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In this study, the effect of temperature, water quality, and the impact of an intense typhoon event on change in 137Cs concentration in the water of agricultural and forested rivers near the Fukushima Daiichi nuclear power plant (Japan) was evaluated using monthly stationary observations obtained under baseflow conditions 2.8–10.6 years after the nuclear accident in 2011. The dissolved 137Cs concentration fluctuated seasonally with water temperature in all rivers, and the increase in dissolved 137Cs concentration for unit increase in temperature was higher in forested rivers than in agricultural rivers. The relationship between water temperature and the apparent distribution coefficient of 137Cs well followed the van 't Hoff equation in the two agricultural rivers, where the enthalpy of reaction was estimated as −15.6 and −19.6 kJ mol−1. The van 't Hoff equation was not well followed for a forested river, where the suspended solids mainly comprised organic matter, suggesting that the dominant process determining dissolved 137Cs concentrations in forested rivers is not only water temperature effect on ion exchange, but rather the input of 137Cs and K+ (competing with 137Cs for exchange sites on mineral particles) into the water phase via litter leaching. Suspended solids concentrations in agricultural rivers correlated negatively with 137Cs concentrations in suspended solids, suggesting an increased proportion of coarse particles or the input of soils with low 137Cs concentration from decontaminated agricultural land. At some sites, 137Cs concentrations in dissolved form and in suspended solids were reduced sharply in association with the passage of Typhoon Hagibis in October 2019, suggesting that Typhoon Hagibis caused large-scale surface erosion that removed the source of 137Cs. [Display omitted] • Trend of 137Cs concentration in river water was analyzed based on 8 years monitoring. • Seasonal change in dissolved 137Cs concentration was mostly affected by temperature. • Typhoon Hagibis caused reduction in particulate/dissolved 137Cs in some rivers. • 137Cs concentration in forested river was poorly regressed by the van't Hoff equation. • The 137Cs reaction enthalpy in two agricultural rivers was −15.6 and −19.6 kJ mol−1. [ABSTRACT FROM AUTHOR]

The nuclear power plant accident in Fukushima had led to pollution of forest ecosystems with 137Cs in 2011. In this study, we simulated the spatiotemporal distribution of 137Cs concentrations of litter layer in the contaminated forest ecosystems in two decades from 2011, which is one of the key environmental components of 137Cs migration in the environment due to the high bioavailability of 137Cs in the litter. Our simulations showed that 137Cs deposition is the most important factor in the degree of contamination of the litter layer but vegetation type (evergreen coniferous/deciduous broadleaf) and mean annual temperature are also important for changes over time. Deciduous broadleaf trees had higher initial concentrations in the litter layer due to the direct initial deposition on the forest floor. However, the concentrations remained higher than those in evergreen conifers after 10 years due to redistribution of 137Cs by vegetation. Moreover, areas with lower average annual temperatures and lower litter decomposition activity retained higher 137Cs concentrations in the litter layer. The results of the spatiotemporal distribution estimation of the radioecological model suggest that, in addition to 137Cs deposition, elevation and vegetation distribution should also be considered in the long-term management of contaminated watersheds, which can be informative in identifying hotspots of 137Cs contamination on a long-term scale. • This study focuses on the litter pollution by 137Cs in Fukushima. • A radioecological model simulates the dynamics of litter 137Cs conc for 10 years. • Vegetation types and temp had a significant effect on the dynamics in litter 137Cs. [ABSTRACT FROM AUTHOR]

