815 research outputs found

    FeII/MgII Emission Line Ratios of QSOs. II. z>6 Objects

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    Near-infrared spectra of four QSOs located at z>6z>6 are obtained with the OH-airglow suppressor mounted on the Subaru telescope. The FeII/MgII emission-line ratios of these QSOs are examined by the same fitting algorithm as in our previous study of z<5.3z<5.3 QSOs. The fitting results show that two out of the four z>6z>6 QSOs have significant FeII emission in their rest-UV spectra, while the other two have almost no FeII features. We also applied our fitting algorithm to more than 10,000 SDSS QSOs and found two trends in the distribution of FeII/MgII against redshift: (1) the upper envelope of the FeII/MgII distribution at z>3z>3 shows a probable declination toward high redshift, and (2) the median distribution settles into lower ratios at z∼1.5z\sim 1.5 with small scatter compared to the other redshift. We discuss an Fe/Mg abundance evolution of QSOs with a substantial contribution from the diverse nature of the broad-line regions in high-redshift QSOs.Comment: 12 pages, 2 figures. Accepted for publication in ApJ (10 October 2004, v614

    Ground-state properties of the one-dimensional attractive Hubbard model with confinement: a comparative study

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    We revisit the one-dimensional attractive Hubbard model by using the Bethe-ansatz based density-functional theory and density-matrix renormalization method. The ground-state properties of this model are discussed in details for different fillings and different confining conditions in weak-to-intermediate coupling regime. We investigate the ground-state energy, energy gap, and pair-binding energy and compare them with those calculated from the canonical Bardeen-Cooper-Schrieffer approximation. We find that the Bethe-ansatz based density-functional theory is computationally easy and yields an accurate description of the ground-state properties for weak-to-intermediate interaction strength, different fillings, and confinements. In order to characterize the quantum phase transition in the presence of a harmonic confinement, we calculate the thermodynamic stiffness, the density-functional fidelity, and fidelity susceptibility, respectively. It is shown that with the increase of the number of particles or attractive interaction strength, the system can be driven from the Luther-Emery-type phase to the composite phase of Luther-Emery-like in the wings and insulating-like in the center.Comment: 13 pages with 10 figures and 2 table

    Expression of vesicular glutamate transporters in sensory and autonomic neurons innervating the mouse urinary bladder

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    Purpose: Vesicular glutamate transporters (VGLUTs), essential for loading glutamate into synaptic vesicles, are present in various neuronal systems. However, the expression of VGLUTs in neurons innervating the urinary bladder has not yet been analyzed. Here, we study the presence of VGLUTs type-1, -2 and -3 (VGLUT1, VGLUT2 and VGLUT3, respectively) in mouse urinary bladder neurons. Materials and Methods: Expression of VGLUT1, VGLUT2 and calcitonin gene-related peptide (CGRP) was analyzed by immunohistochemistry in retrogradely labeled primary afferent and autonomic neurons of BALB/C mice after injecting Fast Blue in the urinary bladder wall. To study VGLUT3, retrograde tracing of the urinary bladder was performed in transgenic mice where VGLUT3 is identified by detection of enhanced green fluorescent protein (EGFP). Results: Most urinary bladder DRG neurons expressed VGLUT2. A smaller percentage of neurons also expressed VGLUT1 or VGLUT3. Coexpression with CGRP was only observed for VGLUT2. Occasional VGLUT2-immunoreactive (IR) neurons were seen in the major pelvic ganglion (MPG). Abundant VGLUT2-IR nerves were detected in the urinary bladder dome, trigone and also the urethra; VGLUT1-IR nerves were discretely present. Conclusions: We present novel data on the expression of VGLUTs in sensory and autonomic neurons innervating the mouse urinary bladder. The frequent association of VGLUT2 and CGRP in sensory neurons suggests interactions between glutamatergic and peptidergic neurotransmissions, potentially influencing commonly perceived sensations in the urinary bladder, such as discomfort and pain.Fil: Brumovsky, Pablo Rodolfo. Universidad Austral. Facultad de Ciencias Biomédicas. Laboratorio de Investigaciones Biomédicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. University of Pittsburgh. Department of Anesthesiology. Pittsburgh Center for Pain Research; Estados UnidosFil: Seal, Rebecca P.. University of Pittsburgh. Department of Anesthesiology. Pittsburgh Center for Pain Research; Estados UnidosFil: Lundgren, Kerstin H.. University of Cincinnati. Department of Neurology; Estados UnidosFil: Seroogy, Kim B.. University of Cincinnati. Department of Neurology; Estados UnidosFil: Watanabe, Masahiko. Hokkaido University School of Medicine. Department of Anatomy; JapónFil: Gebhart, G. F.. University of Pittsburgh. Department of Anesthesiology. Pittsburgh Center for Pain Research; Estados Unido

