2,006 research outputs found

    Aerial Radiometric Survey in West Cumbria 1988. Final Report: Project N611

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    Details and results are presented of aerial radiometric measurements undertaken in summer 1988 over an area of restricted livestock movement in West Cumbria. The project was planned in June and July on the basis of discussions between MAFF and SURRC. The prototype aerial spectrometer developed at SURRC in March was used in a helicopter for three purposes. Firstly the sensitivity and spatial resolution attainable over variable and, in some places mountainous, terrain was confirmed, supporting the conclusions of earlier flight trials in Scotland. Secondly it was confirmed that 134Cs could be detected semi-quantitatively within the survey area, providing insight into the origins of anthropogenic deposition of 137Cs. Finally the distribution of both natural and anthropogenic gamma ray emitting radioactivity was determined within the survey zone. The survey was conducted successfully in between 22nd August and 3rd September 1988. Despite unseasonably poor weather more than 1800 measurements were recorded from an area of over 45000 hectares. The detector performance and sensitivity was as expected, and it has been possible both to detect 134Cs and to produce high resolution maps of the radioactivity within this area. A comparison of the results of other analyses of environmental materials from parts of the survey area, including a programme undertaken by MAFF in 1988, and the aerial results confirms the overall validity of the calibration method used. Both 134Cs and 137Cs maps show considerable spatial variation throughout the survey zone and can be used to identify the areas of peak deposition due to Chernobyl. This basic information may be of use for devising and evaluating agronomic strategies to minimise the transfer of artificial nuclides through the food chain, and to help alleviate the problems experienced by farmers working in the restricted areas since the Chernobyl accident. The prototype detector and method used both show considerable potential for further development

    Development of Luminescence Tests to Identify Irradiated Foods. Project N1701

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    <p>This is the final report of project N170l, commissioned by MAFF from October 1990 until March 1992. The principle aims of the project, at a time when statutory changes involving strict labelling rules were anticipated, were to consolidate the thermoluminescence technique already developed at SURRC and to investigate it's extension to fruits and vegetables.</p> <p>The TL procedures for mineral separation were further developed by the incorporation of pre-concentration steps. These steps were introduced in order to improve the the sensitivity of the TL signal, particularly, where the separation technique resulted in low mineral yield for commercially clean samples. This has resulted in an order of magnitude increase in the absolute, TL, signal levels and provides a means of obtaining larger quantities of minerals for any further quantification, thus reducing the ambiguity of interpretation of data.</p> <p>An EC interlaboratory trial was instigated, using the full mineral separation method with reirradiation on a set of calibrated reference materials and paired (irradiated and unirradiated) samples of 12 commercial grade herbs and spices. Despite the diversity of experience and equipment employed, results from all laboratories showed that it was possible to determine which samples were irradiated. This demonstrated the strength of the separation method that its implementation could be successfully achieved in other laboratories. The procedure was then formally recognised and published, by MAFF, for detection of irradiated food for enforcement of UK legislation.</p> <p>As the mineral debris responsible for TL in herbs and spices occurs ubiquitously on all foodstuffs, which have been exposed to wind and soil, investigating the application of TL to fruits and vegetables was a natural extension of the previous work. An extensive survey was conducted of TL signals from fruits and vegetables, including exotic varieties. Minerals were separated from duplicated pairs of irradiated and unirradiated samples of 22 fruits and 20 vegetables. TL results demonstrated unambiguous discrimination between irradiated and unirradiated vegetables provided that concordance diagrams were used. For soft fruits in particular water based separation produced more variable results. However, subsequent analyses using a full density separation with HCI wash were more successful. It was recognised that whereas herbs and spices are largely protected from exposure to light during production and distribution, this is unlikely to be the case for fruits and vegtables. Since light exposure is known to reduce TL signal intensity, a set of illumination experiments was conducted to investigate the implications of optical bleaching for identification. Light boxes were constructed and characterised to simulated optical bleaching under controlled conditions. Two series of experiments were conducted with irradiated and control mangos. In the first experiment the effects of exposure to two different light sources at a level of 1 J cm-2 were investigated using 40 mangos. In the second experiment the influence of duration of exposure from 1 - 128 J cm-2 was examined for artificial daylight illumination of a further 96 mangos. The results of these studies show that although the TL signal is reduced as a result of exposure to daylight, there exists a residual unbleachable component comprising upto 40-50% of the original signal. In most cases the resulting TL will be distinguishable from background levels.</p> <p>As a result of this work it is now possible to extend TL detection protocols to a wide range of fruits and vegetables. Providing that recontamination with unirradiated minerals has not occurred after irradiation, the majority of treated fruits and vegetables are expected to be detectable. Positive signals will imply an irradiation treatment. There remains some possibility of false negative results from a small proportion of irradiated products.</p&gt

    Long-term Impact of sewage sludge application on rhizobium leguminosarum biovar trifolii: an evaluation using meta-analysis

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    The Long-Term Sludge Experiment (LTSE) began in 1994 at nine UK field sites as part of continuing research into the effects of sludge-borne heavy metals on soil fertility. The long-term effects of Zn, Cu, and Cd on the most probable numbers of cells (MPN) of Rhizobium leguminosarum biovar trifolii were monitored for 8 yr in sludge-amended soils. To assess the statutory limits set by the UK Sludge (Use in Agriculture) Regulations, the experimental data were reviewed using statistical methods of meta-analysis. Previous LTSE studies have focused predominantly on statistical significance rather than effect size, whereas meta-analysis focuses on the magnitude and direction of an effect, i.e., the practical significance rather than its statistical significance. Results showed Zn to be the most toxic element causing an overall significant decrease in Rhizobium MPN of −26.6% during the LTSE. The effect of Cu showed no significant effect on Rhizobium MPN at concentrations below the UK limits, although a −5% decrease in Rhizobium MPN was observed in soils where total Cu ranged from 100 to <135 mg kg−1. Overall, there was nothing to indicate that Cd had a significant effect on Rhizobium MPN below the current UK statutory limit. In summary, the UK statutory limit for Zn appears to be insufficient for protecting Rhizobium from Zn toxicity effects

