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Mt. Fuji is an active basaltic volcano near the Tokyo metropolitan area; future eruptions could thus have serious nationwide impacts. To better understand recent volcanism at Fuji Volcano, we here clarify temporal variations of eruption rate and magma composition since 5.6 ka based on time-series volumetric and geochemical data of eruptive products in a new stratigraphic sequence. Volcanic activity during the studied period consisted of (i) the emission of many lava flows that formed a new volcanic edifice between 5.6 and 3.45 ka, (ii) a period dominated by explosive events both at the summit and on the flanks of the volcano between 3.45 and 2.25 ka, and (iii) a period dominated by flank fissure eruptions since 2.25 ka. The eruption rate (dense-rock equivalent, DRE) was 3.5 km3 DRE/kyr during the edifice-building period, decreased to 0.8 km3 DRE/kyr during the explosive period, and then increased to 2.0 km3 DRE/kyr since 1.5 ka. Erupted magmas were dominantly basaltic and geochemically similar through time, except for increased Sr contents and decreased Ca/Sr ratios during the explosive period. Similarly, the geochemical properties of the parental magmas did not change greatly, although the Sr contents and Ca/Sr ratios of magmas erupted during the explosive period reflect the delayed fractionation of plagioclase due to the increased water contents of the parental magmas at that time. [ABSTRACT FROM AUTHOR]

The article presents a two case study related to two sporadic Japanese children with cantú syndrome (CS) resulting from novel ABCC9 variants. Topics include the CS being rare disease characterized by has generalized hypertrichosis, coarse facial features, neonatal macrosomia, and skeletal abnormalities, the ABCC9 and KCNJ8 genes in patients with clinical manifestations has generalized hypertrichosis, and abnormalities resembling MPS, and the coarse facial features and excessive hair growth.

This article sheds new light on the opening of Japan in the late nineteenth century focusing on the legalization of overseas travel and the introduction of passports. It argues that the Tokugawa shogunate introduced passports as a belated endorsement of the increasingly common practice of undercover border-crossing as it feared losing the political grip. Once the new regulation was in place, most travellers went to China or Korea as petty merchants or low-skill labourers, in part recruited by Western merchants and consuls. The foreign ministry, fearing that unrestricted emigration of labourers and mercenaries might harm the country's international reputation and political stability, limited the number of passports to distribute to the treaty ports. Japan's passport system thus focused more on regulating the overseas travel than promoting it, in contrast to the positive light in which the opening of Japan is commonly portrayed. The government largely succeeded in preventing the unwanted emigration, but never fully controlled the process because of the less vigilant port officials and the ambiguity on some of the borders' exact location. Overall, the investigation into the first two decades of the Japanese passport travellers leads to a more complex understanding of modern Japan's opening of borders. [ABSTRACT FROM PUBLISHER]

Abstract: The Shirakawa ignimbrites were generated by caldera-forming eruptions in the Aizu caldera cluster, northeast Japan, during the Early Pleistocene. They have a total volume of >300km3 dense rock equivalent and consist of the Kumado ignimbrite (1.4Ma) from Ono caldera, the Ashino ignimbrite (1.3Ma) and the Nagurasawa ignimbrite (1.2Ma) from Tonohetsuri caldera, the Nishigo ignimbrite (1.1Ma) from Narioka caldera and the Ten-ei ignimbrite (1.0Ma) from an unknown, concealed caldera. These calderas overlap each other within a 20×20km area in the eastern part of the cluster. The Shirakawa ignimbrites are relatively small in the eruption rate and have sufficient interval times that are longer than the residence times for their magma volume. The individual ignimbrites are composed of 20–40% phenocrysts set in high-silica rhyolite glass and they lack vertical chemical zoning. The SiO2 content of the Kumado, Ashino, Nagurasawa, Nishigo and Ten-ei ignimbrites are 68–70wt.%, 67–70wt.%, 68–69wt.%, 72–74wt.% and 69–70wt.%, respectively. They plot within the medium-K field, but show distinct trends for most major elements at the same SiO2 ranges. Although they all have similar arc-related trace-elements patterns with Nb, Ta and Ti negative anomalies, high LREEs and flat HREEs, they differ in their Zr/Nb, Ba/Th and K/La ratios. Also, isotopic ratios of these pumices from each unit are distinct; 87Sr/86Sr varies from 0.7044 to 0.7047 and 143Nd/144Nd from 0.51271 to 0.51278. These results imply that the ignimbrite sources were renewed with every caldera-forming eruption. Seismic tomography and pre-eruption uplifting of the caldera cluster suggest that a substantial amount of mantle-derived magma was stored within the lower crust and contributed to the evolution of a crustal hot zone. Observed geochemical features also suggest that silicic magmas were generated by the melting of variably assimilated mafic intrusions. To explain the renewal of the Shirakawa magma system, melted materials must have been completely evacuated from a deep-seated source zone by each caldera-forming eruption and different mafic rocks subsequently subsided into the hot zone as raw materials for the next eruption. [Copyright &y& Elsevier]

