2,361 research outputs found
The second generation of optimized beam orbit measurement (BOM) system of LEP: hardware and performance description
The BOM System with its 504 Beam Position Monitors and 40 Processing Electronics Stations, distributed along the 27 km of the LEP tunnel, has been optimized for all beam conditions and modes of operation. The description of the Beam Position Monitors (or PU) behavior in the tunnel is given. The guiding approaches for obtaining both main aspects of the critical BOM performances were: a) high reliability, since most of the electronics is not accessible during operation, and b) resolution, precision and stability of the signal processing equipment for the management of the LEP optics, polarization and energy calibration. The finalized analog signal processing chains, both Wide-Band and Narrow-Band, are described. Since local memories allow for the recording of data at each bunch passage during more than 1000 revolutions, it can be followed by a powerful digital signal processing allowing for many modes of beam observation. Examples are presented of beam and machine behavior studies. The BOM System has been a key instrument for the success of LEP operation
Impact of alpha-tocopherol deficiency and supplementation on sacrocaudalis and gluteal muscle fiber histopathology and morphology in horses.
BackgroundA subset of horses deficient in alpha-tocopherol (α-TP) develop muscle atrophy and vitamin E-responsive myopathy (VEM) characterized by mitochondrial alterations in the sacrocaudalis dorsalis medialis muscle (SC).ObjectivesTo quantify muscle histopathologic abnormalities in subclinical α-TP deficient horses before and after α-TP supplementation and compare with retrospective (r)VEM cases.AnimalsProspective study; 16 healthy α-TP-deficient Quarter Horses. Retrospective study; 10 retrospective vitamin E-responsive myopathy (rVEM) cases .MethodsBlood, SC, and gluteus medius (GM) biopsy specimens were obtained before (day 0) and 56âdays after 5000âIU/450âkg horse/day PO water dispersible liquid α-TP (n = 8) or control (n = 8). Muscle fiber morphology and mitochondrial alterations were compared in samples from days 0 and 56 and in rVEM cases.ResultsMitochondrial alterations more common than our reference range (<2.5% affected fibers) were present in 3/8 control and 4/8 treatment horses on day 0 in SC but not in GM (mean, 2.2; range, 0%-10% of fibers). Supplementation with α-TP for 56âdays did not change the percentage of fibers with mitochondrial alterations or anguloid atrophy, or fiber size in GM or SC. Clinical rVEM horses had significantly more mitochondrial alterations (rVEM SC, 13%â±â7%; GM, 3%â±â2%) and anguloid atrophy compared to subclinical day 0 horses.Conclusions and clinical importanceClinically normal α-TP-deficient horses can have mitochondrial alterations in the SC that are less severe than in atrophied VEM cases and do not resolve after 56âdays of α-TP supplementation. Preventing α-TP deficiency may be of long-term importance for mitochondrial viability
Dynamics of Resonances in Strongly Interacting Systems
The effects of the propagation of particles which have a finite life-time and
an according broad distribution in their mass spectrum are discussed in the
context of a transport descriptions. In the first part some example cases of
mesonic modes in nuclear matter at finite densities and temperatures are
presented. These equilibrium calculations illustrate the dynamical range of
spectral distributions to be adequately covered by non-equilibrium description
of the dynamics of two nuclei colliding at high energies. The second part
addresses the problem of transport descriptions which properly account for the
damping width of the particles. A systematic and general gradient approximation
is presented in the form of diagrammatic rules which permit to derive a
self-consistent transport scheme from the Kadanoff--Baym equation. The scheme
is conserving and thermodynamically consistent provided the self-energies are
obtained within the Phi-derivable two-particle irreducible (2PI) method of
Baym. The merits, the limitations and partial cures of the limitations of this
transport scheme are discussed in detail.Comment: To appear in the proceedings of the International Conference
"Progress in Nonequilibrium Green's Functions III", Kiel, 22.-26. August 200
Where Oil and Water Do Mix
The article of record as published may be found at http://dx.doi.org/10.55540/0031-1723.222
Meta-Analysis of the Relation of Body Mass Index to All-Cause and Cardiovascular Mortality and Hospitalization in Patients With Chronic Heart Failure
Clinical studies have indicated the existence of an "obesity paradox" in patients with chronic heart failure (HF), that is, reduced mortality in patients who have elevated body mass index (BMI) scores compared with normal-weight reference groups. The aim of this study was to investigate the relation of BMI with all-cause and cardiovascular (CV) mortality and hospitalization in patients with chronic HF though a systematic review and meta-analysis of published research. PubMed, the Cumulative Index to Nursing and Allied Health Literature, Cochrane Central, Scopus, web of science and Embase were searched for studies reporting rates of total mortality, cardiac mortality, and risk for hospitalization in patients with HF in various BMI categories
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