Yamaguchi Prefecture Research Articles

Policy Decision-Making for Population Decline Using AI to Estimate Population Density From Well-Being Indicators

This paper examines whether a model that infers habitable area population density from regional well-being indicators can serve as a guide for policy decision-making to address population decline. The study uses 51 subjective evaluation items from the regional well-being indicators and habitable area population density calculated from e-stat, a Japanese government database. The inference model was created through ensemble learning, generating six weak learners and combining them with a meta-model to form the final model. Using data from Shimonoseki City in Yamaguchi Prefecture, Japan, we varied the value of a single subjective evaluation item to observe changes in the inferred population density. The results showed that subjective evaluations related to public transportation, crime prevention, dining options, and local government initiatives significantly impact habitable area population density. Prioritizing these factors could enhance resident satisfaction and potentially mitigate the issue of population decline.

Genetic analysis of a Yayoi individual from the Doigahama site provides insights into the origins of immigrants to the Japanese Archipelago.

Mainland Japanese have been recognized as having dual ancestry, originating from indigenous Jomon people and immigrants from continental East Eurasia. Although migration from the continent to the Japanese Archipelago continued from the Yayoi to the Kofun period, our understanding of these immigrants, particularly their origins, remains insufficient due to the lack of high-quality genome samples from the Yayoi period, complicating predictions about the admixture process. To address this, we sequenced the whole nuclear genome of a Yayoi individual from the Doigahama site in Yamaguchi prefecture, Japan. A comprehensive population genetic analysis of the Doigahama Yayoi individual, along with ancient and modern populations in East Asia and Northeastern Eurasia, revealed that the Doigahama Yayoi individual, similar to Kofun individuals and modern Mainland Japanese, had three distinct genetic ancestries: Jomon-related, East Asian-related, and Northeastern Siberian-related. Among non-Japanese populations, the Korean population, possessing both East Asian-related and Northeastern Siberian-related ancestries, exhibited the highest degree of genetic similarity to the Doigahama Yayoi individual. The analysis of admixture modeling for Yayoi individuals, Kofun individuals, and modern Japanese respectively supported a two-way admixture model assuming Jomon-related and Korean-related ancestries. These results suggest that between the Yayoi and Kofun periods, the majority of immigrants to the Japanese Archipelago originated primarily from the Korean Peninsula.

Business Expansion and Downsizing and Its Factors in Community-Based Group Farms: Empirical Study Based on the Questionnaire in Yamaguchi Prefecture

Business Expansion and Downsizing and Its Factors in Community-Based Group Farms: Empirical Study Based on the Questionnaire in Yamaguchi Prefecture

Molecular and serological investigation of Francisella tularensis among wild animals in Yamaguchi prefecture.

Francisella tularensis is an intracellular gram-negative bacterium known as the causative agent of tularemia, which can be transmitted to humans by direct contact with wild animals or by tick bites. Although F. tularensis is highly pathogenic, its recent prevalence in Japan is underreported due to the small number of reported cases. To clarify the current situation of F. tularensis in wild animals, we conducted surveillance on various species of wild animals in Yamaguchi prefecture. In this study, we screened 809 samples collected from 90 Japanese black bears, 105 Japanese monkeys, 168 sika deer, 205 wild boars, and 84 bats. For seroprevalence analysis, we tested 177 serum samples from 75 black bears and 102 monkeys using the microagglutination test. The results showed that serums from five black bears exhibited slight agglutination. Western blot was performed as a confirmatory test on these five samples, but no positive signals were detected. Additionally, molecular surveillance was conducted using DNA extracted from 464 whole blood and 168 tissues, targeting the gene encoding 23 KDa hypothetical protein by real-time PCR and outer membrane protein A gene by conventional PCR. No positive samples of F. tularensis were detected by either real-time or conventional PCR. Although we did not detect any F. tularensis-positive samples through serological and molecular analyses, continuous surveillance studies are necessary since sporadic human cases have been reported in Japan.

