42,029 research outputs found

    Assessment of Effectiveness of Buffer Zones in Removing Impurities in Runoff from Areas Treated with Poultry Litter. Part II: Source Areas to Buffer Areas Ratio Effects

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    Vegetative filter strips (VFS) are known to reduce runoff losses of nutrients. solids. and other materials from land areas treated with fertilizers . Although VFS effectiveness is known to depend partially on the relative lengths of filter and pollutant source areas. there is little experimental evidence available to quantify this dependence. This is particularly the case when VFS are implemented down-slope of pasture areas treated with animal manures such as poultry litter. This study assessed the influences of pollutant source area (treated with poultry litter) and VFS lengths on VFS removal of total Kjeldahl nitrogen (TKN). ammonia nitrogen (NH3 -N ). nitrate nitrogen (N03-N). ortho-phosphorus (P04-P). total phosphorus (TP). total organic carbon (TOC). total suspended solids (TSS). and fecal coliform (FC) fromincoming runoff for a silt loam soil with fescue cover. Litter-treated lengths of 6.1. 12.2. and 18.3 m with corresponding VFS lengths of up to 18.3 m. 12.2 m. and 6.1 m. respectively, were examined. Runoff was produced from simulated rainfall applied at 50 mm/h for 1 h of runoff. Concentrations of the parameters analyzed were unaffected by litter treated length but demonstrated a first-order decrease with increasing VFS length except in the cases of TSS and FC. Mass transport of TKN. NH3-N. P04-P. and TP increased with increasing litter-treated length (due to increased runoff) and decreased (approximately first-order) with increasing VFS length. Effectiveness of the VFS in terms of TKN. NH3-N. P04 -P. and TP removal from runoff ranged from 6.5 to 96.3% depending on the particular parameter. litter-treated length. and VFS length. The data collected during this study can be helpful in developing and testing simulation models of VFS performance and can thus aid in design of VFS for pasture areas treated with poultry litter

    The Increasing Diversity of America\u27s Youth

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    This brief documents how unfolding demographic forces have placed today’s children and youth at the forefront of America’s new racial and ethnic diversity. Authors Kenneth M. Johnson, Andrew Schaefer, Daniel T. Lichter, and Luke T. Rogers discuss how the rapidly changing racial and ethnic composition of the youth population has important implications for intergroup relations, ethnic identities, and electoral politics. They report that diversity is increasing among America’s youth because there are more minority children and fewer non-Hispanic white children. Minority births exceeded non-Hispanic white births for the first time in U.S. history in 2011 according to Census Bureau estimates. Both the declining number of non-Hispanic white women of prime child-bearing and growing numbers of minority women contributed to this change as did differential fertility rates. The largest gains in child diversity between 2000 and 2012 were in suburban and smaller metropolitan areas. Yet, child diversity is geographically uneven, with minimal diversity in some areas of the country and significant diversity in other areas. They conclude that natural population increase—particularly fertility rates—will continue to reshape the racial and ethnic mix of the country, and this change will be reflected first among the nation’s youngest residents

    Decoding the Mechanism for the Origin of Dark Matter in the Early Universe Using LHC Data

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    It is shown that LHC data can allow one to decode the mechanism by which dark matter is generated in the early universe in supersymmetric theories. We focus on two of the major mechanisms for such generation of dark matter which are known to be the Stau Coannihilation (Stau-Co) where the neutralino is typically Bino like and annihilation on the Hyperbolic Branch (HB) where the neutralino has a significant Higgsino component. An investigation of how one may discriminate between the Stau-Co region and the HB region using LHC data is given for the mSUGRA model. The analysis utilizes several signatures including multi leptons, hadronic jets, b-tagging, and missing transverse momentum. A study of the SUSY signatures reveals several correlated smoking gun signals allowing a clear discrimination between the Stau-Co and the HB regions where dark matter in the early universe can originate.Comment: 7 pages, 5 figs, 2 columns, Accepted for publication in Physical Review

    Physical outcome measure for critical care patients following intensive care discharge

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    Introduction: The aim of this study was to evaluate the most suitable physical outcome measures to be used with critical care patients following discharge. ICU survivors experience physical problems such as reduced exercise capacity and intensive care acquired weakness. NICE guideline ‘Rehabilitation after critical illness’ (1) recommends the use of outcome measures however does not provide any specific guidance. A recent Cochrane review noted wide variability in measures used following ICU discharge (2). Methods: Discharged ICU patients attended a five week multidisciplinary programme. Patients’ physical function was assessed during the programme, at 6 months and 12 months post discharge. Three outcome measures were included in the initial two cohorts. The Six Minute Walk Test (6MWT) and the Incremental Shuttle Walk test (ISWT) were chosen as they have been used within the critical care follow up setting (2). The Chester Step Test (CST) is widely thought to be a good indicator of ability to return to work (one of the programmes primary aims). Ethics approval was waived as the programme was part of a quality improvement initiative. Results: Data was collected for the initial patients attending the programme (n = 13), median age was 52 (IQR = 38-72), median ICU LOS was 19 days (IQR = 4-91), median APACHE II was 23 (IQR = 19-41) and 11 were men. One patient was so physically debilitated that the CST or ISWT could not be completed however a score was achieved using the 6MWT. Another patient almost failed to achieve level 1 of the ISWT. Subsequent patients for this project (total n = 47) have all therefore been tested using the 6MWT. Good inter-rater and intrarater reliability and validity have been reported for the 6MWT (3). Conclusions: Exercise capacity measurement is not achievable for some patients with either the ISWT or the CST due to the severity of their physical debilitation. Anxiety, post-traumatic stress disorder and depression are common psychological problems post discharge (4), therefore using a test with a bleep is not appropriate. Therefore, the 6MWT is the most appropriate physical outcome measure to be used with critical care patients post discharge

