Polissacarídeos amido e celulose enxertados com ácido tioglicólico com ação bactericida

Trabalho apresentado no 31º SEURS - Seminário de Extensão Universitária da Região Sul, realizado em Florianópolis, SC, no período de 04 a 07 de agosto de 2013 - Universidade Federal de Santa Catarina.A necessidade de se obter materiais resistentes à ação de bactérias na indústria farmacêutica tem levado ao aumento de pesquisas no campo de biomateriais, principalmente no que diz respeito à obtenção de materiais de baixo custo. A celulose vem sendo utilizada com muita eficiência para fabricação de filmes, plásticos, espessantes dentre outros. Neste trabalho, propomos a modificação de filmes de celulose bacteriana e amido com acido tioglicólico, sendo realizado teste da atividade bactericida dos mesmos. Foi observado que os filmes de celulose apresentaram uma considerável atividade bactericida frente à bactéria Salmonella, o que potencializa o seu uso como curativos

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

Geostatistical modeling and machine learning as alternative methods to the traditional methodologies of streamflow regionalization in watersheds

A gestão e o planejamento integrado dos recursos hídricos em bacias hidrográficas de países emergentes enfrentam grandes desafios com a falta de informações hidrológicas e monitoramento deficiente. Dentre as suas ferramentas de apoio está a regionalização de vazões: um conjunto de procedimentos que exploram as informações de locais monitorados para estimar a variável de interesse em locais sem monitoramento. Ainda não existe um método universal de regionalização de vazões. Os esforços científicos sobre a adequabilidade de diferentes metodologias para contextos específicos de bacias hidrográficas visam melhorar ou possibilitar a gestão dos recursos hídricos em bacias com pouca ou nenhuma informação hidrológica, favorecendo a gestão dos recursos hídricos com alocação mais eficiente dos recursos humanos e financeiros. Assim, o presente trabalho foi dedicado à avaliação de diferentes métodos e abordagens de regionalização de vazões na bacia hidrográfica do rio Doce para fins de estimativa das vazões mínimas de referência (Q7,10, Q90 e Q95) e média de longa duração (Qmld). No primeiro artigo foram avaliados métodos de regionalização de vazões baseados em interpolação linear, regressões regionais e geoestatística. Objetivou-se comparar o desempenho e a viabilidade de implementação da geoestatística como alternativa às demais metodologias de regionalização de vazões. A geoestatística apresentou desempenho similar às outras abordagens, revelando-se uma alternativa promissora em situações que inviabilizam o emprego das outras metodologias, como em bacias menores e de monitoramento hidrológico precário ou inexistente. O segundo artigo explorou modelos de aprendizado de máquina para a regionalização de vazões. O objetivo foi avaliar o desempenho preditivo de um modelo linear e dos modelos não lineares Random Forest e Splines de regressões adaptativas multivariadas (Earth). O desempenho do modelo linear foi insatisfatório. A covariável mais importante aos modelos não lineares foi a vazão equivalente à precipitação com abstração de 750 mm (Peq750). Ambos os modelos não lineares revelaram grande habilidade preditiva, constituindo alternativas poderosas e promissoras à regionalização de vazões em suporte à gestão dos recursos hídricos na bacia do rio Doce.The management and integrated planning of water resources in watersheds in developing countries face great challenges due to the lack of hydrological information and deficient monitoring. Among their support tools is the streamflow regionalization: a set of procedures that explore the information of monitored sites to estimate the interest variable in locations without monitoring. There is still no universal method of streamflow regionalization. Scientific efforts about the suitability of different methodologies for specific contexts of watersheds aim to improve or enable the water resources management in basins with little or no hydrological information, favoring the water resources management with more efficient allocation of human and financial resources. Thus, the present work was dedicated to the evaluation of different methods and approaches of streamflow regionalization in the Doce river basin for the purpose of estimating the minimum reference streamflows (Q7,10, Q90 and Q95) and long term streamflow (Qmld). In the first article, methods of streamflow regionalization based on linear interpolation, regional regressions and geostatistics were evaluated. The objective was to compare the performance and the feasibility of implementing geostatistics as an alternative to other streamflow regionalization methodologies. Geostatistics has performed similarly to other approaches, proving to be a promising alternative in situations that make the use of other methodologies unfeasible, such as in smaller basins with precarious or nonexistent hydrological monitoring. The second article explored machine learning models for streamflow regionalization. The objective was to evaluate the predictive performance of a linear model and the non-linear models Random Forest and Splines of multivariate adaptive regressions (Earth). The linear model performance it was unsatisfactory. The most important covariate for the non-linear models was the streamflow equivalent to the precipitated volume, considering the subtraction of the precipitation abstraction factor of 750 mm (Peq750). Both non-linear models Random Forest and Earth showed great predictive ability, constituting powerful and promising alternatives to the streamflow regionalization in support of the water resources management in the Doce River basin