Optimal site selection and potential power assessment for tidal power generation in the Seto Inland Sea, Japan, based on high-resolution ocean modelling and multicriteria analysis

In response to Japan's ambitious pursuit of carbon neutrality by 2050, this paper investigates the potential for tidal power generation in the Seto Inland Sea (SIS), Japan, utilising high-resolution ocean modelling and an analytic hierarchy process (AHP) combined with GIS-based spatial analysis. The analysis incorporates a 100 m resolution tidal current and water depth layers from the ocean model. The criteria used for evaluation were divided into main criteria, namely, proximity to existing infrastructure, wave height, and shipping density, and subcriteria, namely, distance from ports, power stations, highly populated areas, and coastlines. The identified optimal locations include the Naruto Strait, Akashi Strait, Matsushima Island, Hanaguri Strait, Funaori Strait, Taizaki Island, Kurushima Strait, Obatake Strait, and Tsuwaji Strait. With a focused analysis of the Obatake Strait in Yamaguchi Prefecture, analytical assessments of potential tidal power were conducted by considering two tidal turbines, Openhydro and Voith. The results indicate a power supply for approximately 100,000 households and a reduction of approximately 198,000 t-CO2 per year in the most optimistic scenario. In a less optimistic scenario, with the installation of only 10% of the maximum capacity, a power supply for approximately 10,000 households and a reduction of approximately 19,800 t-CO2 per year are observed. As Japan targets carbon neutrality by 2050, this research offers vital and practical insights for policymakers, energy planners, and environmentalists, identifying the Seto Inland Sea as a strategic area for tidal power development, aligning with Japan's commitment to a sustainable and resilient energy landscape.

Health and Safety Education for Painting Workers in Small Companies to Make Them Aware That Paint Is "Dangerous and Harmful".

Workers in painting companies may be unaware that the paints they handle have adverse health effects. The present study explored the factors associated with workers' perception of paints as "dangerous and harmful". A questionnaire survey and interviews were conducted with workers engaged in painting operations in small-sized painting companies (fewer than 50 employees) in northern Kyushu and Yamaguchi prefectures. Safety and health education methods making workers perceive paint as "dangerous and harmful" were clarified. Fisher's exact test and logistic regression analysis were used for the survey and hierarchical cluster analysis for the interviews. The factor "Hazard prediction activity (KY Activity)", gender, and job position were identified as factors that make workers perceive paint as "dangerous and harmful". Based on the interview results, "KY Activity" was a keyword and a standardized safety and health activity. Before work, workers gather in a small group to discuss the dangers and hazards of paint, share information, establish action goals, and confirm safety measures. The questionnaire identified "KY Activity" as a factor influencing the workers' perception of paint as "dangerous and harmful". "KY Activity," also extracted from the interviews, is an effective health and safety education method for teaching workers in small-sized painting companies that paint is "dangerous and harmful".

Practices and Awareness Regarding an Infant's Sleep Environment among Japanese Caregivers: A Cross-Sectional Survey.

Preventing sudden, unexpected infant death related to sleep, especially suffocation and sudden infant death syndrome, remains challenging globally. To evaluate factors associated with an unsafe sleep environment (SE) for infants in Japan, this cross-sectional study investigated the current status of practices and awareness among caregivers about a safe SE. Two hundred and fifty-four caregivers of infants in Yamaguchi Prefecture participated. Among the caregivers, 96.0% could not thoroughly practice a safe SE, although 65.0% had knowledge about a safe SE. More unsafe SE practices were significantly associated with 8- to 11-month-old infants than with 0- to 3-month-old infants, using the same practice as for an older child than with accessing information or a familiar person than with mass media as the most useful source of information. The differences in having knowledge were not associated with their practice. Many caregivers obtained information about an infant's SE from mass media and a familiar person. They preferred education via a face-to-face method by medical experts to raise awareness about a safe SE. Thus, efforts need to be developed in Japan in which experts who directly attend to caregivers can truly educate them to ensure that caregivers are continuously aware of the importance of an SE.

A retrospective study of unexpected deaths with alcohol use disorder from Japanese forensic autopsy cases

BackgroundAlcohol use disorder (AUD) is an important target for prevention of alcohol-related problems. In this study, we analyzed forensic autopsy cases to reveal the characteristics of the living conditions and death situations of individuals with AUD. MethodsWe retrospectively investigated 486 cases with a history of alcohol consumption for which a forensic autopsy was performed from 2012 to 2021 in Yamaguchi prefecture. Judgement of AUD was made using DSM-5. Various factors were compared statistically between AUD and non-AUD cases. ResultsOf the 486 cases, 225 (46.2%) were judged to be AUD, including 89 (18.3%) with advanced AUD, 33 (6.8%) were judged not to be AUD, and a judgement could not be made in the remaining cases. AUD was associated with alcohol consumption prior to death. Only 14.3% of the advanced-AUD cases was in treatment for alcohol dependence. The rates of interpersonal, health, financial and legal problems, receipt of public assistance and an extremely cluttered or hoarding house status were higher in all AUD and advanced AUD cases. Living alone, smoking and BMI were also associated with AUD. ConclusionsMany cases of alcohol-related deaths may have AUD, and persons with AUD who undergo a forensic autopsy commonly have multiple socioeconomic factors that may be associated with isolation that is involved in exacerbation of AUD. Further studies of these associations are needed because early diagnosis and treatment of AUD and support for the patient may lead to reduction of alcohol-related deaths.

