Subjective perceived risk factors of exertional heat exhaustion-related symptoms in female collegiate athletes in Japan.

Associations of exertional heat exhaustion (EHE)-related symptoms with lifestyle habits and health factors specific to female athletes, ranked by relative risks from high to low, remain elusive. Addressing this issue would benefit athletes and coaches, ensuring safer practices during summer sports activities. To address this issue, we distributed paper-based questionnaires to seven universities in Japan, and 983 respondents completed our survey. The questionnaires covered various personal characteristics, lifestyle habits, perceived health factors, perceived athletic activity, and EHE-related symptoms. In this retrospective case-control study, we analyzed the relationships of EHE-related symptoms (objective variables) with lifestyle habits, health factors, and athletic activity conditions (explanatory variables) using the partial proportional odds model. The questionnaire responses revealed that perceived dehydration, sickness, loss of appetite, perceived accumulated fatigue, perceived mental stress, lack of ambient wind, and insufficient rest breaks were positively associated with EHE-related symptoms, with relative risks ranging from high to low. Using an air conditioner during sleep and having a sleep duration of ≥ 6 h were associated with a reduced risk of EHE-related symptoms. The study results suggest that female athletes should be allowed to postpone exercise or reduce its intensity and volume based on their perceptions of dehydration, sickness, loss of appetite, accumulated fatigue, and mental stress in summer to prevent heat-related illnesses.

Jump height ingenerated by countermovement and arm swing better correlates with proagility shuttle run tests but not with change of direction deficits in collegiate female athletes.

BACKGROUND: Jumping and linear sprinting performances show a moderate correlation with change of direction (COD) ability. However, the extent of these correlations remains unknown through statistical analysis. Thus, this study statistically compared correlation coefficients between COD, COD deficit (CODD), and jumping and linear sprint performances. METHODS: National-level basketball (29) and baseball (18) intercollegiate female athletes performed 20-m linear sprint, proagility (5-10-5) test, squat jump (SJ), countermovement jump with (CMJarm) and without (CMJ) arm swing and modified reactive strength index (RSImod). Correlation analysis was used to assess factors correlated with COD performance and CODD; subsequently, correlation coefficient comparison test was used to determine better correlations with COD and CODD performance. RESULTS: CMJ (r=-0.483) and CMJarm (r=-0.446) had stronger correlations with 10-m COD (both, P<0.018) than with 10-m linear sprint (r=0.431, P=0.002). For 20-m COD, RSImod, CMJ, and CMJarm (r=-0.491--0.543, P<0.001) better correlated with 20-m COD than with 20-m linear sprints (r=0.436, P=0.002), while RSI (both r=-0.317, P<0.030) and SJ (r=-0.359, r=-0.293, P=0.046) were weakly correlated with 10- and 20-m COD. The differences in correlation coefficients for RSImod, CMJ, and CMJarm were not significant in both 10- and 20-m COD. Ten-meter linear sprint performance only correlated with 10-m CODD, while no correlation was observed with 20-m CODD. CONCLUSIONS: Stronger correlations of RSImod, CMJ, and CMJarm with 10-/20-m COD than with linear sprinting, RSI, and SJ suggest that training focused on improving countermovement and arm swings with jumping may enhance COD performance in female athletes.

Evaluation of virus removal in membrane bioreactor (MBR) and conventional activated sludge (CAS) processes based on long-term monitoring at two wastewater treatment plants.

The membrane bioreactor (MBR) process always offers better wastewater treatment than conventional activated sludge (CAS) treatment. However, the difference in their efficacy of virus reduction remains unknown. To investigate this, we monitored virus concentrations before and after MBR and CAS processes over 2 years. Concentrations of norovirus genotypes I and II (NoV GI and GII), aichivirus (AiV), F-specific RNA phage genotypes I, II, and III (GI-, GII-, and GIII-FRNAPHs), and pepper mild mottle virus (PMMoV) were measured by a quantitative polymerase chain reaction (qPCR) method at two municipal wastewater treatment plants (WWTPs A and B) in Japan. Virus concentration datasets containing left-censored data were estimated by using both maximum likelihood estimation (MLE) and robust regression on order statistics (rROS) approaches. PMMoV was the most prevalent at both WWTPs, with median concentrations of 7.5 to 8.8 log10 copies/L before treatment. Log10 removal values (LRVs) of all viruses based on means and standard deviations of concentrations before and after treatment were consistently higher following MBR than following CAS. We used NoV GII as a model pathogen in a quantitative microbial risk assessment of the treated water, and we estimated the additional reductions required following MBR and CAS processes to meet the guideline of 10-6 DALYs pppy for safe wastewater reuse.

