956 research outputs found
Effect of selenization conditions on the growth and properties of Cu2ZnSn(S,Se)4 thin films
The opto-electronic properties of copper zinc tin sulfide can be tuned to achieve better cell efficiencies by controlled incorporation of selenium. In this paper we report the growth of Cu2ZnSn(S,Se)4 (CZTSSe) using a hybrid process involving the sequential evaporation of Zn and sputtering of the sulfide precursors of Cu and Sn, followed by a selenization step. Two approaches for selenization were followed, one using a tubular furnace and the other using a rapid thermal processor. The effects of annealing conditions on the morphological and structural properties of the films were investigated. Scanning electron microscopy and energy dispersive spectroscopy were employed to investigate the morphology and composition of the films. Structural analyses were done using X-ray diffraction (XRD) and Raman spectroscopy. Structural analyses revealed the formation of CZTSSe. This study shows that regardless of the selenization method a temperature above 450 °C is required for conversion of precursors to a compact CZTSSe layer. XRD and Raman analysis suggests that the films selenized in the tubular furnace are selenium rich whereas the samples selenized in the rapid thermal processor have higher sulfur content
Limited risk of Zika virus transmission by five Aedes albopictus populations from Spain
Background: Aedes albopictus, the Asian tiger mosquito, is an exotic invasive species in Europe. It has substantial public health relevance due to its potential role in transmitting several human pathogens. Out of the European countries, Spain has one of the highest risk levels of autochthonous arbovirus transmission due to both the high density of Ae. albopictus and the extensive tourist influx from vector-endemic areas. This study aims to investigate the susceptibility of five Ae. albopictus populations from mainland Spain and the Balearic Islands to a Brazilian Zika virus (ZIKV) strain. Methods: The F1 generation of each Ae. albopictus population was orally challenged with a ZIKV-infected blood meal (1.8 × 10 PFU/ml). At 7 and 14 days post-infection (dpi), mosquito bodies (thorax and abdomen) and heads were individually analysed through RT-qPCR to determine the infection rate (IR) and dissemination rate (DR), respectively. The saliva of infected mosquitoes was inoculated in Vero cells and the transmission rate was assessed by plaque assay or RT-qPCR on ∼33 individuals per population. Results: The IR and DR ranged between 12-88%, and 0-60%, respectively, suggesting that ZIKV is capable of crossing the midgut barrier. Remarkably, no infectious viral particle was found in saliva samples, indicating a low ability of ZIKV to overcome the salivary gland barrier. A subsequent assay revealed that a second non-infective blood meal 48 h after ZIKV exposure did not influence Ae. albopictus vector competence. Conclusions: The oral experimental ZIKV infections performed here indicate that Ae. albopictus from Spain become infected and disseminate the virus through the body but has a limited ability to transmit the Brazilian ZIKV strain through biting. Therefore, the results suggest a limited risk of autochthonous ZIKV transmission in Spain by Ae. albopictus
GOOD WATER, BUT FOR WHOM? A STUDY ON THE PERCEPTION OF WATER QUALITY BY AMAZONIAN POPULATIONS
In Brazil different regions have inadequate water and sewage treatment facilities, which can be made worse by the installation of large enterprises. The perception of these populations about the scenario in which they live is of great relevance in this context, the present study has the objective of analyzing the socioenvironmental profile and the perception of the water quality and its relation to health damage by populations resident from the area of Belo Monte hydropower plant. A cross-sectional study was conducted with 268 residents of two cities in the interior of Pará-Brazil and the data were obtained from the application of a semi-structured questionnaire. The results showed that the interviewees had minimal education and were low income. Most interviewees reported having running water in their home. However, 63.1% of the interviewees considered the water provided as organoleptically altered and of poor quality. Of the interviewees, 92.5% stated that their water is mainly from wells; 94.8% perceived a relationship between decreasing water quality and increasing health problems. Of these, 85.2% related to the decrease in water quality with renal problems, 75% with liver problems and 28% with hypertension. About 61.6% of respondents reported concerns about lack of basic sanitation. It is concluded that the populations studied understand the importance of quality water consumption and relate water quality to health problems. Therefore, these results serve as an alert to managers regarding the urgent need to improve the quality of life of this population.
Keywords: Pará, sewage systems, drinking water, health, chronic disease.
