Hiroshi Hirai

Iwate University, Morioka, Iwate, Japan

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Publications (42)64.15 Total impact

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    ABSTRACT: after the Great East Japan Earthquake in 2011, inactivity and the homebound status of older victims in affected areas have been a serious public health concern owing to the victims' prolonged existence as evacuees in mountainous areas.
    Age and Ageing 10/2014; · 3.82 Impact Factor
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    ABSTRACT: We examined the relationship between incident functional disability and social participation from the perspective of number of types of organizations participated in and type of social participation in a prospective cohort study.
    PLoS ONE 01/2014; 9(6):e99638. · 3.53 Impact Factor
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    ABSTRACT: To evaluate the impact of satisfied isolation on the onset of functional disability of older Japanese adults, we performed a prospective data analysis. We collected baseline information in 2003 from 13,310 functionally independent residents aged 65 years or older who lived in six municipalities in Aichi prefecture. The onset of functional disability was obtained from municipal databases of the public long-term care insurance system. All participants were followed for up to 4 years. Respondents who had face-to-face and non-face-to-face contacts once or twice per month or less were considered as isolated. We distinguished the isolated person who were satisfied their life or not; 74.1% of isolated older people were categorized as satisfied isolation. Cox’s proportional hazard model revealed that the isolated older people were 1.34 (95%CI: 1.18-1.53) times more likely to develop functional disability. Although the interaction effect between isolation and life satisfaction was not statistically significant, satisfied isolation was associated with 1.27 (95%CI: 1.02-1.58) times higher risk of functional disability than those who were not isolated in older men. Satisfied isolation was also attributable to 11,000 functional disability annually for the older Japanese population.
    Japanese Journal of Gerontology. 10/2013; 35(3):331-341.
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    ABSTRACT: Social participation has been linked to healthy aging and the maintenance of functional independence in older individuals. However, causality remains tenuous because of the strong possibility of reverse causation (healthy individuals selectively participate in social activities). We describe a quasi-experimental intervention in one municipality of Japan designed to boost social participation as a way of preventing long-term disability in senior citizens through the creation of 'salons' (or community centers). In this quasi-experimental intervention study, we compared 158 participants with 1391 non-participants in salon programs, and examined the effect of participation in the salon programs on self-rated health. We conducted surveys of community residents both before (in 2006) and after (in 2008) the opening of the salons. Even with a pre/post survey design, our study could be subject to reverse causation and confounding bias. We therefore utilized an instrumental variable estimation strategy, using the inverse of the distance between each resident's dwelling and the nearest salon as the instrument. After controlling for self-rated health, age, sex, equivalized income in 2006, and reverse causation, we observed significant correlations between participation in the salon programs and self-rated health in 2008. Our analyses suggest that participation in the newly-opened community salon was associated with a significant improvement in self-rated health over time. The odds ratio of participation in the salon programs for reporting excellent or good self-rated health in 2008 was 2.52 (95% CI 2.27-2.79). Our study provides novel empirical support for the notion that investing in community infrastructure to boost the social participation of communities may help promote healthy aging.
    Social Science [?] Medicine 10/2013; 94:83-90. · 2.73 Impact Factor
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    ABSTRACT: BACKGROUND: Recent increases in numbers of older people have been accompanied by increases in those with functional disability. No study has examined the association between community social capital and the onset of functional disability. METHODS: The association between community social capital and the onset of functional disability was examined using data from the Aichi Gerontological Evaluation Study, a prospective cohort established in 2003 in Japan. Perceptions of community social capital (indicators of social cohesion such as trust of others and extent of social participation) in 6953 men and 7636 women aged 65 years or older were surveyed. Multilevel survival analysis using the discrete-time hazard model was applied. RESULTS: During 4-year follow-up, onset of functional disability occurred in 759 men and 1146 women. Women living in communities with higher mistrust had 1.68 (95% CI 1.14 to 2.49) times higher OR of onset of disability, even after adjusting for covariates. Mediators did not substantially change this association. Lack of social participation seemed to affect the health of women, though the effect was marginal (OR for covariates adjusted model =1.12 (95% CI 0.96 to 1.31)). There were no significant ORs among men. CONCLUSIONS: Lower community social capital was associated with higher incidence of onset of functional disability among older women but not among men. Community-based interventions to promote social capital may be useful for preventing functional disability of older Japanese women.
