525 research outputs found

    Strange-Beauty Meson Production at ppˉp\bar p Colliders

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    The production rates and transverse momentum distributions of the strange-beauty mesons BsB_s and BsB_s^* at ppˉp\bar p colliders are calculated assuming fragmentation is the dominant process. Results are given for the Tevatron in the large transverse momentum region, where fragmentation is expected to be most important.Comment: Minor changes in the discussion section. Also available at http://www.ph.utexas.edu/~cheung/paper.htm

    Effectiveness of preoperative planning in the restoration of balance and view in ankylosing spondylitis

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    Object. The object of this study was to assess the effectiveness of preoperative planning in the restoration of balance and view angle in patients treated with lumbar osteotomy in ankylosing spondylitis (AS). Methods. The authors prospectively analyzed 8 patients with a thoracolumbar kyphotic deformity due to AS that was treated using a closing wedge osteotomy (CWO) of the lumbar spine to correct sagittal imbalance and horizontal view. Preoperative planning to predict postoperative balance, defined by the sagittal vertical axis (SVA) and the sacral endplate angle (SEA), and the view angle, defined by the chin-brow to vertical angle (CBVA), was performed using the ASKyphoptan computational program. Results. All patients were treated with a CWO at level L-4 and improved in balance and view angle. The mean correction angle was 35° (range 24-47°). The postoperative SEA improved from 21 to 36° for a mean correction of 15°. In addition, the SVA and CBVA improved significantly. Note, however, that the postoperative results did not exactly reflect the predicted values of the analyzed parameters. Conclusions. Preoperative planning for the restoration of balance and view angle in AS improves understanding of the biomechanical and clinical effects of a correction osteotomy of the lumbar spine. The adaptation of basic clinical and biomechanical principles to restore balance is advised in such a way that the individual SEA is corrected by 15° (maximum 40°) in relation to the horizon and C-7 is balanced exactly above the posterosuperior corner of the sacrum

    Narratives of Industry Responses to Cyberbullying: Perspectives on Self-regulation From and About the Industry

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    In this chapter, we provide an overview of narratives about online inter- mediaries’ responses to cyberbullying from the perspectives of policy makers and the companies, as well as children and parents. Relevant self-regulatory and self- organisational efforts are discussed aswell as the rationales for their adoption; includ- ing how the effectiveness of these efforts is seen from the perspectives of various stakeholders. We draw attention to the relative paucity of data on effectiveness of companies’ mechanisms, particularly from the perspective of any benefits received by children as a result of these interventions and support

    Ratios of BB and DD Meson Decay Constants in Relativistic Quark Model

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    We calculate the ratios of BB and DD meson decay constants by applying the variational method to the relativistic hamiltonian of the heavy meson. We adopt the Gaussian and hydrogen-type trial wave functions, and use six different potentials of the potential model. We obtain reliable results for the ratios, which are similar for different trial wave functions and different potentials. The obtained ratios show the deviation from the nonrelativistic scaling law, and they are in a pretty good agreement with the results of the Lattice calculations.Comment: 13 pages, 1 Postscript figur

    Adapting group schema therapy for older adults with personality disorders:Lessons learnt

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    A first empirical study into group schema therapy in older adults with mood disorders and personality disorder (PD) features has shown that brief group schema therapy has potential to decrease psychological distress and to change early maladaptive schemas (EMS). Effect sizes however were smaller than those found in similar studies in younger adults. Therefore, we set out to adapt the treatment protocol for older adults in order to enhance its feasibility and outcome in this age group. We examined this adapted protocol in 29 older adults (mean age 66 years) with PDs from four Dutch mental health institutes. The primary outcome was symptomatic distress, measured by the Brief Symptom Inventory. Secondary outcomes were measured by the Young Schema Questionnaire, the Schema Mode Inventory, and the short version of the Severity Indices of Personality Problems. Contrary to our expectations, the adapted treatment protocol yielded only a small effect size in our primary outcome, and no significant improvement in EMS, modes and personality functioning. Patients pointed out that they were more aware of their dysfunctional patterns, but maybe they had not been able yet to work on behavioural change due to this schema therapy treatment being too brief. We recommend more intensive treatment for older patients with PDs, as they might benefit from more schema therapy sessions, similar to the treatment dosage in younger PD patients. They might also benefit from a combination of group therapy and individual treatment sessions

    Leptonic widths of high excitations in heavy quarkonia

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    Agreement with the measured electronic widths of the ψ(4040)\psi(4040), ψ(4415)\psi(4415), and Υ(11019)\Upsilon (11019) resonances is shown to be reached if two effects are taken into account: a flattening of the confining potential at large distances and a total screening of the gluon-exchange interaction at r\ga 1.2 fm. The leptonic widths of the unobserved Υ(7S)\Upsilon(7S) and ψ(5S)\psi(5S) resonances: Γe+e(Υ(7S))=0.11\Gamma_{e^+e^-}(\Upsilon (7S))=0.11 keV and Γ(ψ(5S))0.54\Gamma(\psi(5S))\approx 0.54 keV are predicted.Comment: 11 pages revtex

    Decay Constants and Semileptonic Decays of Heavy Mesons in Relativistic Quark Model

