987 resultados para Field Samples
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SUMMARYThe use of a “direct PCR” DNA polymerase enables PCR amplification without any prior DNA purification from blood samples due to the enzyme's resistance to inhibitors present in blood components. Such DNA polymerases are now commercially available. We compared the PCR performance of six direct PCR-type DNA polymerases (KOD FX, Mighty Amp, Hemo KlenTaq, Phusion Blood II, KAPA Blood, and BIOTAQ) in dried blood eluted from a filter paper with TE buffer. GoTaq Flexi was used as a standard DNA polymerase. PCR performance was evaluated by a nested PCR technique for detecting Plasmodium falciparum genomic DNA in the presence of the blood components. Although all six DNA polymerases showed resistance to blood components compared to the standard Taq polymerase, the KOD FX and BIOTAQ DNA polymerases were resistant to inhibitory blood components at concentrations of 40%, and their PCR performance was superior to that of other DNA polymerases. When the reaction mixture contained a mild detergent, only KOD FX DNA polymerase retained the original amount of amplified product. These results indicate that KOD FX DNA polymerase is the most resistant to inhibitory blood components and/or detergents. Thus, KOD FX DNA polymerase could be useful in serological studies to simultaneously detect antibodies and DNA in eluents for antibodies. KOD FX DNA polymerase is thus not limited to use in detecting malaria parasites, but could also be employed to detect other blood-borne pathogens.
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Os mercados financeiros têm um papel fundamental na dinamização das economias modernas. Às empresas cotadas oferece o capital necessário para impulsionar o seu crescimento e aos investidores individuais proporciona a diversificação das suas carteiras, usufruindo desta forma do crescimento e da vitalidade da economia mundial. A gestão de carteiras de ativos financeiros constitui uma área que procura apresentar mecanismos para a obtenção de uma relação ótima entre retorno e risco. Neste sentido, inúmeros estudos têm contribuído de forma significativa para a eficiência e para a prática desta técnica. Esta dissertação pretende analisar a metodologia desenvolvida por Elton-Gruber para a construção de carteiras otimizadas e aplicar as técnicas subjacentes ao mercado acionista português. Para o efeito, serão realizadas pesquisas em fontes bibliográficas da especialidade e serão consultadas bases de dados de cotações históricas das ações e do índice de mercado nacional. A aplicação incidiu sobre ações cotadas no índice PSI-20 durante o período compreendido entre 2010 e 2014. No intuito de melhorar a compreensão das séries de retornos das amostras, o estudo de caráter quantitativo também recorreu à análise estatística. As evidências mostram que a carteira otimizada, no período em análise, contém apenas as ações da empresa Portucel. Este resultado estará condicionado pelos efeitos da crise financeira que iniciou em 2008.
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Perante o elevado consumo de materiais naturais no processo e produtos na área da construção civil, o reaproveitamento de resíduos é uma das soluções a ser estudada. As cinzas agroindustriais têm lugar de destaque entre estes resíduos, pois têm a possibilidade de aplicação em materiais cimentícios, reduzindo assim o consumo de cimento de Portland. O presente estudo debruça-se sobre a substituição parcial (1,5% e 5%) de cimento de Portland por cinzas de casca de amêndoa. Realizaram-se provetes com diferentes tipos de argamassas: (i) uma de controlo sem substituição de cimento (ARF); (ii) uma com 1,5% de substituição parcial de cimento por cinzas de casca de amêndoa (CCA 1,5%); (iii) e uma com 5% de substituição parcial de cimento por cinza de casca de amêndoa (CCA 5%). Executaram-se ensaios para resistências mecânicas aos 3, 7, 14, 28 e 41 dias de idade. A nível químico pode-se concluir que esta cinza de casca de amêndoa não apresentou qualquer potencial pozolânico. A trabalhabilidade na generalidade diminui ligeiramente, contendo cinza de casca de amêndoa, mas ainda assim considerando-se de fácil manuseamento. Em relação às resistências mecânicas, pode-se concluir que o ideal é a substituição parcial de cimento com 1,5%, pois as resistências diminuem com o uso de uma maior percentagem de substituição, ou seja, o ideal é substituir em pequenas percentagens. Com os dados obtidos, conclui-se que as cinzas testadas não apresentam características necessárias para serem consideradas pozolanas e se será viável a sua utilização mesmo como filer.
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A study of head lice infestations among young people, adults and elderly individuals was conducted from August 2010 to July 2013 in Manaus, AM, Northern Brazil. Hair samples collected from 1,860 individuals in 18 barber shops and beauty parlors were examined for the ectoparasite. The occurrence of pediculosis and its association with factors, such as sex, age, ethnicity, hair characteristics and the socioeconomic profile of salon customers, salon location and seasonal variation were determined. The overall occurrence rate was 2.84%. Occurrence was higher in hair samples from non-blacks and the elderly. Higher occurrence was also observed during kindergarten, elementary and junior education school holidays. The results indicate that the occurrence of head lice among young people, adults and the elderly in Manaus is relatively low compared to that determined in children and in other regions of the country. After children, the elderly were the most affected. The study also indicated the need to adopt additional procedures to improve surveys among the population with low or no purchasing power, which is usually the most affected by this ectoparasitic disease.
