631 research outputs found

    Tea and lycopene protect against prostate cancer

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    Prostate cancer is the most common male cancer in developed countries and is increasing in the developing world. Its long latency and geographical variation suggest the possibility of prevention or postponement of onset by dietary modification. To investigate the possible joint effect of lycopene and green tea on prostate cancer risk, a case-control study was conducted in Hangzhou, China, with 130 prostate cancer patients and 274 hospital controls. Information on tea and dietary intakes, and possible confounders was collected using a structured questionnaire. The risk of prostate cancer for the intake of tea and lycopene and their joint effect were assessed using multivariate logistic regression models. Prostate cancer risk was reduced with increased consumption of green tea. The protective effect of green tea was significant (odds ratio 0.14, 95% CI: 0.06-0.35) for the highest quartile relative to the lowest after adjusting for total vegetables and fruits intakes and other potential confounding factors. Intakes of vegetables and fruits rich in lycopene were also inversely associated with prostate cancer risk (odds ratio 0.18, 95% CI 0.08-0.39). Interaction analysis showed that the protective effect from tea and lycopene consumption was synergistic (p<0.01). This study suggests that habitual drinking tea and intakes of vegetables and fruits rich in lycopene could lead to a reduced risk of prostate cancer in Chinese men.Together they have a stronger preventive effect than either component taken separately. This is the first epidemiological study to investigate the joint effect between tea drinking and lycopene intake

    Validity of a food-frequency questionnaire for elderly men in southeast China

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    OBJECTIVE: To investigate the internal validity of a food-frequency questionnaire (FFQ) developed for a case-control study of prostate cancer in southeast China. DESIGN: A comprehensive questionnaire comprising a quantitative FFQ and a short food habit questionnaire (SFHQ) was developed and modified from previous cancer and nutritional studies. The Goldberg formula (ratio of energy intake (EI) to basal metabolic rate (BMR), EI/BMR) was used to assess the validity of the FFQ by making comparisons with physical activity levels. Physical activity levels were measured by the estimated total metabolic equivalents (MET) and the ratio of energy expenditure (EE) to BMR (EE/BMR). Correlation analyses were undertaken to compare the SFHQ variables with those of the quantitative FFQ. SETTING: Hangzhou, Zhejiang Province, China. SUBJECTS: A total of 404 men over 45 years old with or without prostate cancer were recruited from eight hospitals.RESULTS: The partial correlation coefficients, controlling for age and family history of prostate cancer, were moderate to high (P<0.05) for preserved foods intake, fat consumption and tea drinking variables between the SFHQ and the quantitative FFQ. The average EI/BMR was 1.72, with 76% of subjects exceeding the Goldberg cut-off value of 1.35. Apart from weight, BMI, EE/BMR and MET, there were no significant differences in characteristics between low (<1.35) and normal EI/BMR groups. CONCLUSIONS: The FFQ is demonstrated to be a valid instrument to measure energy and food intake for elderly men in southeast China

    Use of a prolactin-Cre/ROSA-YFP transgenic mouse provides no evidence for lactotroph transdifferentiation after weaning, or increase in lactotroph/somatotroph proportion in lactation

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    In rats, a shift from somatotroph dominance to lactotroph dominance during pregnancy and lactation is well reported. Somatotroph to lactotroph transdifferentiation and increased lactotroph mitotic activity are believed to account for this and associated pituitary hypertrophy. A combination of cell death and transdifferentiation away from the lactotroph phenotype has been reported to restore non-pregnant pituitary proportions after weaning. To attempt to confirm that a similar process occurs in mice, we generated and used a transgenic reporter mouse model (prolactin (PRL)-Cre/ROSA26-expression of yellow fluorescent protein (EYFP)) in which PRL promoter activity at any time resulted in permanent, stable, and highly specific EYFP. Triple immunochemistry for GH, PRL, and EYFP was used to quantify EYFP+ve, PRL−ve, and GH+ve cell populations during pregnancy and lactation, and for up to 3 weeks after weaning, and concurrent changes in cell size were estimated. At all stages, the EYFP reporter was expressed in 80% of the lactotrophs, but in fewer than 1% of other pituitary cell types, indicating that transdifferentiation from those lactotrophs where reporter expression was activated is extremely rare. Contrary to expectations, no increase in the lactotroph/somatotroph ratio was seen during pregnancy and lactation, whether assessed by immunochemistry for the reporter or PRL: findings confirmed by PRL immunochemistry in non-transgenic mice. Mammosomatotrophs were rarely encountered at the age group studied. Individual EYFP+ve cell volumes increased significantly by mid-lactation compared with virgin animals. This, in combination with a modest and non-cell type-specific estrogen-induced increase in mitotic activity, could account for pregnancy-induced changes in overall pituitary size

    Lippia (Phyla canescens) and its response to fire

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    Lippia (Phyla canescens), a significant invasive weed, is a recognized threat to floodplain woodlands in Australia, particularly in the Murray-Darling Basin. Current control methods include the use of herbicides, which can be costly and environmentally harmful, particularly in riparian areas. 'Environmentally friendly' control mechanisms are yet to be found, with the potential for biological control still being researched. This research explores the use of fire as a potential control method to help slow the expansion and growth of lippia. Lippia response to fire and the effect of fire in lippia-invaded landscapes has not previously been investigated. Half of the St. Ruth Reserve south of Dalby in Southern Queensland was subject to a control burn in November 2013 by the Western Downs Regional Council in an attempt to reduce lippia abundance in this remnant riparian woodland. This research investigates the response of lippia to the burn. The study will compare the cover abundance of lippia and major functional plant groups between burnt and unburnt (control) sites within the reserve; it will also investigate the impact of fire on lippia germination rates in soil samples from burnt and unburnt sites. Additional studies testing lippia seed viability, using tetrazolium staining, will also be conducted after a range of fire mimicking treatments have been applied to seeds and compared to controls from an unburnt area. This research will contribute to evidence-based decision-making for improved management of lippia-invaded remnant ecosystems

