Implications of long-term land-use change for the hydrology and solute budgets of small catchments in Amazonia

The replacement of undisturbed tropical forest with cattle pasture has the potential to greatly modify the hydrology of small watersheds and the fluxes of solutes. We examined the fluxes of water, Cl(-), NO(3)(-)-N: SO(4)(2--)-S, NH(4)(+)-N, Na(+), K(+), Mg(2+) and Ca(2+) in different flow paths in similar to 1 ha catchments of undisturbed open tropical rainforest and a 20 year-old pasture established from forest in the southwestern Brazilian Amazon state of Rondonia. Storm flow discharge was 18% of incident rainfall in pasture, but only 1% in forest. Quickflow predominated over baseflow in both catchments and in both wet and dry seasons. In the pasture, groundwater and quickflow were important flow paths for the export of all solutes. In the forest, quickflow was important for NO(3)(-)-N export, but all other solutes were exported primarily by groundwater outflow. Both catchments were sinks for SO(4)(2-)-S and Ca(2+), and sources of Na(+). The pasture catchment also lost K(+) and Mg(2+) because of higher overland flow frequency and volume and to cattle excrement. These results show that forest clearing dramatically influences small watershed hydrology by increasing quickflow and water export to streams. They also indicate that tropical forest watersheds are highly conservative for most solutes but that pastures continue to lose important cations even decades after deforestation and pasture establishment. (c) 2008 Elsevier B.V. All rights reserved.

Discharge-calcium concentration relationships in streams of the Amazon and Cerrado of Brazil: soil or land use controlled

Stream discharge-concentration relationships are indicators of terrestrial ecosystem function. Throughout the Amazon and Cerrado regions of Brazil rapid changes in land use and land cover may be altering these hydrochemical relationships. The current analysis focuses on factors controlling the discharge-calcium (Ca) concentration relationship since previous research in these regions has demonstrated both positive and negative slopes in linear log(10)discharge-log(10)Ca concentration regressions. The objective of the current study was to evaluate factors controlling stream discharge-Ca concentration relationships including year, season, stream order, vegetation cover, land use, and soil classification. It was hypothesized that land use and soil class are the most critical attributes controlling discharge-Ca concentration relationships. A multilevel, linear regression approach was utilized with data from 28 streams throughout Brazil. These streams come from three distinct regions and varied broadly in watershed size (< 1 to > 10(6) ha) and discharge (10(-5.7)-10(3.2) m(3) s(-1)). Linear regressions of log(10)Ca versus log(10)discharge in 13 streams have a preponderance of negative slopes with only two streams having significant positive slopes. An ANOVA decomposition suggests the effect of discharge on Ca concentration is large but variable. Vegetation cover, which incorporates aspects of land use, explains the largest proportion of the variance in the effect of discharge on Ca followed by season and year. In contrast, stream order, land use, and soil class explain most of the variation in stream Ca concentration. In the current data set, soil class, which is related to lithology, has an important effect on Ca concentration but land use, likely through its effect on runoff concentration and hydrology, has a greater effect on discharge-concentration relationships.

Runoff sources and land cover change in the Amazon: an end-member mixing analysis from small watersheds

