130 research outputs found

    Comparing in situ turbidity sensor measurements as a proxy for suspended sediments in North-Western European streams

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    Climate change in combination with land use alterations may lead to significant changes in soil erosion and sediment fluxes in streams. Optical turbidity sensors can monitor with high frequency and can be used as a proxy for suspended sediment concentration (SSC) provided there is an acceptable calibration curve for turbidity measured by sensors and SSC from water samples. This study used such calibration data from 31 streams in 11 different research projects or monitoring programmes in six Northern European countries. The aim was to find patterns in the turbidity-SSC correlations based on stream characteristics such as mean and maximum turbidity and SSC, catchment area, land use, hydrology, soil type, topography, and the number and representativeness of the data that are used for the calibration. There were large variations, but the best correlations between turbidity and SSC were found in streams with a mean and maximum SSC of >30-200 mg/l, and a mean and maximum turbidity above 60-200 NTU/FNU, respectively. Streams draining agricultural areas with fine-grained soils had better correlations than forested streams draining more coarse-grained soils. However, the study also revealed considerable differences in methodological approaches, including analytical methods to determine SSC, water sampling strategies, quality control procedures, and the use of sensors based on different measuring principles. Relatively few national monitoring programmes in the six countries involved in the study included optical turbidity sensors, which may partly explain this lack of methodological harmonisation. Given the risk of future changes in soil erosion and sediment fluxes, increased harmonisation is highly recommended, so that turbidity data from optical sensors can be better evaluated and intercalibrated across streams in comparable geographical regions

    Trends and patterns in surface water chemistry in Europe and North America between 1990 and 2016, with particular focus on changes in land use as a confounding factor for recovery

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    The report presents trends in sulphate, nitrate, chloride, base cations, ANC (acid neutralising capacity), pH and DOC at circa 500 ICP Waters sites in Europe and North America for the period 1990-2016. Time series were analysed for trends in annual median values, annual extreme values and change points, that indicate years with sudden changes in trend or level. Also provided is a brief overview of possible implications of land use change for recovery of acidified surface waters

    Comportamento de cultivares de pepino (Cucumis sativus L.) em duas épocas de semeadura

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    Plant development and fruit production of cucumber cultivars 'Marketer IAC- 2 2 0 5 ' , 'Palomar IAC- 3 0 5 0 ' , 'Santee IAC- 2 4 4 1 ' , 'Verde Paulistano IAC-1336' and 'Aodai 1 - 4 3 2 1 ' were compared under two sowing dates, 5 t n of May and 5 t n of December of 1970 in Campinas, SP, Brazil, in a Yellow Red Latossol. Air temperature ranged from 1 2 , 0°C to 26, 8°C in the first period of culture, and from 18,5°C to 30,2°C in the second period. Adequate cultural practices were provided. When the first female flower appeared in the field, insecticides and fungicides applications were interrupted. For all cultivars, yields were higher and fruit quality was better in the first period of culture. Both in May and December cultures, plants have concentrated their highest yields between the third and the penultima te harvesting dates. 'Santee' presented low yields and the quality of its fruits was poor. 'Aodai' showed the best results as to fruit yield and fruit quality. Yields of the other cultivars were similar. 'Verde Paulistano' presented the latest fruit production. 'Marketer' showed a relatively uniform behaviour in both periods of culture. There were found positive correlations between yield in each harvesting date and total yield, total yield and marketable yield, number of fruits and fruits weight, plant height and yield, and number of lateral branches and yield. The relation between marketable and total yield, and fruit average weight, decreased at the end of the plants cycle.O desenvolvimento e a produção de frutos para consumo in natura dos cultivares de pepino 'Marketer IAC-2205', 'Palomar IAC-3050', 'Santee IAC-2441', 'Verde Paulistano IAC-1386' e 'Aodai 1-4321' foram estudados em duas épocas de semeadura, 5 de maio e 5 de dezembro, em Campinas, SP. Para todos os cultivares, as plantas semeadas em dezembro cresceram mais e desenvolveram-se com maior rapidez que as plantas semeadas em maio; entretanto, as produções das plantas semeadas em maio foram maiores e a qualidade de seus frutos foi superior. Tanto para as plantas semeadas em maio como para as semeadas em dezembro, 'Santee' apresentou produções baixas e frutos de má qualidade. 'Aodai' foi o cultivar mais produtivo e seus frutos foram os de melhor qualidade. As produções dos demais cultivares foram equivalentes. 'Verde Paulistano' apresentou a produção mais tardia. 0 comportamento de 'Marketer' foi pouco afetado pelas variações ambientais. As maiores produções de todos os cultivares, nas duas é poças, foram obtidas entre a terceira e a penúltima colheitas. Foram encontradas correlações positivas entre a produção de cada colheita e a produção total, entre a produção total e a produção comerciável, entre o número de frutos e seu peso, entre produção e a altura da planta e entre produção e número de ramos laterais da planta. A relação entre produções comerciável e total e o peso médio dos frutos diminuíram no final do ciclo das plantas

    Meta-analysis identifies seven susceptibility loci involved in the atopic March

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    Eczema often precedes the development of asthma in a disease course called the a 'atopic march'. To unravel the genes underlying this characteristic pattern of allergic disease, we conduct a multi-stage genome-wide association study on infantile eczema followed by childhood asthma in 12 populations including 2,428 cases and 17,034 controls. Here we report two novel loci specific for the combined eczema plus asthma phenotype, which are associated with allergic disease for the first time; rs9357733 located in EFHC1 on chromosome 6p12.3 (OR 1.27; P=2.1 × 10 a'8) and rs993226 between TMTC2 and SLC6A15 on chromosome 12q21.3 (OR 1.58; P=5.3 × 10 a'9). Additional susceptibility loci identified

    Multi-ancestry genome-wide association study of 21,000 cases and 95,000 controls identifies new risk loci for atopic dermatitis

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    Genetic association studies have identified 21 loci associated with atopic dermatitis risk predominantly in populations of European ancestry. To identify further susceptibility loci for this common, complex skin disease, we performed a meta-analysis of >15 million genetic variants in 21,399 cases and 95,464 controls from populations of European, African, Japanese and Latino ancestry, followed by replication in 32,059 cases and 228,628 controls from 18 studies. We identified ten new risk loci, bringing the total number of known atopic dermatitis risk loci to 31 (with new secondary signals at four of these loci). Notably, the new loci include candidate genes with roles in the regulation of innate host defenses and T cell function, underscoring the important contribution of (auto)immune mechanisms to atopic dermatitis pathogenesis
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