212 research outputs found

    Electrochemical behavior of parent and photodegradation products of some selected pesticides

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    Electrochemical behavior of pesticides is extensively studied, but little attention has been given to the study of their degradation products (by-products) by electrochemical methods. However, the degradation products of pesticides can be even more toxic then the parent products and such studies should be encouraged. Therefore, the objective of this work was to evaluate the electroactivity of by-products of imazaquin, methylparathion, bentazon and atrazine, generated by UV irradiation and measured using cyclic and differential pulse voltammetry and UV-visible absorption spectrophotometry. Results have shown that several by-products exhibit electroactivity, allowing, in some cases, the simultaneous determination of both parent and degradation products.EMBRAPACoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)CNPqFAPES

    A importância das políticas de base territorial para evitar os cenários de risco de má nutrição em maiores de 64 anos em Vila Nova de Gaia - estudo de caso nas três freguesias de Valadares, Vilar do Paraíso e Madalena

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    No âmbito do projeto PRONUTRISENIOR (EEA Grant-81NU5) procurou-se desenvolver um índice de risco geonutricional para maiores de 64 anos residentes em Vila Nova de Gaia (VNG) nas freguesias de Valadares, Vilar do Paraíso e Madalena. Para este trabalho foi realizada uma avaliação do território de intervenção da Unidade de Saúde Familiar Nova Via (USF-NV), com o intuito de identificar as principais determinantes geográficas que possam explicar os resultados da avaliação nutricional de uma amostra de 602 utentes da USF-NV maiores de 64 anos (19,6% do universo de utentes maiores de 64 anos). A análise cruzada das características biogeofísicas e socioeconómicas das 3 freguesias, da localização dos fornecedores de alimentos (185) e dos diversos fornecedores de apoio social aos idosos (18), conduziu à identificação preliminar de algumas das variáveis-chave para a caracterização da vulnerabilidade social, económica e ambiental e posteriormente, com suporte na análise hierárquica de processos, caracterizar o risco geonutricional para os idosos destas freguesias. Os resultados preliminares mostram a importância de contemplar no ordenamento territorial o potencial multifinalitário de cada decisão e a necessidade de convocar para a reflexão as especificidades de cada combinação people & place nas suas múltiplas dimensões, se o objetivo for a promoção de contextos saudáveis de vida

    Measurement of the Ge 70 (n,γ) cross section up to 300 keV at the CERN n-TOF facility

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    ©2019 American Physical Society.Neutron capture data on intermediate mass nuclei are of key importance to nucleosynthesis in the weak component of the slow neutron capture processes, which occurs in massive stars. The (n,γ) cross section on Ge70, which is mainly produced in the s process, was measured at the neutron time-of-flight facility n-TOF at CERN. Resonance capture kernels were determined up to 40 keV neutron energy and average cross sections up to 300 keV. Stellar cross sections were calculated from kT=5 keV to kT=100 keV and are in very good agreement with a previous measurement by Walter and Beer (1985) and recent evaluations. Average cross sections are in agreement with Walter and Beer (1985) over most of the neutron energy range covered, while they are systematically smaller for neutron energies above 150 keV. We have calculated isotopic abundances produced in s-process environments in a 25 solar mass star for two initial metallicities (below solar and close to solar). While the low metallicity model reproduces best the solar system germanium isotopic abundances, the close to solar model shows a good global match to solar system abundances in the range of mass numbers A=60-80.Peer reviewedFinal Published versio

    Association of Accelerometry-Measured Physical Activity and Cardiovascular Events in Mobility-Limited Older Adults: The LIFE (Lifestyle Interventions and Independence for Elders) Study.

