Resposta de plantas jovens de limeira-ácida 'Tahiti' a diferentes níveis de irrigação

The aim of this study was to evaluate the effect of different irrigation levels on canopy and root growth, productivity, and fruit quality of young ‘Tahiti’ acid lime trees. The experiment was installed in Piracicaba, Brazil in a 1.0-ha orchard plot with ‘Tahiti’ acid lime trees, grafted on ‘Swingle’ citrumelo rootstock and carried out from August of 2002 to May 2005. Each treatment was assigned to a drip irrigation level, based on ETc as follows: T1) non-irrigated, T2) 25%, T3) 50%, T4) 75% and T5) 100% of ETc determined by weighing lysimeter presented in the orchard plot. Trunk diameter and tree height were evaluated monthly. The roots were evaluated when the trees were 30 and 48 months old. The yield and fruit quality was evaluated in 2004 and 2005. The results showed that irrigation did not influence root distribution in depth, and trees irrigated with 75% and 100% ETc showed horizontal root distribution concentrated until 0.6 m from the trunk. Irrigation did not improve the quality of fruit. Yield increased in all irrigated treatment, but the most efficient yield mean per unit of water applied was the 25% ETc treatment.O objetivo deste trabalho foi avaliar o efeito de diferentes níveis de irrigação sobre o crescimento da copa e raízes, produtividade e qualidade de frutos de plantas jovens de limeira-ácida ‘Tahiti’. O experimento foi instalado em Piracicaba, em um hectare plantado com limeira-ácida ‘Tahiti’ enxertadas sobre porta-enxerto citromelo ‘Swingle’e irrigadas por gotejamento. O experimento foi conduzido durante o período de agosto de 2002 a maio de 2005. Cada tratamento correspondeu a um nível de irrigação baseado nos valores de evapotranspiração da cultura (ETc): T1) não irrigado; T2) 25%; T3) 50%; T4) 75% e T5) 100% da ETc determinada por meio de um lisímetro de pesagem, presente na área. O diâmetro e a altura das plantas foram avaliados mensalmente. As raízes foram avaliadas quando as plantas estavam com 30 e 48 meses de idade. A produtividade e a qualidade dos frutos foram avaliadas em 2004 e 2005. Os resultados mostraram que a irrigação não influenciou na distribuição do sistema radicular em profundidade, e que plantas irrigadas com lâminas de água equivalentes a 75 e 100% da ETc mostraram uma distribuição horizontal de raízes concentradas a 0,60 m de distância do tronco. Aos 48 meses, a irrigação não influenciou na distribuição do sistema radicular no perfil do solo. A irrigação não melhorou a qualidade dos frutos. A produtividade aumentou em todos os tratamentos irrigados, mas o tratamento correspondente à lâmina de 25% da ETc foi o mais eficiente por unidade de água aplicada

Obtaining high purity silica from rice hulls

Many routes for extracting silica from rice hulls are based on direct calcining. These methods, though, often produce silica contaminated with inorganic impurities. This work presents the study of a strategy for obtaining silica from rice hulls with a purity level adequate for applications in electronics. The technique is based on two leaching steps, using respectively aqua regia and Piranha solutions, which extract the organic matrix and inorganic impurities. The material was characterized by Fourier-transform infrared spectroscopy (FTIR), powder x-ray diffraction (XRD), x-ray fluorescence (XRF), scanning electron microscopy (SEM), particle size analysis by laser diffraction (LPSA) and thermal analysis

The Tissue Bioengineering in favor of the Rehabilitation of Individuals With Cleft Lip and Palate

A Bioengenharia tecidual compila conhecimentos de grandes áreas da ciência, os quais são aplicados atualmente em tratamentos de saúde com finalidade reparadora. No HRAC/USP pacientes com fissura labiopalatina são atualmente reabilitados com uso da rhBMP-2. Diante disso, o objetivo do presente estudo foi realizar um trabalho de revisão e atualização enfatizando as características principais da rhBMP-2. O tratamento com este biomaterial tem mostrado taxas de sucesso semelhantes às do tratamento convencional obtido de osso ilíaco para este grupo de pacientes, bem como vantagens adicionais. O conhecimento sobre suas aplicações e cuidados necessários é de grande valia para profissionais e acadêmicos da área de Ciências Biológicas e da Saúde durante o seu processo de formação universitária.Tissue Bioengineering involves knowledge of several science fields, which are currently employed in reparative health treatments. At HRAC/USP, individuals with cleft lip and palate are currently rehabilitated with the use of rhBMP-2. This paper aims to present a review and update with emphasis on the main characteristics of rhBMP-2. The treatment with this biomaterial has demonstrated similar success rates as the conventional treatment obtained from the iliac bone for this group of individuals, as well as additional advantages. Knowledge on its applications and the necessary care is very important for professionals and students in the fields of Biological and Health Sciences during the university training

