63 research outputs found

    Object Classification and Segmentation Based on Deep Learning Using Underwater Mapping Data

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    This paper presents a fast and accurate classification method for underwater objects using underwater mapping data obtained by a small Autonomous Underwater Vehicle (AUV) and autonomous surface vehicle (ASV). For the mapping data, in addition to underwater acoustic reflection intensity images, water depth data, point cloud data and backscattering reflection intensity data are employed. We propose the automatic classification and semantic segmentation method on deep learning using a convolutional neural network (CNN) and PointNet++. In order to verify the effectiveness of the present method, we applied it to the measured several underwater mapping data

    Visualization of Flow Simulation Based on AR Using GNSS Data

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    This paper presents an AR visualization system for flow simulation based on the location-based AR using GNSS data. The accuracy of position data obtained by the GNSS receiving machine is investigated and the position correction method using two GNSS receiving machines is investigated. The present method is applied to the visualization of flow velocity in rivers. The validity and the efficiency of the present method is investigated by the comparison with the marker based AR

    Tsunami Evacuation Simulation Considering Building Collapse and Fire Spread

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    The objective of this study is to develop a tsunami evacuation simulation system that takes into account building collapse and fire spread. Road blockage is determined by calculating the road blockage probability due to building collapse, taking into account the size of the assumed earthquake, location of buildings, and type of building. For fire spread simulation, an existing simulator based on the fire spread rate equation is used. Under average wind direction and speed conditions for the target area, arbitrary fire points are set up and fire spread is represented using fire times for each building obtained from the simulation. The applicability of this system as a scenario is extended. The present system is applied to several examples to demonstrate the validity and effectiveness of the system

    Patient-reported dyspnea and health predict waitlist mortality in patients waiting for lung transplantation in Japan

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    Background: Waitlist mortality due to donor shortage for lung transplantation is a serious problem worldwide. Currently, the selection of recipients in Japan is mainly based on the registration order. Hence, scientific evidence for risk stratification regarding waitlist mortality is urgently needed. We hypothesized that patient-reported dyspnea and health would predict mortality in patients waitlisted for lung transplantation. Methods: We analyzed factors related to waitlist mortality using data of 203 patients who were registered as candidates for lung transplantation from deceased donors. Dyspnea was evaluated using the modified Medical Research Council (mMRC) dyspnea scale, and the health status was determined with St. George's Respiratory Questionnaire (SGRQ). Results: Among 197 patients who met the inclusion criteria, the main underlying disease was interstitial lung disease (99 patients). During the median follow-up period of 572 days, 72 patients died and 96 received lung transplantation (69 from deceased donors). Univariable competing risk analyses revealed that both mMRC dyspnea and SGRQ Total score were significantly associated with waitlist mortality (p = 0.003 and p < 0.001, respectively) as well as age, interstitial lung disease, arterial partial pressure of carbon dioxide, and forced vital capacity. Multivariable competing risk analyses revealed that the mMRC and SGRQ score were associated with waitlist mortality in addition to age and interstitial lung disease. Conclusions: Both mMRC dyspnea and SGRQ score were significantly associated with waitlist mortality, in addition to other clinical variables such as patients' background, underlying disease, and pulmonary function. Patient-reported dyspnea and health may be measured through multi-dimensional analysis (including subjective perceptions) and for risk stratification regarding waitlist mortality

    Antegrade slow pathway mapping of typical atrioventricular nodal reentrant tachycardia based on direct slow pathway capture

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    Background: Radiofrequency (RF) ablation of typical atrioventricular nodal reentrant tachycardia (tAVNRT) is performed without revealing out the location of antegrade slow pathway (ASp). In this study, we studied a new electrophysiological method of identifying the site of ASp. Methods: This study included 19 patients. Repeated series of very high-output single extrastimulations (VhoSESts) were delivered at the anatomical slow pathway region during tAVNRT. Tachycardia cycle length (TCL), coupling interval (CI), and return cycle (RC) were measured and the prematurity of VhoSESts [ΔPM (= TCL – CI)] and the prolongation of RCs [ΔPL (= RC – TCL)] were calculated. Pacing sites were classified into two categories: (i) ASp capture sites [DSPC(+) sites] were calculated. Pacing sites were classified into two categories: (i) ASp capture sites [DSPC(+) sites, where two different RCs were shown, and ASp non-capture sites [DSPC(-) sites], where only one RC was shown. RF ablation was performed at DSPC(+) sites and/or sites with catheter-induced mechanical trauma (CIMT) to ASp. Results: DSPC(+) sites were shown in 13 patients (68%). RF ablation was successful in all patients without any degree of atrioventricular block nor recurrence. Total number of RF applications was 1.8 ± 1.1. Minimal distance between successful ablation sites and DSPC(+)/CIMT sites and His bundle (HB) electrogram recording sites was 1.9 ± 0.8 mm and 19.8 ± 6.1 mm, respectively. ΔPL of more than 92.5 ms, ΔPL/TCL of more than 0.286, and ΔPL/ΔPM of more than 1.565 could identify ASp with sensitivity of 100%, 91.1%, and 88.9% and specificity of 92.9%, 97.0%, and 97.6%, respectively. Conclusions: Sites with ASp capture and CIMT were close to successful ablation sites and could be useful indicators of tAVNRT ablation

