2,143 research outputs found

    Analysis and discussion of four trace metals - copper, lead, mercury, and zinc - taken from selected sites along the Ottawa River in and near Lima, Ohio

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    Eight water and sediment samples collected from the Ottawa River in and near Lima, Ohio, were analyzed for their content of four trace metals - copper, lead, mercury, and zinc - by the atomic absorption process. The four following possible origins of these trace metals were considered: geological pollution, industrial and waste disposal effects, chemical pollution, and automobile exhaust emissions. A discussion as to the desirable levels that have been established for public water supplies and the trace metal requirements of the human metabolism is presented. The effects of these trace elements on the human metabolism is also considered, as copper and zinc are believed to be essential to human health but can be toxic, and lead and mercury are not important in the body's biochemical system but are considered cumulative poisons.No embarg

    The effect of organic farming systems on aspects of the environment - desk study OF0123

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    Key Conclusions 1. The crop rotations of organic systems maintain landscape diversity and biodiversity whilst the maintenance of field boundaries on organic units produces benefits to a wide range of organisms. 2. Inorganic nitrogen fertilisation and herbicide treatments of conventionally managed grassland has reduced the floral diversity of permanent pastures and maintained the low diversity of re-seeded pastures, greatly reducing their value as wildlife habitats. 3. Pesticide use is responsible for the removal of food sourcesfor birds and mammals in the form of weeds and invertebrates, as well as removing whole populations of potentially beneficial insects. 4. The majority of water pollution incidents from farms are caused during storage and spreading of cattle and pig slurries. A higher proportion of organic cattle and virtually all organic pigs are kept on solid manure systems and therefore are les of a risk. 5. The nitrogen balance of individual 'conventional' and 'organic' systems will depend greatly on the circumstances and management practices of the individual farms. Consequently it is not possible to generalise that one system is always better than the other in terms of nitrate leaching risk. With this qualification the literature does indicate that generally, organic systems offer less risk of nitrate leaching. 6. Organic systems are less likely to cause loss of phosphate into surface and ground waters. Both leaching and loss in eroded soil are likely to be reduced. 7. Organic management practicess such as rotations, the regular use of manures and non-use of pesticides usually increase soil organic matter contents. 8. Organic practices are likely to increase earthworm numbers compared to conventional systems. The increased numbers are universally acknowledged to benefit soil fertility although such effects are difficult to quantify. 9. Soil erosion is less of a problem on organic units. 10. Accumulations of copper and zinc in soils are much reduced in organic systems because organic pig and poultry producers do not supplement feeds with these metals as growth promoters. Copper fungicides are more widely used on organic farms and their use should be carefully monitored to prevent harmful effects. 11. The practices adopted by organic farmers can reduce emissions of nitrous oxide and methane. Ammonia emissions will not necessarily be less in organic than in conventional farming. 12. Organic farmers adopt practices which benefit the landscape. They maintain and introduce features largely because they are required by the Organic Standards to do so. They introduce such management practices because they are technically necessary for successful organic production

    Antipsychotic prescribing to patients diagnosed with dementia without a diagnosis of psychosis in the context of national guidance and drug safety warnings: longitudinal study in UK general practice

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    Introduction: Policy interventions to address inappropriate prescribing of antipsychotic drugs to older people diagnosed with dementia are commonplace. In the UK, warnings were issued by the Medicines Healthcare products Regulatory Agency in 2004, 2009 and 2012 and the National Institute for Health and Care Excellence guidance was published in 2006. It is important to evaluate the impact of such interventions. Methods: We analysed routinely collected primary-care data from 111,346 patients attending one of 689 general practices contributing to the Clinical Practice Research Datalink to describe the temporal changes in the prescribing of antipsychotic drugs to patients aged 65 years or over diagnosed with dementia without a concomitant psychosis diagnosis from 2001 to 2014 using an interrupted time series and a before-and-after design. Logistic regression methods were used to quantify the impact of patient and practice level variables on prescribing prevalence. Results: Prescribing of first-generation antipsychotic drugs reduced from 8.9% in 2001 to 1.4% in 2014 (prevalence ratio 2014/2001 adjusted for age, sex and clustering within practices (0.14, 95% confidence interval 0.12–0.16), whereas there was little change for second-generation antipsychotic drugs (1.01, confidence interval 0.94–1.17). Between 2004 and 2012, several policy interventions coincided with a pattern of ups and downs, whereas the 2006 National Institute for Health and Care Excellence guidance was followed by a gradual longer term reduction. Since 2013, the decreasing trend in second-generation antipsychotic drug prescribing has plateaued largely driven by the increasing prescribing of risperidone. Conclusions: Increased surveillance and evaluation of drug safety warnings and guidance are needed to improve the impact of future interventions