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    BACKGROUND:Data are sparse regarding the value of physical activity (PA) surveillance among older adults-particularly among those with mobility limitations. The objective of this study was to examine longitudinal associations between objectively measured daily PA and the incidence of cardiovascular events among older adults in the LIFE (Lifestyle Interventions and Independence for Elders) study. METHODS AND RESULTS:Cardiovascular events were adjudicated based on medical records review, and cardiovascular risk factors were controlled for in the analysis. Home-based activity data were collected by hip-worn accelerometers at baseline and at 6, 12, and 24 months postrandomization to either a physical activity or health education intervention. LIFE study participants (n=1590; age 78.9±5.2 [SD] years; 67.2% women) at baseline had an 11% lower incidence of experiencing a subsequent cardiovascular event per 500 steps taken per day based on activity data (hazard ratio, 0.89; 95% confidence interval, 0.84-0.96; P=0.001). At baseline, every 30 minutes spent performing activities ≥500 counts per minute (hazard ratio, 0.75; confidence interval, 0.65-0.89 [P=0.001]) were also associated with a lower incidence of cardiovascular events. Throughout follow-up (6, 12, and 24 months), both the number of steps per day (per 500 steps; hazard ratio, 0.90, confidence interval, 0.85-0.96 [P=0.001]) and duration of activity ≥500 counts per minute (per 30 minutes; hazard ratio, 0.76; confidence interval, 0.63-0.90 [P=0.002]) were significantly associated with lower cardiovascular event rates. CONCLUSIONS:Objective measurements of physical activity via accelerometry were associated with cardiovascular events among older adults with limited mobility (summary score >10 on the Short Physical Performance Battery) both using baseline and longitudinal data. CLINICAL TRIAL REGISTRATION:URL: http://www.clinicaltrials.gov. Unique identifier: NCT01072500

    Computer-assisted tomography for studies of an Albaqualf

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    Na busca de técnicas mais apuradas para a determinação e avaliação de parâmetros físicos do solo com aplicabilidade em várzeas, vem se destacando a tomografia computadorizada, por medir a densidade e a umidade com boa sensibilidade e alta resolução espacial. O presente trabalho teve como objetivo descrever aspectos e procedimentos da calibração de um minitomógrafo de raios-X e gama para estudo da densidade e umidade de um Planossolo no Rio Grande do Sul, bem como estabelecer parâmetros estatísticos para sua adequada utilização. A calibração do minitomógrafo foi obtida pela regressão linear entre as unidades tomográficas (UT), apresentadas pelo programa de reconstrução de imagem, e os coeficientes de atenuação linear (µl, cm-1), medidos por transmissão direta de raios gama, em amostras dos horizontes A e B do Planossolo, água destilada, benzina e alumínio. Para as medidas de transmissão direta de radiação utilizaram-se recipientes com água destilada, benzina, solo e Al, obtendo-se as seguintes fórmulas para o cálculo da densidade do solo no horizonte A: Ds = [(UT/986,16)-(0,200xq)]/0,267; e no horizonte B: Ds = [(UT/986,16)-(0,200xq)]/0,297, em que UT é o valor médio de UT em cada linha e q é a umidade volumétrica da amostra de solo, em m3 m-3. Com as configurações obtidas, verificou-se variabilidade média de 2,74% e 0,73%, respectivamente, em termos de homogeneidade e repetibilidade. Os erros atribuídos ao equipamento são de 0,051 e 0,046 Mg m-3, respectivamente, nos horizontes A e B, revelando precisão e adaptabilidade no emprego da técnica em estudos do Planossolo._________________________________________________________________________________ ABSTRACT: In order to find better techniques to evaluate the soil physical parameters applied to lowland soils, the computerized tomography has been used to measure soil density and water content with accuracy and high spatial resolution. This work was carried out in order to describe features and calibration procedures of a computerized minitomographer using X-ray and gama-rays as sources of radiation and to establish suitable statistical parameters on the study of soil bulk density and water content in a Planosol (Albaqualf) from Rio Grande do Sul State, Brazil. The minitomographer calibration was obtained from the linear regression equation among the tomography's unities (TU) presented by the image reconstruction program and the linear attenuation coefficient (µl, cm-1), by the measurement of direct transmission of g-rays as source of radiation in soil samples from A and B horizons, distilled water, benzin and aluminum. In order to get measures of the direct radiation transmission, containers with distilled water, benzin, soil and aluminum were used to obtain the following equations to calculate soil bulk density in the A horizon: Ds = [(TU/986.16)-(0.200xq)]/0.267 and in the B horizon: Ds = [(TU/986.16)-(0.200xq)]/0.297, where TU is the mean value in the line and q is the soil volumetric water content (m3 m-3). The obtained configurations allowed to attain average variabilities of 2.74% and 0.73% for homogeneity and repeatability, respectively. The expected errors related to the equipment are 0.051 and 0.046 Mg m-3, to the A and B horizons, respectively. The results showed the technique accuracy and adaptability in the studies of the physical characteristics of a Planosol