Introduction Multi-electrode array (MEA) systems and human induced pluripotent stem (iPS) cell-derived cardiomyocytes are frequently used to characterize the electrophysiological effects of drug candidates for the prediction of QT prolongation and proarrhythmic potential. However, the optimal experimental conditions for obtaining reliable experimental data, such as high-pass filter (HPF) frequency and cell plating density, remain to be determined. Methods Extracellular field potentials (FPs) were recorded from iPS cell-derived cardiomyocyte sheets by using the MED64 and MEA2100 multi-electrode array systems. Effects of HPF frequency (0.1 or 1 Hz) on FP duration (FPD) were assessed in the presence and absence of moxifloxacin, terfenadine, and aspirin. The influence of cell density on FP characteristics recorded through a 0.1-Hz HPF was examined. The relationship between FP and action potential (AP) was elucidated by simultaneous recording of FP and AP using a membrane potential dye. Results Many of the FP waveforms recorded through a 1-Hz HPF were markedly deformed and appeared differentiated compared with those recorded through a 0.1-Hz HPF. The concentration–response curves for FPD in the presence of terfenadine reached a steady state at concentrations of 0.1 and 0.3 μM when a 0.1-Hz HPF was used. In contrast, FPD decreased at a concentration of 0.3 μM with a characteristic bell-shaped concentration–response curve when a 1-Hz HPF was used. The amplitude of the first and second peaks in the FP waveform increased with increasing cell plating density. The second peak of the FP waveform roughly coincided with AP signal at 50% repolarization, and the negative deflection at the second peak of the FP waveform in the presence of E-4031 corresponded to early afterdepolarization and triggered activity. Discussion FP can be used to assess the QT prolongation and proarrhythmic potential of drug candidates; however, experimental conditions such as HPF frequency are important for obtaining reliable data. [ABSTRACT FROM AUTHOR]

Understanding the seasonality of 137Cs concentrations in aquatic animals is crucial for reviving local inland fisheries. The seasonality of 137Cs concentrations in animals is expected to vary, even if focal species consume similarly contaminated foods because the 137Cs excretion rate is species-specific, and 137Cs uptake by foraging autochthonous food resources also vary among seasons. Here, we conducted a seasonal monitoring survey of dissolved 137Cs concentrations as an indicator of the contamination level of food resources and measured 137Cs concentrations in two carnivorous aquatic animals (Palaemon paucidens and Rhinogobius sp.) that share a trophic niche in a stream connected to a dam reservoir. The dissolved 137Cs concentration had clear seasonality—high in summer and low in winter. The 137Cs concentrations in the animals revealed a different seasonal pattern—it peaked in October in P. paucidens and peaked in February in Rhinogobius. Overall, the 137Cs concentration was relatively higher in P. paucidens than in Rhinogobius , suggesting that P. paucidens has a lower excretion rate than Rhinogobius. Consequently, the seasonality of the 137Cs concentration in P. paucidens showed temporal changes similar to those of the dissolved 137Cs concentration, which were likely affected by 137Cs uptake through foraging, whereas that in Rhinogobius was controlled by 137Cs excretion. This study shows that the seasonality of 137Cs concentration can differ between sympatric animals that share a trophic niche. Accumulating knowledge and comparing the seasonality of 137Cs concentrations in fisheries species based on the balance between uptake and excretion will be valuable to determine the appropriate seasons to obtain less-contaminated products. [Display omitted] • Two sympatric species that belong to different phyla was compared. • Stable carbon and nitrogen ratios showed that the two species share a trophic niche. • Dissolved 137Cs concentration peaked in summer and dropped in winter. • The two species showed different seasonality of 137Cs concentrations. • 137Cs seasonality varies with interspecific variations of excretion rates in animals. [ABSTRACT FROM AUTHOR]

