Shizuoka Prefecture Research Articles

Evaluation of water consumption at district scale by analyzing smart water meter data

Abstract In urbanization, understanding of water consumption is necessary for water supply infrastructure development. We have been studying water consumption at Iride-Chibata District in the development of water supply management in Kosai City, Shizuoka Prefecture, Japan. Here the water consumption has been managed by reading water meter at each household every two months. Meanwhile, with the provision of smart metering for electricity, the district has installed the smart meters, which can hourly monitor water consumption, at all of 1,871 households. This study analysed the smart water meter data of all households to evaluate the water consumption at district scale. The average daily water consumption per household was higher on weekends than on weekdays. The hourly consumption showed two peaks at the hours of 7:00 – 11:00, and 18:00 – 22:00, respectively corresponding to morning and evening activities in a household. Either morning or evening, the peaks of weekdays occurred one hour earlier than those of weekends. The evening peaks were higher than the morning ones, that might come from Japanese evening bathing culture. These findings may help for timeframe water supply planning.

ISUT’s Information Support Activities in the Heavy Rain Since July 1, 2021

We report the information support activities conducted by the Information Support Team (ISUT) in the heavy rain since July 1, 2021, after it was dispatched to Shizuoka Prefecture. During the activities, ISUT-SITE and other information were provided and utilized by the disaster response organizations. This study reports on the characteristics and future issues in this disaster response activity.

Surface wave monitoring using ambient noise for detecting temporal variations in underground structures in landslide area

The temporal variation in subsurface structure of a landslide area was monitored using spatial autocorrelation (SPAC) as a simple and robust seismic observational method. The SPAC method is often used in civil engineering to estimate one-dimensional (1D) subsurface structures. However, in this study, we monitor the temporal variation in the SPAC coefficient deviation to evaluate environmental change effects and changes in the subsurface velocity structure. We used a seismic array comprising 10 seismometers in a landslide-prone area in Morimachi Town, western Shizuoka Prefecture, Japan, and continuous observations were performed from October 2020 – May 2022. We obtained a 1D velocity structural model as a reference using the multi-mode SPAC (MMSPAC) method with the averaged SPAC coefficients at different distances for all observation periods. We calculated the daily variation in SPAC coefficient relative to the average for all observation periods. We then applied cluster analysis to the SPAC coefficient deviation, which revealed weekly changes likely due to human activity and the effect of stream surges on nearby streams. After removing stream surge clusters and correcting for the weekly change, we reapplied cluster analysis to identify two major clusters. The differences between the two clusters can be attributed to structural changes in the very near surface (∼5 m) and deeper parts (∼20 m), likely influenced by shallow groundwater due to rainfall. By investigating the location of the landslide mass near the observation site, we suggest that structural changes around 20 m deep may correspond to the depth of potential slip surfaces.

Impact on step count by commitment-based health application.

Prior research has implied that promoting sustaining physical activity through nudges is challenging and boosting health literacy is important for the long-term establishment of behaviors. This study aimed to investigate the effects of commitment-based health application on step count and health literacy. A control experiment was conducted involving employees from companies located in Shizuoka Prefecture, Japan. Participants were divided into three groups: the commitment app group (utilizing a commitment-based application "Minchalle," where teams of around five members were randomly assigned to declare a target step count and report daily step count with pictures), the self-commitment group (individuals declaring a target step count and endeavoring on their own), and the control group (no intervention). Changes in step count and health literacy were examined over one month. A total of 109 employees from 7 companies participated. The changes in step count were an increase of 893 steps for the commitment app group, 243 steps for the self-commitment group, and 178 steps for the control group, with a significant increase in the commitment app group compared to the control group. Regarding health literacy measures, there was significant progress in four items out of five for the commitment app group compared to the control group, and significant progress in one item for the self-commitment group compared to the control group. Communication within the app teams, such as commitment, sharing photos of their goal achievements and provide encouraging comments to others, functioned as social nudges, suggesting the potential for an immediate increase in step count and long-term behavioral reinforcement through improved health literacy.