Prognostic impact and survival outcomes of colon perforation in patients with metastatic colorectal cancer: a multicenter retrospective cohort study.

BACKGROUND: Colon perforation caused by colorectal cancer (CRC) is a fatal condition requiring emergency intervention. For patients with metastatic lesions, surgeons face difficult decisions regarding whether to resect the primary and metastatic lesions. Moreover, there is currently no established treatment strategy for these patients. This study aimed to investigate the clinical practice and long-term outcomes of patients with metastatic CRC diagnosed with the onset of colon perforation. METHODS: We performed a population-based multicenter cohort study. Consecutive patients diagnosed with stage IV CRC between 2008 and 2015 at all designated cancer hospitals in Fukushima Prefecture, Japan, were enrolled in this study. We evaluated the impact of colon perforation on the survival outcomes of patients with metastatic CRC. The main outcome was the adjusted hazard ratio (aHR) of perforation for overall survival (OS). Survival time and HRs were estimated using Kaplan‒Meier and Cox proportional regression analyses. RESULTS: A total of 1258 patients were enrolled (perforation: n = 46; non-perforation: n = 1212). All but one of the patients with perforation underwent primary resection or colostomy and 25 cases were able to receive chemotherapy. The median OS for the perforation and non-perforation groups was 19.0 and 20.0 months, respectively (p = 0.96). Moreover, perforation was not an independent prognostic factor (aHR: 0.99; 95% confidence interval: 0.61-1.28). CONCLUSIONS: In metastatic CRC, perforation is not necessarily a poor prognostic factor. Patients with perforation who undergo primary tumor resection or colostomy and prompt initiation of systemic chemotherapy might be expected to have a survival time similar to that of patients with non-perforated colon.

Phase II Study of Intraperitoneal Administration of Paclitaxel Combined with S-1 and Cisplatin for Gastric Cancer with Peritoneal Metastasis.

BACKGROUND: Intraperitoneal chemotherapy is promising for gastric cancer with peritoneal metastasis. Although a phase III study failed to show a statistically significant superiority of intraperitoneal paclitaxel combined with S-1 and intravenous paclitaxel, the sensitivity analysis suggested clinical efficacy. Thus, attempts to combine intraperitoneal paclitaxel with other systemic therapies with higher efficacy have been warranted. We sought to explore the efficacy of intraperitoneal paclitaxel with S-1 and cisplatin. PATIENTS AND METHODS: Gastric cancer patients with peritoneal metastasis were enrolled in the phase II trial. In addition to the established S-1 and cisplatin regimen every 5 weeks, intraperitoneal paclitaxel was administered on days 1, 8, and 22 at a dose of 20 mg/m2. The primary endpoint was overall survival rate at 1 year after treatment initiation. Secondary endpoints were progression-free survival and toxicity. RESULTS: Fifty-three patients were enrolled and fully evaluated for efficacy and toxicity. The 1-year overall survival rate was 73.6% (95% confidence interval 59.5-83.4%), and the primary endpoint was met. The median survival time was 19.4 months (95% confidence interval, 16.1-24.6 months). The 1-year progression-free survival rate was 49.6% (95% confidence interval, 34.6-62.9%). The incidences of grade 3/4 hematological and non-hematological toxicities were 43% and 47%, respectively. The frequent grade 3/4 toxicities included neutropenia (25%), anemia (30%), diarrhea (13%), and anorexia (17%). Intraperitoneal catheter and implanted port-related complications were observed in four patients. There was one treatment-related death. CONCLUSIONS: Intraperitoneal paclitaxel combined with S-1 and cisplatin is well tolerated and active in gastric cancer patients with peritoneal metastasis.

Effect of backstroke ledge on backstroke start technique for water entry.