• How and to what extent do hardwood mixtures increase soil nitrogen availability in conifer plantations? • Mass-based nitrogen concentration in leaf litterfall of hardwoods was twice that of conifers. • Hardwood mixtures facilitated leaf litter decomposition and soil nitrogen mineralization. • Hardwood mixtures would enhance stand productivity via increasing nitrogen availability. Productivity in conifer plantations can be increased by hardwood mixture. However, the underlying mechanisms that govern the relationship between hardwood mixture and productivity remain poorly understood, particularly with respect to nutrient cycling. We investigated how and to what extent hardwood mixtures alter nitrogen amounts in leaf litterfall, leaf litter decomposition rates, and soil nitrogen mineralization rates in an experiment that used different thinning intensities (i.e., a non-thinned "control" group with few hardwoods, a 33%-thinned "weak" group with a small amount of hardwoods, and a 67%-thinned "intensive" group with abundant hardwoods) in a conifer Cryptomeria japonica plantation (38-year old). Most of the hardwoods were 15-year old trees that have been regenerated after the first thinning. The annual leaf litterfall amount for the conifer was highest in the control group and lowest in the intensive group, whereas the reverse was true for hardwoods, although the hardwoods' annual leaf litterfall amount was approximately half that of conifers, even in the intensive group. Consequently, the annual amount of leaf litterfall of hardwoods and conifers combined was lowest in the intensive group. However, the total amount of nitrogen in the annual leaf litterfall of hardwoods and conifers combined did not differ according to thinning intensity, because the mass-based nitrogen concentration in the leaf litterfall of hardwoods was twice that of conifers. The leaf litter decomposition rate in hardwoods was approximately three times faster than that in conifers irrespective of thinning intensity, mainly due to the lower carbon-to-nitrogen (C:N) ratio. Thus, the total amount of nitrogen in the decomposed leaves of hardwoods and conifers combined, calculated by multiplying the total amount of nitrogen in the annual leaf litterfall of hardwoods and conifers by the decomposition rate and summing the results, was highest in the intensive group. In soil from shallow depths (0–10 cm), the nitrogen mineralization rate increased in the order of control, weak, and intensive, attributable primarily to the C:N ratio, which decreased in the same order. The results indicated that increasing the hardwood content by intensive thinning significantly enhances the availability of soil inorganic nitrogen in conifer plantations, by facilitating leaf litter decomposition and soil nitrogen mineralization. These findings indicate that hardwood mixtures can increase forest productivity by enhancing nitrogen cycling. [ABSTRACT FROM AUTHOR]

• Does hardwood mixture enhance stand productivity in conifer plantations? • Intensive thinning reduced conifer leaves but increased hardwood leaves. • Nitrogen concentration of hardwood leaves was twice that of conifer leaves. • Hardwood mixture enhances stand productivity via increases in leaf nitrogen. • Increased allocation to coniferous foliage will also increase stand productivity. Recent studies have demonstrated positive effects of hardwood mixtures on stand productivity in conifer plantations. However, the extent to which hardwood mixture increases leaf nitrogen levels and improves stand productivity (in terms of nutrient cycling) remains poorly understood. In this study, we estimated leaf nitrogen per stand (leaf N stand) by multiplying mass-based leaf nitrogen (leaf N mass) and leaf mass per stand (leaf M stand) in conifers, hardwoods, and understory plants in a thinning experiment. The experiment, performed in 2018, was conducted under unthinned (Control) with few hardwoods, 33% thinned (Weak) with a small amount of hardwoods, and 67% thinned (Intensive) with abundant hardwoods in a conifer Cryptomeria japonica (C. japonica) plantation. We also investigated the stand volume of conifers and hardwoods during the 12-year period (2008–2020) after the second thinning (2008), in all three groups. Of all plants—conifers (C. japonica), hardwoods, and understory plants—stand volume, leaf M stand , and leaf N stand were all highest in Control and lowest in Intensive. The ratio between the values of Intensive and Control was 27.5% for stand volume, 58.9% for leaf M stand , and 72.8% for leaf N stand. This is due to the fact that the leaf M stand of hardwoods—which had approximately 2–3 times the leaf N mass of C. japonica —increased rapidly with increasing thinning intensity, and the leaf M stand of the understory plants—which had approximately twice the leaf N mass of C. japonica —increased monotonically with increasing thinning intensity, although both the leaf M stand and leaf N stand decreased with increasing thinning intensity in both current-year and old C. japonica leaves. In conifers, the relative increment in stand volume was positively correlated with the leaf mass ratio (ratio between the leaf M stand and stand volume of conifer) and leaf N ratio of conifer (ratio between the leaf N stand and stand volume), suggesting that disproportionate biomass investment in leaves enhances productivity in conifers. The study suggests that hardwood mixture can significantly increase forest productivity, mainly due to a disproportionate increase in leaf nitrogen in hardwoods and an increase in biomass allocation to leaves in conifers in a conifer, C. japonica plantation. [ABSTRACT FROM AUTHOR]