Forest resource distribution and transport cost optimization-based economic evaluation of gasification and steam-turbine biomass power generation systems

The economics of decentralized gasification and centralized steam turbine systems with optimized harvesting, chipping, and transportation costs of unutilized forest biomass were analyzed within the context of the spatial distribution of forest biomass resources using a geographic information system in the Fuji area of Shizuoka Prefecture, Japan. The optimized harvesting, chipping, and transportation costs were 62.50 USD/dry-t for the decentralized system and 65.86 USD/dry-t for the centralized system, confirming that the decentralized system was less expensive than the centralized system. However, electricity production costs for centralized systems, ranging from 0.137 USD/kWh (capacity: 5,000 kW), were found to be more economical than that for decentralized systems, at 0.151–0.165 USD/kWh (capacity: 482 kW), resulting in the higher costs of decentralized systems because of expensive initial investment than that of the centralized system. The rate of heat sold, which lowers the electricity production costs of gasification below those of centralized systems, was 20–40 % for all such plants. To lower the electricity production cost of gasification plants below that of steam-turbine systems, a heat sales rate of approximately 10% and a minimum staff of 0.2 persons for remote operation of the gasification system. Higher heat sales rates further decrease the cost of gasification, making it cheaper than steam-turbine systems even at lower operating rates. To achieve this cost advantage at current low utilization rates, a heat sales rate of 50% and a utilization rate of 90%, based on a unit price of 0.05 USD/kWh, are required.

Spatial distribution of rainfall–runoff characteristics and peak lag time in high‐relief meso‐scale mountain catchments where observations are scarce

AbstractClarifying the relationship between rainfall and runoff characteristics in mountainous areas is crucial to improving flood and sediment disaster prediction. This study investigates that relationship, focusing on meso‐scale catchments of 1–10 km2 in high‐relief mountainous regions where conventional observational data are limited. Such research requires observations in multiple adjoining watersheds due to the variability of runoff patterns in mountainous river systems. However, observations are challenging in meso‐scale catchments due to equipment loss in rivers. This study included seven observation sites with catchment areas of 0.16–9.01 km2 and relative elevations exceeding 1000 m within the Higashigochi River basin, a sub‐branch of the Oi River basin in Shizuoka Prefecture, Japan. Water level gauges were strategically installed at each of these locations to prevent loss. Peak lag time (the time difference between the rainfall and water level peaks), which is crucial to flood hydrograph definition and disaster preparedness, was assessed. The results indicate a general trend of increasing peak lag time with larger catchment area, although spatial heterogeneity was observed at small sites. This finding aligns with prior studies in meso‐scale catchments within mountainous regions with relative elevations of 450 m or less, suggesting that in such meso‐scale catchments, larger catchment area tends to result in longer peak lag times, regardless of topographic undulation. Overall, the impact of topographic undulations on peak lag time appears surprisingly modest, indicating that catchment area plays a more significant role in determining peak lag time. The observed heterogeneity of peak lag time could be attributable to the influence of bedrock groundwater discharge.

The Essential Elements of Japan Super Science High School Projects: A Case Study of Shizuoka Prefecture

To support the enhancement of science and technology, the Japanese government established the Super Science High School in 2002. However, there is a lack of information about this school for international scholars. We addressed this problem by observing and working with SSH in Shizuoka Prefecture and understanding their intended school models. The context of Shizuoka prefecture is interesting because it is well-known for its high-technology manufacturing company. Our “bottom-up” approach was mainly based on observation, in contrasts with other studies using a literaturebased method to define SSH schools. We identified four elements that represent the common goals and strategies employed by SSH: Independence scientific research, Scientific English, courses related to STEM, and international collaboration. This framework offers a clear picture of what exactly SSH schools are. Findings suggest that SSH identity is rooted in pedagogy, school culture, and rigorous instruction, especially in science and technology, including support from scientists and researchers from the surrounding universities as invited speakers, teacher assistance, and opportunities to conduct research in university-level laboratories. Keywords: essential elements, Japan Super Science High School, Projects, Case Study

The Impacts of River Channel Blockages Caused by Sliding Embankment Collapses during Earthquakes

