Soil chemical properties affected by cover crops under no-tillage system

The use of cover crops in no-tillage systems (NTS) can significantly improve the soil's fertility. Thus, a study was performed to evaluate changes in chemical properties of soil caused by cover crops in a no-tillage system. The field experiment consisted of the following crop rotation: cover crops/rice/cover crops/rice. The experimental design was in randomized blocks with three replications. Treatments consisted of four cover crops (Brachiaria brizantha(Hochst. ex A. Rich.) Stapf. cv. Marandu, Brachiaria ruziziensis R. Germ. and C.M. Evrard, Panicum maximum Jacq. cv. Colonião, and Pennisetum glaucum(L.) R. Br. cv. BN-2) and fallow (control treatment). Soil samples were collected at the beginning of the summer crop in Oct 2007, Oct 2008 and Oct 2009 at 0-5 cm soil depth. The use of cover crops provided for a significant increase in the level of nutrients, soil organic matter, cation exchange capacity, and base saturation in the soil. Soil fertility improved from the first to second year with the growing of cover crops. The soil under cover crops P. glaucum, B. ruziziensis, and B. brizantha showed higher fertility than the area under fallow.

Weed suppression by green manure in an agroecological system

ABSTRACT Green manure promotes efficient suppression of weeds, but green manure species can exhibit distinct behaviors, depending on the environmental conditions. This study aimed to evaluate the potential of soil mulching and weed suppression by spring/summer green manure species grown in the spring/summer season, at different growth stages and after management (cut), for 90 days during the cassava crop cycle. The study was carried out in the 2010/2011 season, in a system managed under agroecological principles. The treatments consisted of different green manure species and arrangements: Crotalaria juncea, Cajanus cajan, Canavalia brasiliensis, Canavalia ensiformis, Pennisetum americanum, Crotalaria juncea and Pennisetum americanum intercropped; Mucuna aterrima, Sorghum bicolor, a mixture of all the green manures in study and a control plot under fallow. The experiment was arranged in a randomized block design with four replications. The evaluations of the soil cover either by the green manures or weeds were performed at 45, 90 and 105 days after the emergence of the green manures. The cassava crop was planted under reduced tillage system at 11 days after the cut of the green manures. The percentage of soil covered by weeds and the dry matter produced were evaluated at 30, 60 and 90 days after planting. The results showed that the green manures had a suppressive effect on weeds during their life cycle, as well as during the first months after its management (cut), composing the mulch.

A-scan ultrasound system for real-time puncture safety assessment during percutaneous nephrolithotomy

Background: Kidney stone is a major universal health problem, affecting 10% of the population worldwide. Percutaneous nephrolithotomy is a first-line and established procedure for disintegration and removal of renal stones. Its surgical success depends on the precise needle puncture of renal calyces, which remains the most challenging task for surgeons. This work describes and tests a new ultrasound based system to alert the surgeon when undesirable anatomical structures are in between the puncture path defined through a tracked needle. Methods: Two circular ultrasound transducers were built with a single 3.3-MHz piezoelectric ceramic PZT SN8, 25.4 mm of radius and resin-epoxy matching and backing layers. One matching layer was designed with a concave curvature to work as an acoustic lens with long focusing. The A-scan signals were filtered and processed to automatically detect reflected echoes. Results: The transducers were mapped in water tank and tested in a study involving 45 phantoms. Each phantom mimics different needle insertion trajectories with a percutaneous path length between 80 and 150 mm. Results showed that the beam cross-sectional area oscillates around the ceramics radius and it was possible to automatically detect echo signals in phantoms with length higher than 80 mm. Conclusions: This new solution may alert the surgeon about anatomical tissues changes during needle insertion, which may decrease the need of X-Ray radiation exposure and ultrasound image evaluation during percutaneous puncture.

IDEA MANAGEMENT SYSTEM - AN ESSENTIAL COMPONENT IN THE CONTINUOUS IMPROVEMENT OF QUALITY AND INNOVATION

It is known the power of ideas is tremendous. But there are employees in many companies who have good ideas but not put them into practice. On the other hand, there are many others who have good ideas and are encouraged to contribute their ideas for innovation in the company. This study attempts to identify factors that contribute to success in managing ideas and consequent business innovation. The method used was the case study applied to two companies. During the investigation, factors considered essential for the success of an idea management program were identified, of which we highlight, among others, evidences the results, involvement of the top management, establishment of goals and objectives; recognition; dissemination of good results. Companies with these implemented systems, capture the best ideas from their collaborators and apply them internally. This study intends to contribute to business innovation in enterprises through creation and idea management, mainly through collecting the best ideas of their own employees. The results of this study can be used to help improving deployed suggestions systems, as well as, all managers who wish to implement suggestions systems/ideas management systems.

