-1 and CTLA-4 in blood T lymphocytes during the periparturient period and their relationship with uterine health in dairy cows, as determined by endometrial cytology and serum concentrations of β-hydroxybutyrate (BHB) and non-esterified fatty acids (NEFAs), which are indicators of a negative energy balance. The second objective of this study was to investigate whether the expression of PD-1 and CTLA-4 in T lymphocytes is associated with the serum acute phase-protein haptoglobin concentration during the periparturient period. To address these objectives, 26 clinically healthy dairy cows were used. Peripheral blood was collected 14 days prepartum (T-14), at calving (T0), and 30 days postpartum (T30) to measure the expression of PD-1 and CTLA-4 in blood T lymphocytes by flow cytometry. In addition, we collected blood at T0, 10 days after parturition (T10), and T30 to obtain serum and determine the serum concentrations of NEFA, BHB, and Hp. Endometrial cytology was performed at T10, 20 days after parturition (T20), and T30. In the present study, we observed higher expression of CTLA-4 and PD-1 in T lymphocytes at parturition and in the prepartum period, which could indicate a relationship between these immune checkpoints and immunological tolerance during gestation in dairy cattle. In addition, a negative association between the expression of these immune checkpoints prepartum or at parturition and endometrial cytology at T20 and T30 was observed, indicating the negative implications of these immune response regulators in susceptibility to infections. This finding was further corroborated by the relationship between the serum concentration of haptoglobin and the expression of CTLA-4 and PD-1 by T lymphocytes. However, we did not observe a relationship between the indicators of negative energy balance, evaluated by the serum concentrations of BHB and NEFA, and the expression of the immune checkpoint markers studied. Thus, our findings represent an initial step that paves the way for the development of new therapeutic alternatives directed by the host with the objective of increasing the resistance of dairy cattle to infections in this critical period of life

Doenças associadas à deficiência do sistema complemento

Introdução: O sistema complemento é composto por diversas proteínas plasmáticas e é um importante mecanismo de defesa da imunidade inata e adquirida, que exerce funções homeostáticas e fisiológicas, como a remoção de células apoptóticas e complexos imunes. A deficiência neste mecanismo pode ser hereditária ou adquirida, e leva ao aumento da susceptibilidade a doenças infecciosas e não infecciosas, raras e fatais. Objetivo: Descrever as principais causas e consequências da deficiência do sistema complemento e relacioná-las com múltiplas patologias. Material e Métodos: Trata-se de uma revisão bibliográfica narrativa, tendo como base de dados, artigos publicados no Scientific Electronic Library Online (SciELO), National Library of Medicine (PubMed), Medical Literature Analysis and retrieval System Online (MEDLINE), nos últimos 5 anos. Resultados: A associação do complemento e doenças foram observadas em situações de deficiência do sistema complemento, anormalidades na regulação e nas inflamações. Mutações genéticas ou aumento do consumo do complemento levam à ativação imprópria ou excessiva do complemento, podendo conduzir a consequências lesivas e ao desenvolvimento de diversas doenças, como, lúpus eritematoso sistêmico, síndrome urêmica hemolítica atípica, glomerulopatia C3, hemoglobinúria paroxística noturna, glomerulonefrite pósinfecciosas, artrite reumatoide, dentre outras. Conclusão: É evidente a participação do sistema complemento na patogênese e patogenia de diversas doenças. O investimento em pesquisas, que visem ampliar o entendimento do papel do mecanismo do sistema complemento, pode contribuir para o desenvolvimento de intervenções terapêuticas paliativas e ou de cura de diversas doenças, com a consequente melhoria da qualidade de vida dos indivíduos acometidos

First inventory of the sandfly fauna (Diptera: Psychodidae, Phlebotominae) in the municipality of Juiz de Fora, State of Minas Gerais, Brazil

Introduction: This study aimed to inventory the phlebotomine sandfl y fauna present in the urban area of Juiz de Fora, with an emphasis on the genus Lutzomyia. Methods: Capture was performed from March to September 2012, using HP light traps placed at peridomestic sites, in a municipal kennel and a forest biome. Results: A total of 133 specimens were captured, representing eight species of the genus Lutzomyia. Lutzomyia pascalei was the most prevalent species. Conclusions: This research provides an inventory and description of the spatial locations of the phlebotomine sandfl y fauna of Juiz de Fora.

SOIL ERODIBILITY IN AREAS UNDER CITRUS (CITRUS SINENSIS L. OSBECK) AND FOREST IN RONDÔNIA, BRAZIL

Few studies have studied soil erodibility in areas that have undergone conversion processes from native forest to agricultural areas, especially in agricultural frontier regions. The present study aimed to evaluate soil erodibility in areas under citrus (Citrus sinensis L. Osbeck) and forest, using multivariate statistics and geostatistics in areas under different uses in Southern Rondônia, Brazil. A 42 × 30 m grid with regular spacing between sample points of 6 × 6 m was established for the studied native forest and citrus areas at depths of 0.00-0.20 m. At each sampling point, samples with preserved sod structure were collected at the evaluated depth for determination of soil texture and organic carbon, totaling 288 samples in the two studied areas. In the results it was observed that the area cultivated with citrus and under forest presented a greater predisposition of the soil to suffer erosion interril (Kiwepp), the citrus area also presented a greater susceptibility of the soil to suffer erosion in furrows (Krwepp), on the other hand, this area showed high values of critical shear stress, a fact that signals the resistance of the soil to the beginning of the erosive process. On the other hand, the forest area showed a greater predisposition to suffer erosion (K-factor), a fact possibly linked to the high values of silt and sand, which favored the present erodibility conditions

Sexualidade do cônjuge que cuida do idoso demenciado: revisão integrativa da literatura

O presente estudo teve o objetivo de identificar e analisar a produção científica da sexualidade do cônjuge que cuida do idoso em processo demencial. Realizou-se revisão integrativa de artigos científicos indexados nas bases Lilacs, Medline, CINAHL e Web of Science. Dos 208 artigos, 13 foram selecionados. Os dados foram analisados de acordo com a análise de conteúdo. Os resultados demonstraram que fatores relacionados às alterações provocadas pela demência intervêm de maneira significativa na frequência da atividade sexual do casal, levando ao declínio na intimidade. Por outro lado, um importante aspecto da sexualidade na demência está relacionado à substituição da atividade sexual por outros modos de demonstração de afetividade e intimidade física entre os cônjuges. Percebe-se que o campo de estudo acerca da atividade sexual na demência é promissor e indica a necessidade de novas pesquisas, que contribuam para abordagens mais cientificamente adequadas, incluindo aqui o cuidado terapêutico de Enfermagem