Forest-stream ecosystems are widespread and biodiverse terrestrial landscapes with physical and social connections to downstream human activities. After radiocesium is introduced into these ecosystems, various material flows cause its accumulation or dispersal. We review studies conducted in the decade after the Fukushima nuclear accident to clarify the mechanisms of radiocesium transfer within ecosystems and to downstream areas through biological, hydrological, and geomorphological processes. After its introduction, radiocesium is heavily deposited in the organic soil layer, leading to persistent circulation due to biological activities in soils. Some radiocesium in soils, litter, and organisms is transported to stream ecosystems, forming contamination spots in depositional habitats. While reservoir dams function as effective traps, radiocesium leaching from sediments is a continual phenomenon causing re-contamination downstream. Integration of data regarding radiocesium dynamics and contamination sites, as proposed here, is essential for contamination management in societies depending on nuclear power to address the climate crisis. [Display omitted] • Various material flows in forest-stream ecosystems cause radiocesium migrations. • Studies in forest-stream ecosystems after the Fukushima accident were reviewed. • Radiocesium accumulates in organic forest soils and depositional stream environments. • Integrating biotic and abiotic processes are essential for contamination management. [ABSTRACT FROM AUTHOR]

Summary: A 29-year-old man with a smoking history of 20 pack years was diagnosed with tuberculosis because Mycobacterium tuberculosis was detected in his gastric juice. His chest radiograph showed multiple nodular opacities on left upper lobe. He was treated with anti-tuberculosis drugs in our hospital. Six months after the therapy, he began to complain of dry cough and shortness of breath on exertion. Chest radiograph showed reticular opacities in both upper and middle lung fields. Multiple thick- and thin-walled bizarre-shaped cysts and ill-defined centrilobular opacities were seen mainly in upper and mid-lungs on high-resolution computed tomography (HRCT). He was diagnosed with pulmonary Langerhans-cell histiocytosis (PLCH) by transbronchial lung biopsy specimens from right upper lobe. HRCT findings before the treatment of tuberculosis were retrospectively examined. Several small thin-walled centrilobular cysts were scattered in the right upper and middle lung fields without apparent nodular lesions. We must consider the possibility of PLCH when these findings are detected on HRCT. [Copyright &y& Elsevier]

A study is presented on the applicability of the distribution coefficient ( K d ) absorption/desorption model to simulate dissolved 137 Cs concentrations in Fukushima river water. The upstream Ota River basin was simulated using GEneral-purpose Terrestrial Fluid-flow Simulator (GETFLOWS) for the period 1 January 2014 to 31 December 2015. Good agreement was obtained between the simulations and observations on water and suspended sediment fluxes, and on particulate bound 137 Cs concentrations under both base and high flow conditions. By contrast the measured concentrations of dissolved 137 Cs in the river water were much harder to reproduce with the simulations. By tuning the K d values for large particles, it was possible to reproduce the mean dissolved 137 Cs concentrations during base flow periods (observation: 0.32 Bq/L, simulation: 0.36 Bq/L). However neither the seasonal variability in the base flow dissolved 137 Cs concentrations (0.14–0.53 Bq/L), nor the peaks in concentration that occurred during storms (0.18–0.88 Bq/L, mean: 0.55 Bq/L), could be reproduced with realistic simulation parameters. These discrepancies may be explained by microbial action and leaching from organic matter in forest litter providing an additional input of dissolved 137 Cs to rivers, particularly over summer, and limitations of the K d absorption/desorption model. It is recommended that future studies investigate these issues in order to improve simulations of dissolved 137 Cs concentrations in Fukushima rivers. [ABSTRACT FROM AUTHOR]

Clinical management of macrolide-resistant Mycobacterium avium complex (MR-MAC) lung disease is difficult. To date, there only exist a limited number of reports on the treatment of clarithromycin-resistant MAC (CR-MAC) lung disease. This study aimed to evaluate prognostic factors and identify effective treatments in CR-MAC lung disease. We retrospectively collected clinical data of patients newly diagnosed with CR-MAC lung disease at the Kinki-Chuo Chest Medical Center between August 2010 and June 2018. Altogether, 37 patients with CR-MAC lung disease were enrolled. The median age was 69 years; 30, 22, and 21 patients received clarithromycin, ethambutol, and rifampicin, respectively, on their own or in drug combination. The observed sputum culture conversion rate was 29.7% (11/37 patients). In univariate analysis, ethambutol significantly increased the rate of sputum culture conversion (p = 0.027, odds ratio (OR) 10; 95% confidence interval (CI) 1.11–89.77). Multivariate analysis confirmed that ethambutol increased sputum culture conversion rate (p = 0.026; OR 21.8; 95% CI 1.45–329) while the existence of lung cavities decreased it (p = 0.04; OR 0.088; 95% CI 0.009–0.887). The combined use of ethambutol with other drugs may improve sputum culture conversion rate in CR-MAC lung disease. [ABSTRACT FROM AUTHOR]

