Soft Physics in Pb-Pb at the LHC

The LHC results on particle and transverse energy production and Bose-Einstein correlations show that the system produced in Pb-Pb collisions at psNN = 2:76TeV is significantly larger, lives longer and is hotter and denser than at RHIC energies. The particle spectra and soft particle correlations allow a more detailed study of the properties of the produced system and its initial conditions. This contribution highlights some of the first soft physics results from the LHC.Comment: Presented at the 2011 Hadron Collider Physics symposium (HCP-2011), Paris, France, November 14-18 2011, 3 pages, 5 figur

Commissioning and Prospects for Early Physics with ALICE

The ALICE detector has been commissioned and is ready for taking data at the Large Hadron Collider. The first proton-proton collisions are expected in 2009. This contribution describes the current status of the detector, the results of the commissioning phase and its capabilities to contribute to the understanding of both pp and PbPb collisionsComment: 8 pages, 7 figures, To appear in the proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse

Radiation Tolerance of Single-Sided Microstrip Detector with Si3N4Si_{3}N_{4} Insulator

The ALICE Collaboration is investigating the radiation tolerance and operation of silicon microstrip detectors for the inner tracking system. Detectors with and without an additional layer of Si3N4 insulator were made in one set, using the same thickness of SiO2 insulator. Measurements were made on both types of detectors after irradiation with 20 MeV electrons, using doses up to 2Mrad. The additional Si3N4 layer allows a coupling capacitor breakdown voltage larger than 100 V and capacitor yield larger than 99 percent. However, the leakage current for detectors with double layer insulator is about 20 nA per strip while the leakage current for the single layer SiO2 insulated detectors is only 0.5 nA. The 20 nA leakage current leads to 450 electrons noise when the ALICE 128C electronics with a peaking time of 1.4 microseconds is used. At a 1 nA leakage current the noise is 100 electrons. The ENC for an input capacitance of 5 pF is 300 electrons. Since all detectors show an increased leakage current after irradiation, the difference between the single and duoble layer insulation detectors becomes negligible when doses of the order of several hundreds of krad are applied

Are performance-based measures predictive of work participation in patients with musculoskeletal disorders? A systematic review

Assessments of whether patients with musculoskeletal disorders (MSDs) can participate in work mainly consist of case history, physical examinations, and self-reports. Performance-based measures might add value in these assessments. This study answers the question: how well do performance-based measures predict work participation in patients with MSDs? A systematic literature search was performed to obtain longitudinal studies that used reliable performance-based measures to predict work participation in patients with MSDs. The following five sources of information were used to retrieve relevant studies: PubMed, Embase, AMA Guide to the Evaluation of Functional Ability, references of the included papers, and the expertise and personal file of the authors. A quality assessment specific for prognostic studies and an evidence synthesis were performed. Of the 1,230 retrieved studies, eighteen fulfilled the inclusion criteria. The studies included 4,113 patients, and the median follow-up period was 12 months. Twelve studies took possible confounders into account. Five studies were of good quality and thirteen of moderate quality. Two good-quality and all thirteen moderate-quality studies (83%) reported that performance-based measures were predictive of work participation. Two good-quality studies (11%) reported both an association and no association between performance-based measures and work participation. One good-quality study (6%) found no effect. A performance-based lifting test was used in fourteen studies and appeared to be predictive of work participation in thirteen studies. Strong evidence exists that a number of performance-based measures are predictive of work participation in patients with MSDs, especially lifting tests. Overall, the explained variance was modest