    Multi-objective shop floor scheduling using monitored energy data

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    Modern factories will become more and more directly connected to intermittent energy sources like solar systems or wind turbines as part of a smart grid or a self-sufficient supply. However, solar systems or wind turbines are not able to provide a continuous energy supply over a certain time period. In order to enable an effective use of these intermittent energy sources without using temporary energy storages, it is necessary to rapidly and flexibly adapt the energy demand of the factory to the constantly changing requirements of the energy supply. The adaption of the energy demand to the intermittent supply results in different energy-related objectives for the production system of the factory, such as reducing energy consumption, avoiding power peaks, or achieving a power use within the available power supply. Shop Floor Scheduling can help to pursue these objectives within the production system. For this purpose, a solution methodology based on a meta-heuristic will be described for Flexible Job Shop Scheduling taking into account different energy- as well as productivity-related objectives

    The association between a primary care pay-for performance scheme and suicide in England: a spatial cohort study

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    BackgroundPay-for-performance policies aim to improve population health by incentivising improvements in quality of care.AimsTo assess the relationship between general practice performance on severe mental illness (SMI) and depression indicators under a national incentivisation scheme and suicide risk in England for the period 2006–2014.MethodLongitudinal spatial analysis for 32 844 small-area geographical units (lower super output areas, LSOAs), using population-structure adjusted numbers of suicide as the outcome variable. Negative binomial models were fitted to investigate the relationship between spatially estimated recorded quality of care and suicide risk at the LSOA level. Incidence rate ratios (IRRs) were adjusted for deprivation, social fragmentation, prevalence of depression and SMI as well as other 2011 Census variables.ResultsNo association was found between practice performance on the mental health indicators and suicide incidence in practice localities (IRR=1.000, 95% CI 0.998–1.002). IRRs indicated elevated suicide risks linked with area-level social fragmentation (1.030; 95% CI 1.027–1.034), deprivation (1.013, 95% CI 1.012–1.014) and rurality (1.059, 95% CI 1.027–1.092).ConclusionsPrimary care has an important role to play in suicide prevention, but we did not observe a link between practices' higher reported quality of care on incentivised mental health activities and lower suicide rates in the local population. It is likely that effective suicide prevention needs a more concerted, multiagency approach. Better training in suicide prevention for general practitioners is also essential. These findings pertain to the UK but have relevance to other countries considering similar programmes

    Reactive direction control for a mobile robot: A locust-like control of escape direction emerges when a bilateral pair of model locust visual neurons are integrated

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    Locusts possess a bilateral pair of uniquely identifiable visual neurons that respond vigorously to the image of an approaching object. These neurons are called the lobula giant movement detectors (LGMDs). The locust LGMDs have been extensively studied and this has lead to the development of an LGMD model for use as an artificial collision detector in robotic applications. To date, robots have been equipped with only a single, central artificial LGMD sensor, and this triggers a non-directional stop or rotation when a potentially colliding object is detected. Clearly, for a robot to behave autonomously, it must react differently to stimuli approaching from different directions. In this study, we implement a bilateral pair of LGMD models in Khepera robots equipped with normal and panoramic cameras. We integrate the responses of these LGMD models using methodologies inspired by research on escape direction control in cockroaches. Using ‘randomised winner-take-all’ or ‘steering wheel’ algorithms for LGMD model integration, the khepera robots could escape an approaching threat in real time and with a similar distribution of escape directions as real locusts. We also found that by optimising these algorithms, we could use them to integrate the left and right DCMD responses of real jumping locusts offline and reproduce the actual escape directions that the locusts took in a particular trial. Our results significantly advance the development of an artificial collision detection and evasion system based on the locust LGMD by allowing it reactive control over robot behaviour. The success of this approach may also indicate some important areas to be pursued in future biological research

    A New Population of High Redshift, Dusty Lyman-Alpha Emitters and Blobs Discovered by WISE

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    We report a new technique to select 1.6<z<4.6 dusty Lyman-alpha emitters (LAEs), over a third of which are `blobs' (LABs) with emission extended on scales of 30-100kpc. Combining data from the NASA Wide-field Infrared Survey Explorer (WISE) mission with optical spectroscopy from the W.M. Keck telescope, we present a color criteria that yields a 78% success rate in identifying rare, dusty LAEs of which at least 37% are LABs. The objects have a surface density of only ~0.1 per square degree, making them rare enough that they have been largely missed in narrow surveys. We measured spectroscopic redshifts for 92 of these WISE-selected, typically radio-quiet galaxies and find that the LAEs (LABs) have a median redshift of 2.3 (2.5). The WISE photometry coupled with data from Herschel reveals that these galaxies have extreme far-infrared luminosities (L_IR>10^{13-14}L_sun) and warm colors, typically larger than submillimeter-selected galaxies (SMGs) and dust-obscured galaxies (DOGs). These traits are commonly associated with the dust being energized by intense AGN activity. We hypothesize that the combination of spatially extended Lyman-alpha, large amounts of warm IR-luminous dust, and rarity (implying a short-lived phase) can be explained if the galaxies are undergoing strong `feedback' transforming them from an extreme dusty starburst to a QSO.Comment: Submitted to ApJ Letters, 6 pages, 4 figures. Comments welcom
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