108 research outputs found

    Optimal Toll Rate and Expansion of Urban Expressway

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    A welfare economic approach is tried to an optimal decision of toll rate and expansion of urban expressway network in an equilibrium of toll revenues and cost of service supplied. The model, originated with Yamada, is such that the decision comes into optimality when the maximum consumers' surplus is reached in the equilibrium condition. The paper is concerned with some general aspects of the optimal solution and reexamination of the solution obtained in the past when used a specific demand curve. General aspects obtained are as follows; The extremum condition to consumers' surplus is equivalent to that to diverted traffic (the realized number of expressway users) only when demand curve has such a property that the marginal consumers' surplus to network expansion vanishes. In case that the marginal consumers' surplus does not vanish, the extrema of consumers' surplus is found in the regions of negative marginal diverted traffic if demand curve yields positive marginal surplus, and in the regions of the positive if it gives negative marginal surplus. The contact points of demand and average cost curves give extrema of neither consumers' surplus nor diverted traffic. An implicative finding, made out by Yamada by using a specific demand curve, that optimal network expansion is reached when the marginal service cost to expansion averaged to the marginal diverted traffic to expansion is equal to the value of time saved by using expressway just by mean trip length holds good at the points of the maximum diverted traffic, but not at the contacts of demand and average cost curves. In case of the demand curve, the condition for an equilibrium of revenues and cost to come into existence is that the minimum of the ratio of service cost averaged to the whole population of expressway users to the value of time mentioned above is less than or equal to e(-1)

    A Statistical Analysis of Traffic Accidents in Minor Street Network

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    A statistical analysis is applied to find what states of "block" are dangerous from view point of traffic accident. Here, the block is defined to be an area surrounded by some major streets and is feeded by a minor street network. The accidents under study are those which occur in the whole minor street network. They are grouped into three kinds; pedestrian, vehicle and the gross accidents. And each is classified to three types according to the place where the accident occurs. At the beginning 22 variables are assumed to state a certain relationship of some states of the block with the occurrences of accidents and 12 variables are found significant finally through factor analysis. Further examination has reached several key variables that migth have something significant to cause traffic accidents in the block. The key ones are the number of lanes of street and the number of legs of intersection, especially nearly 2 lanes street and 3-leg intersection, respectively. The case study was carried out on 26 blocks sampled from Osaka City

    Roles of Porphyromonas gulae proteases in bacterial and host cell biology

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    Porphyromonas gulae, an animal-derived periodontal pathogen, expresses several virulence factors, including fimbria, lipopolysaccharide (LPS) and proteases. We previously reported that its invasive efficiency was dependent on fimbriae types. In addition, P. gulae LPS increased inflammatory responses via toll-like receptors. The present study was conducted to investigate the involvement of P. gulae proteases in bacterial and host cell biology. Porphyromonas gulae strains showed an ability to agglutinate mouse erythrocytes and also demonstrated co-aggregation with Actinomyces viscosus, while the protease inhibitors antipain, PMSF, TLCK and leupeptin diminished P. gulae proteolytic activity, resulting in inhibition of haemagglutination and co-aggregation with A. viscosus. In addition, specific proteinase inhibitors were found to reduce bacterial cell growth. Porphyromonas gulae inhibited Ca9-22 cell proliferation in a multiplicity of infection- and time-dependent manner. Additionally, P. gulae-induced decreases in cell contact and adhesion-related proteins were accompanied by a marked change in cell morphology from well spread to rounded. In contrast, inhibition of protease activity prevented degradation of proteins, such as E-cadherin, beta-catenin and focal adhesion kinase, and also blocked inhibition of cell proliferation. Together, these results indicate suppression of the amount of human proteins, such as gamma-globulin, fibrinogen and fibronectin, by P. gulae proteases, suggesting that a novel protease complex contributes to bacterial virulence

    Convolutional neural network can recognize drug resistance of single cancer cells