Risk factors for developing jumper's knee in sport and occupation: a review

<p>Abstract</p> <p>Background</p> <p>The onset of jumper's knee is generally associated with sports and sporting activities. Employees in certain professions might be at risk as well for developing jumper's knee. Therefore, it is of interest to identify risk factors in sport and/or occupation.</p> <p>Findings</p> <p>A systematic search of the international scientific literature was performed until November 2008 in the scientific databases (a) Medline, (b) Embase, and (c) SportDiscus. All types of studies were included. The search strategy retrieved ten articles about risk factors in sport that met the inclusion criteria. Risk factors that could be identified are; playing volleyball (4 studies), playing basketball (3 studies), training and playing volleyball/basketball more than 12 hours per week (2 studies), in combination with weight-bearing activities of at least 5 hours per week (1 study) and playing or training on a hard surface (1 study). No studies were found regarding occupation that fulfilled the inclusion criteria.</p> <p>Conclusion</p> <p>Playing volleyball and basketball has a positive association with the onset or worsening of jumper's knee. Other risk factors are training and playing hours of at least 12 hours per week and/or in combination with weight training of at least 5 hours per week, and/or with playing or training on a hard surface. We did not find a specific occupational risk factor.</p

Lower cerebral blood flow is associated with faster cognitive decline in Alzheimer's disease

OBJECTIVE: To determine whether lower cerebral blood flow (CBF) is associated with faster cognitive decline in patients with Alzheimer's disease (AD). METHODS: We included 88 patients with dementia due to AD from the Amsterdam Dementia Cohort. Mean follow-up was 2 ± 1 years. Linear mixed models were used to determine associations of lower whole brain and regional pseudo-continuous arterial spin labelling measured CBF with rate of cognitive decline as measured with repeated mini-mental state examination (MMSE). Model 1 was adjusted for age, sex, and education. Model 2 was additionally adjusted for normalized gray matter volume, medial temporal lobe atrophy, white matter hyperintensities, microbleeds, and lacunes. Analyses were repeated after partial volume correction (PVC) of CBF. Statistical significance was set at p ≤ 0.05. RESULTS: Patients were 65 ± 7 years old, 44 (50 %) were women, and mean baseline MMSE was 22 ± 4. Annual decline (β[SE]) on the MMSE was estimated at -2.11 (0.25) points per year. Lower whole brain (β[SE]-0.50[0.25]; p ≤ 0.05) and parietal (β[SE]-0.59[0.25]; p < 0.05) CBF were associated with faster cognitive decline. PVC cortical CBF was not associated with cognitive decline. CONCLUSIONS: Lower CBF, in particular in the posterior brain regions, may have value as a prognostic marker for rate of cognitive decline in AD. KEY POINTS: • In AD, lower CBF is associated with more rapid cognitive decline. • Decreasing CBF does not reach a plateau early in AD. • PcASL-CFB has additive value to conventional structural MRI measures in AD

Recovery Courses of Patients Who Return to Work by 3, 6 or 12 Months After Total Knee Arthroplasty

Purpose This study compared the preoperative levels and postoperative recovery courses of physical and mental impairments, activity limitations and participation restrictions of working-age patients who return to work (RTW) by 3, 6 or 12 months after total knee arthroplasty (TKA). Methods A prospective survey study including TKA patients (aged < 65) (n = 146) who returned to work (RdTW) in the first postoperative year. Three groups were compared: those who returned by 3 (n = 35), 6 (n = 40) or 12 (n = 29) months. Surveys were completed preoperatively and at 6 weeks and 3, 6 and 12 months postoperatively. Outcomes represented domains of the International Classification of Functioning, i.e. physical impairments (pain, stiffness, vitality), mental impairments (mental health and depressive symptoms), activity limitations (physical functioning) and participation restrictions (social and work functioning). Results Preoperative knee-specific pain and physical functioning levels were better among patients who RdTW by 3 months, compared to those who returned by 12 months. Patients who RdTW by 3 months experienced significantly better recovery from physical impairments than those who returned by 6 months (on general pain) or 12 months (on general and knee-specific pain and on stiffness). Patients returning by 3 months experienced significantly better recovery from activity limitations (on knee-specific physical functioning). Conclusions To optimize return to work outcome after TKA surgery, the focus should lie on physical impairments (general and knee-specific pain, stiffness) and activity limitations (knee-specific physical functioning) during recovery