New Culture Medium to Xanthan Production by Xanthomonas campestris pv. campestris

Xanthan is a important biopolymer for commercial purpose and it is produced in two stages by Xanthomonas campestris. In the first one, the bacterium is cultivated in the complex medium enriched in nitrogen and the biomass produced is used as inoculum for the next stage in which the gum is produced in another medium. In this work a new medium for the first stage is proposed in place of currently used YM medium. Different formulated growth media were studied and the correspondent biomass produced was analysed as inoculum for the second stage. The inoculum and gum were produced by batch process in shaker at 27A degrees C in pH 6.0 and at 30A degrees C in pH 7.0, respectively. The gum was precipitated with ethanol (3:1 v/v). The dryed biomass and xathan gum produced were determined by drying in oven at 105 and 40A degrees C, respectively. The viscosity of the fermentation broth and 1% gum solution in water were determined in Brookfield viscometer. The formulated medium presented the increase in gum production (30%), broth (136%) and 1% gum solution viscosity (60%) compared to YM, besides the inferior cost. The results showed the importance of the quality of the inoculum from the first stage of the culture which influenced on the gum viscosity in the second stage.

Cardiac glycosides isolated from the Indian-snuff, Maquira sclerophylla Ducke

The hydroalcoholic extract of the powdered bark of the Indian-snuff Maquira sclerophylla Ducke was purified by column chromatography in silica-gel and the major cardenolide isolated from preparative TLC was identified by 1H-NMR, 1 2 C-NMR and IR analyses. The spectra showed that the active substance has strophanthidin as aglicone.

Performance of a reciprocal shaker in mechanical dispersion of soil samples for particle-size analysis

A dispersão da amostra de solo é uma etapa fundamental da análise granulométrica, sendo realizada mediante o uso de dispersantes químicos e agitação mecânica. O objetivo deste trabalho foi avaliar a eficiência de mesa agitadora reciprocante de baixa rotação na dispersão mecânica de amostras de solos de diferentes classes texturais. Foram realizadas análises granulométricas em 61 amostras com quatro repetições, empregando o método da pipeta para determinação da fração argila e tamisagem para determinação das frações areia grossa, areia fina e areia total, sendo o silte determinado por diferença. Na avaliação de desempenho, os resultados obtidos com uso da mesa agitadora reciprocante (MAR) foram comparados com dados disponíveis para as mesmas amostras oriundos de relatórios do Ensaio de Proficiência IAC para Laboratórios de Análises de Solos - Prolab/IAC. Análises de acurácia foram realizadas com base nos valores dos intervalos de confiança definidos para cada fração granulométrica componente de cada amostra ensaiada. Indicadores gráficos também foram utilizados na comparação de dados, por meio de dispersão e ajuste linear. A estatística descritiva indicou preponderância de baixa variabilidade em mais de 90 % dos resultados obtidos para as amostras de texturas arenosa, média e argilosa e em 68 % dos obtidos para as amostras de textura muito argilosa, indicando boa repetibilidade dos resultados obtidos com a MAR. Média variabilidade foi mais frequentemente associada à fração silte, seguida da fração areia fina. Os resultados das análises de sensibilidade indicam acurácia de 100 % nas três frações granulométricas - areia total, silte e argila - para todas as amostras analisadas pertencentes às classes texturais muito argilosa, argilosa e média. Para as nove amostras de textura arenosa, a acurácia média foi de 85,2 %, e os maiores desvios ocorreram em relação à fração silte. Nas aproximações lineares, coeficientes de correlação igual (silte) ou superiores (areia total e argila) a 0,93, bem como diferenças menores do que 0,16 entre os coeficientes angulares das retas e o valor unitário, indicam alta correlação entre os resultados de referência (Prolab/IAC) e os obtidos nos ensaios com a MAR. Conclui-se pelo desempenho satisfatório da mesa agitadora reciprocante de baixa rotação para dispersão mecânica de amostras de solo de diferentes classes texturais para fins de análise granulométrica, permitindo recomendar o uso alternativo do equipamento quando se emprega agitação lenta. As vantagens do uso do equipamento nacional incluem o baixo custo, a possibilidade de análise simultânea de grande número de amostras e o uso de frascos comuns, de vidro ou de plástico, baratos e de fácil reposição.

Evaluating sustainability of an Indian university

The objective of this research is to verify the adherence between the sustainable activities of an Indian university and the variables recommended by Alshuwaikhat and Abubakar (2008) in a framework that analyzed the contributions made by Higher Education Institutions for Sustainable Development. For such, a field work was conducted in India by the first author of this article to get in-depth data about sustainability at the university analyzed. Besides direct observations and gathering documents, interviews were also conducted with professors/scholars, students and employees. It was ascertained that up to the time in which the research was performed, the university studied was not fully adhering to the framework recommended by Alshuwaikhat and Abubakar (2008). Thus, there are still several opportunities for the university studied to be more sustainable. © 2013 Elsevier Ltd. All rights reserved.

Hibridismo cultural: o imaginário europeu na construção da sexualidade feminina do primeiro século de colonização brasileira

The aim of this study is to investigate and analyze the conceptions of sexuality and female sexual behavior and conduct, formed from the merger of information and securities purchased under the eyes, rules and guidelines established relations with the Holy Office during his visit to Inquisitorial Brazil in the late sixteenth century. It is a survey of historical methodology in which we used as the exploratory research and literature. In the sixteenth century the Church increases the pressure to change the sexual mores that were free in the Middle Ages, a fact which influences the rules and regulations that are adopted by the Holy Office regarding the person's sex life. The first structure was based on Brazilian sexual alliance between Indians and settlers, which led to sugar, by the Portuguese, the customs of the land, which included sexual practices free since the Indians were out of Christian influence. Supported by the absence of white women, the settlers took them wives of the earth, usually more than one, creating conflict with the Jesuits who condemned Indian polygamy. In this context, in 1591, landed on Brazilian soil Heitor Furtado de Mendonca, and with it, the First Visitation of the Holy Office to investigate, arguing, exploring feelings and behaviors, to discover the true facts, finally, to demonstrate the errors Faith and punish them with the rigor of ecclesiastical law. His passing opens us to visualize traces of sexuality in the current "Tropic" a racist, misogynist world where black women and degraded land could be subject to the wishes of the white man, with whom he could mate at will. Alone and forgotten, women have not found the colony margin to denounce or to speak and were stigmatized by the look of travelers and writers have been through here.

High connectivity of the crocodile shark between the atlantic and southwest indian oceans: highlights for conservation

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

Conversões e negociações: um estudo dos relatos de missionários protestantes da Church Missionary Society em Uganda-África (1876-1890)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Chaos control and sensitivity analysis of a double pendulum arm excited by an RLC circuit based nonlinear shaker

In this paper the dynamical interactions of a double pendulum arm and an electromechanical shaker is investigated. The double pendulum is a three degree of freedom system coupled to an RLC circuit based nonlinear shaker through a magnetic field, and the capacitor voltage is a nonlinear function of the instantaneous electric charge. Numerical simulations show the existence of chaotic behavior for some regions in the parameter space and this behaviour is characterized by power spectral density and Lyapunov exponents. The bifurcation diagram is constructed to explore the qualitative behaviour of the system. This kind of electromechanical system is frequently found in robotic systems, and in order to suppress the chaotic motion, the State-Dependent Riccati Equation (SDRE) control and the Nonlinear Saturation control (NSC) techniques are analyzed. The robustness of these two controllers is tested by a sensitivity analysis to parametric uncertainties.