12,318,216 research outputs found

    The initial energy density of gluons produced in very high energy nuclear collisions

    Get PDF
    In very high energy nuclear collisions, the initial energy of produced gluons per unit area per unit rapidity, dE/L2/dηdE/L^2/d\eta, is equal to f(g2μL)(g2μ)3/g2f(g^2\mu L) (g^2\mu)^3/g^2, where μ2\mu^2 is proportional to the gluon density per unit area of the colliding nuclei. For an SU(2) gauge theory, we perform a non--perturbative numerical computation of the function f(g2μL)f(g^2\mu L). It decreases rapidly for small g2μLg^2\mu L but varies only by 25\sim 25%, from 0.208±0.0040.208\pm 0.004 to 0.257±0.0050.257\pm 0.005, for a wide range 35.36--296.98 in g2μLg^2\mu L, including the range relevant for collisions at RHIC and LHC. Extrapolating to SU(3), we estimate the initial energy per unit rapidity for Au-Au collisions in the central region at RHIC and LHC.Comment: 11 pages, Latex, 3 figures; revised version-includes additional numerical data; reference adde

    Quantifying health risks in wastewater irrigation

    Get PDF
    The guidelines developed by the World Health Organization for the safe use of wastewater in agriculture are based on a tolerable additional disease burden of 10-6 disability-adjusted life year loss per person per year, equivalent to rotavirus disease and infection risks of approximately 10-4 and 10-3 per person per year, respectively. The combination of standard quantitative microbial risk analysis techniques and 10,000-trial Monte Carlo risk simulations, using ranges of parameter values that reflect real life, are then used to determine the minimum required pathogen reductions for restricted and unrestricted irrigation which ensure that the risks are not exceeded. For unrestricted irrigation the required pathogen reduction is 6- 7 log10 units and for restricted irrigation 3- 4 log10 units. For both restricted and unrestricted irrigation wastewater treatment has to achieve a 3-4-log10 unit pathogen reduction, and in the case of unrestricted irrigation this has to be supplemented by a further 3-4-log10 unit pathogen reduction provided by post-treatment, but pre-ingestion, health protection control measures, such as pathogen die-off between the last irrigation and consumption (0.5- 2 log10 unit reduction per day, depending on ambient temperature) and produce washing in clean water (1 log10 unit reduction). Wastewaters used for both restricted and unrestricted irrigation also have to contain no more than 1 human intestinal nematode egg per liter; if children under the age of 15 are exposed then additional measures are required such as regular deworming at home or at school

    Inter-cluster Filaments of Galaxies Programme: Abundance and Distribution of Filaments in the 2dFGRS Catalogue

    Full text link
    Filaments of galaxies are known to stretch between galaxy clusters at all redshifts in a complex manner. In this Letter, we present an analysis of the frequency and distribution of inter-cluster galaxy filaments selected from the 2dF Galaxy Redshift Survey. Out of 805 cluster-cluster pairs, we find at least 40 per cent have bone-fide filaments. We introduce a filament classification scheme and cast the filaments into several types according to their visual morphology: straight (lying on the cluster-cluster axis; 37 per cent), warped or curved (lying off the cluster-cluster axis; 33 per cent), sheets (planar configurations of galaxies; 3 per cent), uniform (1 per cent) and irregular (26 per cent). We find that straight filaments are more likely to reside between close cluster pairs and they become more curved with increasing cluster separation. This curving is toward a larger mass concentration in general. We also show that the more massive a cluster is, the more likely it is to have a larger number of filaments. Our results are found to be consistent with a Lambda cold dark matter cosmology.Comment: 6 pages, 3 figures, accepted for publication in MNRAS letter

    Tillering Response of \u27Monon\u27 And \u27Newton\u27 Winter Wheats Infested With Biotype L Hessian Fly (Diptera: Cecidomyiidae) Larvae

    Get PDF
    Two wheat, Triticum aestivum, cultivars that differed in their ability to tiller were infested by ovipositing Hessian flies, Mayetiola destructor, under similar controlled conditions. Since a larva typically stunts and kills the stem where it feeds and develops, tiller development of fly infested-wheat seedlings is an important plant trait relative to grain yield. \u27Monon\u27 tillered more than \u27Newton at the 0 infestation level (control). \u27Monon\u27 had about the same number of tillers at 0, 1, 2, and 3 puparia (indicative of the number of feeding larvae) per plant; and \u27Newton\u27 had fewer tillers at 0 than 1, 2, or 3 puparia per stem. However, tillering of both cultivars was less at 4 or more puparia per stem, perhaps due to the depletion of plant nutrients. In general, for both cultivars there was a decrease in leaf length, number and wet weight as the number of puparia increased per tiller