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    It is known that single or isolated tumor cells enter cancer patients' circulatory systems. These circulating tumor cells (CTCs) are thought to be an effective tool for diagnosing cancer malignancy. However, handling CTC samples and evaluating CTC sequence analysis results are challenging. Recently, the convolutional neural network (CNN) model, a type of deep learning model, has been increasingly adopted for medical image analyses. However, it is controversial whether cell characteristics can be identified at the single-cell level by using machine learning methods. This study intends to verify whether an AI system could classify the sensitivity of anticancer drugs, based on cell morphology during culture. We constructed a CNN based on the VGG16 model that could predict the efficiency of antitumor drugs at the single-cell level. The machine learning revealed that our model could identify the effects of antitumor drugs with ~0.80 accuracies. Our results show that, in the future, realizing precision medicine to identify effective antitumor drugs for individual patients may be possible by extracting CTCs from blood and performing classification by using an AI system

    Quantum Monte Carlo study of the pairing correlation in the Hubbard ladder

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    An extensive Quantum Monte Carlo calculation is performed for the two-leg Hubbard ladder model to clarify whether the singlet pairing correlation decays slowly, which is predicted from the weak-coupling theory but controversial from numerical studies. Our result suggests that the discreteness of energy levels in finite systems affects the correlation enormously, where the enhanced pairing correlation is indeed detected if we make the energy levels of the bonding and anti-bonding bands lie close to each other at the Fermi level to mimic the thermodynamic limit.Comment: 10 pages, RevTeX, 5 figures in PostScript file

    External Pancreatic Juice Drainage Through a Percutaneous Endoscopic Drainage Tube for the Patient With a Postoperative Pancreatic Juice Leakage

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    Percutaneous endoscopic gastrostomy (PEG) has been widely accepted for patients who have no swallowing ability but have an intact gut. Its clinical application is mainly for nutritional support and decompression of the intestine in patients with bowel obstruction. In this paper, we report external pancreatic juice drainage through a percutaneous endoscopic drainage tube in a patient with postoperative pancreatic juice leakage. Soon after this procedure, pancreatic juice leakage subsided. This procedure was minimally invasive for the patient and may be a new application of PEG to maintain the good quality of life (QOL) in a patient with pancreatic juice leakage

    Successful amnioinfusion for severe fetal growth restriction with umbilical cord complications: two case reports.

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    Background:There is no established treatment for fetal growth restriction during pregnancy. We report two cases that represent an example of an amnioinfusion-based management strategy for severe fetal growth restriction with umbilical cord complications.Case presentation:We encountered two cases of fetal growth restriction with abnormal fetal Doppler velocity. In one case, fetal ultrasound revealed a hypercoiled umbilical cord with a single umbilical artery and oligohydramnios, while fetal Doppler revealed a reversed end-diastolic flow in the umbilical artery and reversed a-waves of the ductus venosus. Umbilical cord compression was confirmed at 22 weeks and 2 days of gestation, and nine amnioinfusions were performed to relieve the umbilical cord compression. A cesarean section was performed at 31 weeks and 2 days of gestation because of severe preeclampsia. The Asian infant is now a normally developed 6-month-old. In another Asian case, fetal ultrasound revealed a hypercoiled cord, while fetal Doppler revealed a reversed end-diastolic flow in the umbilical artery and intermittent reversed a-waves of the ductus venosus. Umbilical cord compression was confirmed at 24 weeks and 5 days of gestation, and seven amnioinfusions were performed. A cesarean section was performed at 31 weeks and 1 day of gestation because of nonreassuring fetal status. At the age of 1 month, the Asian infant was stable on respiratory circulation. In both cases, fetal Doppler findings improved significantly following amnioinfusions.Conclusions:Amnioinfusion is a symptomatic treatment for umbilical cord compression. However, to determine the therapeutic effect of amnioinfusion, complete resolution of the umbilical cord compression should be ascertained by ultrasonography

    DOCK2 is involved in the host genetics and biology of severe COVID-19

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    「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
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