Determination of radionuclide concentration factor (CF) allows estimating the transfer of environmental radionuclides and potential risks of consuming fish contaminated with radionuclides. Although it is known that biotic and abiotic factors affect fish CF, only a few studies have examined whether these factors differ among ecosystems. We estimated radiocesium (137Cs) CF of 30 different fish species and other aquatic organisms by monitoring three lakes and five rivers in Fukushima, 2–4 y after the Fukushima Dai-ichi Nuclear Power Plant accident. The relative effects of biotic and abiotic factors on 137Cs CF in freshwater organisms were compared between river and lake ecosystems using generalized linear models. Our analysis demonstrated the following. (1) The factors critically affecting fish CF differed between rivers and lakes. The negative effects of suspended solid concentration (SS), total organic carbon (TOC), and salinity were significant for rivers, but not for lakes. Biomagnification of 137Cs in piscivore fish was significant only in the lakes. (2) Fish size significantly affected the CF in both rivers and lakes. Nevertheless, the correlation between 137Cs concentration and piscivore fish size was stronger in lakes than in rivers. (3) The SS, TOC, and salinity simultaneously influenced the CF at every trophic level. However, feeding habit was a stronger determinant of 137Cs bioaccumulation than water chemistry in organisms at higher trophic levels, such as aquatic insects, amphibians, and fish. Our findings indicate that 137Cs accumulation in aquatic organisms is ecosystem-dependent due to different environmental factors and food web structure. Image 1 • 137Cs concentration ratio (CR) evaluated for 30 fish and other biota in Fukushima. • Statistical analysis identified major factors affecting CR in river and lake fish. • 137Cs biomagnification occurred in lake-dwelling but not riverine piscivore fish. • Fish size had the strongest influence on CR in lake-dwelling piscivore fish. • Feeding habit affected CR more than water chemistry at higher trophic levels. [ABSTRACT FROM AUTHOR]

A study is presented on the applicability of the distribution coefficient (K d) absorption/desorption model to simulate dissolved 137Cs concentrations in Fukushima river water. The upstream Ota River basin was simulated using GEneral-purpose Terrestrial Fluid-flow Simulator (GETFLOWS) for the period 1 January 2014 to 31 December 2015. Good agreement was obtained between the simulations and observations on water and suspended sediment fluxes, and on particulate bound 137Cs concentrations under both base and high flow conditions. By contrast the measured concentrations of dissolved 137Cs in the river water were much harder to reproduce with the simulations. By tuning the K d values for large particles, it was possible to reproduce the mean dissolved 137Cs concentrations during base flow periods (observation: 0.32 Bq/L, simulation: 0.36 Bq/L). However neither the seasonal variability in the base flow dissolved 137Cs concentrations (0.14–0.53 Bq/L), nor the peaks in concentration that occurred during storms (0.18–0.88 Bq/L, mean: 0.55 Bq/L), could be reproduced with realistic simulation parameters. These discrepancies may be explained by microbial action and leaching from organic matter in forest litter providing an additional input of dissolved 137Cs to rivers, particularly over summer, and limitations of the K d absorption/desorption model. It is recommended that future studies investigate these issues in order to improve simulations of dissolved 137Cs concentrations in Fukushima rivers. • Study on validity of using the K d absorption/desorption model for simulating dissolved 137Cs levels in a Fukushima river. • Agreement generally good between simulations and observations for water, sediment and particulate 137Cs discharge. • Tuning of K d values for large particles was necessary to reproduce typical base flow dissolved 137Cs concentrations. • Simulations underestimated the seasonal variability of dissolved 137Cs concentrations and peaks during heavy rainfall. [ABSTRACT FROM AUTHOR]

