Plantas de cobertura em pré-safra e adubação nitrogenada na fertilidade do solo em diferentes camadas, cultivado com milho em sistema de plantio direto e convencional

The species of cover crops in pre-harvest of maize crop may influence the soil chemical properties. The objective was to evaluate soil fertility due to the use of plant species cover, previously cultivated with maize crop in no-tillage and conventional and subjected to nitrogen. The experiment was conducted at UNESP in Jaboticabal-SP, in an Oxisol clay during the crop years 2000/01, 2001/02 and 2002/03. The experimental design was randomized blocks in split plots with four replications. The treatments consisted of nitrogen (0, 60 and 120 kg N ha(-1)) and planting systems, and three under no-tillage system with the use of cover crops: Brachiaria, millet, Crotalaria and lablab, and under a conventional tillage. We evaluated at the flowering stage of corn, covering the crop year 2002-2003, the chemical soil layers (0-0.05, 0.05-0.10, 0.10-0.20; 0.20-0.30 m deep). Tillage systems and nitrogen levels influenced differently to the chemical properties of soil layers studied. Regardless of the nitrogen used in the conventional treatment showed lower organic matter content, calcium and value of sum of bases in the topsoil.

Postharvest Conservation of Mature-Green and Ripe 'Paluma' Guava Stored at Two Temperatures

This work aimed to establish the importance of maturation and ripeness stages and the use of refrigeration for the conservation of 'Paluma' guavas. Fruit picked at the mature-green and ripe stages were stored at ambient conditions (21 degrees C and 85% RH) and also at 10 degrees C (85% RH). The fruit were evaluated every 2 or 3 days for weight loss, appearance, decay, color, firmness, soluble solids, titratable acidity, ascorbic acid, total polyphenols extractable content and total antioxidant activity. The fruit stored at 21 degrees C had higher weight loss than those stored at 10 degrees C. Mature-green guavas at 21 degrees C remained in good quality for 6 days, but at 10 degrees C, the preservation period increased to 15 days. Ripe fruit were preserved for 4 days at 21 degrees C, which was extended with refrigeration to 6 days. Mature-green fruit at 21 degrees C had decay in 6 days; while at 10 degrees C decay happened in 18 days. The peel color of mature-green fruits, at 21 degrees C, showed increasing values of luminosity, indicating that its color became lighter (change from green to yellow) and at 10 degrees C it showed constant values until the end of storage. Pulp firmness of mature-green fruit declined during storage as a result of ripening. In ripe fruits such reduction occurred more slowly, since they were softer. The color of the pulp became intense red for mature fruits. Soluble solids were lower in ripe fruit at 21 degrees C, while in mature fruits at 10 degrees C, it increased. The titratable acidity increased in fruits stored at 10 degrees C. The fruits kept at 21 degrees C and the mature guavas kept at 10 degrees C showed no changes in ascorbic acid content. The ripe fruit at 10 degrees C maintained their ascorbic acid levels. Mature guavas, stored at 10 degrees C, had the longest shelf life and higher contents of soluble solids and titratable acidity, with no changes in total polyphenols extractable content and total antioxidant activity.

Crescimento aéreo e radicular da soja e de plantas de cobertura em camadas compactadas de solo

