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331 results on '"Yamazaki, Akio"'

18. Inspiratory and Expiratory Computed Tomography Imaging Clusters Reflect Functional Characteristics in Chronic Obstructive Pulmonary Disease

Author

Matsuo,Yumiko, Ogawa,Emiko, Tsunoda,Yoko, Yamazaki,Akio, Kawashima,Satoru, Uchida,Yasuki, Nakagawa,Hiroaki, Kinose,Daisuke, Yamaguchi,Masafumi, Nakano,Yasutaka, Matsuo,Yumiko, Ogawa,Emiko, Tsunoda,Yoko, Yamazaki,Akio, Kawashima,Satoru, Uchida,Yasuki, Nakagawa,Hiroaki, Kinose,Daisuke, Yamaguchi,Masafumi, and Nakano,Yasutaka

Abstract

Yumiko Matsuo,1,2 Emiko Ogawa,1,2 Yoko Tsunoda,1 Akio Yamazaki,1 Satoru Kawashima,1 Yasuki Uchida,1 Hiroaki Nakagawa,1 Daisuke Kinose,1 Masafumi Yamaguchi,1 Yasutaka Nakano1 1Division of Respiratory Medicine, Department of Internal Medicine, Shiga University of Medical Science, Otsu, Shiga, Japan; 2Health Administration Center, Shiga University of Medical Science, Otsu, Shiga, JapanCorrespondence: Emiko Ogawa, Health Administration Center, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga, 520-2192, Japan, Tel/Fax +81-77-548-2212, Email eogawa@belle.shiga-med.ac.jpPurpose: Disease probability measure (DPM) is a useful voxel-wise imaging assessment of gas-trapping and emphysematous lesions in patients with chronic obstructive pulmonary disease (COPD). To elucidate the progression of COPD, we performed a cluster analysis using the following DPM parameters: normal (DPMNormal), gas-trapping (DPMGasTrap), and emphysematous lesions (DPMEmph). Our findings revealed the characteristics of each cluster and the 3-year disease progression using imaging parameters.Patients and Methods: Inspiratory and expiratory chest computed tomography (CT) images of 131 patients with COPD were examined, of which 84 were followed up for 3 years. The percentage of low attenuation volume (LAV%) and the square root of the wall area of a hypothetical airway with an internal perimeter of 10 mm (√Aaw at Pi10) were quantitatively measured using inspiratory chest CT. A hierarchical cluster analysis was performed using the DPM parameters at baseline. Five clusters were named according to the dominant DPM parameters: normal (NL), normal-GasTrap (NL-GT), GasTrap (GT), GasTrap-Emphysema (GT-EM), and Emphysema (EM).Results: Women were predominantly diagnosed with GT. Forced expiratory volume in 1 s gradually decreased in the following order: NL, NL-GT, GT, GT-EM, and EM. DPMEmph correlated well with LAV%. Four clusters other than NL showed significantly higher values of √Aaw at Pi10

Published
2023

24. WITHDRAWN: Autobullectomy with COVID-19 in a patient with chronic obstructive pulmonary disease

Author

Yokoe, Shinya, primary, Kinose, Daisuke, additional, Ueki, Yasumitsu, additional, Okuda, Shogo, additional, Nakanishi, Tsukasa, additional, Iriyama, Tomoko, additional, Yamazaki, Akio, additional, Kawashima, Satoru, additional, Uchida, Yasuki, additional, Nakagawa, Hiroaki, additional, Yamaguchi, Masafumi, additional, and Nakano, Yasutaka, additional

Published
2023
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25. Predictors of longitudinal changes in body weight, muscle and fat in patients with and ever‐smokers at risk of COPD.

Author

Yamazaki, Akio, Kinose, Daisuke, Kawashima, Satoru, Tsunoda, Yoko, Matsuo, Yumiko, Uchida, Yasuki, Nakagawa, Hiroaki, Yamaguchi, Masafumi, Ogawa, Emiko, and Nakano, Yasutaka

Subjects
*PECTORALIS muscle, *RIB cage, *BODY weight, *ERECTOR spinae muscles, *CHRONIC obstructive pulmonary disease, *EXPIRATORY flow, *BODY mass index, *RIB fractures
Abstract

