ABSTRACT Watermelon is cultivated in practically all Brazilian states; however, there are still disagreements as to the best way to propagate it. In addition, the Northeast region, the main producing region in the country, is increasingly facing the scarcity of low-salinity water. Given this context, this study aimed to evaluate the morphophysiology and mineral contents of the watermelon crop subjected to irrigation water of different electrical conductivities, using seedlings or direct seeding. A randomized block experimental design with split plots was used, with four replications. The plot was formed by the electrical conductivities of the irrigation water (0.3, 1.5, 3.0, and 4.5 dS m-1) and the subplot by the planting methods - DS = direct seeding, TP1 = transplanting of the seedling produced with water of moderate salinity (1.5 dS m-1), and TP2 = transplanting of the seedling produced with water of low salinity (0.3 dS m-1). The highest biomass accumulation was obtained in the direct seeding method. Salt stress increases the intrinsic water use efficiency in watermelon plants. The TP1 and TP2 planting methods led to the highest contents of P and K in the leaf. The increase in the salinity level increases the content of S and reduces the content of Cu and Mn.

RESUMO A melancia é cultivada praticamente em todos os estados brasileiros; entretanto, ainda existem divergências quanto à melhor forma de propagação. Além disso, a região Nordeste, principal região produtora do país, enfrenta cada vez mais a escassez de água com baixos níveis de salinidade. Diante deste contexto, esse estudo teve como objetivo avaliar a morfofisiologia e os teores minerais na cultura da melancia submetida a diferentes condutividades elétricas da água de irrigação, utilizando-se mudas ou semeadura direta. O delineamento experimental foi em blocos ao acaso com parcelas subdivididas, com quatro repetições. A parcela foi formada pelas condutividades elétricas da água de irrigação (0,3; 1,5; 3,0; 4,5 dS m-1) e a subparcela pelos métodos de plantio - SD = semeadura direta, TP1 = transplantio da muda produzida com água de moderada salinidade (1,5 dS m-1) e TP2 = transplantio da muda produzida com água de baixa salinidade (0,3 dS m-1). O maior acúmulo de biomassa foi obtido no método de plantio por semeadura direta. O estresse salino aumenta a eficiência intrínseca do uso da água em plantas de melancia. Os métodos de plantio TP1 e TP2 apresentam os maiores valores nos teores foliares de P e K. O aumento do nível salino aumenta os teores foliares de S e reduz os teores de Cu e Mn.

ABSTRACT Irrigation with brackish water reduces watermelon yield in the Brazilian semiarid region, requiring the establishment of management strategies that reduce the negative impacts caused by salt stress. The objective of this study was to evaluate the morphophysiology and concentration of inorganic solutes in watermelon crops subjected to different electrical conductivities of the irrigation water, using hardened seedlings or direct sowing. The experiment was conducted in the Baixo Acarau Irrigated Perimeter, in the state of Ceara, Brazil. A randomized complete block design was used, with split plots and four replications. The plots consisted of four electrical conductivity levels of the irrigation water (0.3, 1.5, 3.0, and 4.5 dS m-1), and the subplots consisted of three planting systems: DS = direct sowing; TP1 = transplanting of seedlings produced with moderate-salinity water (1.5 dS m-1), and TP2 = transplanting of seedlings produced with low-salinity water (0.3 dS m-1). The following variables were analyzed: vegetative growth, leaf gas exchange, and inorganic solutes. The use of watermelon seedlings produced with moderate-salinity water does not result in higher salt tolerance during the vegetative growth stage. Na+, Cl-, and Ca2+ leaf concentrations increase as the salt stress level is increased, regardless of the planting method. However, plants from seedlings (TP1 and TP2) have higher Na+ and Cl- concentrations when subjected to high salinity levels. The direct sowing method resulted in better performance of growth variables, mainly under low salinity levels.

RESUMO A irrigação com águas salobras reduz o rendimento da melancia no semiárido brasileiro, sendo necessário estabelecer estratégias de manejo que reduzam os impactos negativos provocados pelo estresse salino. Objetivou-se avaliar a morfofisiologia e os teores de solutos inorgânicos da cultura da melancia submetida à diferentes condutividades elétricas da água de irrigação, utilizando-se mudas rustificadas ou semeadura direta. O experimento foi realizado no Perímetro Irrigado Baixo Acaraú, Ceará, Brasil. O delineamento experimental utilizado foi o de blocos ao acaso com parcelas subdivididas, com quatro repetições. As parcelas foram formadas por quatro condutividades elétricas da água de irrigação (0,3; 1,5; 3,0; e 4,5 dS m-1) e as subparcelas por três métodos de plantio: DS = semeadura direta; TP1 = transplantio da muda produzida com água de moderada salinidade (1,5 dS m-1), e TP2 = transplantio da muda produzida com água de baixa salinidade (0,3 dS m-1). Analisou-se as variáveis de crescimento vegetativo, trocas gasosas foliares e os solutos inorgânicos. A utilização de mudas de melancia produzidas com a água de moderada salinidade não resulta em maior tolerância ao estresse salino durante a fase de crescimento vegetativo. Os teores foliares de Na+, Cl- e Ca2+ aumentam com o nível do estresse salino, independentemente do método de plantio. Entretanto, as plantas oriundas de mudas (TP1 e TP2) apresentam as maiores concentrações de Na+ and Cl- sob elevados níveis de salinidade. O método de plantio por semeadura direta apresentou superioridade nas variáveis de crescimento, principalmente sob baixos níveis de salinidade.

