Modeling the Dynamic Transmission of Dengue Fever: Investigating Disease Persistence

Dengue is the most rapidly spreading mosquito-borne viral disease in the world and approximately 2.5 billion people live in dengue endemic countries. In Brazil it is mainly transmitted by Aedes aegypti mosquitoes. The wide clinical spectrum ranges from asymptomatic infections or mild illness, to the more severe forms of infection such as dengue hemorrhagic fever or dengue shock syndrome. The spread and dramatic increase in the occurrence of dengue cases in tropical and subtropical countries has been blamed on uncontrolled urbanization, population growth and international traveling. Vaccines are under development and the only current disease control strategy is trying to keep the vector quantity at the lowest possible levels. Mathematical models have been developed to help understand the disease's epidemiology. These models aim not only to predict epidemics but also to expand the capacity of phenomena explanation. We developed a spatially explicit model to simulate the dengue transmission in a densely populated area. The model involves the dynamic interactions between humans and mosquitoes and takes into account human mobility as an important factor of disease spread. We investigated the importance of human population size, human renewal rate, household infestation and ratio of vectors per person in the maintenance of sustained viral circulation

Liquid-Liquid Equilibrium Data for Systems Containing Palm Oil Fractions plus Fatty Acids plus Ethanol plus Water

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Liquid-liquid extraction is an alternative method for the deacidification of vegetable oils. In contrast to traditional refining techniques, this alternative process minimizes the loss of neutral oil and preserves nutraceutical compounds originally present in crude edible oils. In this work liquid-liquid equilibrium data were measured at conditions that can be used for the deacidification of palm oil and its fractions. Crude palm oil was separated in two fractions, olein and stearin, and their compositions were characterized. Liquid-liquid equilibrium data were determined at 298.15 K and 318.15 K for systems containing palm olein + oleic add + ethanol, anhydrous or with different water contents, and at 323.15 K for systems containing palm stearin + palmitic add + ethanol, anhydrous or with different water contents. Other than their application in the design of liquid-liquid extractors for deacidification of palm oil fractions, these data are also of interest for the production of ethylic biodiesel since the same components are present in the two-phase systems that occur during part of the reactive and purification steps in the biofuel production.56518921898Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [08/56258-8]FAPESP [058/2008]CNPq [480992/2009-6, 304495/2010-7, 620209/2008-9