A segmentation proposal to the consumers’ brazilian beer sector / Proposta de segmentação do mercado brasileiro de cerveja

The objective of this research was to identify the different segments of beer consumers based on the behavior presented during the purchase decision process. A field survey was carried out with a convenience sample of 422 respondents, using questionnaires, available in the authors' relationship networks. In the data analysis, the statistical technique cluster analysis was applied, which allowed the identification of four consumer segments: high involvement consumers, medium consumption consumers, occasion buyers, and low consumption consumers. Results obtained from the investigation show that consumers with high levels of involvement (Group 1) seek a lot of information before consumption. For consumers of average consumption (Group 2), the search for knowledge and references on beers is limited to previous experiences they had and to friends, and they choose beers mainly by the taste and by the country of origin. Occasional consumers (Group 3) usually buy the same brands of beer, but use flavor and brand as a selection criterion. Finally, low-consumption consumers (Group 4) had a consumption of beer for special occasions. They often do not seek information about the product, and they do not do any kind of word-of-mouth marketing. The Main theoretical contribution is the new segmentation proposal method originated from the research. The relevance of this study is related to the new segmentation framework proposed segments that could be used to future studies in other competitive markets

Dietary xylanase and live yeast supplementation influence intestinal bacterial populations and growth performance of piglets fed a sorghum-based diet

This study was to evaluate the effect of xylanase supplementation and the addition of live yeast, Saccharomyces cerevisiae, on growth performance and intestinal microbiota in piglets. One hundred and eighty commercial crossbred 23-d-old piglets (PIC 417) were sorted by initial BW and allocated to 3 treatments: control (CTR) diet, CTR diet supplemented with xylanase at 16,000 birch xylan units/kg (XYL) and XYL diet supplemented with live yeast (2 × 10 10 CFU/g) at 1 kg/t (XYL + LY). Each treatment had 10 replicates, with 6 animals each. A sorghum-based diet and water were available ad libitum for 42 d of the study. Average daily gain (ADG) and average daily feed intake (ADFI) were measured from 0 to 42 d (23- to 65-d-old) and feed conversion ratio (FCR) calculated. At the end of the study, bacterial identification through 16S rRNA (V3 to V4) sequencing of the ileal and caecal digesta from one piglet per replicate was performed. No treatment effects were observed on ADFI. Pigs offered the live yeast in addition to the xylanase had increased ADG compared with those supplemented with xylanase alone (XYL + LY vs. XYL; P = 0.655). FCR was improved with XYL and XYL + LY compared with CTR (P = 0.018). Clostridiaceae counts in the ileum tended to reduce by 10% with XYL and 14% with XYL + LY compared to CTR (P = 0.07). XYL and XYL + LY increased the counts of Lactobacillaceae in the caecum compared with CTR (P < 0.0001). Dietary supplementation of live yeast combined with xylanase improved growth performance and microbial balance of piglets during the nursery phase

Impact of percentage and particle size of sugarcane biochar on the sorption behavior of clomazone in Red Latosol

Biochar is a carbonaceous material that has excellent potential as a fertilizer and soil conditioner. However, there is a lack of information concerning the effects of the amount and particle size of this pyrogenic material on the soil sorption capacity. In this work, evaluation was made of changes in clomazone (CMZ) sorption in a Red Latosol following soil conditioning using different percentages (0.25, 0.5, and 1% w/w) of sugarcane biochar in three particle sizes (<106, 106-508, and 508-610 μm). The conditioned soils presented apparent sorption coefficients (Kd) up to 1300 times higher than that of pure soil, besides changes in the behavior of CMZ sorption. The biochar particle size and percentage influenced sorption of the herbicide as well as its retention in the amended soil during desorption processes. Both sorption and desorption Freundlich constants were linearly correlated with the external surface area of the biochar present in the soil

Use of the theory of index numbers for selection of fertilizer and seed drills of precision

