134 research outputs found

    The effects caused by the replacement of native riparian forest with Eucalyptus sp. on the benthic macro-invertebrate community.

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    The replacement of native riparian forests with exotic plants, especially Eucalyptus sp. can cause changes in ecological processes of small orders rivers. The leaves of Eucalyptus sp. have lower nutrients concentration, higher hardness and secondary metabolites which inhibit the decomposing micro-organisms and benthic macro-invertebrate colonization, which are the connection between the dead organic matter and the rest of the food chain. Thus the aim of the study was to test the following hypothesis: leaf decomposition rate will be lower in the substrate composed of Eucalyptus sp. leaves, when compared to the substrate composed of native tree species leaves; the benthic macro-invertebrates diversity will be lower in the substrate composed of Eucalyptus sp. leaves than the one composed of native tree species leaves. Sixty litter bags were used in the experiment, 30 of them were filled with 5 g of Eucalyptus sp leaves and the other 30 with a mixture of native trees leaves. From the results it was concluded that leaf decomposition rates were similar for both substrates, substrate composed of native trees leaves and substrate composed of Eucalyptus sp. leaves; the benthic macroinvertebrates diversity was lower in the substrate composed of Eucalyptus sp. leaves when compared to the substrate composed of native tree species leaves

    Uso de sensor óptico ativo para caracterização do perfil de NDVI em dosséis de trigo submetidos a diferentes estratégias de manejo.

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    Novas tecnologias associadas a sensores remotos têm sido usadas na cultura de trigo. Destaca-se a possibilidade de uso do monitoramento do cultivo em tempo real com indicadores que permitem estimar o vigor, potencial produtivo ou estado nutricional das plantas com base na reflectância do dossel. O uso de sensores ópticos ativos na pesquisa de trigo pode contribuir na caracterização de resposta de genótipos à práticas culturais, com posterior uso como suporte à tomada de decisão de manejo. Nesse sentido, em Passo Fundo, RS, na safra de inverno 2012, utilizou-se o sensor óptico ativo GreenSeeker® para avaliar linhagens de trigo passiveis de lançamento comercial pela Embrapa. Caracterizou-se os padrões de NDVI dos genótipos em ensaios de densidade de semeadura, doses de nitrogênio, estratégias de aplicação de nitrogênio em cobertura e aplicação de redutor de crescimento. O sensor óptico ativo GreenSeeker® é uma ferramenta importante para discriminação de diferenças de refletância entre dosséis de trigo. Tanto na comparação de genótipos quanto de práticas de manejo empregadas na cultura do trigo, o sensor óptico ativo, permite identificar precocemente diferenças de refletância entre dosséis, que estão associadas com práticas de manejo de cultivo. Ainda, caracteriza-se como uma avaliação não destrutiva e de fácil execução

    Perceived Stress Scale: Reliability and Validity Study in Greece

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    Objective: To translate the Perceived Stress Scale (versions PSS-4, -10 and -14) and to assess its psychometric properties in a sample of general Greek population. Methods: 941 individuals completed anonymously questionnaires comprising of PSS, the Depression Anxiety and Stress scale (DASS-21 version), and a list of stress-related symptoms. Psychometric properties of PSS were investigated by confirmatory factor analysis (construct validity), Cronbach’s alpha (reliability), and by investigating relations with the DASS-21 scores and the number of symptoms, across individuals’ characteristics. The two-factor structure of PSS-10 and PSS-14 was confirmed in our analysis. We found satisfactory Cronbach’s alpha values (0.82 for the full scale) for PSS-14 and PSS-10 and marginal satisfactory values for PSS-4 (0.69). PSS score exhibited high correlation coefficients with DASS-21 subscales scores, meaning stress (r = 0.64), depression (r = 0.61), and anxiety (r = 0.54). Women reported significantly more stress compared to men and divorced or widows compared to married or singled only. A strong significant (p < 0.001) positive correlation between the stress score and the number of self-reported symptoms was also noted. Conclusions: The Greek versions of the PSS-14 and PSS-10 exhibited satisfactory psychometric properties and their use for research and health care practice is warranted

