453 research outputs found

    Cell Ca2+ response to luminal vasopressin in cortical collecting tubule principal cells

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    Cell Ca2+ response to luminal vasopressin in cortical collecting tubule principal cells. Although vasopressin V1 receptors have been shown to exist in both luminal and basolateral membranes of rabbit cortical collecting duct (CCD), exact cell types having V1 receptors remain unestablished. To identify the distribution of V1 receptor by cytoplasmic Ca2+ response, we utilized the confocal imaging system in the microperfused rabbit CCD. Basolateral application of arginine vasopressin (AVP) increased [Ca2+]i mainly in one group of cells which were not stained by fluorescein-isothiocyanate-conjugated peanut agglutinin. Luminal application of AVP increased [Ca2+]i in the same cells which responded to basolateral AVP. These findings provide evidence that V1 receptors, as defined by the [Ca2+]i response, exist in both luminal and basolateral membranes of the rabbit principal cell

    GOVERNING EQUATIONS OF MOTION OF WALKING BEHAVIOR OF UNANCHORED FLAT-BOTTOM CYLINDRICAL SHELL TANKS SUBJECTED TO HORIZONTAL SINOSOIDAL GROUND MOTION

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    ABSTRACT The governing equations of motion of walking phenomena of unanchored flat-bottom cylindrical shell tanks subjected to horizontal sinusoidal ground motion are examined. The equations of motion are derived through variational approach. The physical quantities related to the walking phenomena are the mass of tank itself, tank content, the effective mass of liquid for bulging motion, that for rocking motion, that for rockingbulging interaction motion, and friction force including selfweight reduction effects. The roles of each physical quantity during the walking motion are clearly identified. Comparison of the time history of experimental results and that of analytical ones corroborates accuracy of the proposed equations of motion. INTRODUCTION The large slip of a flat bottom cylindrical shell tank was observed when the tank experienced severe ground motion Kobayashi [3] presented a multi-degree-of-freedom model for the large slip of the tank, which models the fluid-structure interaction and uplift of the tank. However, its applicability is not thoroughly discussed. In contrast, the senior autho

    Mammalian BCAS3 and C16orf70 associate with the phagophore assembly site in response to selective and non-selective autophagy

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    Macroautophagy/autophagy is an intracellular degradation process that delivers cytosolic materials and/or damaged organelles to lysosomes. De novo synthesis of the autophagosome membrane occurs within a phosphatidylinositol-3-phosphate-rich region of the endoplasmic reticulum, and subsequent expansion is critical for cargo encapsulation. This process is complex, especially in mammals, with many regulatory factors. In this study, by utilizing PRKN (parkin RBR E3 ubiquitin protein ligase)-mediated mitochondria autophagy (mitophagy)-inducing conditions in conjunction with chemical crosslinking and mass spectrometry, we identified human BCAS3 (BCAS3 microtubule associated cell migration factor) and C16orf70 (chromosome 16 open reading frame 70) as novel proteins that associate with the autophagosome formation site during both non-selective and selective autophagy. We demonstrate that BCAS3 and C16orf70 form a complex and that their association with the phagophore assembly site requires both proteins. In silico structural modeling, mutational analyses in cells and in vitro phosphoinositide-binding assays indicate that the WD40 repeat domain in human BCAS3 directly binds phosphatidylinositol-3-phosphate. Furthermore, overexpression of the BCAS3-C16orf70 complex affects the recruitment of several core autophagy proteins to the phagophore assembly site. This study demonstrates regulatory roles for human BCAS3 and C16orf70 in autophagic activity

    Periodic super-radiance in Er:YSO crystal

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    We observed periodic optical pulses from an Er:YSO crystal during irradiating with an continuous-wave excitation laser. We refer to this new phenomenon as "periodic super-radiance". This periodicity can be understood qualitatively by a simple model, in which a cyclic process of a continuous supply of population inversion and a sudden burst of super-radiance is repeated. The excitation power dependences of peak interval and the pulse area can be interpreted with our simple model. In addition, the linewidth of super-radiance is much narrower than an inhomogeneous broadening in a crystal. This result suggests that only Er3+ ions in a specific environment are involved in super-radiance.Comment: 7 pages, 5 figure

    Viewing Targets in Infantile Nystagmus

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    The aim of this study was to propose a new pathophysiological hypothesis for involuntary eye oscillation in infantile nystagmus (IN): patients with IN exhibit impaired gaze fixation, horizontal smooth pursuit and optokinetic nystagmus (OKN) and use saccadic eye movements for these underlying impairments. In order to induce saccades, they make enough angle between gaze and target by precedent exponential slow eye movements. IN consists of the alternate appearance of the saccade and the slow eye movements. Unlike most previous theories, IN is therefore considered a necessary strategy allowing for better vision and not an obstacle to clear vision. In five patients with IN, eye movements were analyzed during the smooth pursuit test, saccadic eye movement test, OKN test and vestibulo-ocular reflex (VOR) test. Their gaze fixation, horizontal smooth pursuit, OKN and the last half of the slow phase of VOR were impaired. The lines obtained by connection of the end eye positions of fast phase of nystagmus coincided with the trajectories of targets. The findings indicate that patients followed the target by the fast but not the slow phase of nystagmus, which supports our hypothesis. By setting the direction of slow phase of nystagmus opposite to the direction of the OKN stimulation, enough angle can be effectively made between the gaze and target for the induction of saccade. This is the mechanism of reversed OKN response. In darkness and when eyes are closed, IN weakens because there is no visual target and neither the saccade for catching up the target or slow phase for induction of the saccade is needed

    Distinguishability Measures and Entropies for General Probabilistic Theories

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    As a part of the construction of an information theory based on general probabilistic theories, we propose and investigate the several distinguishability measures and "entropies" in general probabilistic theories. As their applications, no-cloning theorems, information-disturbance theorems are reformulated, and a bound of the accessible informations is discussed in any general probabilistic theories, not resorting to quantum theory.Comment: 17 pages, 1 figure, Related but independent works (arXiv:0909.4801 and arXiv:0909.5075) have appeared recently while we were completing this paper. In v2, we added the reference (arXiv:0909.4801); In v3, "mimimum" is changed to "infimum" in the definition of fidelity so that it is more rigorou

    Variation analysis of multiple tsunami inundation models

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    Researchers have developed tsunami inundation models based on nonlinear shallow water equations to estimate tsunami propagation and inundation. However, their empirical results are not in perfect agreement with those of other research institutes, even though the same governing equations are used. Therefore, we quantitatively evaluated the variability of tsunami simulations in this study. Several research institutes have conducted tsunami simulations under the same input conditions using tsunami inundation models adopted for tsunami hazard assessment, resulting in a certain degree of variability among them. By examining the spatial and temporal differences in various physical quantities, we identified the characteristic topography where the variability between tsunami simulations increases. A novel method for calculating statistics from the area integrals of physical quantities was proposed to demonstrate the variability in the overall simulation results. In addition, the effects of different setting parameters and computational environments on the simulation results of a single model were evaluated. The findings of this study are expected to not only serve as a basis to verify the reliability of source codes employed by users of the tsunami inundation model, but also contribute useful technical information to advance probabilistic tsunami hazard assessment in the future
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