    CrkL directs ASAP1 to peripheral focal adhesions

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    Searching for proteins in platelets that can interact with the N-terminal SH3 domain of CrkL (using a combination of a pull-down assay followed by mass spectrometry), we have found that human platelets express an ADP-ribosylation factor (Arf)-specific GTPase-activating protein (GAP), ASAP1, as a CrkL-binding protein. In spreading platelets, most endogenous ASAP1 is localized at peripheral focal adhesions. To determine the physiologic significance of the CrkL-ASAP1 association, we overexpressed CrkL, ASAP1, or both in combination in COS7 cells. Unlike endogenous ASAP1 in platelets, overexpressed ASAP1 showed diffuse cytoplasmic distribution. However, when co-expressed with wild-type CrkL, both endogenous and expressed ASAP1 accumulated at CrkL-induced focal adhesions. An SH2-mutated CrkL, which cannot localize at focal adhesions, failed to recruit ASAP1 into focal adhesions. Thus, CrkL appears to be a lynchpin between ASAP1 and peripheral focal adhesions

    Screening of clock gene polymorphisms demonstrates association of a PER3 polymorphism with morningness-eveningness preference and circadian rhythm sleep disorder.

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    A system of self-sustained biological clocks controls the 24-h rhythms of behavioral and physiological processes such as the sleep-wake cycle. The circadian clock system is regulated by transcriptional and translational negative feedback loops of multiple clock genes. Polymorphisms in circadian clock genes have been associated with morningness-eveningness (diurnal) preference, familial advanced sleep phase type (ASPT), and delayed sleep phase type (DSPT). We genotyped single-nucleotide polymorphisms in circadian clock genes in 182 DSPT individuals, 67 free-running type (FRT) individuals, and 925 controls. The clock gene polymorphisms were tested for associations with diurnal preference and circadian rhythm sleep disorder (CRSD) phenotypes. The PER3 polymorphism (rs228697) was significantly associated with diurnal preference and the FRT phenotype. The minor allele of rs228697 was more prevalent in evening types than in morning types (sex-adjusted odds ratio (OR), 2.483, Bonferroni-corrected P = 0.012) and in FRT individuals compared with the controls (age- and sex-adjusted OR, 2.021, permutated P = 0.017). Our findings support the notion that PER3 polymorphisms could be a potential genetic marker for an individual\u27s circadian and sleep phenotypes

    Pathophysiology and pathogenesis of circadian rhythm sleep disorders

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    Metabolic, physiological and behavioral processes exhibit 24-hour rhythms in most organisms, including humans. These rhythms are driven by a system of self-sustained clocks and are entrained by environmental cues such as light-dark cycles as well as food intake. In mammals, the circadian clock system is hierarchically organized such that the master clock in the suprachiasmatic nuclei of the hypothalamus integrates environmental information and synchronizes the phase of oscillators in peripheral tissues. The transcription and translation feedback loops of multiple clock genes are involved in the molecular mechanism of the circadian system. Disturbed circadian rhythms are known to be closely related to many diseases, including sleep disorders. Advanced sleep phase type, delayed sleep phase type and nonentrained type of circadian rhythm sleep disorders (CRSDs) are thought to result from disorganization of the circadian system. Evaluation of circadian phenotypes is indispensable to understanding the pathophysiology of CRSD. It is laborious and costly to assess an individual's circadian properties precisely, however, because the subject is usually required to stay in a laboratory environment free from external cues and masking effects for a minimum of several weeks. More convenient measurements of circadian rhythms are therefore needed to reduce patients' burden. In this review, we discuss the pathophysiology and pathogenesis of CRSD as well as surrogate measurements for assessing an individual's circadian phenotype

    Aging and circadian rhythms

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    In many animal species including humans, numerous processes exhibit 24-hour (h) rhythms. The circadian clock regulates daily rhythms of behavior and physiology such as the sleep-wake cycle (activity/rest), autonomic nervous function, and neuroendocrine function. The mammalian master clock located in the suprachiasmatic nuclei (SCN) of the hypothalamus incorporates environmental information and orchestrates peripheral clocks in other tissues and organs. Various characteristics of daily rhythms undergo age-dependent changes with respect to amplitude, entrained phase, free-running period (τ), and reentrainability. The mechanisms underlying aging of the circadian clock have not been fully understood. This review discusses current findings on age-related changes in daily rhythms of behavior and physiology
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