658 research outputs found

    Scoping biological indicators of soil quality Phase II. Defra Final Contract Report SP0534

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    This report presents results from a field assessment of a limited suite of potential biological indicators of soil quality to investigate their suitability for national-scale soil monitoring

    Air Pollution and Subtypes, Severity and Vulnerability to Ischemic Stroke—A Population Based Case-Crossover Study

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    Few studies have examined the association between air pollutants and ischemic stroke subtypes. We examined acute effects of outdoor air pollutants (PM10, NO2, O3, CO, SO2) on subtypes and severity of incident ischemic stroke and investigated if pre-existing risk factors increased susceptibility.We used a time stratified case-crossover study and stroke cases from the South London Stroke Register set up to capture all incident cases of first ever stroke occurring amongst residents in a geographically defined area. The Oxford clinical and TOAST etiological classifications were used to classify subtypes. A pragmatic clinical classification system was used to assess severity. Air pollution concentrations from the nearest background air pollution monitoring stations to patients' residential postcode centroids were used. Lags from 0 to 6 days were investigated.There were 2590 incident cases of ischemic stroke (1995-2006). While there were associations at various lag times with several pollutants, overall, there was no consistent pattern between exposure and risk of ischemic stroke subtypes or severity. The possible exception was the association between NO2 exposure and small vessel disease stroke-adjusted odds ratio of 1.51 (1.12-2.02) associated with an inter-quartile range increase in the lag 0-6 day average for NO2. There were no clear associations in relation to pre-existing risk factors.Overall, we found little consistent evidence of association between air pollutants and ischemic stroke subtypes and severity. There was however a suggestion that increasing NO2 exposure might be associated with higher risk of stroke caused by cerebrovascular small vessel disease

    Connecting global priorities: biodiversity and human health: a state of knowledge review.

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    Healthy communities rely on well-functioning ecosystems. They provide clean air, fresh water, medicines and food security. They also limit disease and stabilize the climate. But biodiversity loss is happening at unprecedented rates, impacting human health worldwide.The report, Connecting Global Priorities: Biodiversity and Human Health, focuses on the complex and multi-faceted connections between biodiversity and human health, and how the loss of biodiversity and corresponding ecosystem services may negatively influence health. One of the first integrative reviews of its kind, the report brings together knowledge from several scientific disciplines, including public health, conservation, agriculture, epidemiology and development. The book is a joint publication of the Convention on Biological Diversity and World Health Organization. Danny Hunter, Senior Scientist, Bioversity International is one of the Lead Coordinating Authors of the book and co-lead author on two chapters:Chapter 5: Agricultural biodiversity and food security Chapter 6: Biodiversity and nutritio

    Preserving the palaeoenvironmental record in Drylands: Bioturbation and its significance for luminescence-derived chronologies

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    Luminescence (OSL) dating has revolutionised the understanding of Late Pleistocene dryland activity. However, one of the key assumptions for this sort of palaeoenvironmental work is that sedimentary sequences have been preserved intact, enabling their use as proxy indicators of past changes. This relies on stabilisation or burial soon after deposition and a mechanism to prevent any subsequent re-mobilisation. As well as a dating technique OSL, especially at the single grain level, can be used to gain an insight into post-depositional processes that may distort or invalidate the palaeoenvironmental record of geological sediment sequences. This paper explores the possible impact of bioturbation (the movement of sediment by flora and fauna) on luminescence derived chronologies from Quaternary sedimentary deposits in Texas and Florida (USA) which have both independent radiocarbon chronologies and archaeological evidence. These sites clearly illustrate the ability of bioturbation to rejuvenate ancient weathered sandy bedrock and/or to alter depositional stratigraphies through the processes of exhumation and sub-surface mixing of sediment. The use of multiple OSL replicate measurements is advocated as a strategy for checking for bioturbated sediment. Where significant OSL heterogeneity is found, caution should be taken with the derived OSL ages and further measurements at the single grain level are recommended. Observations from the linear dunes of the Kalahari show them to have no bedding structure and to have OSL heterogeneity similar to that shown from the bioturbated Texan and Florida sites. The Kalahari linear dunes could have therefore undergone hitherto undetected post-depositional sediment disturbance which would have implications for the established OSL chronology for the region

    Parent Skills Training: Expanding School-Based Services for Adolescent Mothers

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    This article reports the results of a collaborative intervention effort between a teen-parent program and a school of social work Social work faculty and students participated in a program aimed at strengthening parental skills and the utilization of social support among adolescent mothers who were enrolled in a special high school program. The results of this evaluation study point to additional factors, such as empathy training and stress management, which need to be included in a comprehensive service-delivery program for school-age mothers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68359/2/10.1177_104973159200200203.pd

    High speed synchrotron X-ray imaging studies of the ultrasound shockwave and enhanced flow during metal solidification processes

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    The highly dynamic behaviour of ultrasonic bubble implosion in liquid metal, the multiphase liquid metal flow containing bubbles and particles, and the interaction between ultrasonic waves and semisolid phases during solidification of metal were studied in situ using the complementary ultrafast and high speed synchrotron X-ray imaging facilities housed respectively at the Advanced Photon Source, Argonne National Laboratory, US, and Diamond Light Source, UK. Real-time ultrafast X-ray imaging of 135,780 frames per second (fps) revealed that ultrasonic bubble implosion in a liquid Bi-8 wt. %Zn alloy can occur in a single wave period (30 kHz), and the effective region affected by the shockwave at implosion was 3.5 times the original bubble diameter. Furthermore, ultrasound bubbles in liquid metal move faster than the primary particles, and the velocity of bubbles is 70 ~ 100% higher than that of the primary particles present in the same locations close to the sonotrode. Ultrasound waves can very effectively create a strong swirling flow in a semisolid melt in less than one second. The energetic flow can detach solid particles from the liquid-solid interface and redistribute them back into the bulk liquid very effectively

    REALISTIC MODELS WITH A LIGHT U(1) GAUGE BOSON COUPLED TO BARYON NUMBER

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    We recently showed that a new gauge boson γB\gamma_B coupling only to baryon number is phenomenologically allowed, even if mB<mZm_B<m_Z and αB≈0.2\alpha_B \approx 0.2. In our previous work we assumed that kinetic mixing between the baryon number and hypercharge gauge bosons (via an FBμνFμνYF^{\mu\nu}_B F_{\mu\nu}^Y term) was small enough to evade constraints from precision electroweak measurements. In this paper we propose a class of models in which this term is naturally absent above the electroweak scale. We show that the generation of a mixing term through radiative corrections in the low-energy effective theory does not lead to conflict with precision electroweak measurements and may provide a leptonic signal for models of this type at an upgraded Tevatron.Comment: 21 pages, LaTeX, 4 figures in a uuencoded compressed postscript file
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