217 research outputs found

    α-Tocopherol in plasma and milk from organically managed dairy cows fed natural or synthetic vitamin E or seaweed

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    The objective was to compare the effects of supplementing lactating dairy cows with synthetic (All-rac), natural (RRR) α-tocopheryl acetate or seaweed with a control on the concentration of α-tocopherol in blood and milk. Twenty four dairy cows in mid lactation, fed an organic feed ration, were randomly allocated to the four treatments in a replicated Latin square design. Plasma and milk α-tocopherol concentrations were higher in RRR and All-rac than in the other treatments and higher in RRR than in All-rac. RRR-α-tocopherol was the predominant steroisomer (> 86%), in both plasma and milk, whereas the remaining part was largely made up by the three synthetic 2R isomers. In cows fed the control, seaweed and RRR, the proportion of RRR-α-tocopherol in plasma and milk constituted more than 97% of the total α-tocopherol. The study demonstrated that dairy cows in mid and late lactation have preferential uptake of RRR-α-tocopherol compared to other stereoisomer

    Carbonaceous aerosols in Norwegian urban areas

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    Little is known regarding levels and source strength of carbonaceous aerosols in Scandinavia. In the present study, ambient aerosol (PM<sub>10</sub> and PM<sub>2.5</sub>) concentrations of elemental carbon (EC), organic carbon (OC), water-insoluble organic carbon (WINSOC), and water-soluble organic carbon (WSOC) are reported for a curbside site, an urban background site, and a suburban site in Norway in order to investigate their spatial and seasonal variations. Aerosol filter samples were collected using tandem filter sampling to correct for the positive sampling artefact introduced by volatile and semivolatile OC. Analyses were performed using the thermal optical transmission (TOT) instrument from Sunset Lab Inc., which corrects for charring during analysis. Finally, we estimated the relative contribution of OC from wood burning based on the samples content of levoglucosan. <br><br> Levels of EC varied by more than one order of magnitude between sites, likely due to the higher impact of vehicular traffic at the curbside and the urban background sites. In winter, the level of particulate organic carbon (OC<sub><i>p</i></sub>) at the suburban site was equal to (for PM<sub>10</sub>) or even higher (for PM<sub>2.5</sub>) than the levels observed at the curbside and the urban background sites. This finding was attributed to the impact of residential wood burning at the suburban site in winter, which was confirmed by a high mean concentration of levoglucosan (407 ng m<sup>−3</sup>). This finding indicates that exposure to primary combustion derived OC<sub><i>p</i></sub> could be equally high in residential areas as in a city center. It is demonstrated that OC<sub><i>p</i></sub> from wood burning (OC<sub>wood</sub>) accounted for almost all OC<sub><i>p</i></sub> at the suburban site in winter, allowing a new estimate of the ratio TC<sub><i>p</i></sub>/levoglucosan for both PM<sub>10</sub> and PM<sub>2.5</sub>. Particulate carbonaceous material (PCM=Organic matter+Elemental matter) accounted for 46–83% of PM<sub>10</sub> at the sites studied, thus being the major fraction

    Treng kyr i midtlaktasjon ekstra tilskot av E-vitamin?

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    Sjølv om α-tokoferolinnhaldet (39 mg/kg DM) i surfôr ikkje var spesielt høgt, var det tydelegvis nok når surfôropptaket var så høgt som i dette forsøket. Det er grunn til å revurdere tilrådinga om ekstra E-vitamin til mjølkekyr i midt- og seinlaktasjon

    Heavy metal and nitrogen concentrations in mosses are declining across Europe whilst some “hotspots” remain in 2010

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    In recent decades, naturally growing mosses have been used successfully as biomonitors of atmospheric deposition of heavy metals and nitrogen. Since 1990, the European moss survey has been repeated at five-yearly intervals. In 2010, the lowest concentrations of metals and nitrogen in mosses were generally found in northern Europe, whereas the highest concentrations were observed in (south-)eastern Europe for metals and the central belt for nitrogen. Averaged across Europe, since 1990, the median concentration in mosses has declined the most for lead (77%), followed by vanadium (55%), cadmium (51%), chromium (43%), zinc (34%), nickel (33%), iron (27%), arsenic (21%, since 1995), mercury (14%, since 1995) and copper (11%). Between 2005 and 2010, the decline ranged from 6% for copper to 36% for lead; for nitrogen the decline was 5%. Despite the Europe-wide decline, no changes or increases have been observed between 2005 and 2010 in some (regions of) countries

    How to use the world's scarce selenium resources efficiently to increase the selenium concentration in food

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    The world's rare selenium resources need to be managed carefully. Selenium is extracted as a by-product of copper mining and there are no deposits that can be mined for selenium alone. Selenium has unique properties as a semi-conductor, making it of special value to industry, but it is also an essential nutrient for humans and animals and may promote plant growth and quality. Selenium deficiency is regarded as a major health problem for 0.5 to 1 billion people worldwide, while an even larger number may consume less selenium than required for optimal protection against cancer, cardiovascular diseases and severe infectious diseases including HIV disease. Efficient recycling of selenium is difficult. Selenium is added in some commercial fertilizers, but only a small proportion is taken up by plants and much of the remainder is lost for future utilization. Large biofortification programmes with selenium added to commercial fertilizers may therefore be a fortification method that is too wasteful to be applied to large areas of our planet. Direct addition of selenium compounds to food (process fortification) can be undertaken by the food industry. If selenomethionine is added directly to food, however, oxidation due to heat processing needs to be avoided. New ways to biofortify food products are needed, and it is generally observed that there is less wastage if selenium is added late in the production chain rather than early. On these bases we have proposed adding selenium-enriched, sprouted cereal grain during food processing as an efficient way to introduce this nutrient into deficient diets. Selenium is a non-renewable resource. There is now an enormous wastage of selenium associated with large-scale mining and industrial processing. We recommend that this must be changed and that much of the selenium that is extracted should be stockpiled for use as a nutrient by future generations

    Harmful Elements in Estuarine and Coastal Systems

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    Estuaries and coastal zones are dynamic transitional systems which provide many economic and ecological benefits to humans, but also are an ideal habitat for other organisms as well. These areas are becoming contaminated by various anthropogenic activities due to a quick economic growth and urbanization. This chapter explores the sources, chemical speciation, sediment accumulation and removal mechanisms of the harmful elements in estuarine and coastal seawaters. It also describes the effects of toxic elements on aquatic flora and fauna. Finally, the toxic element pollution of the Venice Lagoon, a transitional water body located in the northeastern part of Italy, is discussed as a case study, by presenting the procedures adopted to measure the extent of the pollution, the impacts on organisms and the restoration activities

    The radioanalytical bibliography of Norway (1936–1977)

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