609 research outputs found

    Memory Functioning in Obsessive-Compulsive Disorder

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    A number of studies have reported neuropsychological deficits in obsessive-compulsive disorder (OCD). These have mainly implicated frontal or temporal dysfunction. In this study, we compared the performances of OCD patients and normal subjects using a factorial interpretation of the Wechsler Memory Scale. Our results do not demonstrate significant memory impairment in OCD patients but point to the possibility of frontal lobe dysfunction as a factor in the pathophysiology of OCD

    Monitoring heavy-ion beam losses in the LHC

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    The LHC beam loss monitor (BLM) system, primarily designed for proton operation, will survey particle losses and dump the beam if the loss rate exceeds a threshold expected to induce magnet quenches. Simulations of beam losses in the full magnet geometry allow us to compare the response of the BLMs to ion and proton losses and establish preliminary loss thresholds for quenches. Further simulations of beam losses caused by collimation and electromagnetic interactions peculiar to heavy ion collisions determine the positions of extra BLMs needed for ion operation in the LHC

    Beam Loss Monitors for Heavy Ion Operation

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    The performance of the LHC as a heavy-ion collider is expected to be limited by a variety of beam loss mechanisms that are non-existent, or substantially different, in the case of protons. Among these are ultra-peripheral interactions of the colliding beams and the collimation inefficiency. Loss patterns are different and require additional installations of beam loss monitors. Further, the relation between energy deposition in superconducting magnet coils and the loss monitor signals has to be reassessed for heavy ions in order to determine the thresholds for dumping beams

    Studies on combined momentum and betatron cleaning in the LHC

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    Collimation and halo cleaning for the LHC beams are performed separately for betatron and momentum losses, requiring two dedicated insertions for collimation. Betatron cleaning is performed in IR7 while momentum cleaning is performed in IR3. A study has been performed to evaluate the performance reach for a combined betatron and momentum cleaning system in IR3. The results are presented

    Once daily nebulized beclomethasone is effective in maintaining pulmonary function and improving symptoms in asthmatic children

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    Background and Aim. Compliance with long-term inhaled therapy in asthma is often poor, but it is likely to be improved with a simplified administration, once daily.The present study was designed to assess whether, in childhood asthma, a single dose of nebulized beclomethasone dipropionate once daily was as effective and safe as the same total daily dose administered twice daily. Methods. Asthmatic children, not treated with inhaled steroids for at least a month preceding the study and using short-acting bronchodilators more than once a week were enrolled in a double-blind, double dummy, randomised, multicentric study. After a two week run-in period on nebulised twice daily 400 mcg beclomethasone dipropionate, patients were randomly assigned to twelve weeks of treatment with 800 mcg nebulised beclomethasone dipropionate daily, either in single dose (o.d. group) or divided into two 400 mcg doses (b.i.d. group). Results. 65 children (mean age 8.6 years, mean FEV1 81% of predicted), were valuable for intention to treat. During the run-in period, a significant improvement in FEV1, FVC, morning and evening PEF values and clinical scores was observed. Children then entered the randomised trial: 32 were included in the o.d. group and 33 in the b.i.d. group. During the twelve week treatment period, the observed improvement in pulmonary function parameters was maintained in both treatment groups. Morning and evening PEF showed a progressive slight increase as well as PEF diurnal variability showed a progressive reduction in the two treatment groups during the whole study period without reaching statistical significance. Moreover, in both treatment groups a similar progressive increase in symptom free nights and days and in the percentage of children achieving total asthma symptoms control was detected. Finally, no significant changes in urinary cortisol/creatinine ratio were observed throughout the study period and between groups. Conclusions. A daily dose of 800 mcg of beclomethasone, administered for twelve weeks with a nebuliser either once or twice daily provide similar efficacy in maintaining pulmonary function and symptoms of asthmatic children, with a good tolerability profile

    Memory Functioning in Obsessive-Compulsive Disorder

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    A number of studies have reported neuropsychological deficits in obsessive-compulsive disorder (OCD). These have mainly implicated frontal or temporal dysfunction. In this study, we compared the performances of OCD patients and normal subjects using a factorial interpretation of the Wechsler Memory Scale. Our results do not demonstrate significant memory impairment in OCD patients but point to the possibility of frontal lobe dysfunction as a factor in the pathophysiology of OCD

    Measurements of heavy ion beam losses from collimation

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    The collimation efficiency for Pb ion beams in the LHC is predicted to be lower than requirements. Nuclear fragmentation and electromagnetic dissociation in the primary collimators create fragments with a wide range of Z/A ratios, which are not intercepted by the secondary collimators but lost where the dispersion has grown sufficiently large. In this article we present measurements and simulations of loss patterns generated by a prototype LHC collimator in the CERN SPS. Measurements were performed at two different energies and angles of the collimator. We also compare with proton loss maps and find a qualitative difference between Pb ions and protons, with the maximum loss rate observed at different places in the ring. This behavior was predicted by simulations and provides a valuable benchmark of our understanding of ion beam losses caused by collimation.Comment: 12 pages, 20 figure

    Loss Control and Steering Strategy for the CERN LINAC4

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    A series of runs with the aim of defining alignment and gradient tolerances for the quadrupoles have been performed on the LINAC4 reference layout. The results, the implication on the machine layout and the correction schemes are reported in this paper

    Cancer: repositioned to kill stem cells

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    Chemotherapy-resistant cancer stem cells make it hard to cure many forms of the disease. Repositioning an existing drug to tackle this problem could significantly improve treatment for one form of leukaemia

    Ion and proton loss paterns at the SPS and LHC

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    The collimation system of the LHC, primarily designed for proton operation, must function safely also with 208Pb82+ions. However, the particle-matter interaction in a collimator is different for heavy ions and protons. Heavy ions are subject to nuclear fragmentation, which creates a spectrum of secondary particles exiting the collimators with a Z/A ratio different from the nominal beam. These particles could be lost in a superconducting magnet and the induced heating might cause a quench. The program ICOSIM has previously been used to simulate these losses in the LHC. In this article, we present a benchmark of ICOSIM, using measured proton and ion loss maps in the SPS, and find a good qualitative agreement. We also make a quantitative comparison where the showers of the lost particles are simulated with the FLUKA code in the full magnet geometry. Here a discrepancy of a factor 3.8 is found. Estimation of expected uncertainties continues
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