Biodiesel synthesis from soybean oil using methanol and alkaline catalysts occurs in the following two consecutive steps: dispersion of methanol in the oil and methanolysis. The effect of the alkaline catalysts NaOCH3, KOCH3, NaOH, and KOH in the dispersion step at 30-60 ºC and under mechanical stirring at 400 rpm was evaluated. The dispersion step accounts for 44.6-73.3% of the total synthesis time and was poorly favored compared to methanolysis due to the increase in temperature. The catalysts decreased the dispersion time, although most of them increased the methanol-oil interfacial tension. K-containing catalysts were more active than their Na analogues due to higher adsorption of K+ in the methanol-oil interface and the higher production of methyl esters (which act as emulsifying agents), which promote a more favorable interfacial tension. The alkaline cation effect was more significant in the dispersion step than in the methanolysis step.

Background: Data regarding Hepatitis B and C viruses (HBV and HCV) prevalence among military personnel in Brazil are lacking, but the work-related risk of exposure can be high. The objective of this study was to estimate the seroprevalence of HBV and HCV and the risk factors associated to HBV exposure among Brazilian military personnel.Methods: A cross-sectional study was conducted and included 433 male military adults aged 18-25 years old working in Rio de Janeiro during October 2013. All individuals completed a questionnaire to assess their risk of exposure and provided a blood sample to HBV and HCV testing.Results: None of the participants presented HBsAg or anti-HBc IgM, 18 (4.1%) were positive for total anti-HBc, 247 (57.0%) were positive for anti-HBs, and 3 (0.7%) were anti-HCV reactive. The majority of military personnel with past HBV infection (anti-HBc reactive) and HBV immunity (anti-HBs reactive) had a history of prior dental procedures (88.9% and 77.3%), consumption of alcohol at least once a week (50% and 55.9%), and practiced oral sex (61.1% and 58.3%, respectively). In addition, anti-HBc positivity was common among individuals with a history of surgery (44.4%) and practice of anal sex (50%). At univariate analysis, age group was associated to anti-HBc and anti-HBs positivity.Conclusions: Low rates of HBV and HCV infection were observed among Brazilian military personnel in comparison to the general Brazilian population. HBV immunity rates were relatively low indicating the need for vaccination campaigns in this group.

Comumente, o óleo de andiroba é extraído na Amazônia pelo método tradicional ou ainda por prensa. A eficiência na extração está relacionada ao aquecimento e ao teor de água das sementes. Desta forma, a determinação de um modelo de secagem que represente satisfatoriamente os dados experimentais é de suma importância para minimizar as alterações promovidas pelo processo obtendo-se, consequentemente, produto de qualidade. O objetivo do trabalho foi descrever a cinética de secagem das sementes de andiroba, tal como ajustar os modelos matemáticos aos dados experimentais usando-se secador solar. Foi utilizado, como critério do ajuste dos modelos matemáticos, o coeficiente de determinação, a magnitude do erro médio relativo e o desvio-padrão da estimativa. A secagem em menor tempo (14 dias) da Carapa surinamensis para atingir o teor de água de equilíbrio (12,28%) se deve, possivelmente, ao menor tamanho das sementes e à maior quantidade de óleo em relação à Carapa guianensis. O modelo Logarítmico e o de Midilli et al. foram os que melhor se ajustaram aos dados experimentais para as sementes das duas espécies de andiroba.

The oil of crabwood is commonly extracted in Amazon by traditional or by pressing method. The extraction efficiency is related to the heating and water content of the seeds. Thus, the determination of a drying model that represent satisfactorily the experimental data is of paramount importance to minimize the changes introduced by the process, consequently obtaining a quality product. The objective of this study was to describe the drying kinetics of seeds of crabwood as well as adjust the mathematical models to the experimental data, using solar dryer. The coefficient of determination, the magnitude of the mean relative error and standard deviation of the estimate was used as the criterion of fit of mathematical models. Drying in a shorter period of time (14 days) of Carapa surinamensis to reach the water equilibrium content (12.28%) may be attributed to the smaller size of the seeds and the greater amount of oil compared to Carapa guianensis. Logarithmic and Midilli et al. were the model that best fitted the experimental data for seeds of both species of Andiroba.