The flowpaths by which water moves from watersheds to streams has important consequences for the runoff dynamics and biogeochemistry of surface waters in the Amazon Basin. The clearing of Amazon forest to cattle pasture has the potential to change runoff sources to streams by shifting runoff to more surficial flow pathways. We applied end-member mixing analysis (EMMA) to 10 small watersheds throughout the Amazon in which solute composition of streamwater and groundwater, overland flow, soil solution, throughfall and rainwater were measured, largely as part of the Large-Scale Biosphere-Atmosphere Experiment in Amazonia. We found a range in the extent to which streamwater samples fell within the mixing space determined by potential flowpath end-members, suggesting that some water sources to streams were not sampled. The contribution of overland flow as a source of stream flow was greater in pasture watersheds than in forest watersheds of comparable size. Increases in overland flow contribution to pasture streams ranged in some cases from 0% in forest to 27-28% in pasture and were broadly consistent with results from hydrometric sampling of Amazon forest and pasture watersheds that indicate 17- to 18-fold increase in the overland flow contribution to stream flow in pastures. In forest, overland flow was an important contribution to stream flow (45-57%) in ephemeral streams where flows were dominated by stormflow. Overland flow contribution to stream flow decreased in importance with increasing watershed area, from 21 to 57% in forest and 60-89% in pasture watersheds of less than 10 ha to 0% in forest and 27-28% in pastures in watersheds greater than 100 ha. Soil solution contributions to stream flow were similar across watershed area and groundwater inputs generally increased in proportion to decreases in overland flow. Application of EMMA across multiple watersheds indicated patterns across gradients of stream size and land cover that were consistent with patterns determined by detailed hydrometric sampling.

Feasibility of Electronic Tap-Changing Stabilizers for Medium Voltage Lines-Precedents and New Configurations

Thyristor-based onload tap-changing ac voltage stabilizers are cheap and robust. They have replaced most mechanical tap-changers in low voltage applications from 300 VA to 300 M. Nevertheless, this replacement hardily applies to tap-changers associated to transformers feeding medium-voltage lines (typically 69 kV primary, 34.5 kV line, 10 MVA) which need periodical maintenance of contacts and oil. The Electric Power Research Institute (EPRI) has studied the feasibility of this replacement. It detected economical problems derived from the need for series association of thyristors to manage the high voltages involved, and from the current overload developed under line fault. The paper reviews the configurations used in that field and proposes new solutions, using a compensating transformer in the main circuit and multi-winding coils in the commutating circuit, with reduced overload effect and no series association of thyristors, drastically decreasing their number and rating. The stabilizer can be installed at any point of the line and the electronic circuit can be fixed to ground. Subsequent works study and synthesize several commutating circuits in detail.

Inhibition of immune complex-mediated neutrophil oxidative metabolism: A pharmacophore model for 3-phenylcoumarin derivatives using GRIND-based 3D-QSAR and 2D-QSAR procedures

In this study, twenty hydroxylated and acetoxylated 3-phenylcoumarin derivatives were evaluated as inhibitors of immune complex-stimulated neutrophil oxidative metabolism and possible modulators of the inflammatory tissue damage found in type III hypersensitivity reactions. By using lucigenin- and luminol-enhanced chemiluminescence assays (CL-luc and CL-lum, respectively), we found that the 6,7-dihydroxylated and 6,7-diacetoxylated 3-phenylcoumarin derivatives were the most effective inhibitors. Different structural features of the other compounds determined CL-luc and/or CL-lum inhibition. The 2D-QSAR analysis suggested the importance of hydrophobic contributions to explain these effects. In addition, a statistically significant 3D-QSAR model built applying GRIND descriptors allowed us to propose a virtual receptor site considering pharmacophoric regions and mutual distances. Furthermore, the 3-phenylcoumarins studied were not toxic to neutrophils under the assessed conditions. (C) 2007 Elsevier Masson SAS. All rights reserved.

Interval between surgery and neoadjuvant chemoradiation therapy for distal rectal cancer: Does delayed surgery have an impact on outcome?

