97 research outputs found
tau-->eta(eta')2pi nu, 3pi nu and WZW anomaly
The effects of the anomalous contact terms are taken into account in tau to
eta(eta')2pi nu decay. tau to 3pi nu is computed. Theoretical result agrees
with data. It is the first time the anomalous vertex eta aa is tested. An a_{1}
resonance is predicted in the final state. The decay rate of tau to eta'3pi nu
is predicted.Comment: 15 pages, one latex file for the paper and one p-script file for the
figur
Changes in Soil Organic Carbon and Nitrogen Stocks in Long-Term Experiments in Southern Brazil Simulated with Century 4.5
ABSTRACT The Century model has successfully simulated soil organic matter dynamics in many agroecosystems. However, initial applications in southern Brazil produced mixed results. The objective of this study was to calibrate and validate Century 4.5 to simulate soil carbon (C) and nitrogen (N) dynamics under diverse soil management practices in subtropical Brazil. Soil C and N data from two long-term experiments established on a degraded Acrisol in the early 1980s were used. Treatments were conventional or no-tillage; grass or grass/legume cropping systems; and corn with or without mineral N fertilizer. The calibration process iteratively modified model parameters to match simulated values of C additions and Soil Organic Carbon (SOC) and Soil Organic Nitrogen (SON) stocks to field data measured throughout the 25 years of the experiments. Improved fit between measured and observed data was obtained after key parameter changes. Soil C and N stocks were simulated accurately after these modifications were implemented. Other experimental treatments were used to validate the model. Century successfully simulated increases in C and N stocks under no-tillage cropping systems including legumes. However, the model overestimated Soil Organic Matter (SOM) decomposition in treatments with low N availability, like oat/corn without N fertilizer. Overall, Century version 4.5 showed adequate performance in simulating C and N trajectories of contrasting cropping systems commonly found in southern Brazil. The few discrepancies between measured and modeled SOC stocks do not preclude using Century in regional-scale applications to assess impacts of agricultural practices on soil C and N in southern Brazil
Bringing together Brazilian soil scientists to share soil data.
Brazilian soil scientists have recently created a soil data repository using community-built standards and following open data policies in an attempt to address the issues mentioned above. The Free Brazilian Repository for Open Soil Data - febr -, accessible through www.ufsm.br/febr, is a centralized repository targeted at storing open soil data and serving it in a standardized and harmonized format, for various applications. This paper describes the features of febr and the opportunities that it creates for soil science.Na publicação: Wenceslau Teixeira
Dor e comportamento de mulheres durante o trabalho de parto e parto em diferentes posições
Avaliou-se a intensidade da sensação dolorosa e o comportamento, durante o trabalho de parto e parto, entre mulheres que tiveram parto normal, sem analgesia, nas posições semi-sentada, decúbito lateral esquerdo e litotomia. O estudo foi descritivo, transversal e correlacional. Foram usados um questionário validado que avalia dor e comportamento durante o trabalho de parto e parto, segundo a perspectiva da mulher, e duas escalas de dor: uma analógica e outra alfanumérica. Observou-se que a dor entre as mulheres que pariram em litotomia foi significativamente menor em comparação com decúbito lateral esquerdo (p=0,003), embora a posição tenha sido escolhida pela mulher. Houve associação entre dor e comportamento. A dor no trabalho de parto e parto estavam associadas entre si, assim como o comportamento nesses dois momentos. Os resultados indicam uma associação entre posição no parto e sensação dolorosa, mas não foi possível identificar fatores explicativos, sendo necessário desenvolver estudos longitudinais
Decision-making on childhood vaccination by highly educated parents
OBJECTIVE To analyze the sociocultural aspects involved in the decision-making process of vaccination in upper-class and highly educated families. METHODS A qualitative approach based on in-depth interviews with 15 couples from the city of Sao Paulo, Southeastern Brazil, falling into three categories: vaccinators, late or selective vaccinators, and nonvaccinators. The interpretation of produced empirical material was performed through content analysis. RESULTS The study showed diverse and particular aspects surrounding the three groups’ decisions whether to vaccinate their children. The vaccinators’ decision to vaccinate their children was spontaneous and raised no questions. Most late or selective vaccinators experienced a wide range of situations that were instrumental in the decision to delay or not apply certain vaccines. The nonvaccinator’s decision-making process expressed a broader context of both criticism of hegemonic obstetric practices in Brazil and access to information transmitted via social networks and the internet. The data showed that the problematization of vaccines (culminating in the decision to not vaccinate their children) occurred in the context of humanized birth, was protagonized by women and was greatly influenced by health information from the internet. CONCLUSIONS Sociocultural aspects of the singular Brazilian context and the contemporary society were involved in the decision-making on children’s vaccination. Understanding this process can provide a real basis for a deeper reflection on health and immunization practices in Brazil in light of the new contexts and challenges of the world today
Soil carbon research and global environmental challenges
The role of soil organic carbon (SOC) in maintaining soil conditions and its resulting services is well established. Currently, over 1,000 articles per year are being published in peer-reviewed journals, and increasing at about 10% per year. It was not until the 1980s when the relation between soils and climate change was noted, and it was realized that soils play a key role as a sink and source of greenhouse gases (GHGs) ( Bouwman 1990, Scharpenseel, Ayoub and Schomaker 1990, Jenny 1980). A large number of research projects have been initiated globally in which soil C is a key component, and there have been some excellent reviews ( Lal 2004, Stockmann et al. 2013, Melillo et al. 2011). Yet, there is a lack of focus in soil C research in relation to current environmental challenges. Here we recommend research priorities to advance the knowledge base and use of soil C in relation to global human and environmental challenges: food and fiber production, water scarcity and purification, energy production, climate change, biodiversity, recycling waste, and environmental degradation. We have listed the priorities under three themes: (i) Soil C in space and time, (ii) Soil C properties and processes, and (ii) Soil C depletion and management.ISSN:2167-984
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