Effects of spatial and environmental factors on benthic a macroinvertebrate community

Interactions between terrestrial and aquatic systems influence the structure of river habitats and, consequently, affect their benthic macroinvertebrate composition. The aim of this study was to evaluate the effects of spatial and environmental variables (local physical and chemical variables of water and regional landscape characteristics) on the benthic macroinvertebrate community of the Pandeiros River Basin. Biotic and abiotic variables were evaluated at 20 sampling sites distributed across the primary sub-basins of the Pandeiros River Basin. We found that the macroinvertebrates were primarily affected by environmental variables. The most important environmental variables were pebble proportion and water conductivity at the local scale (7.2% of explained variation) and elevation and nonforest areas at the regional scale (6.9% of explained variation). The spatial variables were representative only in shared explained variation with the environmental matrices (local-spatial = 0.2% and regional-spatial = 2%; all matrices combined = 4.4%). Sampling sites with higher non-forest areas, lower elevations, and steeper slopes presented low pebble fractions and higher electrical conductivities. Habitat diversity was lower when the percentage of pebbles decreased, resulting in decreased taxonomic richness and diversity in macroinvertebrate communities. High electrical conductivities and non-forest areas also had negative effects on macroinvertebrate density due to the loss of habitat diversity. We conclude that higher proportions of pebbles in the substrate and higher altitudes were likely the primary variables for positive effects on the taxonomic richness and density of macroinvertebrate communities

Nota técnica: Análise morfométrica de uma sub-bacia do Rio Piracicaba (MG) utilizando sistemas de informação geográfica

A morfometria de uma bacia hidrográfica pode fornecer subsídios para o adequado planejamento e gestão de recursos hídricos em nível de bacia hidrográfica. Neste sentido, objetivou-se com este estudo realizar a análise morfométrica de uma sub-bacia hidrográfica do Rio Piracicaba (MG), utilizando o Sistema de Informações Geográficas. A área de drenagem e o perímetro da bacia estudada foram estimados em 1.138,80 km² e 205,16 km, respectivamente. A análise dos parâmetros de forma, do sistema de drenagem e do relevo da bacia aponta, respectivamente, baixa susceptibilidade a ocorrência de enchentes, baixa capacidade de drenagem, potencial de degradação por erosão do solo e ocorrência de precipitações bem distribuídas e regulares. O uso de dados advindos de imageamento por satélites integrado às técnicas de geoprocessamento comprovou elevada eficiência como ferramenta para ações atreladas ao planejamento e gestão dos recursos hídricos, sendo ainda eficiente na redução de custos, tempo e padronização científica na execução de experimentos.The morphometry of a watershed can provide subsidies for proper planning and management of water resources at a watershed level. Therefore, the objective of this study was to perform a morphometric analysis of a sub-basin of the Piracicaba river (MG), using the Geographic Information System. The area and perimeter of the study area were estimated to be 1138.80 km2 and 205.16 km, respectively. Shape parameters, drainage parameters, and basin relief parameters pointed, respectively, to low fl ooding susceptibility, low drainage capacity, risk of potential degradation by soil erosion and occurrence of regular and well distributed precipitation. Satellite image data in conjunction with geoprocessing techniques proved to be highly effi cient as a tool for planning and management of water resources, and for reducing costs, time and scientifi c standardization during the execution of the tasks