Microstructural comparison in fault gouges and slip surfaces of active and inactive faults: A case study at Watarigawa area in northeastern Yamaguchi Prefecture, SW Japan

Microstructural comparison in fault gouges and slip surfaces of active and inactive faults: A case study at Watarigawa area in northeastern Yamaguchi Prefecture, SW Japan

Tetrodotoxin Content of the Small Gastropod Nassarius sufflatus

Severe tetrodotoxin (TTX) poisoning due to small gastropods has been documented in Japan. In this study, we investigated the TTX content of the muscles and viscera of Nassarius sufflatus collected off the coast of Futaoi Island, Shimonoseki, Yamaguchi Prefecture, Japan, to prevent the occurrence of TTX poisoning caused by this small gastropod. Live specimens were obtained, and their muscles and viscera were collected. Test solutions were prepared from tissues of specimens and analyzed for TTX by HPLC-fluorescence detection. TTX was detected in both tissues at concentrations ranging from <0.1 to 18.2 μg/g for muscle and <0.1 to 130.7 μg/g for viscera. These results suggested that N. sufflatus accumulates TTX not only in its viscera but also in its muscles, and that precautions should be taken to prevent food poisoning due to this gastropod.

A Novel Estimation of the Composite Hazard of Landslides and Flash Floods Utilizing an Artificial Intelligence Approach

Landslides and flash floods are significant natural hazards with substantial risks to human settlements and the environment, and understanding their interconnection is vital. This research investigates the hazards of landslides and floods in two adopted basins in the Yamaguchi and Shimane prefectures, Japan. This study utilized ten environmental variables alongside categories representing landslide-prone, non-landslide, flooded, and non-flooded areas. Employing a machine-learning approach, namely, a LASSO regression model, we generated Landslide Hazard Maps (LHM), Flood Hazard Maps (FHM), and a Composite Hazard Map (CHM). The LHM identified flood-prone low-lying areas in the northwest and southeast, while central and northwest regions exhibited higher landslide susceptibility. Both LHM and FHM were classified into five hazard levels. Landslide hazards predominantly covered high- to moderate-risk areas, since the high-risk areas constituted 38.8% of the study region. Conversely, flood hazards were mostly low to moderate, with high- and very high-risk areas at 10.49% of the entire study area. The integration of LHM and FHM into CHM emphasized high-risk regions, underscoring the importance of tailored mitigation strategies. The accuracy of the model was assessed by employing the Receiver Operating Characteristic (ROC) curve method, and the Area Under the Curve (AUC) values were determined. The LHM and FHM exhibited an exceptional AUC of 99.36% and 99.06%, respectively, signifying the robust efficacy of the model. The novelty in this study is the generation of an integrated representation of both landslide and flood hazards. Finally, the produced hazard maps are essential for policymaking to address vulnerabilities to landslides and floods.

Abstract 13771: Left Atrial Size and Frailty Indexes Predict Poor Prognosis in Hospitalized Elderly Patients With Heart Failure