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SUMMARY Cryptococcosis caused by Cryptococcus neoformans is the second most common fungal opportunistic pathogen and a lifethreatening infection with serious clinical manifestations especially in HIV/AIDS and other immunocompromised patients. In Nigeria, HIV/AIDS infection has reached an alarming level. Despite this, information on the presence of this fungus in clinical and environmental samples is very scanty in Nigeria and many other parts of Africa. We set out to evaluate the presence of Cryptococcus neoformans or C. gattii in pigeon droppings obtained from Southeastern Nigeria. One hundred and seventy-seven samples of pigeon droppings from six sample types were collected. The area covered comprised of ten cities and other locations spanning across five States in Nigeria. Using established techniques, Cryptococcus neoformans was isolated from 39 of the 177 (22.0%) samples overall. No C. gattiiwas isolated. Most of the isolates (32.4%) were recovered from dovecotes (11 of 34) followed closely by samples taken from markets (31.8%; seven of 22) and least from the church (4.0%; one of 25). The highest isolation rate (38.9%) was found in samples from Enugu-Ezike(seven of 23) while the least came from Afikpoand the other locations each with 9.1% isolation rate. This is the first large-scale screening of Cryptococcus neoformans from pigeon droppings in Nigeria. The ecological and epidemiological significance of these findings are discussed.
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SUMMARY Human Adenoviruses (HAdV) are notably resistant in the environment. These agents may serve as effective indicators of fecal contamination, and may act as causative agents of a number of different diseases in human beings. Conventional polymerase chain reaction (PCR) and, more recently, quantitative PCR (qPCR) are widely used for detection of viral agents in environmental matrices. In the present study PCR and SYBR(r)Green qPCR assays were compared for detection of HAdV in water (55) and sediments (20) samples of spring and artesian wells, ponds and streams, collected from dairy farms. By the quantitative methodology HAdV were detected in 87.3% of the water samples and 80% of the sediments, while by the conventional PCR 47.3% and 35% were detected in water samples and sediments, respectively.
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SUMMARY Cerebral toxoplasmosis can be highly debilitating and occasionally fatal in persons with immune system deficiencies. In this study, we evaluated the Toxoplasma gondii-specific IgG subclass antibody response in 19 cerebrospinal fluid (CSF) samples from patients with cerebral toxoplasmosis who had a positive IgG anti-T. gondii ELISA standardized with a cyst antigen preparation. There were no significant differences between the rates of positivity and the antibody concentrations (arithmetic means of the ELISA absorbances, MEA) for IgG1 and IgG2, but the rates of positivity and MEA values for these two IgG subclasses were significantly higher than those for IgG3 and IgG4. The marked IgG2 response in CSF from patients with cerebral toxoplasmosis merits further investigation.
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Three species of Siphomycetes: Rhizopus arhizus, Rhizopus equinus and Rhizopus nigricans, as well as a Septomycete: Emericella nidulans, have been examined by means of a scanning electron microscope. Among the difjerent Rhizopus, this technique showed differences in the appearance of the sporangia. In Emericella nidulans, scanning microscopy enábled one to ascertain that the "Hull cells" were completely hollow and also demonstrated the ornemented aspect of the ascospores.
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Dissertação para obtenção do Grau de Doutor em Nanotecnologias e Nanociências
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics
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Proteinuria was detected in 24.7% of 89 individuals with hepatosplenic schistosomiasis and in only 4.6% of 86 subjects with mild hepato-intestinal schistosomiasis, all of them living in comparable conditions in two endemic areas in Bahia, Brazil. From nine individuals who hadproteinuria over30 mg/100ml, eight had hepatosplenic schistosomiasis. These findings maybe related to the presence of schistosomal nephropathy and reveal the significance of this condition in thefield in endemic areas of schistosomiasis.
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Finance from the NOVA – School of Business and Economics
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RESTAPIA 2012 - Int. Conf. on Rammed Earth Conservation, Valencia, 21-23 June 2012
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Thirteen communities from 7 Argentinian provinces were selected for the evaluation of serology as an indicator of transmission of Chagas disease. Of the communities appraised, 6 did not have a history of previous treatment with insecticides and 7 had received sporadic or continuous insecticide treatment. The inhabitants of 20% of the houses of each locality were studied by serology. The samples were obtained byfinger pricking and 50 fil of blood were mixed with 150μl of 50% glycerine solution in tissue culture media to be assayed by Indirect Hemagglutination and Indirect Immunofluorescence tests. In untreated areas, the prevalence of infection in infants 0-4 years old was 17.5%, reaching to over 22% for the 5-9 year old group, and to 33.3% in 10-14 year old individuals. The prevalence in treated and surveyed areas was 2.6% in 0-4 year old children, 5.4% in 5-9 year old and 6,2% in 10-14 year old youngsters. The differences between both areas were statistically significant (p < 0.005). This study favors serology as a valid indicator for the evaluation of transmission of Chagas disease in rural areas.