Background and Objective: Weight and muscle loss are predictors of poor outcomes in chronic obstructive pulmonary disease. However, to our knowledge, no study has investigated the predictors of longitudinal weight loss or its composition from functional and morphological perspectives. Methods: This longitudinal observational study with a median follow‐up period of 5 years (range: 3.0–5.8 years) included patients with COPD and ever‐smokers at risk of COPD. Using chest computed tomography (CT) images, airway and emphysematous lesions were assessed as the square root of the wall area of a hypothetical airway with an internal perimeter of 10 mm (√Aaw at Pi10) and the percentage of low attenuation volume (LAV%). Muscle mass was estimated using cross‐sectional areas (CSAs) of the pectoralis and erector spinae muscles, and fat mass was estimated using the subcutaneous fat thickness at the level of the 8th rib measured using chest CT images. Statistical analyses were performed using the linear mixed‐effects models. Results: In total, 114 patients were enrolled. Their body mass index remained stable during the study period while body weight and muscle CSA decreased over time and the subcutaneous fat thickness increased. Reduced forced expiratory volume in 1 s and peak expiratory flow (PEF) at baseline predicted the future decline in muscle CSA. Conclusion: Severe airflow limitation predicted future muscle wasting in patients with COPD and ever‐smokers at risk of COPD. Airflow limitation with a PEF slightly below 90% of the predicted value may require intervention to prevent future muscle loss. [ABSTRACT FROM AUTHOR]

Published
2023
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42. The Effectiveness of Revenue-Neutral Carbon Taxes

Author

AHMADI, Younes, YAMAZAKI, Akio, Department of Economics, University of Calgary, and 政策研究大学院大学 / National Graduate Institute for Policy Studies

Subjects
Carbon tax, revenue-recycling, manufacturing emission
Abstract

This paper investigates the effectiveness of carbon taxes in the manufacturing sector by examining British Columbia’s revenue-neutral carbon tax. We theoretically demonstrate that the magnitude of plants’ exposure to the policy monotonically increases with its emission intensity. Using detailed confidential plant-level data, we directly exploit the variations in plants’ emission intensity to isolate the emission effect of the policy. We find that the carbon tax lowers emission by 2 percent. Furthermore, we find that the policy had a positive output effect, suggesting that the carbon tax encouraged plants to produce more with less energies. These findings are possibly due to the revenue neutrality of the policy, especially through the reduction of the corporate income taxes. It incentivized plants to invest in both energy-saving and productivity-enhancing technologies., JEL Classification Codes: H23, Q5, L6, Yamazaki acknowledges generous financial support from the Policy Research Center at the National Graduate Institutefor Policy Studies (GRIPS)., http://www.grips.ac.jp/list/jp/facultyinfo/yamazaki-akio/

Published
2020

43. Environmental Taxes and Productivity: Lessons from Canadian Manufacturing

Author

YAMAZAKI, Akio and 政策研究大学院大学 / National Graduate Institute for Policy Studies

Subjects
manufacturing, productivity, Environmental tax, revenue-recycling
Abstract

This paper investigates how environmental taxes affect manufacturing productivity by examining British Columbia’s revenue-neutral carbon tax. I develop a new hypothesis, the “Productivity Dividend Hypothesis,” to show that environmental taxes can positively affect productivity by recycling tax revenues to reduce corporate income taxes. This revenue-recycling increases investment and could raise productivity more than environmental taxes lower productivity by diverting resources from production. I evaluate this hypothesis using detailed confidential plant-level data. I find that the carbon tax lowers productivity, although this is offset to some extent by the revenue-recycling. For some plants, the policy generates a net gain in productivity., JEL Classification Codes: D22, H23, L6, Q5, The author acknowledges generous funding from Productivity Partnership (PP) and Smart Prosperity Institute (SPI), supported by the Social Sciences and Humanities Research Council of Canada., http://www.grips.ac.jp/list/jp/facultyinfo/yamazaki-akio/

Published
2020

44. An optimization methodology for neural network weights and architectures

Author

Ludermir, Teresa B., Yamazaki, Akio, and Zanchettin, Cleber

Subjects
Neural networks -- Analysis, Mathematical optimization -- Analysis, Perceptrons -- Design and construction, Neural network, Business, Computers, Electronics, Electronics and electrical industries
Abstract

This paper introduces a methodology for neural network global optimization. The aim is the simultaneous optimization of multilayer perceptron (MLP) network weights and architectures, in order to generate topologies with few connections and high classification performance for any data sets. The approach combines the advantages of simulated annealing, tabu search and the backpropagation training algorithm in order to generate an automatic process for producing networks with high classification performance and low complexity. Experimental results obtained with four classification problems and one prediction problem has shown to be better than those obtained by the most commonly used optimization techniques. Index Terms--Multilayer perceptron (MLP), optimization of weights and architectures, simulating annealing, tabu search.

Published
2006

50. Usefulness of β-lactam and Macrolide Combination Therapy for Treating Community-acquired Pneumonia Patients Hospitalized in the Intensive Care Unit: Propensity Score Analysis of a Prospective Cohort Study

Author

Ito, Akihiro, primary, Ishida, Tadashi, additional, Tachibana, Hiromasa, additional, Nakanishi, Yosuke, additional, Tokioka, Fumiaki, additional, Yamazaki, Akio, additional, Washio, Yasuyoshi, additional, Irie, Hiromasa, additional, and Otake, Takanao, additional

Published
2020
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