    Journal of epidemiology and community health 07/2012; · 3.04 Impact Factor
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    ABSTRACT: To evaluate the gender-specific impact of social exclusion on the mortality of older Japanese adults, we performed a prospective data analysis using the data of the Aichi Gerontological Evaluation Study (AGES). In AGES, we surveyed functionally independent residents aged 65 years or older who lived in six municipalities in Aichi prefecture, Japan. We gathered baseline information from 13,310 respondents in 2003. Information on mortality was obtained from municipal databases of the public long-term care insurance system. All participants were followed for up to 4 years. We evaluated social exclusion in terms of the combination of social isolation, social inactivity, and relative poverty. Cox's proportional hazard model revealed that socially excluded older people were at significantly increased risk (9-34%) for premature mortality. Those with simultaneously relative poverty and social isolation and/or social inactivity were 1.29 times more likely to die prematurely than those who were not socially excluded. Women showed stronger overall impact of social exclusion on mortality, whereas relative poverty was significantly associated with mortality risks for men. If these associations are truly causal, social exclusion is attributable to 9000-44,000 premature deaths (1-5%) annually for the older Japanese population. Health and social policies to mitigate the issue of social exclusion among older adults may require gender-specific approaches.
    Social Science [?] Medicine 05/2012; 75(5):940-5. · 2.73 Impact Factor
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    ABSTRACT: The story of Roseto, Pennsylvania, USA, is one of the most widely cited studies of the putative influence of community social cohesion on population health. However, few contemporary studies of community-based "social capital" on health have addressed "communities" as unique places with unique histories outside of a Western context. In the present study, we focus on a specific region of Japan (which we call the M-region to preserve anonymity). Using survey data and qualitative interviews, we discuss the historical and contextual origins of the high social capital in the M-region that could account for its relatively good health profile. The analysis of survey data suggested that the residents of M-region have higher norms of reciprocity and participate more in horizontal organizations (including volunteer group, citizen or consumer group, sports group or club, and hobby group), and it also indicated better health status and behaviors in some outcomes among the residents of M-region. Based on qualitative interviews, the origins of social capital in the M-region appeared to be rooted in the strong sense of solidarity fostered by the fact that many of the residents were recruited into the region by the same local employer (a steel manufacturing company). Our study points to the need to ground studies of community-based "social capital" and health on detailed knowledge of the historical context of specific places.
    Social Science [?] Medicine 04/2012; 75(1):225-32. · 2.73 Impact Factor
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    ABSTRACT: Studies have shown that people with cognitive impairment have poor dental health. However, the direction of causality remains unknown. This prospective cohort study aimed to determine the association between four self-reported dental health variables and dementia onset in older Japanese people. Analysis was conducted on 4425 residents 65 years or older. Four self-reported dental health variables included the number of teeth and/or use of dentures, ability to chew, presence/absence of a regular dentist, and taking care of dental health. Data were collected using self-administered questionnaires given in 2003. Records of dementia onset during 2003 to 2007 were obtained from municipalities in charge of the public long-term care insurance system. Age, income, body mass index, present illness, alcohol consumption, exercise, and forgetfulness were used as covariates. Dementia onset was recorded in 220 participants. Univariate Cox proportional hazards models showed significant associations between the dental health variables and dementia onset. In models fully adjusted for all covariates, hazard ratios (95% confidence intervals) of dementia onset of respondents were as follows: 1.85 (1.04-3.31) for those with few teeth and without dentures; 1.25 (0.81-1.93) for those who could not chew very well; 1.44 (1.04-2.01) for those who did not have a regular dentist; and 1.76 (0.96-3.20) for those who did not take care of their dental health. Few teeth without dentures and absence of a regular dentist, not poor mastication and poor attitudes toward dental health, were associated with higher risk of dementia onset in the older Japanese cohort even after adjustment for available covariates.
