Growth patterns and scaling laws governing AIDS epidemic in Brazilian cities

Brazil holds approximately 1/3 of population living infected with AIDS (acquired immunodeficiency syndrome) in Central and South Americas, and it was also the first developing country to implement a large-scale control and intervention program against AIDS epidemic. In this scenario, we investigate the temporal evolution and current status of the AIDS epidemic in Brazil. Specifically, we analyze records of annual absolute frequency of cases for more than 5000 cities for the first 33 years of the infection in Brazil. We found that (i) the annual absolute frequencies exhibit a logistic-type growth with an exponential regime in the first few years of the AIDS spreading; (ii) the actual reproduction number decaying as a power law; (iii) the distribution of the annual absolute frequencies among cities decays with a power law behavior; (iv) the annual absolute frequencies and the number of inhabitants have an allometric relationship; (v) the temporal evolution of the annual absolute frequencies have different profile depending on the average annual absolute frequencies in the cities. These findings yield a general quantitative description of the AIDS infection dynamics in Brazil since the beginning. They also provide clues about the effectiveness of treatment and control programs against the infection, that has had a different impact depending on the number of inhabitants of cities. In this framework, our results give insights into the overall dynamics of AIDS epidemic, which may contribute to select empirically accurate models.Comment: 12 pages, 6 figure

Is it necessary to soak rice grains to prepare Rhizoctonia solani AG-4 inoculum?

A study was conducted to evaluate the effects on the development of root rot on common bean, cv. 'Dufrix' after treatment with four volumes of water (0, 30%, 60%, and 90%, v/w) added to rice grains previously immersed in water for 24 hours before autoclaving and colonization of grains by Rhizoctonia solani AG-4. Colonized rice grains and non-infested rice grains were mixed in pots with sterilized soil and sand (2:1), where beans were sown. Based on results of area under plant emergence curve, plant height, plant dry weight, and disease severity, we conclude that inoculum is more effective in causing disease when no water is added to the rice grains before autoclaving.CNPqFAPEMI

A Herpetofauna Do Parque Nacional Da Serra Das Confusões, Piauí, Brasil, Com Uma Lista Regional Para Uma área Ecotonal Entre O Cerrado E A Caatinga

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Different physiognomies at Parque Nacional da Serra das Confusões (PNSCo) were intensively sampled aiming to access the distribution pattern of its herpetofauna. Sixty six species were found in the park (47 reptiles and 19 amphibians); the rarefaction curve for lizards, although not fully stabilized in an asymptote, indicates that the sampling effort was enough to reveal most lizard species occurring in the area; and richness estimators recovered values close to observed. For amphibians, the curve shows a weak tendency to stabilization with richness estimators indicating that additional records could be done. Field work carried out at PNSCo has highlighted an unique herpetofauna: five new species were described and there are three candidates as new species. The regional list including Cerrados’s units - Estação Ecológica Serra Geral do Tocantins (EESGT) and Estação Ecológica de Uruçuí-Una (EEUU) with Caatinga’s ones - PNSCo and Parque Nacional da Serra da Capivara (PNSCa), shows a high herpetofaunal diversity (191 species) to the region. The cluster analysis recovered the Cerrados’s units and Caatinga’s ones, in separate clusters evidencing a species turnover between domains, despite its geographical proximity. Thus, although there is widespread fauna throughout region shared by the units, each reserve holds its own faunal identity, harboring a singular assemblage of species. © 2016, Universidade Estadual de Campinas UNICAMP. All rights reserved.1632011/50206-9, FAPESP, Fundação de Amparo Pesquisa do Estado de São Paulo303545/2010-0, CNPq, Conselho Nacional de Desenvolvimento Científico e Tecnológico565046/2010-1, CNPq, Conselho Nacional de Desenvolvimento Científico e TecnológicoFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Sistemas aquosos bifásicos uma ferramenta sustentável para a extração de ácido clavulânico a partir de diferentes fontes