New Japanese regulations governing earth embankment construction were introduced after a debris flow in Atami City, Shizuoka Prefecture, caused significant damage. Slope failures block river channels during earthquakes, triggering flooding, inundation, and debris flows. Appropriate risk assessments are crucial for residential areas potentially impacted by earthen embankment landslides during seismic events. This study evaluates the methods used to assess the potential damage caused by such landslides and previous research on the harm caused by embankment failures during earthquakes. We derived predictive equations based on statistical analyses of historical dam landslides that triggered river channel blockages when residential earth embankments failed in the Nigawa Yurino area. The equations describe the morphologies of landslide dams in river channels. The results indicated that the predictive equations were reasonably accurate. We built and validated a two-dimensional model of landslide dam overtopping and breaching using experimental data on a gently sloping dam. We derived the outflow volumes associated with residential earth embankment failures when full reservoirs breached in the Nigawa Yurino area. Our findings suggest that the peak outflow volumes after such embankments breach are generally lower than those associated with dam landslides or deep-seated dam failures, but higher than those of glacial lake outburst floods.

Long-term prognosis after stapled and hand-sewn ileal pouch–anal anastomoses for familial adenomatous polyposis: a multicenter retrospective study

PurposeThe long-term prognosis of stapled and hand-sewn ileal pouch–anal anastomoses in familial adenomatous polyposis patients in Japan remains unknown. This study aimed to compare the overall survival in familial adenomatous polyposis patients who underwent stapled or hand-sewn ileal pouch–anal anastomosis.MethodsThis multicenter retrospective study was conducted at 12 institutions in Shizuoka Prefecture, Japan. The clinical outcomes of 53 eligible familial adenomatous polyposis patients who underwent stapled (n = 24) and hand-sewn (n = 29) ileal pouch–anal anastomosis were compared.ResultsThe median follow-up duration was 171.5 months. The incidence of adenoma in the remnant rectum or anal transitional zone and metachronous rectal cancer was significantly more common in stapled ileal pouch–anal anastomosis (adenoma: stapled, 45.8%, vs. hand-sewn, 10.3%, p = 0.005; metachronous rectal cancer: 29.2%, vs. none, p = 0.002). The number of deaths was remarkably higher in stapled ileal pouch–anal anastomosis (p = 0.002). Metachronous rectal cancer was the most common cause of death. Overall survival was worse in stapled ileal pouch–anal anastomosis than in hand-sewn ileal pouch–anal anastomosis (120 months, 90.7% vs. 96.6%; 240 months, 63.7% vs. 96.6%; p = 0.044). Cox regression analysis revealed the independent effects of preoperative advanced colorectal cancer and stapled ileal pouch–anal anastomosis on overall survival.ConclusionStapled ileal pouch–anal anastomosis negatively affected the overall survival of familial adenomatous polyposis patients. Therefore, hand-sewn ileal pouch–anal anastomosis is recommended for better prognosis in these patients.

Quantifying variabilities in monoterpene emission among natural individuals of an urban-greening species (Quercus phylliraeoides) using a rapid measuring method

Quercus phillyraeoides, a strong monoterpene-emitting species, is widely planted in urban and suburban areas in Japan. Urban-greening plants with terpenoid emission may affect air quality by increasing photochemical oxidants through the reaction between their terpenoid emissions and urban gases. In mitigating this issue, replacing the original plants with low-emitting variants can be a workable approach without substantially altering the original landscapes and ecotopes. This study aimed to identify the low- or non-emitting variants among Q. phillyraeoides. To deal with a large number of Q. phillyraeoides samples, a method using detached leaves was adopted and optimized for observation of terpenoid emission rates from Q. phillyraeoides. The testing showed that the emission rate would be relatively stable at approximately 40 min of incubation under a photosynthetic photon flux density of ∼1000 μmol m–2 s–1 and a surrounding temperature of 30°C. Although the emission rates were different from those derived using the conventional method (i.e., the leaf cuvette method), they were well calibrated, with a regression line between the datasets of the two methods. We used this method to inspect the monoterpene emission rate from Q. phillyraeoides in multiple locations in Shizuoka Prefecture and detected a variability in the monoterpene emission rate (no detection to 14.8 nmol m–2 s–1), which were independent of environmental effects for each location. The Q. phillyraeoides individuals with no emission of monoterpenes are expected to be suitable for propagation as non-terpenoid-emitting greening materials.