    Psychosomatic Medicine 03/2012; 74(3):241-8. · 4.08 Impact Factor
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    ABSTRACT: Why are some communities more cohesive than others? The answer to the puzzle has two parts: (a) due to variations in the attributes of residents, and/or (b) due to variations in the attributes of places. However, few studies have sought to examine the community-level determinants of social capital. In the present study, we examined the associations between social capital and different area characteristics: (1) neighborhood walkability, (2) date of community settlement, and (3) degree of urbanization. We based our analysis on 9414 respondents from the Aichi Gerontological Evaluation Study (AGES), conducted in 2003. No significant positive association was found between the walkability score and any of the social capital indices. In contrast, community age and degree of urbanization were associated with many of the social capital indicators, even after controlling for characteristics of the residents. Community social capital thus appears to be more consistently linked to the broader historical and geographic contexts of neighborhoods, rather than to the proximal built environment (as measured by walkability).
    Health & Place 03/2012; 18(2):229-39. · 2.42 Impact Factor
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    ABSTRACT: We sought to examine prospectively the difference in the association between incident functional disability and exercise with or without sports organization participation. The study was based on the Aichi Gerontological Evaluation Study (AGES) Cohort Study data. In October 2003, self-reported questionnaires were mailed to 29,374 non-disabled Japanese individuals aged 65 years or older. Of these, 13,310 individuals were introduced to the Study, and they were followed for 4 years. Analysis was carried out on 11,581 subjects who provided all necessary information for the analysis. Analysis was carried out on incident functional disability by 4 groups of different combinations of performance of exercise and participation in a sports organization Active Participant (AP), Exercise Alone (EA), Passive Participant (PP) and Sedentary (S). Compared to the AP group, the EA group had a hazard ratio (HR) of 1.29 (1.02-1.64) for incident functional disability. No significant difference was seen with the PP group, with an HR of 1.16 (0.76-1.77). When a measure of social networks was added to the covariates, the HR of the EA group dropped to 1.27 (1.00-1.61), and significant differences disappeared. In contrast, it showed hardly any change when social support was added. The results suggested that, even with a regular exercise habit, incident functional disability may be better prevented when a person participates in a sports organization than when he/she does not. In addition, participation in a sports organization correlates positively with social networks, which may lead to a small decrease in incident functional disability.
    PLoS ONE 01/2012; 7(11):e51061. · 3.53 Impact Factor
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    ABSTRACT: To examine if self-reported number of teeth, denture use and chewing ability are associated with incident falls. Longitudinal cohort study (the Aichi Gerontological Evaluation Study). 5 Japanese municipalities. 1763 community-dwelling individuals aged 65 years and older without experience of falls within the previous year at baseline. Self-reported history of multiple falls during the past year at the follow-up survey about 3 years later. Baseline data on the number of teeth present and/or denture use and chewing ability were collected using self-administered questionnaires. Logistic regression analyses controlled for sex, age, functional disability during follow-up period, depression, self-rated health and educational attainment. 86 (4.9%) subjects reported falls at the follow-up survey. Logistic regression models fully adjusted for all covariates showed that subjects having 19 or fewer teeth but not using dentures had a significantly increased risk for incident falls (OR 2.50, 95% CI 1.21 to 5.17, p=0.013) compared with those having 20 or more teeth. Among subjects with 19 or fewer teeth, their risk of falls was not significantly elevated so long as they wore dentures (OR 1.36, 95% CI 0.76 to 2.45, p=0.299). No significant association was observed between chewing ability and incident falls in the fully adjusted model. Having 19 or fewer teeth but not using dentures was associated with higher risk for the incident falls in older Japanese even after adjustment for multiple covariates. Dental care to prevent tooth loss and denture treatment for older people might prevent falls, although the authors cannot exclude the possibility that the association is due to residual confounding.