The article presents a study that examines the hydrological process and other factors that affect nutrient discharge in the Todoroki watershed in Ishigaki Island, Japan. It says that nutrient discharges affect coral reefs because of an increase in macroalgae. It states that nutrient analyzer was used at the Todoroki River to measure dissolved nutrients. It adds that nutrient discharge is a stressor for coral reefs, which stresses the need to adopt ways to protect reef ecosystems.

Abstract: Six large Late Miocene to Quaternary calderas, >10 km in diameter, cluster together with several medium to small calderas and stratovolcanoes in a 60×30 km area of the Aizu volcanic field, southern NE Japan arc. These caldera volcanoes were built on a WNW–ESE trending highland coincident with a local uplifted swell since Late Miocene. The flare-up of felsic volcanism occurred synchronously along the NE Japan arc. Pyroclastic flow sheets from the calderas spread over the surrounding intra-arc basins and are interstratified with various sediments. Geochronological data indicates that the large-caldera eruptions have occurred six times since 8 Ma, at intervals of 1 to 2 million years. Late Miocene to Early Pliocene extra-caldera successions in the basin consist of nine sedimentary facies associations: (1) primary pyroclastics, (2) lahars, (3) gravelly fluvial channels, (4) sandy fluvial channels, (5) floodplains, (6) tidal flats, (7) delta fronts, (8) pro-delta slopes, and (9) pro-delta turbidites. The distribution of facies associations show westward prograding of volcaniclastic aprons, made up of braid delta, braidplain, pyroclastic flow sheet, and incised braided river deposits. The extra-caldera successions record: 1) an increase in felsic volcanism with an associated high rate of volcaniclastic sediment supply at about 10 Ma, prior to catastrophic caldera-forming eruptions; and 2) progradation of volcaniclastic aprons toward the back-arc side in response to the succeeding caldera-forming eruptions and sea-level changes, until about 3 Ma. [Copyright &y& Elsevier]

Abstract: During Japan Sea back-arc opening between 21 and 15 Ma, low-K tholeiitic basalts erupted in the Abukuma Mountains on the trench side of NE Japan. The basaltic rocks in this region are divided into two units by a hiatus. The lower unit consists of the 20 Ma Tenmyosan volcanic rocks, including many monogenetic basaltic volcanoes whose vents occur throughout the district. The upper unit is the Ryozen Formation that occurred at about 16 Ma. This Formation is composed of a subaerial basaltic polygenetic volcanic edifice, with a diameter of ca. 30 km. Minor amounts of andesitic and dacitic gravels occur in the distal portion of the Ryozen edifice. Low-K tholeiitic basalts of the Tenmyosan volcanic rocks and the Ryozen Formation have similar in major and trace element compositions. Their MgO content decrease from 13.2 to 3.4 wt.% with increasing incompatible element abundances and more pronounced negative Nb and Ta anomalies. Nd, Sr and Pb isotopic compositions of the Tenmyosan basalt display a range of values for SrI (0.7040–0.7050), NdI (0.5127–0.5129) and 206Pb/204Pb (18.2–18.5). These features suggest that the Tenmyosan monogenetic volcanism at the early stage of the Japan Sea opening was generated by intermittent ascent of minor mafic melts from heterogeneous sources. Isotopic data for the Ryozen basalt define a binary mixing trend between a depleted and enriched crust-like source, varying with SiO2 content. These chemical changes show that, as the opening progressed, the asthenospheric source of the Ryozen basalts became more homogeneous and depleted (SrI; 0.7043, Nd; 0.5129, 206Pb/204Pb; 18.2), and continuous ascent of the basaltic melt was able to make a large magma chamber that was associated with significant crustal assimilation. On the other hand, hornblende dacite in the Ryozen Formation has SiO2 contents between 66 and 74 wt.%, high Mg# from 41.7 to 54.3. The dacite also shows high Sr (417–650 ppm) and Sr/Y (35–112), and high La/Yb (12–20). Compared with the basaltic rocks, the Ryozen dacite has relatively low SrI (0.70436) and high NdI (0.5128–0.5129). These features show that the dacite has no genetic relationship with the basaltic rocks and can be considered an adakite, traditionally viewed as product of eclogitic slab melting. The 14 Ma Nodegamiyama andesite has SiO2 in 54 to 55 wt.%, high Mg# (59.0–62.3), high Cr and high Ni contents. The isotopic ratios of this andesite are enriched (SrI; 0.7054–0.7055, NdI; ~0.5127, 206Pb/204Pb; ~18.5). This high-Mg andesite may be generated by melting of subducting sediments and interaction of such melts with overlying mantle peridotites. Although the downgoing Pacific plate was Cretaceous in age and thus too cold to melt under normal conditions, incursion of the hot asthenosphere above the slab during the Japan Sea opening may have caused melting to occur. [Copyright &y& Elsevier]