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    We investigate the BB and DD mesons in the relativistic quark model by applying the variational method with the Gaussian wave function. We calculate the Fermi momentum parameter pFp_{_F}, and obtain pF=0.500.54p_{_F} = 0.50 \sim 0.54 GeV, which is almost independent of the input parameters, αs\alpha_s, mbm_b, mcm_c and mspm_{sp}. We then calculate the ratio fBf_B/fDf_D, and obtain the result which is larger, by the factor of about 1.3, than MD/MB\sqrt{M_D / M_B} given by the naive nonrelativistic analogy. This result is in a good agreement with the recent Lattice calculations. We also calculate the ratio (MBMB)(M_{B^*}-M_{B})/(MDMD)(M_{D^*}-M_{D}). In these calculations the wave function at origin ψ(0)\psi (0) is essential. We also determine pFp_{_F} by comparing the theoretical prediction of the ACCMM model with the lepton energy spectrum of BeνXB \rightarrow e \nu X from the recent ARGUS analysis, and find that pF=0.27 ± 0.270.22p_{_F}=0.27~\pm~^{0.22}_{0.27} GeV, when we use mc=1.5m_c=1.5 GeV. However, this experimentally determined value of pFp_{_F} is strongly dependent on the value of input parameter mcm_c.Comment: 15 pages (Latex) (uses epsfig.sty, 1 figure appended as a uuencoded compressed ps-file

    What's the effect of the implementation of general practitioner cooperatives on caseload? Prospective intervention study on primary and secondary care

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    <p>Abstract</p> <p>Background</p> <p>Out-of-hours care in the primary care setting is rapidly changing and evolving towards general practitioner 'cooperatives' (GPC). GPCs already exist in the Netherlands, the United Kingdom and Scandinavia, all countries with strong general practice, including gatekeepers' role. This intervention study reports the use and caseload of out-of-hours care before and after implementation of a GPC in a well subscribed region in a country with an open access health care system and no gatekeepers' role for general practice.</p> <p>Methods</p> <p>We used a prospective before/after interventional study design. The intervention was the implementation of a GPC.</p> <p>Results</p> <p>One year after the implementation of a GPC, the number of patient contacts in the intervention region significantly increased at the GPC (OR: 1.645; 95% CI: 1.439-1.880), while there were no significant changes in patient contacts at the Emergency Department (ED) or in other regions where a simultaneous registration was performed. Although home visits decreased in all general practitioner registrations, the difference was more pronounced in the intervention region (intervention region: OR: 0.515; 95% CI: 0.411-0.646, other regions: OR: 0.743; 95% CI: 0.608-0.908). At the ED we observed a decrease in the number of trauma cases (OR: 0.789; 95% CI: 0.648-0.960) and of patients who came to hospital by ambulance (OR: 0.687; 95% CI: 0.565-0.836).</p> <p>Conclusions</p> <p>One year after its implementation more people seek help at the GPC, while the number of contacts at the ED remains the same. The most prominent changes in caseload are found in the trauma cases. Establishing a GPC in an open health care system, might redirect some patients with particular medical problems to primary care. This could lead to a lowering of costs or a more cost-effective out of hours care, but further research should focus on effective usage to divert patient flows and on quality and outcome of care.</p

    Management of superficial venous thrombosis based on individual risk profiles: protocol for the development and validation of three prognostic prediction models in large primary care cohorts

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    BACKGROUND: Superficial venous thrombosis (SVT) is considered a benign thrombotic condition in most patients. However, it also can cause serious complications, such as clot progression to deep venous thrombosis (DVT) and pulmonary embolism (PE). Although most SVT patients are encountered in primary healthcare, studies on SVT nearly all were focused on patients seen in the hospital setting. This paper describes the protocol of the development and external validation of three prognostic prediction models for relevant clinical outcomes in SVT patients seen in primary care: (i) prolonged (painful) symptoms within 14 days since SVT diagnosis, (ii) for clot progression to DVT or PE within 45 days and (iii) for clot recurrence within 12 months. METHODS: Data will be used from four primary care routine healthcare registries from both the Netherlands and the UK; one UK registry will be used for the development of the prediction models and the remaining three will be used as external validation cohorts. The study population will consist of patients ≥18 years with a diagnosis of SVT. Selection of SVT cases will be based on a combination of ICPC/READ/Snowmed coding and free text clinical symptoms. Predictors considered are sex, age, body mass index, clinical SVT characteristics, and co-morbidities including (history of any) cardiovascular disease, diabetes, autoimmune disease, malignancy, thrombophilia, pregnancy or puerperium and presence of varicose veins. The prediction models will be developed using multivariable logistic regression analysis techniques for models i and ii, and for model iii, a Cox proportional hazards model will be used. They will be validated by internal-external cross-validation as well as external validation. DISCUSSION: There are currently no prediction models available for predicting the risk of serious complications for SVT patients presenting in primary care settings. We aim to develop and validate new prediction models that should help identify patients at highest risk for complications and to support clinical decision making for this understudied thrombo-embolic disorder. Challenges that we anticipate to encounter are mostly related to performing research in large, routine healthcare databases, such as patient selection, endpoint classification, data harmonisation, missing data and avoiding (predictor) measurement heterogeneity
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