O cultivo de plantas de cobertura com sistema radicular vigoroso em rotação de culturas pode melhorar a qualidade física de solos compactados. O objetivo deste trabalho foi avaliar o crescimento aéreo e radicular da soja e de cinco espécies utilizadas como plantas de cobertura de verão (guandu, guandu anão, mucuna preta, labe labe e crotalária juncea), em solo submetido a três níveis de compactação em subsuperfíce. Utilizou-se um Nitossolo Vermelho argiloso em vasos montados com anéis de PVC sobrepostos, com diâmetro interno de 20 cm e altura de 50 cm. A camada compactada localizada de 20-30 cm de profundidade foi caracterizada pelas densidades do solo de 1,13, 1,34 e 1,56 g cm-3 e 0,26, 0,66 e 1,98 MPa de impedância mecânica, respectivamente. Aos 60 dias da emergência das plantas, determinaram-se as massas da matéria seca da parte aérea e das raízes, a densidade do comprimento radicular e o diâmetro médio radicular. Apesar de alterar a distribuição do sistema radicular ao longo do perfil do solo, o impedimento físico em subsuperfície não diminuiu a produção total de raízes da soja e dos adubos verdes, com exceção da crotalária juncea. A mucuna preta foi a leguminosa mais tolerante e a soja a mais sensível à compactação do solo. O sistema radicular da crotalária juncea apresentou potencial de formação de bioporos compatível ao da mucuna preta, apesar de ter sido relativamente mais sensível à compactação do solo. O diâmetro médio das raízes da soja e da crotalária juncea apresentou correlação significativa com o crescimento radicular dentro da camada de solo compactado.

The Genome Sequence of Taurine Cattle: A Window to Ruminant Biology and Evolution

To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specific variations in genes associated with lactation and immune responsiveness. Genes involved in metabolism are generally highly conserved, although five metabolic genes are deleted or extensively diverged from their human orthologs. The cattle genome sequence thus provides a resource for understanding mammalian evolution and accelerating livestock genetic improvement for milk and meat production.

Analysis of the efficiency of silicate clay on the control of Xanthomonas axonopodis PV. passiflorae in vitro and in seedlings of yellow passion fruit contaminated

The bacterial spot in yellow passion fruit plants, caused by the bacteria Xanthomonas axonopodis pv. passiflorae, occurs in all producing areas of the country, and is responsible for great economic losses in the culture of passion fruit. This study aimed to test the efficiency of the silicate clay in the inhibition of the bacteria Xanthomonas axonopodis pv. passiflorae in vitro, and in both preventive and curative control of the bacterial spot in seedlings of yellow passion fruit plants. The silicate clay was added to the growth medium at concentrations of. 0.5, 1.0, 1.5 and 2.0%, placed in Petri dishes. After the culture medium was cooler, the bacterial suspension was inoculates (10(7) UFC.mL(-1)) with a handle, and left incubating at 28 degrees C for three days, and then the bacterial growth was evaluated. Subsequently, the product at the same concentrations above was sprayed on seedlings of 'Afruvec' passion fruit, as preventive or curative. The inoculation of the bacteria was made by foliar spraying of bacterial suspension (10(7) ufc.mL(-1)), 24 hours before or after the curative and preventive treatments, respectively. The severity of the disease was measured comparing each four true leaves from bottom up, with a diagrammatic scale. In the concentrations evaluated, the silicate clay inhibited both bacteria in vitro and symptoms of bacterial spot in the curative treatment. In preventive treatment, significant results were obtained using more than 1.0% of clay silicates. Based on these results, the clay silicate can be recommended, the concentration of 1.0-2.0% for the control of bacterial spot of passion fruit plants, in foliar sprays.

Different origins of green-light photoluminescence emission in structurally ordered and disordered powders of calcium molybdate

A strong greenish-light photoluminescence (PL) emission was measured at room temperature for disordered and ordered powders of CaMoO4 prepared by the polymeric precursor method. The structural evolution from disordered to ordered powders was accompanied by XRD. Raman spectroscopy, and TEM imagery. High-level quantum mechanical calculations in the density functional framework were used to interpret the formation of the structural defects of disorder powders in terms of band diagram and density of states. Complex cluster vacancies [MoO3 center dot V-O(z)] and [CaO7 center dot V-O(z)] (where V-O(z) = V-O(X), V-O(center dot), V-O(center dot center dot)) were suggested to be responsible to the appearance of new states shallow and deeply inserted in the band gap. These defects give rise to the PL in disordered powders. The natural PL emission of ordered CaMoO4 was attributed to an intrinsic slight distortion of the [MoO4] tetrahedral in the short range.