RESUMO :No Brasil, diferentes regiões têm instalações inadequadas de tratamento de água e esgoto, o que pode ser agravado pela instalação de grandes empresas. A percepção dessas populações sobre o cenário em que vivem é de grande relevância neste contexto, o presente estudo tem como objetivo analisar o perfil socioambiental e a percepção da qualidade da água e sua relação com danos à saúde por populações residentes da área. da usina hidrelétrica de Belo Monte. Um estudo transversal foi realizado com 268 moradores de duas cidades do interior do Pará-Brasil e os dados foram obtidos a partir da aplicação de um questionário semiestruturado. Os resultados mostraram que os entrevistados tinham educação mínima e baixa renda. A maioria dos entrevistados relatou ter água encanada em casa. No entanto, 63,1% dos entrevistados consideraram a água fornecida como organoléptica- mente alterada e de má qualidade. Dos entrevistados, 92,5% afirmaram que a água é proveniente principalmente de poços; 94,8% perceberam uma relação entre diminuir a qualidade da água e aumentar os problemas de saúde. Destes, 85,2% relacionaram-se à diminuição da qualidade da água com problemas renais, 75% com problemas hepáticos e 28% com hipertensão. Cerca de 61,6% dos entrevistados relataram preocupações sobre a falta de saneamento básico. Conclui-se que as populações estudadas entendem a importância do consumo de água de qualidade e relacionam a qualidade da água a problemas de saúde. Portanto, esses resultados servem de alerta para os gestores quanto à necessidade urgente de melhorar a qualidade de vida dessa população.
Palavras-chave: Pará, sistemas de esgoto, água potável, saúde, doença crônic
Clinical outcomes of patients with acute myeloid leukemia: evaluation of genetic and molecular findings in a real-life setting
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Branch and bound based coordinate search filter algorithm for nonsmooth nonconvex mixed-integer nonlinear programming problems
Publicado em "Computational science and its applications – ICCSA 2014...", ISBN 978-3-319-09128-0. Series "Lecture notes in computer science", ISSN 0302-9743, vol. 8580.A mixed-integer nonlinear programming problem (MINLP) is a problem with continuous and integer variables and at least, one nonlinear function. This kind of problem appears in a wide range of real applications and is very difficult to solve. The difficulties are due to the nonlinearities of the functions in the problem and the integrality restrictions on some variables. When they are nonconvex then they are the most difficult to solve above all. We present a methodology to solve nonsmooth nonconvex MINLP problems based on a branch and bound paradigm and a stochastic strategy. To solve the relaxed subproblems at each node of the branch and bound tree search, an algorithm based on a multistart strategy with a coordinate search filter methodology is implemented. The produced numerical results show the robustness of the proposed methodology.This work has been supported by FCT (Fundação para a Ciência e aTecnologia) in the scope of the projects: PEst-OE/MAT/UI0013/2014 and PEst-OE/EEI/UI0319/2014
Estimación de caudales ecológicos basada en simulación del hábitat físico en un pequeño río del sudeste de Brasil
El método de simulación del hábitat físico, integrado en el marco de la metodología IFIM (Instream Flow Incremental Methodology) y en otros marcos metodológicos hoy día, utiliza variables hidráulicas e índices de idoneidad del hábitat (a escala de microhábitat) para predecir los cambios potenciales del hábitat al cambiar el caudal circulante. Este enfoque se ha utilizado para simular los cambios potenciales de idoneidad del hábitat para tres especies de peces tropicales de diferentes órdenes, Bryconamericus ornaticeps, Ancistrus multispinis y Geophagus brasiliensis. El estudio se realizó en dos tramos de un río en la zona de mata atlántica al sudeste de Brasil, durante el verano de 2013 e invierno de 2014. Se midieron las características topográficas e hidráulicas por transectos (calado, velocidad media, tipos de sustrato) y se estudió el uso del microhábitat por los peces mediante observación directa bajo el agua (snorkelling); esto permitió elaborar curvas de idoneidad de microhábitat para las tres especies. Mediante la simulación del hábitat físico se obtuvieron las curvas que relacionan dos indicadores, el HSI (indice medio de idoneidad en un tramo), y el HPU (Hábitat Potencial Útil) con el caudal del río. Sobre dichas curvas se observaron los caudales importantes para el mantenimiento de los hábitats de las tres especies. Los resultados indicaron un caudal mínimo-minimorum de 0.25 m3 s-1 en época seca para conservar el hábitat de los peces. También se determinó un rango óptimo de 0.65-0.85 m3 s-1 para el hábitat de las tres especies. Los resultados pueden apoyar la elaboración de una primera propuesta de régimen ecológico de caudales, en el marco de un proceso de gestión adaptativa de los recursos hídricos, para conservar la salud del río São Pedro y los diversos servicios ecosistémicos que aporta a la sociedad.Da Costa, M.; Moretti Mattos, T.; Muñoz Mas, R.; Martinez-Capel, F.; Fernandes, V.; Aráujo, F. (2015). Estimación de caudales ecológicos basada en simulación del hábitat físico en un pequeño río del sudeste de Brasil. Cuadernos de la Sociedad Española de Ciencias Forestales. (41):245-252. http://hdl.handle.net/10251/60209S2452524
Alcohol use and cognitive functioning in young adults : improving causal inference
Background and Aims: There have been few longitudinal studies of association between alcohol use and cognitive functioning in young people. We aimed to examine whether alcohol use is a causal risk factor for deficient cognitive functioning in young adults.