    Scientific Opinion on safety and efficacy of coated granulated cobaltous carbonate monohydrate as feed additive for all species

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    &lt;p&gt;Cobalt(III) is a component of cobalamin. Its essentiality as trace element results from the capacity of certain animal species to synthesise cobalamin by the gastrointestinal microbiota. Feeding cobalt(II) carbonate hydroxide (2:3) monohydrate up to the maximum authorised total cobalt in feed is safe for the target animals. Cobalt is predominantly excreted via the faecal route. Absorbed cobalt follows aqueous excretion routes. About 43&amp;thinsp;% of body cobalt is stored in muscle; however, kidney and liver are the edible tissues containing the highest cobalt concentrations and are most susceptible to reflect dietary cobalt concentrations. In animals with the capacity to synthesise cobalamin, cobalt is also deposited in tissues as vitamin B&lt;sub&gt;12&lt;/sub&gt;. Cobalt(II) cations are genotoxic under &lt;em&gt;in vitro&lt;/em&gt; and &lt;em&gt;in vivo&lt;/em&gt; conditions. Cobalt(II) carbonate has carcinogen, mutagen and reproduction toxicant (CMR) properties. No data are available on the potential carcinogenicity of cobalt(II) following oral exposure. However, oral exposure may potentially entail adverse threshold-related effects in humans. The estimated population intake of cobalt most likely includes the contribution of foodstuffs from animals fed cobalt-supplemented feedingstuffs. An increase in cobalt exposure by the use of cobalt-containing feed additives is therefore not expected. Considering the population exposure to cobalt, about 4–10 times lower than the health-based guidance value, no safety concern for the consumer is expected for threshold effects of oral cobalt. Cobalt(II) carbonate is a skin and eye irritant, and a dermal and respiratory sensitiser. Its dust is a hazard to persons handling the substance. Exposure by inhalation must be avoided. The use of cobalt from any source at the authorised maximum content in feed does not provide a risk to the environment. The coated granulated cobalt(II) carbonate hydroxide (2:3) monohydrate is available for cobalamin synthesis in the rumen and therefore effective in ruminants; this conclusion is extrapolated to horses and rabbits.&lt;/p&gt

    The effect of kale cultivar and sowing date on dry matter intake, crop utilization, liveweight gain and body condition score gain of pregnant, non-lactating dry dairy cows in winter in New Zealand

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    An outdoor grazing study on kale was conducted with pregnant, nonlactating (dry) dairy cows over a 42-day winter grazing period commencing 9 June 2008. Kale treatments consisted of two kale cultivars varying in leaf:stem proportion ("Regal," a leafy variety and "Caledonian," a stemmy variety) and two sowing dates (8 November and 15 December). Measurements were made for dry-matter (DM) utilization, apparent DM intake, liveweight gain and changes in body condition score (BCS) for a total of 120 cows allocated to three replicate groups of the four factorial treatments. Cows were offered a daily allowance of 10 kg DM/cow of kale and 2.2 kg DM/cow of straw. Pregrazing DM yield was higher for kale sown in November (16,517 kg DM/ha) than December (13,867 kg DM/ha), but was unaffected by cultivar (average 15,192 kg DM/ha). "Regal" kale had a higher percentage of leaf compared with "Caledonian" (33.6% vs. 25.6%), lower content of NDF (32.4% vs. 34.1%), but similar metabolizable energy content (12.1 MJ/kg DM for both) in the whole plant. Despite the differences in pregrazing DM yield and forage quality among treatments, no differences were found in DM utilization (between 88.5% and 90.2%), apparent DM intake (between 9.4 and 9.6 kg DM/cow.day), liveweight gain (between 0.53 and 0.67 kg/cow.day) and BCS gain (between 0.43 and 0.46 unit/cow over 42 days). Manipulation of kale yield and quality through choice of cultivar and sowing date had no effect on the performance of pregnant, nonlactating dairy cows

    Harnessing mtDNA variation to resolve ambiguity in 'Redfish' sold in Europe

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    Morphology-based identification of North Atlantic Sebastes has long been controversial and misidentification may produce misleading data, with cascading consequences that negatively affect fisheries management and seafood labelling. North Atlantic Sebastes comprises of four species, commonly known as ‘redfish’, but little is known about the number, identity and labelling accuracy of redfish species sold across Europe. We used a molecular approach to identify redfish species from ‘blind’ specimens to evaluate the performance of the Barcode of Life (BOLD) and Genbank databases, as well as carrying out a market product accuracy survey from retailers across Europe. The conventional BOLD approach proved ambiguous, and phylogenetic analysis based on mtDNA control region sequences provided a higher resolution for species identification. By sampling market products from four countries, we found the presence of two species of redfish (S. norvegicus and S. mentella) and one unidentified Pacific rockfish marketed in Europe. Furthermore, public databases revealed the existence of inaccurate reference sequences, likely stemming from species misidentification from previous studies, which currently hinders the efficacy of DNA methods for the identification of Sebastes market samples
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