    The Apparent Host Galaxy of PKS 1413+135: HST, ASCA and VLBA Observations

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    PKS 1413+135 (z=0.24671) is one of very few radio-loud AGN with an apparent spiral host galaxy. Previous authors have attributed its nearly exponential infrared cutoff to heavy absorption but have been unable to place tight limits on the absorber or its location in the optical galaxy. In addition, doubts remain about the relationship of the AGN to the optical galaxy given the observed lack of re-emitted radiation. We present new HST, ASCA and VLBA observations which throw significant new light on these issues. The HST observations reveal an extrremely red color (V-H = 6.9 mag) for the active nucleus of PKS 1413+135, requiring both a spectral turnover at a few microns due to synchrotron aging and a GMC-sized absorber. We derive an intrinsic column N_H = 4.6^{+2.1}_{-1.6} times 10^{22}cm^{-2} and covering fraction f = 0.12^{+0.07}_{-0.05}. As the GMC is likely in the disk of the optical galaxy, our sightline is rather unlikely (P ~ 2 times 10^{-4}). The properties of the GMC typical of GMCs in our own galaxy. The HI absorber appears centered 25 milliarcseconds away from the nucleus, while the X-ray and nearly all of the molecular absorbers must cover the nucleus, implying a complicated geometry and cloud structure, with a molecular core along our line of sight to the nucleus. Interestingly, the HST/NICMOS data require the AGN to be decentered relative to the optical galaxy by 13 +/- 4 milliarcseconds. This could be interpreted as suggestive of an AGN location far in the background compared to the optical galaxy, but it can also be explained by obscuration and/or nuclear structure, which is more consistent with the observed lack of multiple images.Comment: 27 pages, 8 figures; accepted to A

    Soundness of Unravelings for Conditional Term Rewriting Systems via Ultra-Properties Related to Linearity

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    Unravelings are transformations from a conditional term rewriting system (CTRS, for short) over an original signature into an unconditional term rewriting systems (TRS, for short) over an extended signature. They are not sound w.r.t. reduction for every CTRS, while they are complete w.r.t. reduction. Here, soundness w.r.t. reduction means that every reduction sequence of the corresponding unraveled TRS, of which the initial and end terms are over the original signature, can be simulated by the reduction of the original CTRS. In this paper, we show that an optimized variant of Ohlebusch's unraveling for a deterministic CTRS is sound w.r.t. reduction if the corresponding unraveled TRS is left-linear or both right-linear and non-erasing. We also show that soundness of the variant implies that of Ohlebusch's unraveling. Finally, we show that soundness of Ohlebusch's unraveling is the weakest in soundness of the other unravelings and a transformation, proposed by Serbanuta and Rosu, for (normal) deterministic CTRSs, i.e., soundness of them respectively implies that of Ohlebusch's unraveling.Comment: 49 pages, 1 table, publication in Special Issue: Selected papers of the "22nd International Conference on Rewriting Techniques and Applications (RTA'11)

    Histidine-rich Glycoprotein Could Be an Early Predictor of Vasospasm after Aneurysmal Subarachnoid Hemorrhage

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    Cerebral vasospasm (CVS) is a major contributor to the high morbidity and mortality of aneurysmal subarachnoid hemorrhage (aSAH) patients. We measured histidine-rich glycoprotein (HRG), a new biomarker of aSAH, in cerebrospinal fluid (CSF) to investigate whether HRG might be an early predictor of CVS. A total of seven controls and 14 aSAH patients (8 males, 6 females aged 53.4±15.4 years) were enrolled, and serial CSF and serum samples were taken. We allocated these samples to three phases (T1-T3) and measured HRG, interleukin (IL)-6, fibrinopeptide A (FpA), and 8-hydroxy-2’-deoxyguanosine (8OHdG) in the CSF, and the HRG in serum. We also examined the release of HRG in rat blood incubated in artificial CSF. In contrast to the other biomarkers examined, the change in the CSF HRG concentration was significantly different between the nonspasm and spasm groups (p<0.01). The rat blood/CSF model revealed a time course similar to that of the human CSF samples in the non-spasm group. HRG thus appears to have the potential to become an early predictor of CVS. In addition, the interaction of HRG with IL-6, FpA, and 8OHdG may form the pathology of CVS

    Topological Dislocations and Mixed State of Charge Density Waves

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    We discuss the possibility of the ``mixed state'' in incommensurate charge density waves with three-dimensional order. It is shown that the mixed state can be created by applying an electric field perpendicular to the chains. This state consists of topological dislocations induced by the external field and is therefore similar to the mixed states of superfluids (type-II superconductor or liquid Helium II). However, the peculiar coupling of charge density waves with the electric field strongly modifies the nature of the mixed state compared to the conventional superfluids. The field and temperature dependence of the properties of the mixed state are studied, and some experimental aspects are discussed.Comment: 10 pages, Revtex format, no figures, to appear in Phys. Rev. Let

    The Korean Financial System: Overcoming the Global Financial Crisis and Addressing Remaining Problems

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