    BMJ Open 01/2012; 2(4). · 1.58 Impact Factor
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    ABSTRACT: Studies have reported that the predictive ability of self-rated health (SRH) for mortality varies by sex/gender and socioeconomic group. The purpose of this study is to evaluate this relationship in Japan and explore the potential reasons for differences between the groups. The analyses in the study were based on the Aichi Gerontological Evaluation Study's (AGES) 2003 Cohort Study in Chita Peninsula, Japan, which followed the four-year survival status of 14,668 community-dwelling people who were at least 65 years old at the start of the study. We first examined sex/gender and education-level differences in association with fair/poor SRH. We then estimated the sex/gender- and education-specific hazard ratios (HRs) of mortality associated with lower SRH using Cox models. Control variables, including health behaviors (smoking and drinking), symptoms of depression, and chronic co-morbid conditions, were added to sequential regression models. The results showed men and women reported a similar prevalence of lower SRH. However, lower SRH was a stronger predictor of mortality in men (HR = 2.44 [95% confidence interval (CI): 2.14-2.80]) than in women (HR = 1.88 [95% CI: 1.44-2.47]; p for sex/gender interaction = 0.018). The sex/gender difference in the predictive ability of SRH was progressively attenuated with the additional introduction of other co-morbid conditions. The predictive ability among individuals with high school education (HR = 2.39 [95% CI: 1.74-3.30]) was similar to that among individuals with less than a high school education (HR = 2.14 [95% CI: 1.83-2.50]; p for education interaction = 0.549). The sex/gender difference in the predictive ability of SRH for mortality among this elderly Japanese population may be explained by male/female differences in what goes into an individual's assessment of their SRH, with males apparently weighting depressive symptoms more than females.
    PLoS ONE 01/2012; 7(1):e30179. · 3.53 Impact Factor
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    ABSTRACT: We examined the relationship between income, mortality, and loss of years of healthy life in a sample of older persons in Japan. We analyzed 22,829 persons aged 65 or older who were functionally independent at baseline as a part of the Aichi Gerontological Evaluation Study (AGES). Two outcome measures were adopted, mortality and loss of healthy life. Independent variables were income level and age. The occurrence of mortality and need for care during these 1,461 days were tracked. Cox regressions were used to calculate the hazard ratio for mortality and loss of healthy life by income level. We found that people with lower incomes were more likely than those with higher incomes to report worse health. For the overall sample, using the governmental administrative data, the hazard ratios of mortality and loss of healthy life-years comparing the lowest to the highest income level were 3.50 for men and 2.48 for women for mortality and 3.71 for men and 2.27 for women for loss of healthy life. When only those who responded to questions about income on the mail survey were included in the analysis, the relationships became weaker and lost statistical significance.
    Current Gerontology and Geriatrics Research 01/2012; 2012:701583.
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    ABSTRACT: To determine the association between dental health status and onset of functional disability in older Japanese people. Prospective cohort study. Six Japanese municipalities. Four thousand four hundred twenty-five community-dwelling individuals aged 65 and over. The outcome measure was the onset of functional disability based on public records of people receiving long-term care insurance benefits, determined through a standardized multistep assessment of functional and cognitive impairment including a personal interview and an examination by a physician. Disability data were analyzed for 4,425 respondents during 2003 to 2007. Self-reported number of remaining teeth and eating ability were used as measures of dental health status. Age, sex, body mass index, self-rated health, present illness, smoking, alcohol, exercise, and equivalent income were used as covariates. In the age- and sex-adjusted Cox proportional hazard models, there were significant associations between number of remaining teeth, eating ability, and onset of disability. After adjusting for sociodemographic, behavioral, and health status variables, respondents with 19 or fewer teeth had a significant 1.21 (95% confidence interval = 1.06-1.40) times higher hazard ratio for the onset of functional disability. In contrast, eating ability was not significantly associated with the onset of disability. Poor dental status was associated with a higher risk of onset of functional disability in older Japanese people. Sociodemographic, behavioral, and health status covariates explained the association between eating ability and onset of disability.
