143 research outputs found

    Canonical coordinates for moduli spaces of rank two irregular connections on curves

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    In this paper, we study a geometric counterpart of the cyclic vector which allow us to put a rank 2 meromorphic connection on a curve into a ``companion'' normal form. This allow us to naturally identify an open set of the moduli space of GL2\mathrm{GL}_2-connections (with fixed generic spectral data, i.e. unramified, non resonant) with some Hilbert scheme of points on the twisted cotangent bundle of the curve. We prove that this map is symplectic, therefore providing Darboux (or canonical) coordinates on the moduli space, i.e. separation of variables. On the other hand, for SL2\mathrm{SL}_2-connections, we give an explicit formula for the symplectic structure for a birational model given by Matsumoto. We finally detail the case of an elliptic curve with a divisor of degree 22.Comment: a sign fixed and a reference adde

    X-ray magnetic circular dichroism and photoemission study of the diluted ferromagnetic semiconductor Zn1x_{1-x}Crx_xTe

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    We have performed x-ray magnetic circular dichroism (XMCD) and valence-band photoemission studies of the diluted ferromagnetic semiconductor Zn1x_{1-x}Crx_xTe. XMCD signals due to ferromagnetism were observed at the Cr 2p absorption edge. Comparison with atomic multiplet calculations suggests that the magnetically active component of the Cr ion was divalent under the tetrahedral crystal field with tetragonal distortion along the crystalline a-, b-, and c-axes. In the valence-band spectra, spectral weight near the Fermi level was strongly suppressed, suggesting the importance of Jahn-Teller effect and the strong Coulomb interaction between the Cr 3d electrons

    PLOD2 is essential to functional activation of integrin β1 for invasion/metastasis in head and neck squamous cell carcinomas.

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    Identifying the specific functional regulator of integrin family molecules in cancer cells is critical because they are directly involved in tumor invasion and metastasis. Here we report high expression of PLOD2 in oropharyngeal squamous cell carcinomas (SCCs) and its critical role as a stabilizer of integrin β1, enabling integrin β1 to initiate tumor invasion/metastasis. Integrin β1 stabilized by PLOD2-mediated hydroxylation was recruited to the plasma membrane, its functional site, and accelerated tumor cell motility, leading to tumor metastasis in vivo, whereas loss of PLOD2 expression abrogated it. In accordance with molecular analysis, examination of oropharyngeal SCC tissues from patients corroborated PLOD2 expression associated with integrin β1 at the invasive front of tumor nests. PLOD2 is thus implicated as the key regulator of integrin β1 that prominently regulates tumor invasion and metastasis, and it provides important clues engendering novel therapeutics for these intractable cancers

    Fatigue Strength Analysis and Fatigue Damage Evaluation of Roller Chain

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    This paper deals with the roller chain commonly used for transmission of mechanical power on many kinds of industrial machinery, including conveyors, cars, motorcycles, bicycles, and so forth. It consists of a series of four components called a pin, a bush, a plate, and a roller, which are driven by a sprocket. To clarify the fatigue damage, in this paper, the finite element method (FEM) is applied to those components under three different types of states, that is, the press-fitting state, the static tensile state, and the sprocket-engaging state. By comparing those states, the stress amplitude and the average stress of each component are calculated and plotted on the fatigue limit diagram. The effect of the plastic zone on the fatigue strength is also discussed. The results show that the fatigue crack initiation may start around the middle inner surface of the bush. As am example, the FEM results show that the fatigue crack of the inner plate may start from a certain point at the hole edge. The results agree with the actual fractured position in roller chains used in industry

    On the moduli spaces of framed logarithmic connections on a Riemann surface

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    We describe some results on moduli space of logarithmic connections equipped with framings on a nn-pointed compact Riemann surface

    Influence of Self-Efficacy on Cancer-Related Fatigue and Health-Related Quality of Life in Young Survivors of Childhood Cancer

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    This study aims to elucidate how self-efficacy influences cancer-related fatigue and health-related quality of life (HRQoL) in young survivors of childhood cancer. Forty-six young survivors (age range, 8-18 years) of childhood cancer who were currently in complete remission completed measures for self-efficacy (Pediatric General Self-Efficacy Scale (PedsSE)), cancer-related fatigue (Cancer-related Fatigue Score (CRFS)), and HRQoL (Pediatric Quality of Life Inventory 4.0 Generic Core Scale, Pediatric Quality of Life Inventory (PedsQL)). Structural relationships between the PedsSE and CRFS or PedsQL, including the effects of potential demographic or clinical confounders, were examined by machine learning random forest algorithms and structural equation modeling. According to the distribution of the PedsQL, six survivors with PedsQL < 70 were determined to have compromised HRQoL (referred to as low-PedsQL survivors). The random forest model identified six variables for the prediction of the CRFS, with the PedsSE being the most important, and eight variables for the distinction of low-PedsQL survivors, with the CRFS being the most and the PedsSE the third most important variable. The structural equation model indicated that a direct influence of the PedsSE on the PedsQL was less detectable (beta = -0.049), whereas an indirect influence of the PedsSE on the PedsQL via the CRFS was evident (beta = 0.333). The model explained 51% of the variation of the CRFS and 28% of the variation of the PedsQL. The PedsSE was strongly correlated with altered mood in the subclass of the CRFS (r = -0.470), and altered mood was strongly correlated with the PedsQL (r = 0.737). In conclusion, self-efficacy is a major determinant of cancer-related fatigue and influences HRQoL via cancer-related fatigue in survivors of childhood cancer. The main pathway from self-efficacy to HRQoL is thought to be via the emotional aspect of cancer-related fatigue. However, unlike adult survivors of cancer, self-efficacy for young survivors may not contribute much to self-management behaviors that maintain HRQoL

    On the moduli spaces of framed logarithmic connections on a Riemann surface

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    We describe some results on moduli space of logarithmic connections equipped with framings on a nn-pointed compact Riemann surface.Comment: Final version; to appear in Comptes Rendus S\'erie Math\'ematiqu

    Poor performance on the Iowa gambling task in children with obsessive-compulsive disorder

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    Background: Several lines of evidence implicate orbitofrontal cortex dysfunction in the pathophysiology of obsessive-compulsive disorder (OCD). The purpose of this study was to investigate neuropsychological dysfunction of the orbitofrontal cortex in children with OCD. Methods: The Iowa Gambling Task (IGT), which reflects orbitofrontal cortex function, and the Wisconsin Card Sorting Test (WCST), which is associated with functioning of the dorsolateral prefrontal cortex, were administered to 22 children with OCD and 22 healthy controls matched for gender, age, and intelligence. Results: OCD patients displayed poor performance on the IGT. In contrast, performance on the WCST was not impaired in OCD patients compared to controls. Conclusions: These findings are in line with previous studies demonstrating that OCD in childhood is associated with a dysfunction of orbitofrontal-striatal-thalamic circuitry.ArticleANNALS OF GENERAL PSYCHIATRY. 11:25 (2012)journal articl

    Fatigue strength improvement of roller chain by press fitting between pin and plate

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    To improve the fatigue strength of the roller chain, the fatigue test is conducted by varying the press-fitting ratio between the pin and the holed plate. To model what occurs in a chain under load, a single plate specimen is prepared by press-fitting two pins into two holes at the ends of the plate. The FEM analysis is performed to obtain the stress amplitude and the average stress. The results, in both cases demonstrate that the fatigue strength is improved by the press-fit between the pin and the hole. The fatigue improvement mechanism is discussed based on the stress analysis
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