This study aimed to investigate how the use of a backstroke ledge (BSL) affects backstroke start performance in terms of flight distance and water entry posture in competitive backstroke swimmers. Ten male swimmers performed a maximum of 15 m in backstroke, starting with or without a BSL. Two 120 Hz and one 60 Hz video cameras were used to analyse the kinematic variables and angular momentum of the whole body. Using a BSL reduced the time to reach 5 and 15 m compared with not using a BSL (p < 0.04). Using a BSL heightened vertical position of the centre of mass (CM) at take-off, lengthened flight distance, and increased angular momentum (p < 0.02). Additionally, the lower limb entry angle was larger, and the hole entry posture angle was smaller with a BSL than without a BSL (p < 0.04). These results suggest that a high CM position at the start of the backstroke with a BSL increased the flight distance, and a large angular momentum enabled hole entry as well as improved the horizontal velocity after water entry. Hence, increases in flight distance and velocity after water entry were contributing factors in improving the start performance of the backstroke when using a BSL.

Subjective perceived risk factors of exertional heat exhaustion-related symptoms in male collegiate athletes in Japan: a case-control study.

The purpose of this study was to investigate associations between lifestyle habits, health factors, athletic activity conditions, and exertional heat exhaustion (EHE)-related symptoms among male college athletes in Japan based on a self-completed questionnaire. The paper-based questionnaires were distributed to 11 universities in Japan, and 2006 respondents completed the survey. Data of personal characteristics (age, body mass), lifestyle habits (sleep duration, use of air-conditioner while sleeping, and practice duration), perceived health factors (loss of appetite, sleep deprivation, sickness, dehydration, accumulated fatigue, and mental stress), perceived athletic activity (insufficient rest breaks, high ambient temperature, excessive humidity, strong solar radiation, lack of ambient wind, and clothing discomfort), and EHE-related symptoms (dizziness, headaches, nausea, and malaise) were collected. The association between lifestyle habits, health factors, athletic activity conditions (explanatory variables), and EHE-related symptoms (objective variables) was analyzed using the partial-proportional odds model. "Perceived dehydration" (odds ratios [ORs] 1.70-2.31, p < 0.002)," "sickness" (ORs 1.35-1.76), p < 0.001), "perceived accumulated fatigue" (ORs 1.13-1.31, p ≤ 0.001), "perceived mental stress" (ORs 1.17-1.31, p < 0.019), "lack of ambient wind" (ORs 1.12-1.19, p < 0.022), "loss of appetite" (ORs 1.16-1.23, p < 0.037), and "sleep deprivation" (ORs 1.15-1.17, p < 0.025) were positively associated with EHE-related symptoms, whereas "using an air conditioner during sleeping" (ORs 0.91, p = 0.047) during summer seasons was negatively associated. These findings suggest that athletes should be allowed to postpone or downregulate exercise intensity and/or volume based on their perceptions of dehydration, sickness, accumulated fatigue, mental stress, loss of appetite, and/or sleep deprivation in the summer to prevent heat illness.

Clinical Features and Survival of Young Adults with Stage IV Gastric Cancer: a Japanese Population-Based Study.

PURPOSE: With the aging of society, the mean age of patients with gastric cancer (GC) in Japan has increased. However, there are few documented outcomes for young patients with stage IV GC. We investigated the clinical characteristics and prognosis of such patients aged < 40 years using a dataset from an integrated population-based cohort study. METHODS: We conducted this multicenter population-based cohort study to determine whether earlier onset of GC was a poor prognostic factor. We enrolled patients with metastatic GC aged < 40 years (young group) and those aged between 60 and 75 years (middle-aged group). Patients were histologically diagnosed as having gastric adenocarcinoma. We evaluated the overall survival (OS) of both groups and the hazard ratio (HR) for OS based on age. The adjusted HR with 95% confidence interval (CI) was evaluated using the Cox proportional hazards model after adjusting for confounding factors, including sex, histology, number of metastatic lesions, surgical resection, and chemotherapy. RESULTS: This study enrolled 555 patients. The patients were classified into the young (n = 20) and the middle-aged group (n = 535). The median OS durations were 5.7 and 8.8 months in the young and middle-aged groups, respectively (p = 0.029). The adjusted HR (95% CI) of the young group was 1.88 (1.17-3.04, p = 0.009). CONCLUSION: Age was an independent prognostic factor in patients with stage IV GC. Further studies investigating the genomic characteristics of GC and exploring more effective chemotherapeutic agents are required.

Assessing critical loads and exceedances for acidification and eutrophication in the forests of East and Southeast Asia: A comparison with EANET monitoring data.