    Lower Richness of Small Wild Mammal Species and Chagas Disease Risk

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    A new epidemiological scenario involving the oral transmission of Chagas disease, mainly in the Amazon basin, requires innovative control measures. Geospatial analyses of the Trypanosoma cruzi transmission cycle in the wild mammals have been scarce. We applied interpolation and map algebra methods to evaluate mammalian fauna variables related to small wild mammals and the T. cruzi infection pattern in dogs to identify hotspot areas of transmission. We also evaluated the use of dogs as sentinels of epidemiological risk of Chagas disease. Dogs (n = 649) were examined by two parasitological and three distinct serological assays. kDNA amplification was performed in patent infections, although the infection was mainly sub-patent in dogs. The distribution of T. cruzi infection in dogs was not homogeneous, ranging from 11–89% in different localities. The interpolation method and map algebra were employed to test the associations between the lower richness in mammal species and the risk of exposure of dogs to T. cruzi infection. Geospatial analysis indicated that the reduction of the mammal fauna (richness and abundance) was associated with higher parasitemia in small wild mammals and higher exposure of dogs to infection. A Generalized Linear Model (GLM) demonstrated that species richness and positive hemocultures in wild mammals were associated with T. cruzi infection in dogs. Domestic canine infection rates differed significantly between areas with and without Chagas disease outbreaks (Chi-squared test). Geospatial analysis by interpolation and map algebra methods proved to be a powerful tool in the evaluation of areas of T. cruzi transmission. Dog infection was shown to not only be an efficient indicator of reduction of wild mammalian fauna richness but to also act as a signal for the presence of small wild mammals with high parasitemia. The lower richness of small mammal species is discussed as a risk factor for the re-emergence of Chagas disease

    Cell Pattern in Adult Human Corneal Endothelium

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    A review of the current data on the cell density of normal adult human endothelial cells was carried out in order to establish some common parameters appearing in the different considered populations. From the analysis of cell growth patterns, it is inferred that the cell aging rate is similar for each of the different considered populations. Also, the morphology, the cell distribution and the tendency to hexagonallity are studied. The results are consistent with the hypothesis that this phenomenon is analogous with cell behavior in other structures such as dry foams and grains in polycrystalline materials. Therefore, its driving force may be controlled by the surface tension and the mobility of the boundaries

    Dietary factors associated with metabolic syndrome in Brazilian adults

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    <p>Abstract</p> <p>Background</p> <p>Metabolic Syndrome (MS) is defined as the association of numerous factors that increase cardiovascular risk and diet is one of the main factors related to increase the MS in the population. This study aimed to evaluate the association of diet on the presence of MS in an adult population sample.</p> <p>Methodology</p> <p>305 adults were clinically screened to participate in a lifestyle modification program. Anthropometric assessments included waist circumference (WC), body fat and calculated BMI (kg/m<sup>2</sup>) and muscle-mass index (MMI kg/m<sup>2</sup>). Dietary intake was estimated by 24 h dietary recall. Fasting blood was used for biochemical analysis. MS was diagnosed using NCEP-ATPIII (2001) criteria with adaptation for glucose (≥ 100 mg/dL). Logistic regression (Odds ratio) was performed in order to determine the odds ratio for developing MS according to dietary intake.</p> <p>Results</p> <p>An adequate intake of fruits, OR = 0.52 (CI:0.28-0.98), and an intake of more than 8 different items in the diet (variety), OR = 0.31 (CI:0.12-0.79) showed to be a protective factor against a diagnosis of MS. Saturated fat intake greater than 10% of total caloric value represented a risk for MS diagnosis, OR = 2.0 (1.04-3.84).</p> <p>Conclusion</p> <p>Regarding the dietary aspect, a risk factor for MS was higher intake of saturated fat, and protective factors were high diet variety and adequate fruit intake.</p
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