Background: Left ventricular ejection fraction (LVEF) is a cardiac index used to diagnose and determine heart failure (HF) treatment strategy. However, in elderly patients with HF, LVEF is not a good predictor of prognosis. We have previously found that patient outcomes are associated with left atrial (LA) size and noncardiac factors such as malnutrition, muscle weakness, and cognitive dysfunction. This study examined whether a combination of LA function and noncardiac indicators related to frailty can predict an accurate prognosis in hospitalized elderly patients. Methods: Hospitalized HF patients over 65 years of age from January 2019 to December 2022 were consequently enrolled in the Yamaguchi Prefectural Grand Medical (YPGM) Center. We divided three categories: sinus rhythm (SR) with normal LA, SR with LA enlargement (LAE), and persistent or chronic atrial fibrillation (AFib) with LAE. Cox proportional hazard analyses were employed to determine the prognosis factors, i.e., the primary outcome as all-cause death or HF readmission and the secondary outcome as major adverse cardiac and cerebrovascular events (MACCE). Results: Overall, 676 HF patients were admitted to YPGM Center. Of those, 462 (median age 84.0, 47% female) met the study criteria. During the follow-up of 204.0 days, 46 patients reached all-cause death (10%), 82 experienced HF readmission (18%), and 116 developed MACCE (25%). LA volume index (LAVI) (Hazard ratio [HR]: 1.012; 95% confidence interval [CI]: 1.003-1.022; p = 0.013) and handgrip strength (HR: 0.917; 95%CI: 0.868-0.970; p = 0.002) were associated with the primary outcome. Nutritional status assessed by geriatric nutritional risk index (GNRI) was associated with the primary and secondary outcome (HR: 0.956; 95%CI: 0.927-0.985; p = 0.003, and HR: 0.937; 95%CI: 0.909-0.966; p &lt; 0.001, respectively), but neither AFib nor LVEF. The adverse events were lower in SR with the normal LA group than in other groups. Furthermore, a multiple logistic regression model, including LAVI, AFib, GNRI, and handgrip strength, most accurately predicted the primary outcome than those with the AFib or LVEF. Conclusion: The value of benefits as a prognosis lies more in LAVI and frailty indexes than in the presence of AFib and LVEF in elderly HF patients.

Association of physical activity with psychological distress and happiness in mothers of children with autism spectrum disorders during the COVID-19 pandemic

BackgroundThe coronavirus disease 2019 (COVID-19) pandemic may have severely impacted the psychological status of mothers of children with autism spectrum disorder (ASD). Although a previous study reported that physical activity (PA) moderated psychological distress in parents of children with ASD during the COVID-19 pandemic, the effect of PA on the happiness levels of such parents during the pandemic remains unclear. This study investigated the associations among PA, psychological distress, and happiness in mothers of children with ASD during the COVID-19 pandemic.MethodsThis cross-sectional study was designed to evaluate mothers of children with disabilities. Questionnaires were collected from mothers living in Yamaguchi and Okayama Prefectures, Japan, between February and December 2022. During this period, three large waves of the COVID-19 pandemic occurred in Japan. Of the 601 respondents, 334 mothers had children with ASD and offered valid data. PA was assessed using the short form of the International Physical Activity Questionnaire. Psychological distress and happiness were assessed using the six-item Kessler Psychological Distress Scale (K6) and the Subjective Happiness Scale (SHS).ResultsThe mothers had markedly higher K6 scores (6.49) and more than half of them had moderate-to-severe psychological distress, whereas the SHS scores (4.46) were similar to that of the general Japanese population. In a multivariable-adjusted model based on the analysis of covariance, the K6 score was not associated with any PA items. In contrast, SHS scores were positively associated with moderate-intensity PA (MPA) and total moderate- to vigorous-intensity PA (MVPA), independent of K6. In the post-hoc test, mothers who did some (4.52) or enough (≥ 150 min/week) MPA (4.56) had a higher SHS score than those who did not (4.09). Similarly, mothers who engaged in sufficient (≥ 600 MET-min/week) total MVPA had higher SHS scores (4.57) than those who did not engage in MVPA (4.12).ConclusionsThe mothers of children with ASD during the COVID-19 pandemic had markedly higher psychological distress, though none of the PA items were associated with stress levels. However, PA was positively associated with happiness in mothers of children with ASD independent of their stress levels.

Wastewater treatment plants elevating microplastic abundances, ecological risks, and loads in Japanese rivers: a source-to-sink perspective.