Spatial variations in sulfur (S) and nitrogen (N) deposition have changed in East and Southeast Asia in recent decades. Nevertheless, in this region, including the tropics, regional-scale assessments of the long-term risk of acidification and eutrophication (N saturation) for terrestrial ecosystems using a critical load approach have not been updated since 2001. To evaluate future risks, maps of critical loads and exceedances were updated using recently acquired spatial datasets of soil properties, soil minerals, climate, tree plantations, and the annual S and N depositions estimated using the Community Multiscale Air Quality (CMAQ) model. The resulting maps were verified using data on long-term trends in soil pH and nitrate concentration in surface water acquired by the Acid Deposition Monitoring Network in East Asia (EANET). It was found that N deposition exceeded the critical load for eutrophication not only in East Asia but also in some parts of the tropical monsoon and humid regions in Southeast Asia, whereas S deposition partly exceeded the critical load for soil acidification in China and small parts of the tropical monsoon region. The high-risk areas for eutrophication coincided well with the EANET sites, where the increase in nitrate concentration in the surface water was significant over the last 20 years. Hence, the estimated map of the critical load exceedance for eutrophication is more plausible for assessing the risk in East and Southeast Asia than that for acidification, although the critical load exceedance for acidification would be sufficiently significant as an updated risk map based on the latest input values. This update also suggests that increased N deposition around megacities, water discharge, and tree plantations may play an important role in the spatial variability of eutrophication risks in the tropics of Southeast Asia.

Impact of histological subtype on prognosis in stage IV colorectal cancer: A population-based cohort study.

BACKGROUND: There are a few established prognostic factors for stage IV colorectal cancer. Thus, this study aimed to evaluate the impact of histological subtypes on prognosis and metastatic patterns in patients with stage IV colorectal cancer. METHODS: This was a population-based, multicenter, cohort study. We included consecutive patients diagnosed with stage IV colorectal cancer between 2008 and 2015 at all designated cancer hospitals in Fukushima prefecture, Japan. Patients were classified into two groups according to histological subtypes as follows: poorly differentiated adenocarcinoma (Por), mucinous adenocarcinoma (Muc), or signet-ring cell carcinoma (Sig) and well (Wel) or moderately differentiated adenocarcinoma (Mod). We evaluated the relationship between these histological groups and survival time. After adjusting for other clinical factors, we calculated the hazard ratio for Por/Muc/Sig. RESULTS: A total of 1,151 patients were enrolled, and 1,031 and 120 had Wel/Mod and Por/Muc/Sig, respectively. The median overall survival was 19.2 and 11.9 months for Wel/Mod and Por/Muc/Sig, respectively (p < 0.001). The adjusted hazard ratio for Por/Muc/Sig with regard to survival time was 1.42 (95% confidence interval: 1.13-1.77). Por/Muc/Sig had a lower incidence of liver and lung metastases and a higher incidence of peritoneal dissemination and metastasis to rare organs, such as the bone and brain. CONCLUSIONS: The Por/Muc/Sig histological subtype was an independent prognostic factor for poor prognosis among patients with stage IV colorectal cancer. The histological subtype may be useful for predicting the prognosis of patients with stage IV colorectal cancer and designing the treatment strategy.

Clinical impact of gastrectomy for gastric cancer patients with positive lavage cytology without gross peritoneal dissemination.

BACKGROUND: The prognosis of gastric cancer patients with positive lavage cytology without gross peritoneal dissemination (P0CY1) is poor. The survival benefit of gastrectomy for these patients has not been established. PATIENTS AND METHODS: In this population-based cohort study, we investigated the impact of radical gastrectomy with lymph node dissection for P0CY1 patients. Patients who were diagnosed with Stage IV gastric cancer from 2008 to 2015 in all nine cancer-designated hospitals in a tertiary medical area were listed. Patients who were diagnosed with histologically proven adenocarcinoma in both the primary lesion and lavage cytology during the operation or a diagnostic laparoscopic examination were enrolled. Patients with a gross peritoneal lesion or other metastatic lesions were excluded. The primary outcome was the adjusted hazard ratio (aHR) of gastrectomy for overall survival. We also evaluated the survival time in patients who underwent gastrectomy or chemotherapy in comparison to patients managed without primary surgery or with best supportive care. RESULTS: One hundred patients were enrolled. The aHR (95% confidence interval) of gastrectomy was 0.677 (0.411-1.114, p = 0.125). The median survival time in patients who received gastrectomy (n = 74) was 21.7, while that in patients managed without primary surgery (n = 30) was 20.5 months (p = 0.155). The median survival time in patients who received chemotherapy (n = 76) was 23.0 months, while that in patients managed without chemotherapy was 8.6 months (p < 0.001). CONCLUSION: Gastrectomy was not effective for improving the survival time in patients with P0CY1 gastric cancer. Surgeons should prioritize the performance of chemotherapy over surgery as the initial treatment.