Gradual correction of phosphorus availability in the no-tillage system

ABSTRACT In areas cultivated under no-tillage system, the availability of phosphorus (P) can be raised by means of the gradual corrective fertilization, applying phosphorus into sowing furrows at doses higher than those required by the crops. The objective of this work was to establish the amount of P to be applied in soybean crop to increase content of P to pre-established values at the depth of 0.0 to 0.10 m. An experiment was carried out on a clayey Haplorthox soil with a randomized block experimental design distributed in split-split plot, with four replications. Two soybean crop systems (single or intercropped with Panicum maximum Jaca cv. Aruana) were evaluated in the plots. In addition, it was evaluated four P levels (0, 60, 120 and 180 kg ha-1 P2O5) applied in the first year in the split plots; and four P levels (0, 30, 60 and 90 kg ha-1 P2O5) applied in the two subsequent crops in the split-split plot. Contents of P were extracted by Mehlich-1 and Anion Exchange Resin methods from soil samples collected in the split-split plot. It was found that it is necessary to apply 19.4 or 11.1 kg ha-1 of P2O5, via triple superphosphate as source, to increase 1 mg dm-3 of P extracted by Mehlich-1 or Resin, respectively, in the 0.0 to 0.10 m layer of depth. The soil drain P character decreases as the amount of this nutrient supplied in the previous crops is increased.

Financial strategies for minimizing corporate income taxes under Brazil's new global tax system

In 1996, Brazil adopted a worldwide income tax system for corporations. This system represents a fundamental change in how the Brazílian government treats multinational transactions and the tax minimizing strategies relevant to businesses. In this article, we describe the conceptual basis for worldwide tax systems and the problem of double taxation that they create. Responses to double taxation by both the governments and the priva te sector are considered. Namely, the imperfect mechanisms developed by Brazil and other countries for mitigating double taxation are analyzed. We ultimately focus on the strategies that companies utilize in order not only to avoid double texetion, but also to take advantage of tax havens.

Ambivalent implications of health care information systems: a study in the Brazilian public health care system

This article evaluates social implications of the "SIGA" Health Care Information System (HIS) in a public health care organization in the city of São Paulo. The evaluation was performed by means of an in-depth case study with patients and staff of a public health care organization, using qualitative and quantitative data. On the one hand, the system had consequences perceived as positive such as improved convenience and democratization of specialized treatment for patients and improvements in work organization. On the other hand, negative outcomes were reported, like difficulties faced by employees due to little familiarity with IT and an increase in the time needed to schedule appointments. Results show the ambiguity of the implications of HIS in developing countries, emphasizing the need for a more nuanced view of the evaluation of failures and successes and the importance of social contextual factors.

Metamorfoses em espelho de água : identidade, perfil, contextos e mudança nas (auto)representações dos professores

RESUMO: Nos últimos trinta anos, em Portugal, ocorreram processos de democratização política e de modernização da sociedade e das instituições, tendo como impulso as vontades nacionais e as mudanças ocorridas no Mundo em globalização, lideradas, no campo da educação, por agentes como a OCDE ou o Banco Mundial, e pela integração de Portugal na União Europeia. À implementação da(s) reforma(s), correspondeu uma mudança de paradigma educativo e organizacional, a criação de uma escola para todos, a emergência de novos alunos e de novos mandatos à Escola, a contingência de novas respostas educativas. Tais reformas constituiram instrumentos de mudança das organizações escolares e do sistema educativo, mas também do que significa ser professor, reformulando o desempenho e a “performatividade” docente (Ball, 2002), induzindo uma nova “identidade social” (Bernstein, 1996 e Dubar, 2006), produzindo novos modos de “fabricação da alma dos professores” (Foucault, 1996). Neste sentido, a autora procurou analisar, numa perspectiva crítica, as representações de professores do Ensino Básico, sobre os mecanismos de (re)configuração das suas identidades/perfis profissionais, recorrendo a uma investigação qualitativa descritiva, que privilegia a análise de conteúdo dos seus discursos sobre o tema, recolhidos segundo a técnica focus group. O estudo indiciou que os alunos são factor de realização, de risco e de mudança do perfil docente, actuando como uma quinta dimensão da (re)construção identitária dos Professores, a par da formação, do associativismo, do Estado e do Mercado, constituindo factor importante a ter em conta nos estudos sobre identidade docente. ABSTRACT: In the past thirty years, in Portugal, radical changes on politics and policies have been occurring, to achive the society and its institutions democratization and modernization, led by national wills and the changes occured in the World, stimulated, in the Education area, by global agencies like OECD, or the World Bank, and the integration of Portugal in the European Union. These reforms are connected to a new educational and organizational paradigm, the creation of a school for all, the emergence of new pupils, new demands to School and teachers, the imperative of new pedagogical solutions for educational problems, and are not only changing instruments in schools and in the educational system, but are also a powerful way to change “what to be a teacher” means, to re-formulate the teaching performance and “performativity” (Ball, 2002), to recompose his/her “social identity” (Bernstein, 1996; Dubar, 2006), or, in Michel Foucault (1996) words, to produce “new ways to manufacture teachers soul”. In this sense, the author intended to analyze, on a critical perspective, the representations of portuguese teachers of basic education (K12), on the mechanisms of (re)configuration of their professional identities/profiles, appealing to a qualitative descriptive research, which privileges the analysis of content of their speeches on the subject, collected according to the focus group technique, what, in its development, was brought near a circle of culture (in the sense of Paulo Freire‟s pedagogy). At least, pupils are the most important references and motivation to teachers changes, reflecting professional satisfaction and well done, but also risk, acting like a fifth dimension of teachers identity (re)construction, together with training, associative involvement, State and Market, and they must be considered on teatching identity studies.