The objectives of this work were to systemize the data contained in a set of technical catalogues referring to models of fertilizer and seed drills of precision to analyze the available information in order to prepare a database with technical characteristics and to propose a classification index for the models based on these characteristics. 93 catalogues of fertilizer and seed drills of precision supplied by Brazilian manufacturers were analyzed for generating information to characterize 250 models. On the basis of 31 technical characteristics available in catalogues, a database was prepared in which 9 of these characteristics were used in the formulation of an index number, called -Index of Adequacy- (IA). The application of IA allowed to classify the 250 models in five different categories (A, B, C, D and E), where 73% of the analyzed models composed the categories A and B, indicated for small and medium farms; 19% composed the category C, indicated for medium and large farms; and 8% of the models composed the categories D and E, indicated for large farms. It may be concluded that the adequacy index is a tool that could be used by producers in the decision-making to select most adequate fertilizer and seed drill for farm characteristics.Com este trabalho, objetivou-se sistematizar dados contidos em um conjunto de catálogos tecnológicos referentes aos modelos de semeadoras-adubadoras de precisão disponíveis no mercado nacional, analisar as informações disponíveis, construir um banco de dados com as características técnicas e propor um índice classificatório para os modelos. Analisaram-se 93 catálogos fornecidos por fabricantes nacionais, possibilitando caracterizar 250 modelos de semeadoras-adubadoras de precisão. Com base em 31 características técnicas disponíveis nos catálogos, construiu-se um banco de dados utilizando-se nove dessas características, na formulação de um número índice denominado -Índice de Adequação- (IA). A aplicação do IA permitiu que se classificassem os 250 modelos em cinco categorias (A, B, C, D e E), sendo que 73% dos modelos analisados integraram as categorias A e B, indicadas para pequenas e médias propriedades; 19% completaram a categoria C, indicada para médias e grandes propriedades e 8% dos modelos integraram as categorias D e E, indicadas para grandes propriedades. Conclui-se, portanto, que o IA é uma ferramenta que poderá ser utilizada por produtores na tomada de decisão, para escolha da semeadora-adubadora mais adequada às características da propriedade.22222

Protein Supplementation Is Vital for Beef Cattle Fed with Tropical Pasture

The production of beef on pasture is one of the potentials of Brazilian agriculture, mainly due to the territorial extension and climatic conditions. Therefore, the production of beef on tropical pastures mainly consists of the use of tropical forages; when correctly handled, forage plants show good productivity and improvement in the nutritive value. Among main factors that affect the performance of beef cattle fed on pastures, the availability and quality of the pasture stand first. In tropical regions, during the dry period of the year, the production of forage as well as its nutritive value is diminished. Hence, it is necessary to use protein supplements as a feed strategy to promote increased intake and improved nutrient utilization efficiency by animals. In view of this, by-products of biodiesel from oilseeds, such as peanuts, cottonseed and sunflower seeds, with high nutritional values can be used as an animal feed alternative to the protein sources commonly used for the formulation of supplements. Protein supplementation contributes to an increase in live weight gain as well as improvement in ruminal microbiota activity and, consequently, potentiates nutrient utilization efficiency in beef cattle fed with tropical pasture

Drug release mechanisms of chemically cross-linked albumin microparticles: effect of the matrix erosion

Albumin (BSA) microparticles were developed as a biotechnological alternative for drug delivery. Vitamin B12 (Vit-B12) was used as a model drug. The microparticles were obtained from maleic anhydride-functionalized BSA and N′,N′-dimethylacrylamide (DMAAm) in a W/O emulsion without and with PVA. The microparticles produced at 15 min of stirring without PVA showed the best results in terms of size, homogeneity, and sphericity. In such a case, BSA played a role as a surface active agent, replacing PVA. For longer stirring times, BSA was unable to act as an emulsifier. These microparticles showed an uncommon release profile, consisting of a two-step release mechanism, at the pH range studied. Considering that a two-step release mechanism is occurring, the experimental data were adjusted by applying modified power law and Weibull equations in order to describe release mechanism n and release rate constant k, respectively. Each one of the release stages was related to a specific value of n and k. The second stage was driven by a super case II transport mechanism, as a result of diffusion, macromolecular relaxation, and erosion. A third model, described by Hixson–Crowell, confirmed the erosion mechanism. Vit-B12 diffusion kinetics in aqueous solutions (i.e., without the microparticles) follows a one-step process, being k dependent on the pH, confirming that the two-step release mechanism is a characteristic profile of the developed microparticles. The microparticles released only 2.70% of their initial drug load at pH 2, and 58.53% at pH 10