438 research outputs found

    The human 'pitch center' responds differently to iterated noise and Huggins pitch

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    A magnetoencephalographic marker for pitch analysis (the pitch onset response) has been reported for different types of pitch-evoking stimuli, irrespective of whether the acoustic cues for pitch are monaurally or binaurally produced. It is claimed that the pitch onset response reflects a common cortical representation for pitch, putatively in lateral Heschl's gyrus. The result of this functional MRI study sheds doubt on this assertion. We report a direct comparison between iterated ripple noise and Huggins pitch in which we reveal a different pattern of auditory cortical activation associated with each pitch stimulus, even when individual variability in structure-function relations is accounted for. Our results suggest it may be premature to assume that lateral Heschl's gyrus is a universal pitch center

    Studies of the Giant Dipole Resonance in 27^{27}Al, 40^{40}Ca, 56^{56}Fe, 58^{58}Ni and 208^{208}Pb with high energy-resolution inelastic proton scattering under 0∘^\circ

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    A survey of the fine structure of the Isovector Giant Dipole Resonance (IVGDR) was performed, using the recently commissioned zero-degree facility of the K600 magnetic spectrometer at iThemba LABS. Inelastic proton scattering at an incident energy of 200 MeV was measured on 27^{27}Al, 40^{40}Ca, 56^{56}Fe, 58^{58}Ni and 208^{208}Pb. A high energy resolution (ΔE≃\rm{\Delta}\it{E} \simeq 40 keV FWHM) could be achieved after utilising faint-beam and dispersion-matching techniques. Considerable fine structure is observed in the energy region of the IVGDR and characteristic energy scales are extracted from the experimental data by means of a wavelet analysis. The comparison with Quasiparticle-Phonon Model (QPM) calculations provides insight into the relevance of different giant resonance decay mechanisms. Photoabsorption cross sections derived from the data assuming dominance of relativistic Coulomb excitation are in fair agreement with previous work using real photons.Comment: 15 pages, 15 figure

    Low-energy electric dipole response in 120Sn

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    The electric dipole strength in 120Sn has been extracted from proton inelastic scattering experiments at E_p = 295 MeV and at forward angles including 0 degree. Below neutron threshoild it differs from the results of a 120Sn(gamma,gamma') experiment and peaks at an excitation energy of 8.3 MeV. The total strength corresponds to 2.3(2)% of the energy-weighted sum rule and is more than three times larger than what is observed with the (gamma,gamma') reaction. This implies a strong fragmentation of the E1 strength and/or small ground state branching ratios of the excited 1- states.Comment: 7 pages, 6 figure

    Pro-inflammatory pattern of IgG1 Fc glycosylation in multiple sclerosis cerebrospinal fluid.

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    Background Immunoglobulin G (IgG) effector functions are regulated by the composition of glycans attached to a conserved N-glycosylation site in the Fc part. Intrathecal production of IgG, especially IgG1, is a hallmark of multiple sclerosis (MS), but nothing is known about IgG Fc glycosylation in MS and in cerebrospinal fluid (CSF) in general. Methods We applied mass spectrometry of tryptic Fc glycopeptides to analyze IgG Fc glycosylation (sialylation, galactosylation, fucosylation, and bisecting N-acetylglucosamine (GlcNAc)) in 48 paired CSF and serum samples from adult patients with MS or a first demyelinating event highly suggestive of MS (designated as MS cases), and from healthy volunteers and patients with other non-inflammatory diseases (control group). p values were adjusted for multiple testing. Results Our experiments revealed four main results. First, IgG1 glycosylation patterns were different in CSF vs. serum, in the MS group and even in control donors without intrathecal IgG synthesis. Second, in MS patients vs. controls, IgG1 glycosylation patterns were altered in CSF, but not in serum. Specifically, in CSF from the MS group, bisecting GlcNAc were elevated, and afucosylation and galactosylation were reduced. Elevated bisecting GlcNAc and reduced galactosylation are known to enhance IgG effector functions. Third, hypothesis-free regression analysis revealed that alterations of afucosylation and bisecting GlcNAc in CSF from MS cases peaked 2–3 months after the last relapse. Fourth, CSF IgG1 glycosylation correlated with the degree of intrathecal IgG synthesis and CSF cell count. Conclusions The CNS compartment as well as the inflammatory milieu in MS affect IgG1 Fc glycosylation. In MS, the CSF IgG1 glycosylation has features that enhance Fc effector functions

    Very late-onset neuromyelitis optica spectrum disorder beyond the age of 75

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    Aquaporin-4 antibody (AQP4-Ab)-positive neuromyelitis optica spectrum disorder (NMOSD) is a rare but often severe autoimmune disease with median onset around 40 years of age. We report characteristics of three very-late-onset NMOSD (including complete NMO) patients >75 years of age, in whom this diagnosis initially seemed unlikely because of their age and age-associated concomitant diseases, and briefly review the literature. All three patients, aged 79, 82 and 88 years, presented with a spinal cord syndrome as the first clinical manifestation of AQP4-Ab-positive NMOSD. They all had severe relapses unless immunosuppressive therapy was initiated, and one untreated patient died of a fatal NMOSD course. Two patients developed side effects of immunosuppression. We conclude that a first manifestation of NMOSD should be considered even in patients beyond the age of 75 years with a compatible syndrome, especially longitudinally extensive myelitis. Early diagnosis and treatment are feasible and highly relevant. Special attention is warranted in the elderly to recognize adverse effects of immunosuppressive therapies as early as possible

    Prevalence of antibodies against influenza A and B viruses in children in Germany, 2008 to 2010

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    The prevalence of influenza A and B virus-specific IgG was determined in sera taken between 2008 and 2010 from 1,665 children aged 0-17 years and 400 blood donors in Germany. ELISA on the basis of whole virus antigens was applied. Nearly all children aged nine years and older had antibodies against influenza A. In contrast, 40% of children aged 0-4 years did not have any influenza A virus-specific IgG antibodies. Eighty-six percent of 0-6 year-olds, 47% of 7-12 year-olds and 20% of 13-17 year-olds were serologically naive to influenza B viruses. By the age of 18 years, influenza B seroprevalence reached approximately 90%. There were obvious regional differences in the seroprevalence of influenza B in Germany. In conclusion, seroprevalences of influenza A and influenza B increase gradually during childhood. The majority of children older than eight years have basal immunity to influenza A, while comparable immunity against influenza B is only acquired at the age of 18 years. Children aged 0-6 years, showing an overall seroprevalence of 67% for influenza A and of 14% for influenza B, are especially at risk for primary infections during influenza B seasons
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