O ácido clavulânico (AC) é um inibidor de β-lactamases que tem vindo a ser largamente utilizado na área médica. Embora seja de extrema importância, o desenvolvimento de processos alternativos de produção e purificação é ainda insignificante, sendo fundamental o estudo de técnicas de extração mais biocompatíveis, como os Sistemas Aquosos Bifásicos (SABs). Assim, este trabalho objetivou o estudo de Sistemas Aquosos Bifásicos baseados em polímeros como uma ferramenta alternativa para a extração de AC. Foram testados dois SPAB compostos por Polietileno Glicol (PEG) com massa molecular (M) de 4000 g/mol e Poliacrilato de Sódio de 8000 g/mol, nos quais foi alterado o eletrólito indutor da formação de fases, em particular, sulfato de sódio (Na2SO4,) e cloreto de sódio (NaCl). Ademais, este trabalho visou também avaliar a eficiência de extração do AC, bem como compreender o efeito dos contaminantes no processo de migração. Para tal, foi avaliada a extração do AC a partir de três fontes distintas: solução pura (99,9%); solução comercial (60%); diretamente a partir do sobrenadante de um meio fermentando de Streptomyces clavuligerus. Os resultados obtidos demonstraram que independentemente da fonte inicial do AC, ambos os SABs poliméricos promoveram uma partição preferencial do AC para a fase rica em PEG, sendo o coeficiente de partição maior nos sistemas com Na2SO4 do que com NaCl. Após identificar a grande capacidade de partição de AC, o SAB com PEG/NaPA/Na2SO4 foi também utilizado para avaliar a partição de proteínas presente no meio fermentado, sendo também obtida uma preferencial partição destas para a fase rica em PEG. Assim, apesar da baixa capacidade de purificação de AC frente a proteínas contaminantes, os SABs estudados demonstraram que podem ser uma técnica alternativa sustentável e bastante econômica para uma etapa inicial de clarificação/concentração de bioprodutos a partir de caldos fermentados

Effects of Eucalyptus pulp refining on the performance and durability of fibre-cement composites

Although Eucalyptus pulp has been widely used in the paper industry, there is limited information concerning its use as reinforcement in fibre-cement composites. The objective of this study was to evaluate effects of mechanical treatment (refining) of the Eucalyptus pulp on fibre properties as well as performance and microstructure of fibre-cement composites. The composites were evaluated before and after accelerated ageing cycles. The refining increased the capacity of Eucalyptus fibres to capture mineral particles, improving the adherence of the fibres with the matrix. This improved fibre-matrix interface led to better mechanical properties at 28 days of cure but higher mineralisation of fibres and consequently increased brittleness of composites after accelerated ageing (soak and dry) cycles. Unrefined fibres maintained the toughness of composites after ageing cycles. This indicates that refining may weaken the fibres thus affecting the mechanical performance (mainly decreasing modulus of rupture and toughness) of composites after ageing cycles. These results are useful for understanding effects of refined fibre conditions (morphology, mechanical strength and surface properties) on mechanisms of fibre-matrix adherence, fibre mineralisation and degradation of fibre-cement composites.FAPESP (05/59072-4, 07/05299-3)FAPEMIGCAPESCNP

Production of Galacto-oligosaccharides during lactose hydrolysis by Aspergillus oryzae β-galactosidase immobilized on polysiloxane-polyvinyl alcohol magnetic support