    Journal of the American Geriatrics Society 12/2011; 60(2):338-43. · 4.22 Impact Factor
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    ABSTRACT: Objectives: This prospective cohort study attempted to examine the associations between subjective levels of happiness and risks of loss of healthy life expectancy among Japanese men and women who is over 65 years old, living in the community settings. Methods: Study subjects were 8,248 (4016 men and 4232 women) aged Japanese free from dementia nor disabled conditions at baseline 2003, included in Aichi Gerontological Evaluation Study (AGES). Loss of healthy life expectancy (HLE) was assessed through public long-term care insurance databases and national resident registry. Sex-specific age and multivariable adjusted hazard ratios (HRs) were calculated according to the perceived levels of happiness from Cox proportional hazard models to estimate the risks of loss of HLE. Additionally, one-to-one nearest neighbor propensity score matching analysis were also carried out using a logit model. Result: Among followed up period for 4 years in median, a total of 490 loss of HLE were documented. The multivariable hazard ratios (HRs) of loss of HLE was calculated, and to compare with the highest levels of happiness to those in the lowest were 0.70 (95%CI:0.58-0.86), p for trend p=0.03 in total population. The hazard ratios and the 95% CIs calculated in the matching technique were not grossly different. Conclusion: A higher levels of happiness was found to be associated with lower risks of loss of HLE in the later stage of life, suggesting a protective role of positive psychological conditions on health.
    139st APHA Annual Meeting and Exposition 2011; 10/2011
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    ABSTRACT: Background: Both depression and dementia are common among the old. However, studies which clarified the association between baseline depression and dementia are relatively few. Methods: To investigate such association, we used the AGES (Aichi Gerontological Evaluation Study) data. Subjects were functionally independent elderly (65+) at baseline (N=13,295) in 6 communities. They were followed from 2003 to 2007 for dementia onset. Dementia onset was determined according to the criterion (based on face to face interview and physician diagnosis) used in Japan's Public Long-Term Care Insurance System. Depression was assessed by GDS-15. Cox hazard proportional model stratified by sex was employed to calculate hazard ratios for dementia onset. Results: Out of 13,295 subjects, 225 men (3.5%) and 324 women (4.8%) developed dementia during the follow-up. Dementia onset increased exponentially with age. In Cox models, even after adjustment for age and illnesses, depression at baseline significantly predicted dementia onset among men with hazard ratios of 1.70 (p
    139st APHA Annual Meeting and Exposition 2011; 10/2011
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    ABSTRACT: Cardiovascular diseases, cancer, and respiratory disease are major causes of death in developed countries. No study has simultaneously compared the contribution of oral health with these major causes of death. This study examined the association between oral health and cardiovascular diseases, cancer, and respiratory mortality among older Japanese. Self-administered questionnaires were mailed to participants in the Aichi Gerontological Evaluation Study (AGES) Project in 2003. Mortality data were analyzed for 4425 respondents. Three categories of oral health were used: 20 or more teeth, 19 or fewer teeth and eat everything, 19 or fewer teeth and eating difficulty. Sex, age, body mass index (BMI), self-rated health, present illness, exercise, smoking, alcohol, education, and income were used as covariates. During 4.28 years' follow-up, 410 people died, 159 from cancer, 108 of cardiovascular diseases, and 58 of respiratory disease. Multivariate adjusted Cox proportional hazard models showed that, compared with the respondents with 20 or more teeth, respondents with 19 or fewer teeth and with eating difficulty had a 1.83 and 1.85 times higher hazard ratio for cardiovascular disease mortality and respiratory disease mortality, respectively. There was no significant association with cancer mortality. Oral health predicted cardiovascular and respiratory disease mortality but not cancer mortality in older Japanese.