    Fatores de risco para quedas em pacientes adultos hospitalizados: um estudo caso-controle

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    Objective: to identify risk factors for falls in hospitalized adult patients. Methods: a matched case-control study (one control for each case). A quantitative study conducted in clinical and surgical units of a teaching hospital in Southern Brazil. The sample comprised 358 patients. Data were collected over 18 months between 2013-2014. Data analysis was performed with descriptive statistics and conditional logistic regression using Microsoft Excel and SPSS version 18.0. Results: risk factors identified were: disorientation/confusion [OR 4.25 (1.99 to 9.08), p<0.001]; frequent urination [OR 4.50 (1.86 to 10.87), p=0.001]; walking limitation [OR 4.34 (2.05 to 9.14), p<0.001]; absence of caregiver [OR 0.37 (0.22 to 0.63), p<0.001]; postoperative period [OR 0.50 (0.26 to 0.94), p=0.03]; and number of medications administered within 72 hours prior the fall [OR 1.20 (1.04 to 1.39) p=0.01]. Conclusion: risk for falls is multifactorial. However, understanding these factors provides support to clinical decision-making and positively influences patient safety.Objetivo: identificar los factores de riesgo para la ocurrencia de caídas en pacientes adultos hospitalizados. Métodos: un estudio caso-control emparejado (un control para cada caso). Investigación cuantitativa llevada a cabo en unidades clínicas y quirúrgicas de un hospital universitario en el Sur de Brasil. La muestra constó de 358 pacientes. Se recopilaron datos durante 18 meses, entre 2013-2014. El análisis de los datos se realizó mediante estadística descriptiva y regresión logística condicional, utilizando el Microsoft Excel y el SPSS versión 18.0. Resultados: los factores de riesgo identificados fueron: desorientación/confusión [OR 4,25 (1,99 a 9,08), p<0,001]; micción frecuente [OR 4,50 (1,86 a 10,87), p=0,001]; limitación para caminar [OR 4,34 (2,05 a 9,14), p<0,001]; ausencia de cuidadores [OR 0,37 (0,22 a 0,63), p<0,001]; período postoperatorio [OR 0,50 (0,26 a 0,94), p=0,03]; y número de medicamentos administrados dentro de las 72 horas previas a la caída [OR 1,20 (1,04 a 1,39) p=0,01]. Conclusión: los riesgos de caídas son multifactoriales. Sin embargo, la comprensión de estos factores respalda la toma de decisiones clínicas y tiene un impacto positivo en la seguridad del paciente.Objetivo: identificar os fatores de risco para a ocorrência de quedas em pacientes adultos hospitalizados. Métodos: estudo do tipo caso-controle pareado (um controle para cada caso). Pesquisa quantitativa realizada em unidades clínicas e cirúrgicas de um hospital universitário da região Sul do Brasil. A amostra incluiu 358 pacientes. Os dados foram coletados durante 18 meses, entre 2013-2014. A análise dos dados foi realizada por meio de estatística descritiva e regressão logística condicional, utilizando o Microsoft Excel e o SPSS versão 18.0. Resultados: os fatores de risco identificados foram: desorientação/confusão [OR 4,25 (1,99 a 9,08), p<0,001]; micção frequente [OR 4,50 (1,86 a 10,87), p=0,001]; limitação para caminhar [OR 4,34 (2,05 a 9,14), p<0,001]; ausência de cuidador [OR 0,37 (0,22 a 0,63), p<0,001]; período pós-operatório [OR 0,50 (0,26 a 0,94), p=0,03]; e o número de medicamentos administrados nas 72 horas anteriores à queda [OR 1,20 (1,04 a 1,39) p=0,01]. Conclusão: os riscos para quedas são multifatoriais. Todavia, conhecê-los dá suporte à decisão clínica do enfermeiro, o que contribui para a busca das melhores intervenções preventivas e impacta positivamente na segurança dos pacientes