Movement of 137Cs in the bottom sediment of a shallow lake was investigated by collecting columnar sediment cores from the entire area once a year, and also from three representative points every 3 months over 3 years from the 137Cs fallout in March 2011. The 137Cs inventory in the sediment increased remarkably near the mouths of urban rivers; however, the distribution of the 137Cs inventory did not change remarkably in most areas, and horizontally slow downstream movement of 137Cs was observed. Image 1 • 137Cs movement in Lake Nishiura after the FDNPP accident was investigated. • Vertical mixing and accumulation of 137Cs was active in sediment at shallow depths. • Spatial distribution of 137Cs was almost unchanged since March 2011. • 137Cs increased remarkably around the river mouth of the inflowing urban rivers. • Suspended solids of urban rivers showed relatively high 137Cs levels and mobility. [ABSTRACT FROM AUTHOR]

• The new tensile tests combining with finite element simulations were developed. • Weakening during post-necking deformation was firstly found in 1.5-GPa class steel. • Weakening behavior did not follow the previously developed damage models. • X-ray diffraction analyses detected material damage relating the weakening. • Unobservable vacancies are likely responsible for damage resulting in weakening. The weakening behavior of ultra-high-strength steel(UHSS) remains unknown, even though it is a requirement for the accurate prediction of strain localization and ductile fracture in automobile applications. In this study, we, therefore, revealed the stress–strain curves of UHSSs up to their ductile fracture under different stress triaxialities for the first time. Smooth and notched tiny round-bar specimens cut from UHSSs with 1.6 mm thickness were subjected to tensile tests, during which the forces and neck diameters of the specimens were measured. Notably, the evaluated flow stresses in the 1.5 GPa-class notched UHSS specimens exhibited weakening of up to 3%. This was in contrast to the 980 MPa-class UHSS specimens, which did not exhibit notch-induced weakening. The absence of weakening during stress measurements, as confirmed by synchrotron X-ray diffraction (XRD) analysis, suggested that weakening was caused by material damage. However, the weakening behavior did not follow the previously developed damage models based on microvoid formation. The volume fraction of the microvoids, as observed by X-ray computer tomography, was extremely small (at 0.2%) and cannot account for the 3% material weakening indicated by the flow stress measurement results. A new damage mechanism, associated with unobservable small lattice vacancies, was implied in UHSSs deformation under high stress triaxialities. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Predicting the environmental fate of 137Cs in forest ecosystems along with the concentrations of 137Cs in tree parts are important for the managements of radioactively contaminated forests. In this study, we calibrate the Forest RothC and Cs model (FoRothCs), a forest ecosystem 137Cs dynamics model, using observational data obtained over six years from four forest sites with different levels of 137Cs contamination from Fukushima Prefecture. To this end, we applied an approximate Bayesian computation (ABC) technique based on the observed 137Cs concentrations (Bq kg−1) of five compartments (leaf, branch, stem, litter, and soil) in a Japanese cedar plantation. The environmental decay (increment) constants of the five compartments were used as the summary statistics (i.e., the metric for model performance) to infer the five parameters related to 137Cs transfer processes in FoRothCs. The ABC technique successfully reconciled the model outputs with the observed trends in 137Cs concentrations at all sites during the study period. Furthermore, the estimated parameters are in agreement with the literature values (e.g., the root uptake rates of 137Cs). Our study demonstrates that model calibration with ABC based on the trends in 137Cs concentrations of multi compartments is useful for reducing the prediction uncertainty of 137Cs dynamics in forest ecosystems. Highlights • Forest 137Cs dynamics model "FoRothCs" is calibrated with six-years observations. • Approximate Bayesian computation with observable data improved model perfor-mance. • Trends of 137Cs activities of forest parts can be good metric for model assessment. [ABSTRACT FROM AUTHOR]