Clinical Impact of Primary Tumor Site in Stage IV Colorectal Cancer: A Statewide Cohort Study.

BACKGROUND/AIM: We investigated the clinical impact of the primary tumor site in stage IV colorectal cancer (CRC). PATIENTS AND METHODS: In this statewide multicenter retrospective cohort, patients with stage IV CRC from nine hospital-based cancer registries across the Fukushima Prefecture (2008-2015) were categorized based on three primary tumor sites: right colon cancer (RCC), left colon cancer (LCC), and rectal cancer. Overall survival was assessed using Cox regression analysis. RESULTS: A total of 1,211 patients were included. The most common clinical symptom was obstruction in LCC and bleeding in rectal cancer. Liver metastases were multiple and larger in LCC, while lung metastases were multiple in rectal cancer. Compared to LCC, the adjusted hazard ratio (HR) for overall survival was 1.19 [95% confidence interval (CI)=1.01-1.39, p=0.032] in RCC and 1.03 (95% CI=0.86-1.23, p=0.77) in rectal cancer. CONCLUSION: RCC was independently associated with a worse prognosis in stage IV CRC.

A grading system for predicting the prognosis of gastric cancer with liver metastasis.

OBJECTIVE: The prognosis of patients with liver metastases from gastric cancer is determined using tumor size and number of metastases; this is similar to the factors used for the prediction of liver metastases from colorectal cancer. The relationship between the degree of liver metastasis from gastric cancer and prognosis with reference to the classification of liver metastasis from colorectal cancer was investigated. METHODS: This was a multi-institutional historical cohort study. Among patients with stage IV gastric cancer, who visited the cancer hospitals in Fukushima Prefecture, Japan, between 2008 and 2015, those with simultaneous liver metastasis were included. Abdominal pretreatment computed tomography images were reviewed and classified into H1 (four or less liver metastases with a maximum diameter of ≤5 cm); H2 (other than H1 and H3) or H3 (five or more liver metastases with a maximum diameter of ≥5 cm). The hazard ratio for overall survival according to the H grade (H1, H2 and H3) was calculated using the Cox proportional hazards model. RESULTS: A total of 412 patients were analyzed. Patients with H1, H2 and H3 grades were 118, 162 and 141, respectively, and their median survival time was 10.2, 5.7 and 3.1 months, respectively (log-rank P < 0.001). The adjusted hazard ratio for overall survival was H1: H2: H3 = reference: 1.39 (95% confidence interval: 1.04-1.85): 1.69 (95% confidence interval: 1.27-2.27). CONCLUSIONS: The grading system proposed in this study was a simple and easy-to-use prognosis prediction index for patients with liver metastasis from gastric cancer.

Comparison of spatial and temporal changes in riverine nitrate concentration from terrestrial basins to the sea between the 1980s and the 2000s in Japan: Impact of recent demographic shifts.

Nitrogen (N) is an essential nutrient but may become a pollution source in the environment when the N concentration exceeds a certain threshold for humans and nature. Nitrate is a major N species in river water with notable spatial and temporal variations under the influences of natural factors and anthropogenic N inputs. We analyzed the relationship between riverine N (focusing on nitrate) concentration and various factors (land use, climate, basin topography, atmospheric N deposition, agricultural N sources and human-derived N) in 104 rivers located throughout the Japanese Archipelago except small remote islands. We aimed to better understand processes and mechanisms to explain the spatial and temporal changes in riverine nitrate concentration. A publicly available river water quality database observed in the 1980s (1980-1989) and 2000s (2000-2009) was used. This study is the first to evaluate the long-term scale of 20 years in the latter half of Japan's economic growth period at the national level. A geographic information system (GIS) was employed to determine average values of each variable collected from multiple sources of statistical data. We then performed regression analysis and structural equation modeling (SEM) for each period. The forestland area influenced by the basin topography, climate (i.e., air temperature) and other land uses (i.e., farmland and urban area) played a major role in decreasing nitrate concentrations in both the 1980s and 2000s. Atmospheric N deposition (especially N oxides) and agricultural N sources (fertilizer and manure) were also significant variables regarding the spatial variations in riverine nitrate concentrations. The SEM results suggested that human-derived N (via food consumption) intensified by demographic shifts during the 2000s increased riverine nitrate concentrations over other variables within the context of spatial variation. These findings facilitate better decision making regarding land use, agricultural practices, pollution control and individual behaviors toward a sustainable society.