Patterns of long-term care service use and multimorbidity in older Japanese adults: A cross-sectional study of claim data.

The long-term care (LTC) insurance system provides a combination of several services in Japan; therefore, it is important to clarify service utilization. Furthermore, it is important to consider multimorbidity among older adults, who frequently present several diseases. This study aimed to clarify LTC service utilization patterns, including those for newly added multifunctional services, and to describe the basic characteristics, including multimorbidity, of these patterns. We included 37 419 older adults in care need levels 1-5, living at home, who used LTC services in October 2017. We used LTC and medical claims data that were linked using unique identifiers from the National Health Insurance, Advanced Elderly Medical Insurance, and LTC Insurance of Shizuoka Prefecture in Japan. LTC service utilization patterns were identified using cluster analysis based on service fees. Multimorbidity was analyzed using the Charlson Comorbidity Index (CCI) and compared characteristics in these patterns. Six LTC service utilization patterns were identified: light use (51.0%), intensive use of day care (33.7%), intensive use of short stay (6.3%), intensive use of home help (5.1%), multifunctional LTC in small-group homes (MLS) use (3.7%), and MLS and home-visiting nurses (MLSH) use (0.2%). MLSH use had the highest CCI (3.6 ± 2.3). Intensive use of day care and short stay had the lowest CCI (2.6 ± 1.9). The characteristics of multimorbidity differed by LTC service utilization patterns. Our findings are useful for considering service utilization that takes into account the characteristics of older adults. Geriatr Gerontol Int 2024; 24: 283-289.

Field survey of the phase and sex ratios of the brown alga Dictyota dichotoma (Dictyotales, Phaeophyceae) using sex‐specific molecular markers

SUMMARYDominance of one phase (i.e. diploid or haploid) has been reported in various isomorphic macroalgae; however, studies of the relative frequencies of the two phases are limited to a few taxa owing to the difficulty in identifying phases of sterile thalli. In Dictyota dichotoma, we have previously documented the dominance of fertile sporophytes. In the present study, the phase and sex ratios of sterile thalli of D. dichotoma were determined using newly developed sex‐specific markers. Differentially expressed genes were detected by transcriptome analyses of female and male gametophytic strains and a sporophytic strain aiming to identify candidate sex‐specific genes. These candidates were aligned with genome sequences on the sex chromosomes of Ectocarpus siliculosus and were identified as putative sex‐specific genes of D. dichotoma. Two primer sets were designed to discriminate phase and sex by the presence or absence of PCR products, and these markers were applied to examine the phase and sex ratios of D. dichotoma in various habitats and seasons. The proportion of sporophytes against 33–50 thalli examined in each of the five habitats at Ebisu Island, Shizuoka Prefecture was 88–100%, and the proportion of fertile sporophytes against total sporophytes (fertility proportion) varied among the habitats (0–54%). The fertile sporophytes were remarkably larger than the sterile sporophytes. At Tateyama, Chiba Prefecture, the dominance of sporophytes occurred in all seasons. The fertility proportion of sporophyte was relatively high from February (62.4%) to May (91.9%) and lower than 23% in other seasons. When artificial substrates were anchored in the middle of the D. dichotoma population, newly recruited thalli were all sporophytes, suggesting infrequent reproduction via tetraspores in nature. Based on these findings, we discuss potential fitness differences between the phases of D. dichotoma.

Comparison of the Utilization of Disaster Medical Assistance Teams (DMATs) and Multiple Physician-staffed Helicopters in Mass Casualty Responses

Abstract Objective To investigate the differences between doctor helicopters (DHs) and disaster medical assistance teams (DMATs) based on past examples and the current situation in Shizuoka Prefecture. Methods First, we examined cases in Shizuoka Prefecture from 2014 to 2023, where incidents involving five or more injured individuals were simultaneously managed using multiple DHs. Next, we investigated the presence of DMATs in Shizuoka Prefecture and assessed their role in disaster responses within the prefecture. Results Since 2014, there have been eight incidents in Shizuoka Prefecture where multiple DHs were deployed to respond to mass casualties. In contrast, Shizuoka DMATs were placed on standby three times during the same period, with one active deployment during a disaster caused by a landslide in Atami. The other two cases were managed solely by DHs and ambulance teams. Conclusion Localized disasters in Shizuoka Prefecture have seen the effective use of multiple DHs for timely patient transportation, particularly when suitable weather conditions permit. In contrast, DMATs are primarily deployed for extended medical activities lasting more than one day. This differentiation highlights the importance of choosing the appropriate medical response approach based on the nature and scope of the disaster.