    Pathogenicity of the root-knot nematode Meloidogyne javanica on potato

    Get PDF
    Host–parasite relationships and pathogenicity of Meloidogyne javanica on potatoes (newly recorded from Malta) were studied under glasshouse and natural conditions. Potato cvs Cara and Spunta showed a typical susceptible reaction to M. javanica under natural and artificial infections, respectively. In potato tubers, M. javanica induced feeding sites that consisted of three to four hypertrophied giant cells per adult female. Infection of feeder roots by the nematode resulted in mature large galls which usually contained at least one mature female and egg mass. In both tubers and roots, feeding sites were characterized by giant cells containing granular cytoplasm and many hypertrophied nuclei. Cytoplasm in giant cells was aggregated alongside the thickened cell walls. Stelar tissues within galls appeared disorganized. The relationship between initial nematode population density ( P ) [0–64 eggs + second-stage juveniles (J2s) per cm 3 soil] and growth of cv. Spunta potato seedlings was tested under glasshouse conditions. A Seinhorst model [ y = m + (1 − m ) z ( P − T ) ] was fitted to fresh shoot weight and shoot height data of nematode-inoculated and control plants. Tolerance limits ( T ) for fresh shoot weight and shoot height of cv. Spunta plants infected with M. javanica were 0·50 and 0·64 eggs + J2s per cm 3 soil, respectively. The m parameter in that model (i.e. the minimum possible y -values) for fresh shoot weight and shoot height were 0·60 and 0·20, respectively, at P = 64 eggs + J2s per cm 3 soil. Root galling was proportional to the initial nematode population density. Maximum nematode reproduction rate was 51·2 at a moderate initial population density ( P = 4 eggs + J2s per cm 3 soil).peer-reviewe

    Phases of the infinite U Hubbard model

    Full text link
    We apply the density matrix renormalization group (DMRG) to study the phase diagram of the infinite U Hubbard model on 2-, 4-, and 6-leg ladders. Where the results are largely insensitive to the ladder width, we consider the results representative of the 2D square lattice model. We find a fully polarized ferromagnetic Fermi liquid phase when n, the density of electrons per site, is in the range 1>n>n_F ~ 4/5. For n=3/4 we find an unexpected commensurate insulating "checkerboard" phase with coexisting bond density order with 4 sites per unit cell and block spin antiferromagnetic order with 8 sites per unit cell. For 3/4 > n, the wider ladders have unpolarized groundstates, which is suggestive that the same is true in 2D

    A South African review of harmonic emission level assessment as per IEC61000-3-6

    Get PDF
    Large-scale renewable power producing plants are being integrated into South African networks. Network operators need to ensure that Renewable Power Plants (RPP) do not negatively affect the power quality levels of their networks, as harmonics amongst others could become a concern. IEC 61000-3-6 details a method for allocating voltage harmonic emission limits for distorting loads. This method works well for the allocation of emission limits; however it does not address the management of harmonic emissions once a plant is connected to the network. The management of harmonic emissions requires that network operators measure or quantify the emissions from loads and generators to determine compliance. Post-connection quantification of harmonic levels and compliance is a challenge for network operators. The question asked is “How should a network operator measure/quantify the harmonic emissions of a load/generator to establish compliance with the calculated limits as per IEC 61000-3-6”. This paper reviews within a South African context methods of assessing harmonic emission levels and then evaluates these methods by means of field data. Opportunities for improvement are identified and operational requirements discussed

    Juvenile Probation Officer Workload and Caseload Study: Alaska Division of Juvenile Justice