Breast Cancer Detection from a Urine Sample by Dog Sniffing: A Preliminary Study for the Development of a New Screening Device, and a Literature Review.

BACKGROUND: Breast cancer is a leading cause of cancer death worldwide. Several studies have demonstrated that dogs can sniff and detect cancer in the breath or urine sample of a patient. This study aims to assess whether the urine sample can be used for breast cancer screening by its fingerprints of volatile organic compounds using a single trained sniffer dog. This is a preliminary study for developing the "electronic nose" for cancer screening. METHODS: A nine-year-old female Labrador Retriever was trained to identify cancer from urine samples of breast cancer patients. Urine samples from patients histologically diagnosed with primary breast cancer, those with non-breast malignant diseases, and healthy volunteers were obtained, and a double-blind test was performed. Total of 40 patients with breast cancer, 142 patients with non-breast malignant diseases, and 18 healthy volunteers were enrolled, and their urine samples were collected. RESULTS: In 40 times out of 40 runs of a double-blind test, the trained dog could correctly identify urine samples of breast cancer patients. Sensitivity and specificity of this breast cancer detection method using dog sniffing were both 100%. CONCLUSIONS: The trained dog in this study could accurately detect breast cancer from urine samples of breast cancer patients. These results indicate the feasibility of a method to detect breast cancer from urine samples using dog sniffing in the diagnosis of breast cancer. Although the methodological standardization is still an issue to be discussed, the current result warrants further study for developing a new breast cancer screening method based on volatile organic compounds in urine samples.

Benefit of intensive chemotherapy for elderly patients aged 80 years or older with metastatic colorectal cancer: a state-wide multicenter cohort study.

BACKGROUND: It remains unclear whether intensive chemotherapy for Stage IV colorectal cancer (CRC) patients aged 80 years or older is beneficial prognostically. This study aimed to investigate the overall survival of Stage IV CRC patients aged ≥ 80 years receiving intensive chemotherapy. METHODS: The study design was a population-based, multicenter, historical cohort study. The extracted participants' data were consecutive patients diagnosed as Stage IV CRC between January 2008 and May 2015 in nine hospitals in Japan. Patients were classified into two groups according to age: aged group (≥ 80 years) and younger group (< 80 years old). Intensive chemotherapy was defined as at least two courses of doublet chemotherapy with oxaliplatin-or irinotecan-based regimens. The primary outcome was the adjusted hazard ratio (HR) of age ≥ 80 years in patients who undergoing intensive chemotherapy. RESULTS: During the study period, 1259 patients were treated for Stage IV CRC in the participating hospitals. In total, 231 patients (18.3%) were in the aged group, and 1028 (81.7%) were in the younger group, and 788 (62.6%) underwent intensive chemotherapy. The median overall survival for the aged and younger group patients was 21.0 months (interquartile range (IQR), 10.6-34.1 months) and 24.3 months (IQR 12.6-39.3 months), respectively. The adjusted HR of age ≥ 80 years was 1.29 (confidence intervals 0.84-2.00). CONCLUSION: Stage IV CRC patients aged 80 years or older receiving intensive chemotherapy had a similar prognosis to those aged < 80 years. Avoiding intensive chemotherapy for mCRC patients simply because they are ≥ 80 years old is not recommended.

Spatial and temporal distributions of enteric viruses and indicators in a lake receiving municipal wastewater treatment plant discharge.

