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This study aimed to evaluate the morphogenic and structural characteristics and the population stability index of ryegrass (Lolium multiflorum Lam.) tillers when the pasture was submitted to two stocking methods during grazing cycles. The experimental design was a complete randomized block, with repeated measurements over time (n=6 cycles), two treatments (stocking methods) and three area replicates. In the continuous stocking method, the highest population density of tillers was observed. The highest tiller weight occurred in the rotational stocking method. The morphogenic variables and the other structural variables were not altered by the stocking methods and showed differences during the grazing cycles. The tiller population stability index was similar in the two pasture management strategies, and both can be used for ryegrass management considering this parameter.

Este estudo teve como objetivo avaliar as características morfogênicas, estruturais e o índice de estabilidade populacional de perfilhos do azevém (Lolium multiflorum Lam.) quando a pastagem foi submetida a dois métodos de lotação, durante ciclos de pastejo. O delineamento experimental foi em blocos completos casualizados, com medidas repetidas ao longo do tempo (n = 6 ciclos), dois tratamentos (métodos de lotação) e três repetições de área. No método de lotação contínua, foi observada a maior densidade populacional de perfilhos. O maior peso de perfilhos ocorreu no método de lotação rotativa. As variáveis morfogênicas e as demais variáveis estruturais não foram alteradas pelos métodos de lotação e apresentaram diferenças durante os ciclos de pastejo. O índice de estabilidade populacional de perfilhos foi semelhante nas duas estratégias de manejo do pasto e ambas podem ser utilizadas para o manejo do azevém considerando-se esse parâmetro.

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The present study aims to determine the appropriate defoliation management for the production of seeds and forage in arrowleaf clover via trail analysis. The results obtained demonstrated that defoliation practices have a great influence on the composition of seed yield and germination power. In addition, when the goal is the maximum balance between dry matter production and seed yield, this can be achieved in up to two defoliation practices. These results are confirmed by analyzing the positive association between the weight of a thousand seeds and the seed yield. When the third defoliation practice is performed, it negatively correlates with the weight of a thousand seeds, suggesting that, with the increase in defoliation frequency, there is a lower weight of a thousand seeds, and, therefore, lower seed yield. Therefore, management planning in Trifolium vesiculosum Savi that aims at natural reseeding, maximum yield and seed germination must prioritize one to two defoliation practices, aiming to promote favorable conditions for the perennialization of the species. In this context, the trail analysis proved to be a useful tool as a criterion for obtaining the ideal management aiming at the production of seeds and forage in vesicular clover.(AU)

O presente estudo visa determinar o manejo de desfolha adequado para a produção de sementes e de forragem em trevo-vesiculoso via análise de trilha. Os resultados obtidos demonstraram que as práticas de desfolha possuem grande influência na composição do rendimento de sementes e no poder germinativo. Além disso, quando o objetivo for o máximo equilíbrio entre a produção de matéria seca e o rendimento de sementes, esse pode ser alcançado em até duas práticas de desfolha. Esses resultados são confirmados ao se analisar a associação positiva entre o peso de mil sementes e o rendimento de sementes. Quando realizada a terceira prática de desfolha, esta se correlaciona negativamente com o peso de mil sementes, sugerindo que, com o aumento da frequência de desfolha, ocorre menor peso de mil sementes e, por conseguinte, menor rendimento de sementes. Portanto, o planejamento do manejo em T. vesiculosum Savi que objetive a ressemeadura natural, o máximo rendimento e a germinação de sementes deve priorizar até duas práticas de desfolha, visando promover condições favoráveis para a perenização da espécie. Nesse contexto, a análise de trilha demonstrou ser uma ferramenta útil como critério para obtenção do manejo ideal visando à produção de sementes e de forragem em trevo-vesiculoso.(AU)

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The Finite Element Method is a well-known technique, being extensively applied in different areas. Studies using the Finite Element Method (FEM) are targeted to improve cardiac ablation procedures. For such simulations, the finite element meshes should consider the size and histological features of the target structures. However, it is possible to verify that some methods or tools used to generate meshes of human body structures are still limited, due to nondetailed models, nontrivial preprocessing, or mainly limitation in the use condition. In this paper, alternatives are demonstrated to solid modeling and automatic generation of highly refined tetrahedral meshes, with quality compatible with other studies focused on mesh generation. The innovations presented here are strategies to integrate Open Source Software (OSS). The chosen techniques and strategies are presented and discussed, considering cardiac structures as a first application context.

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Foram estudadas as características do processo de ingestão de forragem por cordeiras em azevém (Lolium multiflorum Lam.) nos estádios fenológicos vegetativo, pré-florescimento e florescimento, por meio de testes de pastejo e da técnica da dupla pesagem. O delineamento experimental foi o inteiramente ao acaso, com três tratamentos e cinco repetições no estádio vegetativo e seis nos demais estádios. Os diferentes estádios fenológicos não influenciam a taxa de ingestão, a massa do bocado e a profundidade de bocado quando a oferta de forragem não é limitante ao consumo. O aumento na taxa de bocados é o mecanismo utilizado por cordeiras para manter a taxa de ingestão constante. Os modelos de regressão múltipla indicam que, dentre os atributos do pasto, sua altura é o de maior importância para determinar mudanças no comportamento ingestivo de cordeiras.

Utilizing grazing tests and the double weighing technique, the characteristics of the forage intake process of lambs grazing Italian Ryegrass pasture at vegetative, pre-flowering and flowering phenological stages were studied. A completely randomized design with three treatments and five replicates in the vegetative stage and six replicates in the other phenological stages was used. The intake rate, bite mass and bite depth were not influenced by the phenological stages when the intake was not limited by the forage allowance. By increasing bite rate lambs maintained a constant rate of intake. The multiple regression models indicate that among the herbage attributes, the sward height is the most important to determine changes in the grazing behavior of lambs on Italian Ryegrass pasture.