    Get PDF
    This report describes results of a study to measure and analyze the workload and caseload of Juvenile Probation Officers (JPOs) within the Alaska Division of Juvenile Justice. More specifically, this study assessed the resources needed in both rural and urban Alaska to adequately meet minimum probation standards, to continue the development and enhancement of system improvements, and to fully implement the restorative justice field probation service delivery model.Bureau of Justice Assistance Grant No. 2008-IC-BX-K001Section I – Juvenile Probation Officer Workload and Caseload Study Table 1. Total Time Available by Office Figure 1. Referrals for New Offenses, by Depth of Processing Table 2. Average Caseloads by Office: FY06-08 Table 3. Summary Estimates for Hours Required per Type of Case Table 4. Final Results Table 5. Workload Burdens / Section II – Workload Elements Table 6. Total Time Available by Office Figure 2. Referrals for New Offenses, by Depth of Processing Table 7. Average Caseloads for Ultimate Probation Officers: FY06-08 Table 8. Average Caseloads for Immediate Probation Officers: FY06-08 Table 9. Summary Estimates for Hours Required per Type of Case / Section III – Workload Calculations Table 10. Total Hours Needed by Office Table 11. Total Hours Needed and Available by Office Table 12. Positions Needed by Office Table 13. Workload Burdens by Office Table 14. Summary of Final Results Table 15. Final Results with Average Times Required per Case Table 16. Final Results with Average Case Dispositions Table 17. Final Results with Average Times Required per Case and Case Dispositions Table 18. Summary of Final Results Table 19. Time Study Comparisons / Appendix A – Time Available Table A.1. Number of Positions by Region and Location Table A.2. Average Hours per Week Required for Other Activities Table A.3. Total Hours Available per Year by Position and Office / Appendix B – Number of Cases Figure B.1. Referrals for New Offenses, by Depth of Processing Table B.1. Average Caseloads for Ultimate Probation Officers: FY06-08 Table B.2. Average Caseloads for Immediate Probation Officers: FY06-08 / Appendix C – Time Required Table C.1. Summary Estimates for Hours Required per Type of Case Table C.2. Average Estimates (in Minutes) per Type of Case and Activity Table C.3. Detailed Estimates (in Minutes) for Time Required per Dismissed Case Table C.4. Detailed Estimates (in Minutes) for Time Required per Case Adjusted Without a Referral Table C.5. Detailed Estimates (in Minutes) for Time Required per Case Adjusted With a Referral Table C.6. Detailed Estimates (in Minutes) for Time Required per Informal Probation Case Table C.7. Detailed Estimates (in Minutes) for Time Required per Petitioned Cas

    Integration of patient-reported outcome measures with key clinical outcomes after immediate latissimus dorsi breast reconstruction and adjuvant treatment

    No full text
    Background: linical evidence on patient-reported outcome measures (PROMS) in breast reconstruction is lacking. The aim of this study was to evaluate PROMs in implant-assisted latissimus dorsi (LDI) or tissue-only autologous latissimus dorsi (ALD) flap reconstruction in relation to complications and adjuvant treatments.Methods: this was a prospective cohort study involving six UK centres. Eligible patients had primary early-stage breast cancer. The European Organization for Research and Treatment of Cancer quality-of-life questionnaire (QLQ)-C30 and QLQ-BR23, Functional Assessment of Cancer Therapy—Breast Cancer scale (FACT-B), Body Image Scale, and Hospital Anxiety and Depression Scale were completed before operation and at 3, 6 and 12 months after surgery.Results: a total of 182 patients (82 LDI and 100 ALD) were recruited between 2007 and 2010 with symptomatic (59·9 per cent) or screen-detected (39·6 per cent) cancers. Some 64·3 per cent had lymph node-negative disease; 30 per cent of the LDI group had radiotherapy, compared with 53·0 per cent in the ALD group (P = 0·004). Early complications up to 3 months after surgery were reported in 66 and 51·0 per cent of patients in the LDI and ALD groups respectively (P = 0·062) and long-term complications (4–12 months) in 48 and 45·0 per cent (P = 0·845). Role functioning and pain (P = 0·002 for both) were adversely affected in the ALD group compared with results in the LDI group, with no significant effects of radiotherapy on any health-related quality of life (HRQL). Chemotherapy and early complications adversely affected HRQL, which improved between 3 and 12 months after surgery (P < 0·010 for all).Conclusion: there is evidence of similar HRQL between types of latissimus dorsi breast reconstruction for up to a year after surgery. There appear to be no overarching effects for radiotherapy after mastectomy on the specific HRQL domains studied in the short term. The identification of variables that affect HRQL is important, including their integration into the analysis of PROM
    corecore