Radiocesium (137Cs) contamination of the freshwater ecosystems adjacent to the Fukushima Daiichi Nuclear Power Plant (FDNPP) in Japan has persisted long after the accident that occurred at the facility in March 2011. It is necessary to elucidate the dynamics of 137Cs in various aquatic ecosystems to predict 137Cs concentrations in fish and manage freshwater fisheries in the vicinity of FDNPP. To these ends, we applied stable isotope analysis to evaluate changes in 137Cs levels through trophic positions and the relative importance of the 137Cs sources at the trophic bases of two rivers and two lakes in Fukushima. The δ15N analyses disclosed that 137Cs decreases from primary producers to fish consumers in the river food web and 137Cs increases among fish consumers with increasing trophic position in the lake food web. The δ13C analysis revealed that autochthonous 137Cs contributed to fish contamination. The periphyton-dependent and zooplankton-dependent fish had comparatively higher 137Cs concentrations in the rivers and lakes, respectively. Cesium-137 supply from the pelagic food web was observed to contribute to greater 137Cs levels in the fish consumers inhabiting the lakes. The results of this study show that stable isotope analysis may help clarify 137Cs dynamics in freshwater food webs and identify the important 137Cs sources in the food web. Identifying important 137Cs sources and trophic transfers depending on the ecosystem help guide regulatory and management frameworks to establish profitability of the food fish stocks there and maintain food security. • Radiocesium (137Cs) dynamics in freshwater food webs determined by stable isotope analysis. • δ15N analysis revealed 137Cs decrease with increasing trophic position in river food webs. • δ15N analysis revealed 137Cs increase with increasing trophic position in lake fish food webs. • δ13C indicated importance of periphyton-derived 137Cs in river fish contamination. • δ13C demonstrated importance of plankton-derived 137Cs in lake fish contamination. [ABSTRACT FROM AUTHOR]

Introduction Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are anticipated to be a useful tool for conducting proarrhythmia risk assessments of drug candidates. However, a torsadogenic risk prediction paradigm using hiPSC-CMs has not yet been fully established. Methods Extracellular field potentials (FPs) were recorded from hiPSC-CMs using the multi-electrode array (MEA) system. The effects on FPs were evaluated with 60 drugs, including 57 with various clinical torsadogenic risks. Actual drug concentrations in medium were measured using the equilibrium dialysis method with a Rapid Equilibrium Dialysis device. Relative torsade de pointes (TdP) scores were determined for each drug according to the degree of FP duration prolongation and early afterdepolarization occurrence. The margins were calculated from the free concentration in medium and free effective therapeutic plasma concentration. Each drug's results were plotted on a two-dimensional map of relative TdP risk scores versus margins. Results Each drug was categorised as high, intermediate, or low risk based on its location within predefined areas of the two-dimensional map. We categorised 19 drugs as high risk; 18 as intermediate risk; and 17 as low risk. We examined the concordance between our categorisation of high and low risk drugs against the torsadogenic risk categorisation in CredibleMeds®. Our system demonstrated high concordance, as reflected in a sensitivity of 81%, specificity of 87%, and accuracy of 83%. Discussion These results indicate that our torsadogenic risk assessment is reliable and has a potential to replace the hERG assay for torsadogenic risk prediction, however, this system needs to be improved for the accurate of prediction of clinical TdP risk. Here, we propose a novel drug induced torsadogenic risk categorising system using hiPSC-CMs and the MEA system. [ABSTRACT FROM AUTHOR]

Abstract: Mycobacterium abscessus and Mycobacterium massiliense lung infections have different clarithromycin susceptibilities, making proper identification important; however, standard multi-gene sequencing in clinical laboratories is laborious and time consuming. We developed a pyrosequencing-based method for rapid identification of strains belonging to the M. abscessus group by targeting erm(41). We examined 55 isolates from new pulmonary M. abscessus infections and identified 28 M. abscessus, 25 M. massiliense, and 2 Mycobacterium bolletii isolates. Multi-gene sequencing of 16S rRNA, hsp65, rpoB, and the 16S–23S ITS region was concordant with the results of erm(41) pyrosequencing; thus, the M. abscessus group can be identified by single-nucleotide polymorphisms in erm(41). The method also enables rapid identification of polymorphic, inducible clarithromycin-resistant sequevars (T28 or C28). Pyrosequencing of erm(41) is a rapid, reliable, high-throughput alternative method for identifying and characterizing M. abscessus species. Further testing of a diverse collection of isolates is necessary to demonstrate the discriminatory power of erm(41) sequencing to differentiating species with this highly divergent group. [Copyright &y& Elsevier]