Although lake water can be used as a source of drinking water and recreational activities, there is a dearth of research on the occurrence and fate of enteric viruses. Over a period of 14 months at six points in 2014-2015, we conducted monthly monitoring of the virological water quality of a Japanese lake. The lake receives effluent from three surrounding wastewater treatment plants and retains water for about two weeks. These features allowed us to investigate the occurrence and fate of viruses in the lake environment. Human enteric viruses such as noroviruses and their indicators (pepper mild mottle virus and F-specific RNA bacteriophage [FRNAPH] genogroups) were quantified by PCR-based assays. Additionally, FRNAPH genogroups were quantified by infectivity-based assays to estimate the degree of virus inactivation. Pepper mild mottle virus, genogroup II (GII) norovirus, and GI-FRNAPH were identified in relatively high frequencies (positive in >40% out of 64 samples), with concentrations ranging from 1.3 × 101 to 2.9 × 104 copies/L. Human enteric viruses and some indicators were not detected and less prevalent, respectively, after April 2015. Principal component analysis revealed that the virological water quality changed gradually over time, but its differences between the sampling points were not apparent. FRNAPH genogroups were inactivated during the warm season (averaged water temperature of >20 °C) compared to the cool season (averaged water temperature of <20 °C), which may have been due to the more severe environmental stresses such as sunlight and water temperature. This suggests that the infection risk associated with the use of the lake water may have been overestimated by the gene quantification assay during the warm season.

Estimating spatial variation in the effects of climate change on the net primary production of Japanese cedar plantations based on modeled carbon dynamics.

Spatiotemporal prediction of the response of planted forests to a changing climate is increasingly important for the sustainable management of forest ecosystems. In this study, we present a methodology for estimating spatially varying productivity in a planted forest and changes in productivity with a changing climate in Japan, with a focus on Japanese cedar (Cryptomeria japonica D. Don) as a representative tree species of this region. The process-based model Biome-BGC was parameterized using a plant trait database for Japanese cedar and a Bayesian optimization scheme. To compare productivity under historical (1996-2000) and future (2096-2100) climatic conditions, the climate scenarios of two representative concentration pathways (i.e., RCP2.6 and RCP8.5) were used in five global climate models (GCMs) with approximately 1-km resolution. The seasonality of modeled fluxes, namely gross primary production, ecosystem respiration, net ecosystem exchange, and soil respiration, improved after two steps of parameterization. The estimated net primary production (NPP) of stands aged 36-40 years under the historical climatic conditions of the five GCMs was 0.77 ± 0.10 kgC m-2 year-1 (mean ± standard deviation), in accordance with the geographical distribution of forest NPP estimated in previous studies. Under the RCP2.6 and RCP8.5 scenarios, the mean NPP of the five GCMs increased by 0.04 ± 0.07 and 0.14 ± 0.11 kgC m-2 year-1, respectively. The increases in annual NPP were small in the southwestern region because of the decreases in summer NPP and the small increases in winter NPP under the RCP2.6 and RCP8.5 scenarios, respectively. Under the RCP2.6 scenario, Japanese cedar was at risk in the southwestern region, in accordance with previous studies, and monitoring and silvicultural practices should be modified accordingly.

Differences in the Repeated Sprint Performance Between the First and Latter Halves of Trials Under Conditions of Several Thermal States in Exercising Muscles.

ABSTRACT: Inoue, K, Yamashita, N, Kume, M, and Yoshida, T. Differences in the repeated sprint performance between the first and latter halves of trials under conditions of several thermal states in exercising muscles. J Strength Cond Res 35(3): 782-790, 2021-The purpose of this study was to determine whether the effects of thermal states in exercising muscle on repeated sprint cycling (RSC) performance differ between the first and latter half of trials. Nine male subjects performed 8 × 8 seconds of RSC with a 40-second rest period. The subjects wore water-perfused trousers with water at 6° C (COLD), 17° C (COOL), 30° C (WARM), or 44° C (HOT). During the first half of trials, the peak power output (PPO), mean power output (MPO), and sum of work output (SWO) were significantly (p < 0.05) greater under the WARM and HOT conditions than under the COLD and COOL conditions, and a difference in the PPO and MPO between WARM and HOT was noted in the second sprint bout during the first half of the exercise. However, during the latter half of trials, there was no significant difference in the PPO, MPO, and SWO among the 4 conditions. The tympanic temperature (Tty) was significantly elevated under the HOT condition but fell under the COLD and COOL conditions, whereas the Tty under the WARM condition did not change significantly (p < 0.05) during the experiment. The total sweat loss was significantly (p < 0.05) greater in the HOT condition than in the other conditions. These results suggest that the effect of thermal states in exercising muscle on the RSC performance is greater in the first half of exercise than in the latter half, possibly because of the elevation of the core temperature and sweat loss under HOT conditions.