Little were certain about how wastewater treatment plants (WWTPs) affected the Japanese riverine microplastic contamination. This study explored the influences of WWTPs on microplastic pollution, assessed ecological risks, and looked at the sources-to-sinks phenomenon (WWTPs-to-rivers-to-marine) in riverine settings in Japan's Yamaguchi prefecture. Fifty surface water samples from the five selected rivers (Koya, Saba, Shimaji, and Fushino, Nishiki) and 11 effluent samples from WWTPs in the rivers' catchment were examined. Microplastics were analyzed using filtration, wet-peroxidation, density-separation, and attenuated reflectance-Fourier transform infrared spectroscopy techniques. Results suggested that the less populated and rural river (Nishiki) was less contaminated compared to the WWTPs and urban areas affected rivers (Koya, Saba, Shimaji, and Fushino). The WWTPs increased microplastic abundance twofold in the downstream regions compared to upstream stations. Microplastic characterization showed that the smaller microplastics < 500µm, fiber-shaped, transparent, blue, and green color particles were major. Polymer identification demonstrated that the polyethylene, polypropylene, and polyethylene terephthalate were prevalent both for the rivers and WWTP effluents. There was a significant emission of microplastics from WWTPs to rivers (4.671 billion pieces per day; 71.8kg per day) and rivers to Seto Inland Sea (0.13/billion pieces per day/km2; 7.1kg per day). The per capita MP emissions to the rivers via WWTPs ranged from 0.02 to 6.49g per day, which was approximately 2% of per capita single-use plastic wastes in Japan. An assessment of ecological risks showed that the WWTPs posed high ecological risks to rivers, and built up the pollution hotspots to their downstream areas by releasing higher number of microplastics and highly toxic polymers. Overall, the WWTPs influenced the rivers through both abundances and characteristics (shapes-size-color-polymers), increased the complexity of microplastic compositions as well as elevated ecological risks in the rivers. This study contributed to bridging the knowledge gaps about microplastic sources-to-sinks, ecological risks, and pollution management in Japan and beyond.

Low-temperature thermochronology of Ryoke belt granitoids, SW Japan: New insights into the recent cooling history from monazite fission-track dating

Traditional low-temperature thermochronology techniques such as apatite fission track (AFT) and apatite (U-Th-Sm)/He (AHe) have so far produced limited information on the neotectonic (late Miocene and younger) evolution of Japan. However, the development of monazite fission track (MFT) dating, which has an ultra-low temperature sensitivity (<∼25 – 46°C), provides a fresh opportunity to directly analyse recent denudation histories. Low-temperature thermochronology methods have been applied to granitoid samples from the Ryoke belt, located in eastern Yamaguchi and Nara Prefectures, SW Japan. Zircon (U-Th)/He (ZHe), AFT and AHe data and modelled thermal histories reveal Late Cretaceous - Pliocene cooling related to granitoid thermal relaxation combined with paleo-Izanagi and Pacific plate subduction along the eastern Eurasian continental margin. MFT dating reveals Plio – Pleistocene cooling ages, coincident with elastic loading caused by Philippine Sea plate subduction since the Middle - Late Miocene, along with the Quaternary collision of NE and SW Japan at the Itoigawa-Shizuoka Tectonic Line. Silica concentration, non-thermal “radiation assisted” annealing, and changing climatic conditions are proposed as possible caveats on MFT annealing kinetics since the samples are residing in an “open” system. Taking all these factors into consideration, the apparent MFT ages are interpreted as minimum cooling ages, being slightly younger than the thermal events that cooled the samples through the MFT nominal closure temperature. Estimated denudation rates based on MFT dating are higher in Nara relative to eastern Yamaguchi Prefecture, with the difference likely reflecting variations in the tectonic regime, timing of uplift and uplift mechanisms of the two regions.

The impact of geriatric nutritional risk index on one-year outcomes in hospitalized elderly patients with heart failure.

Strategies that accurately predict outcomes in elderly heart failure (HF) patients have not been sufficiently established. In previous reports, nutritional status, ability to perform activities of daily living (ADL), and lower limb muscle strength are known prognostic factors associated with cardiac rehabilitation (CR). In the present study, we investigated which CR factors can accurately predict one-year outcomes in elderly patients with HF among the above factors. Hospitalized patients with HF over 65 years of age from January 2016 to January 2022 were retrospectively enrolled in the Yamaguchi Prefectural Grand Medical (YPGM) Center. They were consequently recruited to this single-center retrospective cohort study. Nutritional status, ADL, and lower limb muscle strength were assessed by geriatric nutritional risk index (GNRI), Barthel index (BI), and short physical performance battery (SPPB) at discharge, respectively. One year after discharge, the primary and secondary outcomes were evaluated by all-cause death or HF readmission and major adverse cardiac and cerebrovascular events (MACCE), respectively. Overall, 1,078 HF patients were admitted to YPGM Center. Of those, 839 (median age 84.0, 52% female) met the study criteria. During the follow-up of 228.0 days, 72 patients reached all-cause death (8%), 215 experienced HF readmission (23%), and 267 reached MACCE (30%: 25 HF death, six cardiac death, and 13 strokes). A multivariate Cox proportional hazard regression analysis revealed that the GNRI predicted the primary outcome (Hazard ratio [HR]: 0.957; 95% confidence interval [CI]: 0.934-0.980; p < 0.001) and the secondary outcome (HR: 0.963; 95%CI: 0.940-0.986; p = 0.002). Furthermore, a multiple logistic regression model using the GNRI most accurately predicted the primary and secondary outcomes compared to those with the SPPB or BI models. A nutrition status model using GNRI provided a better predictive value than ADL ability or lower limb muscle strength. It should be recognized that HF patients with a low GNRI at discharge may have a poor prognosis at one year.