The Importance of Daily Relationships in Mitigating Conflicts between Migrant Entrepreneurs and Local Residents in Depopulated Japan: Case Study of Minami-Izu, Shizuoka Prefecture

The Importance of Daily Relationships in Mitigating Conflicts between Migrant Entrepreneurs and Local Residents in Depopulated Japan: Case Study of Minami-Izu, Shizuoka Prefecture

Assessment of Low-density Lipoprotein Cholesterol Levels and Non-invasive Vascular Health in School-aged Children: A Study in Ogasa District, Shizuoka Prefecture.

The present study assessed low-density lipoprotein cholesterol (LDL-C) levels in school-aged children from the Ogasa District of Shizuoka Prefecture and evaluated the utility of non-invasive vascular tests, namely flow-mediated dilation (FMD) and intima-media thickness (IMT), in pediatric patients with familial hypercholesterolemia (FH). We analyzed the lipid test results of 8,568 students screened for prevention of lifestyle-related diseases and 78 children under 15 years old with cholesterol levels exceeding 220 mg/dL who visited Chutoen General Medical Center. We examined the LDL-C distribution from school-age screenings and conducted FMD and IMT assessments on those meeting the 2022 Pediatric FH Guidelines criteria. Among the screened students, 186 (2.2%) exhibited LDL-C levels above 140 mg/dL, including 123 fourth-graders (2.8%) and 63 first-year junior high students (1.5%). The mean LDL-C level across all students was 90.0 mg/dL (standard deviation: 21.3 mg/dL), with the 95th percentile at approximately 125.0 mg/dL. Of the 78 children who visited the hospital, 65 met the FH diagnostic criteria. In children ≥ 10 years old, no significant IMT differences were observed between the Definitive and Probable FH groups and the Possible FH group; however, a significant difference in the FMD percentage was noted between these groups (9.9% [8.1%-11.9%] vs. 14.2% [11.6%-16.3%], P=0.003). Our findings highlight the LDL-C distribution in FH screening and suggest a potential reduction in FMD in pediatric FH patients ≥ 10 years old. These results emphasize the importance of initiating pharmacological interventions in school-aged children to maintain optimal LDL-C levels for lifelong cardiovascular health.

Tejin starts carbon fiber production with acrylonitrile from waste and biomass-residue

On December 21, 2023, Teijin Limited announced that it will begin production and sales of TenaxTM Carbon Fiber made with sustainable acrylonitrile (AN) using waste and residue from biomass-derived products or recycled raw materials that have received ISCC PLUS certification from the International Sustainability and Carbon Certification system. The TenaxTM Carbon Fiber under ISCC Plus certification will be produced at Teijin's Mishima plant in Shizuoka Prefecture, Japan, using the mass balance approach. With this method, materials are verifiably tracked through complex value chains, for example, when biomass-derived raw materials are mixed with petroleum-derived raw materials to create products.

Optimal search conditions for identification of patients with chronic myeloid leukemia from Japanese National Health Insurance data

This study investigated which conditions could be used to identify patients with chronic myeloid leukemia (CML) from a National Health Insurance claims dataset. During April 2012 and September 2018, 1,789,462 employees were enrolled in the dataset for Shizuoka Prefecture residents. The number of patients with the ICD-10 code for CML was 761. Among them, 246 who had been prescribed a tyrosine kinase inhibitor were considered as having true CML. The positive predictive value was calculated as 32.3% when CML was identified by ICD-10 code alone. Combination of ICD-10 code with prescribed drugs was required to accurately identify patients with CML from the insurance database.

Alocasia odora poisoning due to calcium oxalate needle crystals in Japan.

