99 research outputs found

    Organophosphorus pesticides residues in cooked tomato (Licopersicum esculentum).

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    The study aimed to evaluate the residual concentrations of OP in tomato after different cooking times

    Determinants of acquisition and clearance of human papillomavirus infection in previously unexposed young women

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    Background Global variation in human papillomavirus (HPV) prevalence and persistence may be explained by differences in risk factors, such as sexual activity, oral contraceptive use, and behavioral factors. We evaluated determinants of acquisition and clearance of HPV infection among young women previously unexposed to HPV. Methods Five hundred thirty-four women aged 15 to 25 years who were cytology and HPV DNA negative, and seronegative for anti-HPV-16/18 antibodies, were recruited (July 2000–September 2001) from study centers in Brazil, the United States, and Canada (NCT00689741/NCT00120848). They were followed up for 76 months. Cervical samples were HPV genotyped via polymerase chain reaction. We used multivariable (forward stepwise, P = 0.15) Cox proportional hazards regression to estimate rate ratios (RR) and 95% confidence intervals (CI), separately according to length of follow-up time. Results On short-term follow-up (0–27 months), 257 (48%; 8535.80 person-months; incidence rate = 30.11; 95% CI, 26.64–34.02) incident HPV infections were detected. Marital status, lifetime number of sex partners, history of any sexually transmitted disease, and occasional use of oral contraceptives were strongly associated with acquisition of any HPV. Having 2 or more lifetime sex partners (RR, 2.03; 95% CI, 1.37–3.02) and a history of any sexually transmitted disease (RR, 1.98; 95% CI, 1.19–3.29) were the most important determinants of high-risk HPV (hrHPV) incidence. During the entire follow-up (0–76 months), an increased hrHPV clearance was found among women in North America (RR, 1.38; 95% CI, 1.08–1.78) and black women (RR, 1.64; 95% CI, 1.04–2.60). Greater number of lifetime partners was associated with reduced clearance rates for any HPV (RR, 0.65; 95% CI, 0.43–0.98). Conclusions We identified variation in risk of HPV acquisition and clearance among women unexposed to HPV at baseline

    Desempenho agronômico de variedades de mandioca em sistema irrigado.

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    Este trabalho teve como objetivo avaliar a produtividade e adaptação das variedades de mandioca ARN, BRS 399, BRS 400, BRS 401 e Cacau na região norte do estado do Tocantins em sistema irrigado. O ensaio foi conduzido na área experimental do Instituto Federal do Tocantins (IFTO), campus Colinas do Tocantins. O delineamento utilizado foi em blocos casualizados, sendo os tratamentos as variedades de mandiocas mencionadas, com quatro repetições. Cada repetição apresentou quatro linhas de dez plantas, sendo que a parcela experimental útil foi composta pelas duas linhas centrais, na qual avaliou-se as cinco plantas centrais de cada linha útil. O manejo de irrigação adotado foi o de fitas gotejadoras. Foram realizadas três adubações e a avaliação ocorreu nove meses após o plantio. As variáveis avaliadas foram: altura da planta e da primeira bifurcação, massa da parte aérea, massa das raízes tuberosas (produtividade das raízes), índice de colheita, tempo de cocção, teor de amido e rendimento de farinha. Os resultados evidenciaram a existência de diferenças significativas, entre as cinco variedades testadas, para os parâmetros altura da planta e da primeira ramificação, massa da parte aérea, produtividade de raízes e tempo de cocção. Todas as variedades obtiveram produtividade satisfatória, sendo que a BRS 401, BRS 400 e a BRS 399 destacaram-se por apresentar 61,26, 52,34 e 49,70 t/ha, respectivamente. As variedades Cacau, ARN e BRS 401 apresentaram os menores tempo de cocção, 16, 17 e 18,5 minutos, respectivamente. O genótipo BRS 401 apresentou maior altura de planta, e da primeira ramificação, maiores produtividades de raiz (61,26 t/ha) e da parte aérea (30,97 t/ha). De modo geral, todas as variedades apresentaram resultados satisfatórios e podem ser recomendadas para o plantio na região norte do Tocantins

    Produção de polibenzoxazina a partir da lignina do bagaço da cana-de-açúcar.

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    Este Comunicado Técnico visa apresentar um processo para produção de uma resina benzoxazina, em escala de laboratório, a partir da lignina extraída do bagaço da cana-de-açúcar.bitstream/item/206830/1/CT-261.pd

    Seagrass and submerged aquatic vegetation (VAS) habitats off the Coast of Brazil: state of knowledge, conservation and main threats

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    Seagrass meadows are among the most threatened ecosystems on earth, raising concerns about the equilibrium of coastal ecosystems and the sustainability of local fisheries. The present review evaluated the current status of the research on seagrasses and submerged aquatic vegetation (SAV) habitats off the coast of Brazil in terms of plant responses to environmental conditions, changes in distribution and abundance, and the possible role of climate change and variability. Despite an increase in the number of studies, the communication of the results is still relatively limited and is mainly addressed to a national or regional public; thus, South American seagrasses are rarely included or cited in global reviews and models. The scarcity of large-scale and long-term studies allowing the detection of changes in the structure, abundance and composition of seagrass habitats and associated species still hinders the investigation of such communities with respect to the potential effects of climate change. Seagrass meadows and SAV occur all along the Brazilian coast, with species distribution and abundance being strongly influenced by regional oceanography, coastal water masses, river runoff and coastal geomorphology. Based on these geomorphological, hydrological and ecological features, we characterised the distribution of seagrass habitats and abundances within the major coastal compartments. The current conservation status of Brazilian seagrasses and SAV is critical. The unsustainable exploitation and occupation of coastal areas and the multifold anthropogenic footprints left during the last 100 years led to the loss and degradation of shoreline habitats potentially suitable for seagrass occupation. Knowledge of the prevailing patterns and processes governing seagrass structure and functioning along the Brazilian coast is necessary for the global discussion on climate change. Our review is a first and much-needed step toward a more integrated and inclusive approach to understanding the diversity of coastal plant formations along the Southwestern Atlantic coast as well as a regional alert the projected or predicted effects of global changes on the goods and services provided by regional seagrasses and SAV
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