Background: The optimal interval between neoadjuvant chemoradiation therapy (CRT) and surgery in the treatment of patients with distal rectal cancer is controversial. The purpose of this study is to evaluate whether this interval has an impact on survival. Methods and Materials: Patients who underwent surgery after CRT were retrospectively reviewed. Patients with a sustained complete clinical response (cCR) 1 year after CRT were excluded from this study. Clinical and pathologic characteristics and overall and disease-free survival were compared between patients undergoing surgery 12 weeks or less from CRT and patients undergoing surgery longer than 12 weeks from CRT completion and between patients with a surgery delay caused by a suspected cCR and those with a delay for other reasons. Results: Two hundred fifty patients underwent surgery, and 48.4% had CRT-to-surgery intervals of 12 weeks or less. There were no statistical differences in overall survival (86% vs. 81.6%) or disease-free survival rates (56.5% and 58.9%) between patients according to interval (<= 12 vs. >1 2 weeks). Patients with intervals of 12 weeks or less had significantly higher rates of Stage III disease (34% vs. 20%; p = 0.009). The delay in surgery was caused by a suspected cCR in 23 patients (interval, 48 +/- 10.3 weeks). Five-year overall and disease-free survival rates for this subset were 84.9% and 51.6%, not significantly different compared with the remaining group (84%; p = 0.96 and 57.8 %; p = 0.76, respectively). Conclusions: Delay in surgery for the evaluation of tumor response after neoadjuvant CRT is safe and does not negatively affect survival. These results support the hypothesis that shorter intervals may interrupt ongoing tumor necrosis. (C) 2008 Elsevier Inc.

Reticular angiomatoid ""malignant"" fibrous histiocytoma-a case report with cytogenetics and molecular genetic analyses

Angiomatoid ""malignant"" fibrous histiocytoma is a rare sarcoma of low malignant potential that occurs most commonly in the extremities of children and young adults. Herein, we present a case of angiomatoid malignant fibrous histiocytoma with unusual histologic features arising in the mediastinum of an 80-year-old man. The tumor exhibited a reticular growth pattern and myxoid stroma. The tumor cells expressed epithelial membrane antigen and desmin. Cytogenetic analysis revealed the translocation t(2;22)(q33;q12). Molecular genetic analysis confirmed the rearrangement of the EWSR1 locus and the presence of the EWSR1/CREB1 fusion. This report expands the clinicopathologic spectrum of angiomatoid malignant fibrous histiocytoma and underscores the value of integrating morphologic, immunophenotypic, and molecular findings in the identification of its unusual morphologic variants. (C) 2011 Elsevier Inc. All rights reserved.

The anti-MMP activity of benzalkonium chloride

Objective: This study evaluated the ability of benzalkonium chloride (BAC) to bind to dentine and to inhibit soluble recombinant MMPs and bound dentine matrix metalloproteinases (MMPs). Methods: Dentine powder was prepared from extracted human molars. Half was left mineralized; the other half was completely demineralized. The binding of BAG to dentine powder was followed by measuring changes in the supernatant concentration using UV spectrometry. The inhibitory effects of BAC on rhMMP-2, -8 and -9 were followed using a commercially available in vitro proteolytic assay. Matrix-bound endogenous MMP-activity was evaluated in completely demineralized beams. Each beam was either dipped into BAG and then dropped into 1 mL of a complete medium (CM) or they were placed in 1 mL of CM containing BAG for 30 days. After 30 days, changes in the dry mass of the beams or in the hydroxyproline (HYP) content of hydrolysates of the media were quantitated as indirect measures of matrix collagen hydrolysis by MMPs. Results: Demineralized dentine powder took up 10-times more BAG than did mineralized powder. Water rinsing removed about 50% of the bound BAC, whilst rinsing with 0.5 M NaCl removed more than 90% of the bound BAG. BAG concentrations 0.5 wt% produced 100% inhibition of soluble recombinant MMP-2, -8 or -9, and inhibited matrix-bound MMPs between 55 and 66% when measured as mass loss or 76-81% when measured as solubilization of collagen peptide fragments. Conclusions: BAC is effective at inhibiting both soluble recombinant MMPs and matrix-bound dentine MMPs in the absence of resins. (C) 2010 Elsevier Ltd. All rights reserved.