CHISA 2008 - 18th International Congress of Chemical and Process Engineering (CD-ROM of Full Texts)Galactooligosaccharides (GOSs) are nondigestible food ingredients that encourage proliferation of selected groups of the colonic microflora, thereby altering the composition toward a more beneficial community. The GOSs can be formed enzymatically and are produced from lactose by the action of β -galactosidases which have transgalactosylation activity. β-Galactosidase is an enzyme with wide industrial applications, mostly in the dairy industry for the hydrolysis of lactose and, more recently, in the synthesis of galactooligosaccharides. The GOS produced during lactose hydrolysis by A. oryzae-galactosidase immobilized on Polysiloxane-Polyvinyl Alcohol Magnetic (mPOS-PVA) was studied. The initial lactose concentration in the reaction media affected the total amounts and types of GOS roduced. In general, higher initial lactose concentrations produced more and larger GOS. A maximum GOS production of 25-26% (w/w) of total sugars was achieved at near 50% lactose conversion from 400 g/L of lactose at pH 4.5 and 40 ºC. The major types of GOS formed were tri-saccharides, accounting for more than 70% of the total GOS produced in the reactions. Any changes in GOS formation were observed in different temperature and pH, but the reaction rate was affected. The concentrations encountered near maximum GOS greatly inhibited the reactions and reduced GOS yield in the presence of galactose and glucose. The mPOS-PVA as the support matrix for enzyme immobilization did not affect the GOS formation characteristics of the enzyme, s uggesting no diffusion limitation in the enzyme carrier. Furthermore, the mPOS-PVA β -galactosidase preparation retained about 70% of the initial activity after being reutilized 15-times. Data obtained were fitted to kinetic model based on the Michaelis-Menten mechanism by non linear regression to determine the influence of the temperature and the lactose concentration on the activity of the enzyme. Hence, one can conclude that mPOS-PVA is an attractive and efficient support for β-galactosidase immobilization, due to the simplicity of the matrix preparation and immobilization methodology, the catalytic properties of the derivative thus produced and the straightforward removal of the enzymatic derivative from the reaction medium by simply applying a magnetic field around the bioreactorinfo:eu-repo/semantics/publishedVersio

Cattle Fecal Decomposition on \u3cem\u3ePennisetum purpureum\u3c/em\u3e Schum. Pastures Managed under Different Post-Grazing Stubble Heights

Pasture management may affect cattle diet. Post-grazing stubble height is a pasture structural characteristic intrinsically linked to forage quantity and quality. Stubble height also indicates forage utilization rate, and as a result, affects nutrient pathway return (excreta or litter) and ultimately, nutrient cycling. Cattle excreta deposition affects soil chemical and physical characteristics (Carran and Theobald 2000). Slow release of nutrients from cattle dung, however, delays nutrient bioavailability for subsequent forage growth (Haynes and Williams 1993). This study evaluated how different post-grazing stubble heights on elephant grass (Pennisetum purpureum Schum.) pastures may affect cattle dung decomposition and nutrient release

Pernambuco Semiarid Native Rhizobial Populations Nitrogen Fixation Potential with Native \u3cem\u3eMacroptilium\u3c/em\u3e

Nitrogen (N) is one of nature´s most abundant elements, accounting for about 78% of the atmospheric gases, but mostly as the inert N2 form. As such it is not directly available to plants, and is relatively scarce in most agroecosystems. Biological nitrogen fixation (BNF) through diazotrophic bacteria represents ca. 63% of the yearly N input in terrestrial ecosystems (Taiz and Zeiger 2004). Legumes which form effective symbiosis with the diazotrophic group of bacteria commonly known as rhizobia, are a very important source of available N. Tropical forage legumes are usually able to nodulate with a diverse population of rhizobia, and may have a relevant contribution to nitrogen availability in pastures (Santos et al. 2003). This diversity may be exploited to find more symbiotically efficient bacterial strains, thereby increasing legume effects on pastures. One way to evaluate this diversity is to isolate strains from different regions, vegetation covers or cultivation systems, and environmental conditions. This practice would potentially lead to a large number of isolates, which would increase the chance of finding some more efficient than those currently available (Chagas Junior et al, 2010). Native legumes, including several species of Macroptilium are an important forage resource in the Brazilian Northeast semiarid, contributing to the quality of ruminant diet, but they are still not well known in regards to their BNF ability. This work evaluated nodulation efficiency of Macroptilium lathyroides when inoculated with Litolic Neossol from eight municipalities of Pernambuco State semiarid