Experimental and theoretical correlation of very intense visible green photoluminescence in BaZrO3 powders

Very intense visible green photoluminescence (PL) was observed at room temperature in structurally ordered-disordered BaZrO3 powders. Ab initio calculations, ultraviolet-visible absorption spectroscopy, electron paramagnetic resonance, and PL were performed. Theoretical and experimental results showed that local defects in the cubic structure caused by [ZrO5 center dot V-O(z)] complex clusters, where V-O(z) = V-O(x), V-O(center dot), and V-O(center dot center dot), play an important role in the formation of hole-electron pairs, giving rise to a charge gradient in the structure which is responsible for PL emission. (c) 2008 American Institute of Physics.

Determination of the numerical parameters of a continuous damage model for the structural analysis of clay brick masonry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relationship between green management and environmental training in companies located in Brazil: A theoretical framework and case studies

The main objective of this study is to understand the relationship between green management and environmental training in Brazilian companies, underscoring how this relationship takes place and its most important factors. For such, 9 case studies were conducted at large ISO 14001 certified companies, leaders in their market segments. Several interviews were conducted for each case, documents were collected and visits were made for direct observation. The main contributions and results of this study were: (a) a proposal for a theoretical framework relating the evolutionary stages of green management and the characteristics of environmental training; (b) it was ascertained, as per the proposed theoretical framework, that organizational culture and teamwork, top management support and more technical green management practices are the factors that seem to connect and convert environmental training into more proactive green management, especially for companies in the proactive green management stage; (c) the identification of the co-evolution between the companies' stage of green management and their environmental training level, which is the identified relationship mechanism between environmental training and green management. In other words, the higher the level of adoption of activities recommended for green management, the more evolved the green management practiced at the companies tends to be; and (d) identification that the proposed theoretical framework tends to be useful, mainly because it can explain the relationship between green management and environmental training at the company in the proactive stage. (C) 2012 Elsevier B.V. All rights reserved.

Are supplier selection criteria going green? Case studies of companies in Brazil

Purpose - The purpose of this paper is to verify if Brazilian companies are adopting environmental requirements in the supplier selection process. Further, this paper intends to analyze whether there is a relation between the level of environmental management maturity and the inclusion of environmental criteria in the companies' selection of suppliers.Design/methodology/approach - A review of mainstream literature on environmental management, traditional criteria in the supplier selection process and the incorporation of environmental requirements in this context. The empirical study's strategy is based on five Brazilian case studies with industrial companies. Face-to-face interviews and informal conversations are to be held, explanations made by e-mail with representatives from the purchasing, environmental management, logistics and other areas, and observation and the collection of company documents are also employed.Findings - Based on the cases, it is concluded that companies still use traditional criteria to select suppliers, such as quality and cost, and do not adopt environmental requirements in the supplier selection process in a uniform manner. Evidence found shows that the level of environmental management maturity influences the depth with which companies adopt environmental criteria when selecting suppliers. Thus, a company with more advanced environmental management adopts more formal procedures for selecting environmentally appropriate suppliers than others.Originality/value - This is the first known study to verify if Brazilian companies are adopting environmental requirements in the supplier selection process.

GREEN MACHINING ORIENTED TO DIMINISH DENSITY GRADIENT FOR MINIMIZATION of DISTORTION IN ADVANCED CERAMICS

After sintering advanced ceramics, there are invariably distortions, caused in large part by the heterogeneous distribution of density gradients along the compacted piece. To correct distortions, machining is generally used to manufacture pieces within dimensional and geometric tolerances. Hence, narrow material removal limit conditions are applied, which minimize the generation of damage. Another alternative is machining the compacted piece before sintering, called the green ceramic stage, which allows machining without damage to mechanical strength. Since the greatest concentration of density gradients is located in the outer-most layers of the compacted piece, this study investigated the removal of different allowance values by means of green machining. The output variables are distortion after sintering, tool wear, cutting force, and the surface roughness of the green ceramics and the sintered ones. The following results have been noted: less distortion is verified in the sintered piece after 1mm allowance removal; and the higher the tool wear the worse the surface roughness of both green and sintered pieces.