Modelagem e simulação de um secador intermitente de fluxos contracorrentes para frutos do cafeeiro

Este trabalho foi realizado com o objetivo de desenvolver um modelo computacional para simular a secagem de frutos café em um secador intermitente de fluxos contracorrente, empregando a linguagem de simulação EXTEND™ e o Modelo de Thompson (THOMPSON; PEART; FOSTER, 1968). Para validação do modelo desenvolvido foram utilizados dados experimentais obtidos por Silva (1991), em que foram empregados três níveis de temperatura do ar de secagem de 60, 80 e 100 °C. O modelo desenvolvido foi validado, sendo constatados desvios absolutos de 1,8% b.u e 1,1 kg e erros relativos de 11% e 1,6% na previsão dos parâmetros teor de água final e consumo de lenha, respectivamente. O modelo validado foi empregado na condução de experimentos tipo comparação de cenários. O primeiro experimento refere a alterações do ciclo operacional em que foram alterados os tempos de movimentação e de parada do fluxo da massa de grãos. E o segundo refere à alteração da configuração do secador quanto às alturas das câmaras de secagem e descanso. O ciclo operacional com os tempos de movimentação de um minuto e de parada de dezesseis minutos, para a temperatura do ar de secagem de 100 °C, proporcionou o melhor desempenho, sendo constatado tempo secagem de 12,3 h, consumo de lenha de 109,5 kg, consumo específico de energia de 7660 kJ.kg-1 de água evaporada, e capacidade de secagem de 87,86 kg.h-1. Quanto à configuração do secador, o melhor desempenho ocorreu para altura da câmara de secagem de 2,3 m usando a temperatura do ar de secagem de 100 °C, em que foram simulados tempo de secagem de 12,0 h, consumo de lenha de 106,5 kg, consumo específico de energia, de 7433 kJ.kg-1 de água evaporada, e capacidade de secagem de 90 kg.h-1. Desse modo, na condução da secagem de frutos de café em um secador intermitente de fluxos contracorrentes é recomendado o ciclo operacional com tempos de movimentação de um minuto e o de parada de dezesseis minutos, e não empregar a câmara de descanso. Essa conclusão está fundamentada em índices de desempenho do secador. Ressalta-se que não foram simulados os impactos nos parâmetros de qualidade.

Apresentação do primeiro caso autóctone de doença de Chagas diagnosticado no Estado de Santa Catarina, Brasil

Apresentação do primeiro caso de doença de Chagas, diagnosticado no município de Gaspar, Estado de Santa Catarina, Brasil. Como não se conseguiu demonstrar a presença de triatomíneos na região, não foi possível determinar especìficamente o mecanismo de transmissão.

Modelos matemáticos de localização aplicados à organização espacial de unidades de saúde

Modelos matemáticos de localização têm tido aplicação crescente na área de saúde em nível internacional. No Brasil, embora de uso incipiente, existe enorme potencial para a utilização desses modelos na área de saúde pública. Nesse sentido são apresentados diversos modelos de localização com aplicação em saúde pública, analisando a localização de serviços não emergenciais, de serviços de emergência e a localização de serviços hierarquicamente relacionados. Mostrou-se a aplicação de um modelo hierárquico à localização de serviços de assistência materna e perinatal no Município do Rio de Janeiro, RJ (Brasil). Nesta parte, após a apresentação de alguns dados da assistência materna e perinatal no município, foi proposto um modelo hierárquico de quatro níveis (localização de unidades ambulatoriais, maternidades, centros de neonatologia e hospitais gerais) e analisado o impacto que a adoção da metodologia teria em comparação com o sistema atual.