    Journal of dental research 09/2011; 90(9):1129-35. · 3.46 Impact Factor
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    ABSTRACT: Although many studies have reported the association between neighborhood built environment (BE) and physical activity (PA), less is known about the associations for older populations or in countries besides the US and Australia. The aim of this paper is to examine the associations for older adult populations in Japan. Our analyses were based on cross-sectional data from the Aichi Gerontological Evaluation Study (AGES), conducted in 2003. The respondents were older adults, aged 65 years or over (n = 9,414), from 8 municipalities across urban, suburban, and rural areas. The frequency of leisure time sports activity and total walking time were used as the outcome variables. Using geographic information systems (GIS), we measured residential density, street connectivity, number of local destinations, access to recreational spaces, and land slope of the respondents' neighborhoods, based on network distances with multiple radii (250 m, 500 m, 1,000 m). An ordinal logistic regression model was used to analyze the association between PA and BE measures. Population density and presence of parks or green spaces had positive associations with the frequency of sports activity, regardless of the selected buffer zone. The analysis of total walking time, however, showed only a few associations. Our findings provide mixed support for the association between PA and the characteristics of BE measures, previously used in Western settings. Some characteristics of the neighborhood built environment may facilitate leisure time sports activity, but not increase the total walking time for Japanese older adults.
    BMC Public Health 08/2011; 11:657. · 2.08 Impact Factor
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    ABSTRACT: Few prospective cohort studies have assessed the association between social capital and mortality. The studies were conducted only in Western countries and did not use the same social capital indicators. The present prospective cohort study aimed to examine the relationships between various forms of individual social capital and all-cause mortality in Japan. Self-administered questionnaires were mailed to subjects in the Aichi Gerontological Evaluation Study (AGES) Project in 2003. Mortality data from 2003 to 2008 were analyzed for 14,668 respondents. Both cognitive and structural components of individual social capital were collected: 8 for cognitive social capital (trust, 3; social support, 3; reciprocity, 2) and 9 for structural social capital (social network). Cox proportional hazard models stratified by sex with multiple imputation were used. Age, body mass index, self-rated health, current illness, smoking history, alcohol consumption, exercise, equivalent income and education were used as covariates. During 27,571 person-years of follow-up for men and 29,561 person-years of follow-up for women, 790 deaths in men and 424 in women were observed. In the univariate analyses for men, lower social capital was significantly related to higher mortality in one general trust variable, all generalised reciprocity variables and four social network variables. For women, lower social capital was significantly related to higher mortality in all generalised reciprocity and four social network variables. After adjusting for covariates, lower friendship network was significantly associated with higher all-cause mortality among men (meet friends rarely; HR = 1.30, 95%CI = 1.10-1.53) and women (having no friends; HR = 1.81, 95%CI = 1.02-3.23). Among women, lower general trust was significantly related to lower mortality (most people cannot be trusted; HR = 0.65, 95%CI = 0.45-0.96). Friendship network was a good predictor for all-cause mortality among older Japanese. In contrast, mistrust was associated with lower mortality among women. Studies with social capital indices considering different culture backgrounds are needed.
    BMC Public Health 06/2011; 11:499. · 2.08 Impact Factor

Publication Stats

225 Citations
64.15 Total Impact Points

Institutions

  • 2011–2014
    • Iwate University
      • Department of Civil and Environmental Engineering
      Morioka, Iwate, Japan
  • 2012
    • Harvard Medical School
      Boston, Massachusetts, United States
    • Juntendo University
      • Faculty of Health Care and Nursing
      Edo, Tōkyō, Japan
  • 2011–2012
    • Ritsumeikan University
      • Research Center for Disaster Mitigation of Urban Cultural Heritage
      Kioto, Kyōto, Japan
  • 2007–2012
    • Nihon Fukushi University
      Mihama, Hiroshima, Japan
  • 2010
    • Hamamatsu University School of Medicine
      • Division of Community Health and Preventive Medicine
      Hamamatu, Shizuoka, Japan
  • 2009
    • University Hospital Medical Information Network
      Edo, Tōkyō, Japan
  • 2008
    • Osaka University of Commerce
      Ōsaka, Ōsaka, Japan