    A Framework for Designing Learning Analytics Information Systems

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    Learning analytics offers new opportunities in higher education, yet the design and development of educational data analytics are facing several challenges. Little guidance is available for researchers and developers when it comes to designing, developing, and implementing learning analytics information systems in higher education. Hence, this study proposes a comprehensive conceptual framework for designing learning analytics information systems incorporating both computational and educational aspects. The framework provides systematic support for learning analytics researchers and designers. It is constructed based on the process and critical dimensions of learning analytics and instructional systems design. By applying the framework to analyze a previously published study, we provide a better understanding of its key qualities. Furthermore, the application of the framework to design a new learning analytics information system provides forward engineering support

    Machine Learning to Support an Interactive Theorem Prover

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    Groundwater thresholds for drought resilience in floodplain woodlands: a case study from the northern Murray-Darling Basin

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    In ephemeral river systems, canopy condition in dominant riparian and floodplain tree species may depend on access to shallow groundwater resources, particularly during drought. However, unsustainable groundwater extraction and chronic groundwater decline, evident in many agricultural landscapes worldwide, effectively decouples tree roots from deep soil moisture resources, increasing the susceptibility of trees to changes in precipitation. In such regions, drought may trigger loss of canopy condition and have long term consequences for the function and survival of trees and the composition, structure and function of ecosystems they dominate. However, critical groundwater depth thresholds have been difficult to identify. This study used a novel approach including boosted regression trees, quantile regression and threshold analysis to explore the relationship between groundwater depth and tree condition for two dominant tree species, Eucalyptus camaldulensis (river red gum) and E. populnea (poplar box); both species occur on the Upper Condamine floodplain, a region experiencing groundwater depth declines of 25+m in the northern Murray-­‐Darling Basin, southern Queensland. Distinct non-­‐linear responses were apparent, with minimum groundwater depth thresholds identified at 12.1m for E. camaldulensis and 12.6m for E.populnea, beyond which canopy condition declined significantly. This approach represents a repeatable method of quantifying ecological response thresholds along groundwater depth gradients. Its application may enable safe operating limits for groundwater resource management to be identified, supporting improved decision making to support resilient floodplain ecosystems. This will be particularly important in regions where groundwater decline driven by increasing water demand and drying climates is predicted

    Does the Consumption of Green Tea Reduce the Risk of Lung Cancer Among Smokers?

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    Experimental and epidemiological studies were reviewed to assess whether the consumption of green tea could reduce the risk of lung cancer in smokers. Articles published since 1990 were located by searching electronic databases PubMed, Ovid and Science Direct, using keywords ‘lung cancer’, ‘tea’ and ‘smoking’ without any restriction on language. After relevant articles had been located, further papers were obtained from their reference lists. Evidence from experimental studies (in vitro animal and human trials) suggested that regular intake of green tea may be protective against tobacco carcinogens. However, the mechanism behind the protective effect is only partly understood. In most of the epidemiological studies reviewed, the green tea exposure was within 5 years of the interview or follow-up, which would coincide with the induction period and latent period of lung cancer. Longer term studies are thus needed to further quantify the cancer risk. There is some evidence suggesting regular intake of green tea at high level (>3 cups per day) may reduce the risk of smokers developing lung cancer. Improvement in measuring green tea intake is required in order to confirm the evidence from epidemiological studies

    Implications for workability and survivability in populations exposed to extreme heat under climate change: A modelling study

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    Background: Changes in temperature and humidity due to climate change affect living and working conditions. An understanding of the effects of different global temperature changes on population health is needed to inform the continued implementation of the Paris Climate Agreement and to increase global ambitions for greater cuts in emissions. By use of historical and projected climate conditions, we aimed to investigate the effects of climate change on workability (ie, the ability to work) and survivability (the ability to survive). Methods: In this modelling study, we estimated the changes in populations exposed to excessive heat stress between the recent past (ie, 1986–2005) and 2100. We used climate data from four models to calculate the wet-bulb globe temperature, an established heat exposure index that can be used to assess the effects of temperature, humidity, and other environmental factors on humans. We defined and applied thresholds for risks to workability (where the monthly mean of daily maximum wet-bulb globe temperature exceeds 34°C) and survivability (where the maximum daily wet-bulb globe temperature exceeds 40°C for 3 consecutive days), and we used population projections to quantify changes in risk associated with different changes to the global temperature. Findings: The risks to workability increase substantially with global mean surface temperature in all four climate models, with approximately 1 billion people affected globally after an increase in the global temperature of about 2·5°C above pre-industrial levels. There is greater variability between climate models for exposures above the threshold for risks to survivability than for risks to workability. The number of people who are likely to be exposed to heat stress exceeding the survivability threshold increases with global temperature change, to reach around 20 million people globally after an increase of about 2·5°C, estimated from the median of the models, but with a large model uncertainty. More people are likely to be exposed to heat stress in urban than in rural areas. Population exposure can fluctuate over time and change substantially within one decade. Interpretation: Exposure to excessive heat stress is projected to be widespread in tropical or subtropical low-income and middle-income countries, highlighting the need to build on the Paris Agreement regarding global temperature targets, to protect populations who have contributed little to greenhouse gas emissions. The non-linear dependency of heat exposure risk on temperature highlights the importance of understanding thresholds in coupled human-climate systems
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