The effects of abiotic variables on detritus decomposition in Brazilian subtropical mangroves

AIM: The objective of this study was to determine the rate of decomposition of two dominant arboreal species (Rhizophora mangle and Avicennia schaueriana) in two Brazilian subtropical mangroves (Ratones and Itacorubi) and their relationship with abiotic factors during two periods of the year (winter and summer). METHODS: Senescent leaves (4 ± 0.1 g dry weight) were placed into litter bags (20 × 25 cm with 1 cm mesh size) and submersed in mangrove forests during a winter and a summer sampling period. Replicates (n = 4) of each detritus sample were obtained from the mangroves after 7, 15, 30, 60, 90 and 120 days of incubation during both time periods. During each period, in situ measurements were taken to obtain the temperature, electrical conductivity, pH, and dissolved oxygen in the water column. RESULTS: The species R. mangle and A. schaueriana exhibited slow rates of decomposition at Itacorubi and intermediate rates at Ratones during the winter, while quick rates were observed at both sites during the summer; this result suggested that water temperature is an influential factor. There was no difference in the loss of mass between the sites during the winter, but in the summer, the highest values were observed for R. mangle in Ratones site. The highest summer temperatures were negatively associated with mass loss, suggesting that the temperature is an influential factor. During the winter, remaining mass was associated negatively with electrical conductivity, possibly because of a greater resource available to decomposing communities, and it was also positively associated with oxygen, revealing a pattern opposite to that observed in the literature. CONCLUSIONS: Our results showed that decomposition accelerated with higher temperatures and that electrical conductivity decelerated with increased dissolved oxygen, confirming the effects of abiotic factors on both detritus decomposition and mangrove functioning

CARACTERIZAÇÃO MORFOMÉTRICA DA BACIA HIDROGRÁFICA DO RIO CATOLÉ GRANDE, BAHIA, BRASIL

O presente estudo tem como objetivo determinar as características morfométricas da bacia hidrográfica do Rio Catolé Grande, BA, utilizando dados SRTM em ambiente de Sistema de Informações Geográficas (SIG). De posse do MDEHC e da delimitação da bacia foram obtidas diferentes características morfométricas. A área de drenagem encontrada foi de 3.128,81 km2 e o perímetro de 343,95 km. A bacia do Rio Catolé Grande apresentou altitude média de 652,69 m, declividade média de 13,51%, coeficiente de compacidade de 1,72, fator de forma de 0,29 e índice de circularidade de 0,33. A densidade de drenagem obtida foi de 0,34 km km-2. Após a análise dos resultados obtidos, concluiu-se que a bacia possui formato irregular, baixa densidade de drenagem e baixa susceptibilidade a enchentes em condições normais de precipitação. As técnicas de geoprocessamento aplicadas e os dados SRTM utilizados se mostraram eficazes na obtenção das características morfométricas, sendo os resultados obtidos de forma rápida, confiável e com reprodutibilidade científica. Palavra-chave: morfometria, recursos hídricos, geoprocessamento.   MORPHOMETRIC CHARACTERIZATION OF CATOLÉ GRANDE RIVER WATERSHED, BAHIA STATE, BRAZIL ABSTRACT This study aimed to determine the morphometric characteristics of Catolé Grande river watershed, Bahia state, Brazil, through SRTM data by using Geographic Information System (GIS). After obtaining MDEHC data and the watershed delimitation, different morphometric characteristics were also obtained. The drainage area found was 3.128,81 km2 and the perimeter was 343,95 km. Watershed of Catolé Grande river presents average height of  652.69 m, average declivity of 13.51%, compactness coefficient of 1.72,  form factor 0.29 and circle index 0.33. Drainage density obtained for the watershed was 0.34 km km-2. After analysis of results obtained, it was concluded that the basin has irregular format, low drainage density and low susceptibility of the floods in normal precipitation condition . The applied Geoprocessing techniques and SRTM data used were efficient for obtaining morphometric characteristics. The results were obtained quickly, reliable and with scientific replication. Keywords: morphometry, water resources, geoprocessing. DOI: http://dx.doi.org/10.14583/2318-7670.v02n04a0