Objective: To elucidate the actual circumstances of damage caused by Japanese Alocasia (A) odora. Materials and Methods: We investigated cases in Japan from our own hospital in the eastern part of Shizuoka Prefecture as well as published reports. Results: A. dorais found in western Japan, and plants of the Alocasia genus are cultivated often. A. odora is frequently associated with food poisoning because its aboveground parts resemble those of Satoimo (Colocasia esculenta). Moreover, A. odora contains insoluble calcium oxalate crystals, which cause poisoning symptoms, such as oral pain, nausea, vomiting, and laryngeal edema, resulting in near asphyxia, diarrhea following shock, and skin dermatitis. Calcium oxalate crystals are abundant in Araceae family plants, and cases of health damage owing to the accidental ingestion of Araceae plants have been reported worldwide. Conclusion: Due to the strong irritation felt in the mouth upon contact with the plant, it is advisable to immediately spit out the plant and rinse the mouth. In addition to drug administration, ensuring a secure airway may be necessary if there is a risk of asphyxiation.

Activity of a Medical Relief Team from Shizuoka Hospital that was Dispatched to the Noto Peninsula Earthquake in Reiwa 6 (2024).

The present study aimed to report on the activity of a medical relief team from Juntendo Shizuoka Hospital that was dispatched to the Noto Peninsula Earthquake in Reiwa 6. Narrative report. The activities conducted on-site in the Noto Peninsula involved multiple deployments of the Juntendo University Shizuoka Hospital Disaster Medical Assistance Team (JS-DMAT). The first deployment from January 2nd to January 6th faced challenges due to damaged infrastructure, particularly roads, affecting mobility. The team focused on hospital medical support, patient transportation, and DMAT headquarters assistance. The second deployment, from January 8th to January 12th, encountered persistently damaged roads, leading to incidents but no significant vehicle damage. The team engaged in screening, zoning, medical examinations, and DMAT headquarters support in evacuation shelters. The third team's planned activities in early February were canceled by Shizuoka Prefecture.Additionally, on January 7, 2024, personnel from Juntendo Shizuoka Hospital participated in the Shizuoka Prefectural DMAT Coordination Headquarters activity, documenting DMAT activities and assessing team members' health. The Ministry of Health, Labour and Welfare's request for the fourth Shizuoka Prefecture DMAT dispatch led to the selection of the second JS-DMAT for deployment. The activities related to the Noto Peninsula earthquake by JS-DMAT were reported. Lessons from this disaster are being sought to guide future disaster response preparations.

Evaluation of the Influence of Genetic and Environmental Factors on the Ephedrine Alkaloids Content of Ephedra sinica.

Ephedra herb, a dried terrestrial stem of Ephedra sinica, is used in traditional Japanese medicine (Kampo) and Chinese medicine to treat the common cold, headaches, bronchial asthma, and nasal inflammation. E. sinica predominantly contains two ephedrine alkaloids-(-)-ephedrine and (+)-pseudoephedrine-which are crucial for its medicinal effects. This study aimed to reveal the influence of genetic and environmental factors on ephedrine alkaloids content using statistical genetic analyses. To evaluate the influence of genetic factors on ephedrine alkaloids content, 25 clonal lines were cultivated in Ibaraki and the broad-sense heritability of the traits was estimated. The heritabilities of (-)-ephedrine, (+)-pseudoephedrine, and "total alkaloids" (TA) content were 0.871, 0.969, and 0.865, respectively. The heritabilities of ephedrine alkaloids content were high. To evaluate the influence of environmental factors on ephedrine alkaloids content, four clonal lines which have different genotypes were cultivated in three locations (Ibaraki, Shizuoka, and Yamanashi prefectures). The effects of genotype (G), location (L), and genotype by environment (G × E) interactions on ephedrine alkaloids content were found to be significant (p < 0.05) by two-way ANOVA, and, in particular, the genotypic effects were found to be the largest. Our results indicate that the ephedrine alkaloids content in E. sinica is under relatively strong genetic control and remains stable under various environments. These findings suggest that E. sinica with a higher and stable ephedrine alkaloids content could be cultivated in different locations through selective breeding.