Age offsets between radiocarbon samples and changes in Holocene depositional ocean environments captured in sediment cores near Ube City, Yamaguchi Prefecture, Japan

Radiocarbon ages from contemporaneous samples of varying types can show large age differences (Nakamura et al., 2016; Raymond and Bauer, 2001), and changes in offsets between these ages (δage) within a core have been scarcely examined. Changes in δage have previously suggested disturbances or shifts to the depositional setting (Nakamura et al., 2016; Ishiwa et al., 2021; Yokoyama et al., 2019). Radiocarbon dating of ocean sediment cores from near Ube City, Yamaguchi prefecture, Japan revealed periods of slower and rapid sedimentation which aligned with, respectively, post-Holocene High Stand (HHS, ∼7–4 cal ka BP (Yokoyama, 2021)) conditions and sea level fall, and pre-HHS conditions with rising sea levels.δage patterns implied that the reliability of sample types as depositional age indicators may depend on the depositional environment. Radiocarbon ages and relative sea level (RSL) curves suggested that local inundation may have occurred up to ∼ 200 years earlier than previously reported. In addition to constraining the relative timing of sea transgression and regression during the HHS, this study highlights the need to examine the depositional setting to accurately represent depositional ages.

Plasticrust generation and degeneration in rocky intertidal habitats contribute to microplastic pollution

Plasticrusts are a plastic form that consists of plastic encrusting intertidal rocks. To date, plasticrusts have been reported on Madeira island (Atlantic Ocean), Giglio island (Mediterranean Sea) and in Peru (Pacific Ocean) but information on plasticrust sources, generation, degeneration and fate is largely missing. To address these knowledge gaps, we combined plasticrust field surveys, experiments and monitorings along the Yamaguchi Prefecture (Honshu, Japan) coastline (Sea of Japan) with macro-, micro- and spectroscopic analyses in Koblenz, Germany. Our surveys detected polyethylene (PE) plasticrusts that derived from very common PE containers and polyester (PEST) plasticrusts that resulted from PEST-based paint. We also confirmed that plasticrust abundance, cover and distribution were positively related to wave exposure and tidal amplitude. Our experiments showed that plasticrusts are generated by cobbles scratching across plastic containers, plastic containers being dragged across cobbles during beach clean-ups, and waves abrading plastic containers on intertidal rocks. Our monitorings found that plasticrust abundance and cover decreased over time and the macro- and microscopic examinations indicated that detached plasticrusts contribute to microplastic pollution. The monitorings also suggested that hydrodynamics (wave occurrence, tidal height) and precipitation drive plasticrust degeneration. Finally, floating tests revealed that low density (PE) plasticrusts float whereas high density (PEST) plasticrusts sink suggesting that polymer type floatability influences the fate of plasticrusts. By tracking the entire lifespan of plasticrusts for the first time, our study contributes fundamental knowledge of plasticrust generation and degeneration in the rocky intertidal zone and identified plasticrusts as novel microplastic sources.

Supply status and levels of schoolchild care facilities on elementary school districts in Yamaguchi prefecture

AbstractThe purpose of this study is to clarify the relationship between the regional categories and operational types of after‐school childcare in elementary school districts in Yamaguchi Prefecture. Based on the analysis of school district characteristics using the locational conditions and the number of pupils as indicators, school districts were classified into the following four types: “urban type”, “plain type”, “middle type”, and “mountainous type”.

Practices and Future Perspectives of Death Investigation in Forensic Autopsy in Yamaguchi Prefecture

Practices and Future Perspectives of Death Investigation in Forensic Autopsy in Yamaguchi Prefecture