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Foram estudadas as características do processo de ingestão de forragem por cordeiras em azevém (Lolium multiflorum Lam.) nos estádios fenológicos vegetativo, pré-florescimento e florescimento, por meio de testes de pastejo e da técnica da dupla pesagem. O delineamento experimental foi o inteiramente ao acaso, com três tratamentos e cinco repetições no estádio vegetativo e seis nos demais estádios. Os diferentes estádios fenológicos não influenciam a taxa de ingestão, a massa do bocado e a profundidade de bocado quando a oferta de forragem não é limitante ao consumo. O aumento na taxa de bocados é o mecanismo utilizado por cordeiras para manter a taxa de ingestão constante. Os modelos de regressão múltipla indicam que, dentre os atributos do pasto, sua altura é o de maior importância para determinar mudanças no comportamento ingestivo de cordeiras.(AU)

Utilizing grazing tests and the double weighing technique, the characteristics of the forage intake process of lambs grazing Italian Ryegrass pasture at vegetative, pre-flowering and flowering phenological stages were studied. A completely randomized design with three treatments and five replicates in the vegetative stage and six replicates in the other phenological stages was used. The intake rate, bite mass and bite depth were not influenced by the phenological stages when the intake was not limited by the forage allowance. By increasing bite rate lambs maintained a constant rate of intake. The multiple regression models indicate that among the herbage attributes, the sward height is the most important to determine changes in the grazing behavior of lambs on Italian Ryegrass pasture.(AU)

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The results obtained through biological research usually need to be analyzed using computational tools, since manual analysis becomes unfeasible due to the complexity and size of these results. For instance, the study of quasispecies frequently demands the analysis of several, very lengthy sequences of nucleotides and amino acids. Therefore, bioinformatics tools for the study of quasispecies are constantly being developed due to different problems found by biologists. In the present study, we address the development of a software tool for the evaluation of population diversity in quasispecies. Special attention is paid to the localization of genome regions prone to changes, as well as of possible hot spots.

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Toxoplasmosis is an anthropozoonotic widespread disease, caused by the coccidian protozoan parasite Toxoplasma gondii. Since there are no data regarding the genotoxicity of the parasite in vivo, this study was designed to evaluate the genotoxic potential of the toxoplasmosis on isogenic mice with normal diet or under dietary restriction and submitted to a treatment with sulfonamide (375 microg/kg per day). DNA damage was assessed in peripheral blood, liver and brain cells using the comet assay (tail moment). The results for leucocytes showed increases in the mean tail moment in mice under dietary restriction; in infected mice under normal diet; in infected, sulfonamide-treated mice under normal diet; in infected mice under dietary restriction and in infected sulfonamide-treated mice under dietary restriction. In liver and brain cells, no statistically significant difference was observed for the tail moment. These results indicated that dietary restriction and T. gondii were able to induce DNA damage in peripheral blood cells, as detected by the comet assay.

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Chemical safety is recognized in Agenda 21(UNCED--Rio 92), as one of the most serious problems to be faced worldwide being a problem not just of governability, restricted more to the role of states and governments, but of governance at the national and international levels. It poses greater challenges for countries like Brazil where the issues of democracy, security, sustainability and equity, which are fundamental to governance, are merely incipient and still far from solved. Taking as references the analysis of four cases in the Brazilian context, we illustrate the situation from less densely populated areas (as in the cases of mercury use by gold miners in the Amazon and pesticides in agricultural producing areas), through medium-sized towns (as in the accident with cesium 137 in Goiânia), to the major urban and industrial centers (as in the cases of lead from battery renovators and benzene in the oil and steel industries and oil refineries). What can be seen is a situation where problems connected with chemical safety have grown in intensity and extent far more than the capacity to deal with them. In industrializing countries, the formulation of chemical safety policies must take into account not only the complexity and uncertainties involved in understanding the problems, but also the aspects relating to the different modes and levels of vulnerability. This is necessary in order to attempt to build better contextualized and more participatory knowledge and decision-making processes at the local and global levels, which we take as basic prerequisites for governance.

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This study provides an overview of the theoretical discussion on potential uses for biological monitoring of exposure to chemical substances as related to human health, considering different concepts: definitions, uses, and limitations of internal dose and biological effect indicators and their availability for the substances to be quantified; knowledge of reference values, action levels, and limits based on health and negotiated patterns in biological monitoring interpretation and perspectives; and ethical and social problems in practice and within different preventive practices and their use in public health. Biological monitoring is the result of an exposure situation with conclusions based on scientific and consensus values, rules, and legislation. Biological monitoring as a continuous process and related to actually observed cases has helped establish technological exposure reference values and consensus levels as indicators for improving the environment and the workplace. As a step in the decision-making process in risk analysis, biological monitoring needs to be critically assessed as to its ethical aspects in light of the end use of results and values, which are references for application of this methodology.

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The offshore oil industry is characterized by complex systems in relation to technology and organization of work. Working conditions are hazardous, resulting in accidents and even occasional full-scale catastrophes. This article is the result of a study on work-related accidents in the offshore platforms in the Campos Basin, Rio de Janeiro State. The primary objective was to provide technical back-up for both workers' representative organizations and public authorities. As a methodology, we attempt to go beyond the immediate causes of accidents and emphasize underlying causes related to organizational and managerial aspects. The sources were used in such a way as to permit classification in relation to the type of incident, technological system, operation, and immediate and underlying causes. The results show the aggravation of safety conditions and the immediate need for public authorities and the offshore oil industry in Brazil to change the methods used to investigate accidents in order to identify the main causes in the organizational and managerial structure of companies.

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