Hospitais filantrópicos e a operação de planos de saúde próprios no Brasil

OBJETIVO: Descrever o desempenho gerencial de hospitais filantrópicos com operadoras de planos de saúde em comparação com o conjunto de hospitais filantrópicos no Brasil. MÉTODOS: Foram comparadas as estruturas gerenciais presentes nos hospitais filantrópicos com operadoras próprias de planos de saúde com aquelas observadas num conjunto representativo do setor hospitalar filantrópico, em seis dimensões: direção e planejamento, econômico-financeira, recursos humanos, serviços técnicos, serviços logísticos e tecnologia de informações. Consideraram-se os dados de uma amostra aleatória de 69 hospitais, extraída do setor hospitalar filantrópico, e 94 hospitais filantrópicos com operadoras próprias de planos de saúde. Nos dois casos incluíram-se apenas os hospitais com menos de 599 leitos. RESULTADOS: Foram identificados resultados mais positivos para o conjunto de hospitais com operadoras próprias de planos de saúde em todas as dimensões gerenciais comparadas. Em particular, destacaram-se as dimensões econômico-financeira e de tecnologia de informações, nas quais mais de 50% dos hospitais com operadoras apresentaram quase todas as condições consideradas. CONCLUSÕES: O setor hospitalar filantrópico é importante na prestação de serviços ao Sistema Único de Saúde. Os desafios para a sua manutenção e desenvolvimento impõem encontrar alternativas. O fomento de uma parceria público-privado neste segmento, por meio da operação de planos próprios ou prestação de serviços a outros planos de saúde convivendo com o SUS, constitui um campo que merece uma análise mais aprofundada.

Mecanismos de microrregulação aplicados por operadoras de planos de saúde sobre hospitais privados

OBJETIVO: Analisar os mecanismos de microrregulação aplicados pelas operadoras de planos de saúde nas práticas de gestão da clínica e de qualificação assistencial em hospitais prestadores de serviços. MÉTODOS: Estudo transversal realizado em inquérito de abrangência nacional, cujo universo foi constituído pelos hospitais prestadores de serviços às operadoras de planos de saúde em 2006. Foi construída uma amostra de 83 unidades, estratificada segundo macrorregião do Brasil e tipo de hospital. Os dados foram obtidos por meio de aplicação de questionário em entrevista aos dirigentes dos hospitais. RESULTADOS: A microrregulação que as operadoras de planos de saúde exercem sobre os hospitais em termos da qualificação da assistência foi muito baixa ou quase nula. A atuação das operadoras foi majoritariamente destinada ao intenso controle da quantidade de serviços utilizados pelos pacientes. Os hospitais que prestavam serviços a operadoras de planos de saúde não constituíam micro-sistemas de saúde paralelos ou suplementares ao Sistema Único de Saúde (SUS). Observou-se que os prestadores hospitalares privados eram majoritariamente vinculados ao SUS. Entretanto, não pertenciam à rede alguma de prestadores privados, ainda que fossem objeto de forte regulação da utilização de seus serviços, exercida pelas operadoras de planos de saúde. A intervenção das operadoras de planos de saúde enquanto gestoras de sistemas de cuidado foi incipiente ou quase ausente. Aproximadamente a metade dos hospitais declarou adotar diretrizes clínicas, enquanto apenas 25,4% afirmaram exercer a gestão da patologia e 30,5% mencionaram a gestão dos casos. CONCLUSÕES: As relações contratuais entre hospitais e operadoras de planos de saúde se constituem em contratos meramente comerciais com pouca ou nenhuma incorporação de aspectos relativos à qualidade da assistência contratada, limitando-se, em geral, a aspectos como definição de valores, de prazos e procedimentos para pagamento.

Demonstração dos resultados dos projetos ALFA LEAL e RexNet

O presente artigo descreve o âmbito, objetivos, atividades e resultados obtidos nos projetos LEAL e RexNet, fi nanciados pelo programa América Latina – Formação Acadêmica (ALFA), da Comissão Européia (CE). O aspecto mais relevante consistiu na realização de atividades conjuntas que permitiram estabelecer e fortalecer laços de cooperação entre as duas redes, cada uma constituída por mais de dez Instituições de Ensino Superior (IES) da Europa e da América Latina. É de realçar ainda a realização de um workshop conjunto integrado na Conferência Internacional em Aprendizagem Interativa e Combinada Auxiliada por Computador (ICBL’07) que decorreu em Florianópolis, Santa Catarina, Brasil, em Maio de 2007, sob a organização do CEFET/SC.