    Instability of nonminimally coupled scalar fields in the spacetime of slowly rotating compact objects

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    Nonminimally coupled free scalar fields may be unstable in the spacetime of compact objects. Such instability can be triggered by classical seeds or, more simply, by quantum fluctuations giving rise to the so-called {\em vacuum awakening effect}. Here, we investigate how the parameter space which characterizes the instability is affected when the object gains some rotation. For this purpose, we focus on the stability analysis of nonminimally coupled scalar fields in the spacetime of slowly spinning matter shells.Comment: 11 pages, 6 figure

    Classification of pain and its treatment at an intensive care rehabilitation clinic

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    Introduction Treatment in an Intensive Care Unit (ICU) often necessitates uncomfortable and painful procedures for patients throughout their admission. There is growing evidence to suggest that chronic pain is becoming increasingly recognised as a long term problem for patients following an ICU admission [1]. Intensive Care Syndrome: Promoting Independence and Return to Employment (InS:PIRE) is a five week rehabilitation programme for patients and their caregivers after ICU discharge at Glasgow Royal Infirmary. This study investigated the incidence and location of chronic pain in patients discharged from ICU and classified the analgesics prescribed according to the World Health Organization analgesic Methods The InS:PIRE programme involved individual sessions for patients and their caregivers with a physiotherapist and a pharmacist along with interventions from medical, nursing, psychology and community services. The physiotherapist documented the incidence and pain location during the assessment. The pharmacist recorded all analgesic medications prescribed prior to admission and at their clinic visit. The patient’s analgesic medication was classified according to the WHO pain ladder from zero to three, zero being no pain medication and three being treatment with a strong opioid. Data collected was part of an evaluation of a quality improvement initiative, therefore ethics approval was waived. Results Data was collected from 47 of the 48 patients who attended the rehabilitation clinic (median age was 52 (IQR, 44-57) median ICU LOS was 15 (IQR 9-25), median APACHE II was 23 (IQR 18-27) and 32 of the patients were men (67 %)). Prior to admission to ICU 43 % of patients were taking analgesics and this increased to 81 % at the time of their clinic visit. The number of patients at step two and above on the WHO pain ladder also increased from 34 % to 56 %. Conclusions Of the patients seen at the InS:PIRE clinic two-thirds stated that they had new pain since their ICU admission. Despite the increase in the number and strength of analgesics prescribed, almost a quarter of patients still complained of pain at their clinic visit. These results confirm that pain continues to be a significant problem in this patient group. Raising awareness in primary care of the incidence of chronic pain and improving its management is essential to the recovery process following an ICU admission

    Quantum versus classical instability of scalar fields in curved backgrounds

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    General-relativistic stable spacetimes can be made unstable under the presence of certain nonminimally coupled free scalar fields. In this paper, we analyze the evolution of linear scalar-field perturbations in spherically symmetric spacetimes and compare the classical stability analysis with a recently discussed quantum field one. In particular, it is shown that vacuum fluctuations lead to natural seeds for the unstable phase, whereas in the classical framework the presence of such seeds in the initial conditions must be assumed.Comment: 5 pages, 1 figure; condensed and revised version matching published on

    Synergy and Group Size in Microbial Cooperation

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    Microbes produce many molecules that are important for their growth and development, and the consumption of these secretions by nonproducers has recently become an important paradigm in microbial social evolution. Though the production of these public goods molecules has been studied intensely, little is known of how the benefits accrued and costs incurred depend on the quantity of public good molecules produced. We focus here on the relationship between the shape of the benefit curve and cellular density with a model assuming three types of benefit functions: diminishing, accelerating, and sigmoidal (accelerating then diminishing). We classify the latter two as being synergistic and argue that sigmoidal curves are common in microbial systems. Synergistic benefit curves interact with group sizes to give very different expected evolutionary dynamics. In particular, we show that whether or not and to what extent microbes evolve to produce public goods depends strongly on group size. We show that synergy can create an “evolutionary trap” which can stymie the establishment and maintenance of cooperation. By allowing density dependent regulation of production (quorum sensing), we show how this trap may be avoided. We discuss the implications of our results for experimental design
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