Design: Linear regression was used to examine the relationship between longitudinal latent class patterns of binge drinking and subsequent cognitive functioning. Two-sample Mendelian randomisation (MR) tested evidence for the causal relationship between alcohol use and cognitive functioning.
Setting: South West England.
Participants: The observational study included 3,155 adolescents and their parents (fully adjusted models) from the Avon Longitudinal Study of Parents and Children (ALSPAC). Genetic instruments for alcohol use were based on almost 1,000,000 individuals from the GWAS & Sequencing Consortium of Alcohol and Nicotine use (GSCAN). Genome-wide association studies for cognitive outcomes were based on 2,500 individuals from ALSPAC.
Measurements: Binge drinking was assessed at approximately 16, 17, 18, 21, and 23 years. Cognitive functioning comprised working memory, response inhibition, and emotion recognition assessed at 24 years of age. Ninety-nine independent genome-wide significant SNPs associated with ‘number of drinks per week’ were used as the genetic instrument for alcohol consumption. Potential confounders were included in the observational analyses.
Findings: Four binge drinking classes were identified: ‘low-risk’ (41%), ‘early-onset monthly’ (19%), ‘adult frequent’ (23%), and ‘early-onset frequent’ (17%). The association between early-onset frequent binge drinking and cognitive functioning: working memory (b=0.09, 95%CI=-0.10 to 0.28), response inhibition (b=0.70, 95%CI=-10.55 to 11.95), and emotion recognition (b=0.01, 95%CI=-0.01 to 0.02) in comparison to low-risk drinkers were inconclusive as to whether a difference was present. Two-sample MR analyses similarly provided little evidence that alcohol use is associated with deficits in working memory using the inverse variance weight (b=0.29, 95%CI=-0.42 to 0.99), response inhibition (b=-0.32, 95%CI=-1.04 to 0.39), and emotion recognition (b=0.03, 95%CI=-0.55 to 0.61).
Conclusions: Binge drinking in adolescence and early adulthood may not be causally related to deficiencies in working memory, response inhibition, or emotion recognition in youths
Plantio direto, adubação verde e suplementação com esterco de aves na produção orgânica de berinjela.
Sob manejo orgânico, foram avaliados, em Seropédica, RJ, os sistemas de plantio direto da berinjela(Solanum melongena) nas palhadas de Crotalaria juncea (crotalária), Pennisetum glaucum (milheto, cv. BRS 1501)e vegetação espontânea (pousio), em comparação com o plantio convencional (aração e gradagem ou enxada rotativa). Simultaneamente, foram avaliados três tipos de cultivo: berinjela em monocultura, em consórcio com crotalária e em consórcio com caupi (Vigna unguiculata, cv. Mauá). Não houve diferença entre os sistemas de plantio direto e convencional quanto à produção comercial da berinjela. A palhada da crotalária foi mais eficiente que a do milheto e do pousio para cobertura morta do solo e conseqüentemente o controle de plantas espontâneas foi maior. O cultivo simultâneo com as leguminosas não acarretou redução da produtividade da berinjela.Em um segundo estudo, foram comparados plantio direto (palhadas de crotalária e da vegetação espontânea) e plantio convencional, combinados com doses crescentes de cama de aviário (0, 100, 200 e 400 kg ha-1 de N)aplicada em cobertura. Em termos de aporte de biomassa, a crotalária foi novamente superior à vegetação espontânea.A berinjela respondeu à adubação orgânica, com produtividade máxima de 50,6 t ha-1 , correspondendo à maior dose empregada, contra 36,9 t ha-1 referentes ao controle
Investigation of the Mechanisms Underlying the Gastroprotective Effect of Cymbopogon Citratus Essential Oil
Cymbopogon citratus is a medicinal plant popularly used in Brazil for the treatment of various diseases, and the research interest in this plant is justifiable because of its potential medicinal value in stomachache and gastric ulcer. This study was aimed to test the validity of this practice by using experimental models of gastric ulcer and to clarify the mechanisms of gastroprotection by C. citratus leaves essential oil (EOCC). EOCC was evaluated for the ability to protect the gastric mucosa against injuries caused by necrotizing agents (absolute ethanol and aspirin) in rodents. The results of this study revealed that EOCC posses a dose-independent anti-ulcer effect against the different experimental models. EOCC pretreatment depicted a higher preventive index in ethanol-(88%) and aspirin-induced (76%) acute ulceration. On pretreatment of mice with indomethacin, the cyclooxygenase inhibitor slightly suppressed the gastroprotective effect of EOCC (48.5%). Furthermore, EOCC gastroprotection was not attenuated in mice pretreated with L-NAME (85.2%), glibenclamide (100%), or yohimbine (79.7%), the respective inhibitors of nitric oxide synthase, K+ATP channel activation, and α2 receptors. These results confirmed the traditional use of C. citratus for the treatment of gastric ulcer. Thus, we provide the first evidence that EOCC reduces gastric damage induced by ethanol, at least in part, by mechanisms that involve endogenous prostaglandins
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