Selective sorption of mercury(II) from aqueous solution with an organically modified clay and its electroanalytical application

The organo-clay used in this work was prepared from a Na-montmorillonite (Wyoming-USA deposit) by treatment with water solution of hexadecyltrimethylammonium cations. As organo-clays exhibit strong sorptive capabilities for organic molecules, 2-mercapto-5-amino-1,3,4-thiadiazole organofunctional groups, with potential usefulness in chemical analysis, were incorporated on its solid surface. The physically adsorbed reagent did not present any restrictions in coordinating with several metal ions on the surface. The resultant organo-clay complex exhibited strong sorptive capability for removing mercury ions from water in which other metals and ions were also present. The purpose of this work is to study the selective separation of mercury(II) from aqueous solution using the organo-clay complex, measured by batch and chromatographic column techniques, and its application as preconcentration agent in a chemically modified carbon paste electrode for determination of mercury(II) in aqueous solution.

Influence of nitrogen fertilization and green manure on the economic feasibility of no-tilled wheat in the Cerrado

É importante a busca por melhores rentabilidades para a cultura do trigo por meio de tecnologias que reduzam custos de produção e proporcionem sustentabilidade à agricultura brasileira. Assim, o objetivo deste trabalho foi avaliar a rentabilidade da cultura do trigo em sistema plantio direto, visando reduzir doses de nitrogênio em cobertura, pelo cultivo de adubos verdes anterior ao do trigo. O experimento foi realizado em Selvíria (MS), Brasil, no ano 2009/10. O delineamento utilizado foi o de blocos casualizados com 36 tratamentos, em parcelas subdividas, com quatro repetições. As parcelas foram formadas por seis tipos de adubos verdes (guandu BRS Mandarim, Crotalaria juncea, milheto BRS 1501, pousio e os consórcios milheto + guandu e milheto + crotalária), que forneceram palha para o plantio direto do trigo no inverno, após a cultura de arroz na safra de verão. As subparcelas foram formadas por seis doses de nitrogênio (0, 25, 50,75, 100 e 125 kg ha-1 de N) em uma aplicação em cobertura, ten-do como fonte a ureia. O trigo cultivado, após a semeadura dos adubos verdes na safra de inverno anterior, sem a aplicação de nitrogênio em cobertura e na dose 25 kg ha-1 de N, apresentou com maior frequência custos de produção superior à receita bruta. O custo de produção de trigo cultivado após os consórcios de milheto + guandu e milheto + crotalária na safra de inverno anterior, associado a doses de nitrogênio de 50 e 75 kg ha-1 de N, proporcionou maior lucratividade em relação aos demais adubos verdes avaliados.

Recovery of soil physical properties by green manure, liming, gypsum and pasture and spontaneous native species

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

First in vivo evaluation of the mutagenic effect of Brazilian green propolis by comet assay and micronucleus test

Propolis is a hive product containing chiefly beeswax and plant-derived substances such as resin and volatile compounds. Propolis has been used in various parts of the world as an antiseptic and wound healer since ancient times, and interest in the product has recently increased. Considering the lack of data concerning the in vivo mutagenicity of green propolis, the capacity of this natural product to cause damage to the DNA was evaluated, using the alkaline single-cell gel electrophoresis (SCGE) and micronucleus test, in the peripheral blood cells of mice. The doses tested by gavage were 1000, 1500 and 2000 mg/kg. Micronucleus and SCGE assays showed that green propolis caused an increase in the damage to DNA in the peripheral blood cells of mice. The polychromatic: normochromatic erythrocytes ratio was not statistically different from the negative control. Considering the doses and the results obtained in this study, the acute consumption of green propolis produced some mutagenic effects on the blood cells of mice. (C) 2008 Elsevier Ltd. All rights reserved.