    Three versions of Perceived Stress Scale: validation in a sample of Chinese cardiac patients who smoke

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    <p>Abstract</p> <p>Background</p> <p>Smoking causes heart disease, the major cause of death in China and Hong Kong. Stress is one major trigger of smoking and relapse, and understanding stress among smoking cardiac patients can therefore help in designing effective interventions to motivate them to quit. The objective of this study was to examine the psychometric properties of the Perceived Stress Scale (PSS), and to compare the appropriateness of the three versions of the scale (PSS-14, PSS-10, and PSS-4) among Chinese cardiac patients who were also smokers.</p> <p>Methods</p> <p>From March 2002 to December 2004, 1860 cardiac patients who smoked were recruited at the cardiac outpatient clinics of ten acute hospitals in Hong Kong, and 1800 questionnaires were analysed. Participants completed a questionnaire including the PSS, nicotine dependence and certain demographic variables. The psychometric properties of the PSS were investigated: construct validity using confirmatory factor analysis, reliability using Cronbach's alpha and concurrent validity by examining the relationship with smoking- and health-related variables.</p> <p>Results</p> <p>For all the three versions of the PSS, confirmatory factor analyses corroborated the 2-factor structure of the scale, with the positive and negative factors correlating significantly and negatively to a moderate extent (<it>r </it>< -0.5), and high Cronbach's alpha values for the two subscales (alpha > 0.5). All the correlations of the two subscales and the smoking- and health-related variables were statistically significant and in the expected directions although of small magnitudes, except daily cigarette consumption.</p> <p>Conclusions</p> <p>The findings confirmed the satisfactory psychometric properties of all three Chinese versions of PSS. We recommend the use of PSS-10 for research which focuses on the two components of perceived stress, as it shows a higher reliability; and the use of PSS-4 if such partition is not essential and space for multiple measures is limited.</p

    In Vivo Manganese Exposure Modulates Erk, Akt and Darpp-32 in the Striatum of Developing Rats, and Impairs Their Motor Function

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    Abstract Manganese (Mn) is an essential metal for development and metabolism. However, exposures to high Mn levels may be toxic, especially to the central nervous system (CNS). Neurotoxicity is commonly due to occupational or environmental exposures leading to Mn accumulation in the basal ganglia and a Parkinsonian-like disorder. Younger individuals are more susceptible to Mn toxicity. Moreover, early exposure may represent a risk factor for the development of neurodegenerative diseases later in life. The present study was undertaken to investigate the developmental neurotoxicity in an in vivo model of immature rats exposed to Mn (5, 10 and 20 mg/kg; i.p.) from postnatal day 8 (PN8) to PN12. Neurochemical analysis was carried out on PN14. We focused on striatal alterations in intracellular signaling pathways, oxidative stress and cell death. Moreover, motor alterations as a result of early Mn exposure (PN8-12) were evaluated later in life at 3-, 4-and 5-weeks-ofage. Mn altered in a dose-dependent manner the activity of key cell signaling elements. Specifically, Mn increased the phosphorylation of DARPP-32-Thr-34, ERK1/2 and AKT. Additionally, Mn increased reactive oxygen species (ROS) production and caspase activity, and altered mitochondrial respiratory chain complexes I and II activities. Mn (10 and 20 mg/kg) also impaired motor coordination in the 3 rd , 4 th and 5 th week of life. Trolox TM , an antioxidant, reversed several of the Mn altered parameters, including the increased ROS production and ERK1/2 phosphorylation. However, Trolox TM failed to reverse the Mn (20 mg/kg)-induced increase in AKT phosphorylation and motor deficits. Additionally, Mn (20 mg/kg) decreased the distance, speed and grooming frequency in an open field test; Trolox TM blocked only the decrease of grooming frequency. Taken together, these results establish that short-term exposure to Mn during a specific developmental window (PN8-12) induces metabolic and neurochemical alterations in the striatum that may modulate later-life behavioral changes. Furthermore, some of the molecular and behavioral events, which are perturbed by early Mn exposure are not directly related to the production of oxidative stress
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