196 research outputs found

    Neurochemical Correlates of Brain Atrophy in Fibromyalgia Syndrome: A Magnetic Resonance Spectroscopy and Cortical Thickness Study.

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    (1) Background: Recently, a series of clinical neuroimaging studies on fibromyalgia (FM) have shown a reduction in cortical volume and abnormally high glutamate (Glu) and glutamate + glutamine (Glx) levels in regions associated with pain modulation. However, it remains unclear whether the volumetric decreases and increased Glu levels in FM are related each other. We hypothesized that higher Glu levels are related to decreases in cortical thickness (CT) and volume in FM patients. (2) Methods: Twelve females with FM and 12 matched healthy controls participated in a session of combined 3.0 Tesla structural magnetic resonance imaging (MRI) and single-voxel MR spectroscopy focused on the thalami and ventrolateral prefrontal cortices (VLPFC). The thickness of the cortical and subcortical gray matter structures and the Glu/Cr and Glx/Cr ratios were estimated. Statistics included an independent t-test and Spearman's test. (3) Results: The Glu/Cr ratio of the left VLPFC was negatively related to the CT of the left inferior frontal gyrus (pars opercularis (p = 0.01; r = -0.75) and triangularis (p = 0.01; r = -0.70)). Moreover, the Glx/Cr ratio of the left VLPFC was negatively related to the CT of the left middle anterior cingulate gyrus (p = 0.003; r = -0.81). Significantly lower CTs in FM were detected in subparts of the cingulate gyrus on both sides and in the right inferior occipital gyrus (p < 0.001). (4) Conclusions: Our findings are in line with previous observations that high glutamate levels can be related, in a concentration-dependent manner, to the morphological atrophy described in FM patients

    Study of the beam dynamics in a linac with the code retar

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    The three-dimensional fully relativistic and self- consistent code RETAR has been developed to model the dynamics of high-brightness electron beams and, in particular, to assess the importance of the retarded radiative part of the emitted electromagnetic fields in all conditions where the electrons experience strong accelerations. In this analysis we evaluate the radiative energy losses in the electron emission process from the photocathode of an injector, during the successive acceleration of the electron beam in the RF cavity and the focalization due to the magnetic field of the solenoid. The analysis is specifically carried out with parameters of importance in the framework of the SPARC and PLASMONX projects

    WA92: a fixed target experiment to trigger on and identify beauty particle decays

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    We describe the detectors and trigger system used in the CERN WA92 experiment. The experiment was designed to study the production and decay of beauty particles from 350 GeV/c c\,  π−\,\pi^- interactions in copper and tungsten targets. Charged particle tracking is performed using the Omega spectrometer. Silicon microstrip detectors are used to provide precise tracking information in the region of the production and the decay of heavy-flavoured particles and to trigger on the resulting high impact parameter tracks. The precision of vertex reconstruction corresponds to ±3.7%\pm 3.7\% of the mean B-decay proper lifetime. Lepton and high transverse momentum hadron signals are also used in the trigger, which accepts 29\% of B-decays and rejects 98\% of non-beauty interactions

    Measurement of the beauty production cross-section in 350 GeV/c π−\pi^- -Cu interactions

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    Using a sample of 10810^8 triggered events, produced in π−\pi^--- \,Cu interactions at 350~GeV/c/c, we have identified 26 beauty events. The estimated background in this sample is 0.6±0.60.6 \pm 0.6 events. From these data, assuming a linear A-dependence, we measure a beauty production cross-section integrated over all xFx_F of 5.7+1.3−1.1 (stat.)+0.6−0.5 (syst.) 5.7 {+1.3 \atop -1.1}~{\mathrm {(stat.)}} {+0.6 \atop -0.5}~{\mathrm {(syst.)}}~nb/N

    Measurement of hadronic shower punchthrough in magnetic field

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    The total punchthrough probability of showers produced by negative pions, positive pions, positive kaons and protons, has been measured as a function of depth in an absorber in a magnetic field ranging from 0 to 3 Tesla. The incident particle momentum varied from 10 to 300 GeV/c. The lateral shower development and particle multiplicity at several absorber depths have been determined. The measurements are compared with the predictions of Monte Carlo simulation programs

    Determination of σ(e+e−→π+π−)\sigma(e^+e^-\to \pi^+ \pi^-) from radiative processes at DAΊ\PhiNE

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    We have measured the cross section σ(e+e−→π+Ï€âˆ’Îł)\sigma(e^+e^-\to\pi^+\pi^-\gamma) with the KLOE detector at DAΊ\PhiNE, at an energy W=Mϕ=1.02W=M_\phi=1.02 GeV. From the dependence of the cross section on m(π+π−)=W2−2WEÎłm(\pi^+\pi^-)=\sqrt{W^2-2WE_\gamma}, where EÎłE_\gamma is the energy of the photon radiated from the initial state, we extract σ(e+e−→π+π−)\sigma(e^+e^-\to\pi^+\pi^-) for the mass range 0.35<m2(π+π−)<0.950.35<m^2(\pi^+\pi^-)<0.95 GeV2^2. From our result we extract the pion form factor and the hadronic contribution to the muon anomaly, aÎŒa_\mu.Comment: Contributed paper to EPS 2003 and LP 200

    The hadronic cross section measurement at KLOE

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    KLOE uses the radiative return to measure cross section σ(e+e-->π+π-Îł) at the electron-positron collider DAΊNE. Divinding by a theoretical radiator function, we obtain the cross section σ(e+e-->π+π-Îł) for the mass range 0.35π<0.95GeV2. We calculate the hadronic contribution to the muon anomaly for the given mass range: aÎŒ=388.7+/-0.8stat+/-3.5syst+/-3.5t

    Status report of the RD5 experiment

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