Abstract: Geochemical and isotopic data are reported for 20 Ma high-magnesian andesite (HMA) lavas erupted on the forearc side of Central Japan in the Choshi coastal area (Chiba). Rarely olivine-phyric (<3% vol), these rocks have ca. 56 wt.% SiO2, Na2O ranging between 3.9 and 4.2 wt.%, and relatively low K2O/Na2O ratios (ca. 0.44). Their Mg numbers are relatively high (ca. 0.64) and matched by high Cr (>345 ppm), high Sr (>520 ppm), high Sr/Y (ca. 30), and high [La/Yb]N (>8), conforming to the definition of low-silica adakites, transitional in character to HMA. However, despite slight negative Nb and Ta ‘troughs’ in a few samples, their incompatible element distribution patterns appear closer to those of intra-plate basalts, apparently confirming previous suggestions that terms such as HMA and adakite cover a diverse range of compositions. Enriched in radiogenic Sr and Nd (ca. 0.7040 to 0.7043 and 0.5128 to 0.51275, respectively), the Choshi HMA shows relatively low 206Pb/204Pb (18.25 to 18.35) and 208Pb/204Pb (38.37 to 38.48) ratios, resembling those of late Miocene intra-plate basalts in the Japan Sea and SW Japan. In this regard the Choshi HMA differs from those of the ‘classic’ Middle Miocene (14 to 12 Ma) HMA described from the Setouchi volcanic belt (e.g. Tatsumi, 1981), a short distance to the west which also shows relative high K contents. Although HMAs have been generally attributed to subduction-related processes, the lack of high field strength element (HFSE) depletions cf. large ionic lithophile elements (LILE) in most Choshi HMA suggests an absence of so-called ‘subduction signatures’. Accordingly, we suggest that the Choshi HMA probably tapped a fertile (asthenospheric) region of the convecting mantle wedge, primitive melt products having acquired HMA-like character as a result of shallow level modification by interaction with lithospheric components, aided by thermal input resulting from mantle extrusion, during the early stages of Japan Sea opening (23–15 Ma). [Copyright &y& Elsevier]

The author explores the blunders in negotiation of Japan with North Korean government following its abduction of Japanese citizens. He believes that the massive public relations strategy of Japanese government toward its citizens has affected the negotiation process and eventually backfired on the government. He notes that the abductions from Japan by agents of North Korean government happened from 1977 to 1983. He highlights that resolution of the abduction issue was an implausible precondition for the normalization of diplomatic relations.

The objective of this study is to develop a new method for deriving statistical distribution of maximum discharge from the distribution of annual maximum daily rainfall by using a random cascade model. This model is used to probabilistically downscale daily rainfall into hyetographs in which the daily rainfall is randomly generated according to its probabilistic distribution. Then maximum discharge is calculated from downscaled hyetograph by means of a rainfall-runoff model. Finally, the distribution of maximum discharge is derived numerically. This technique is applied to the Doki River Basin, a small basin in Japan, where the influence of human activities is limited. The observed annual maximum discharge data from 1976 to 1998 are used to verify the calculated distribution of maximum discharge. It is shown that the distribution of maximum discharge was well reproduced. [ABSTRACT FROM AUTHOR]

River incision into bedrock results in the decrease of burial depths, which can be of critical importance, for example, in the safe long-term storage of high-level radioactive waste. For the long-term prediction of river erosion, it is essential to know the rate of incision during the Late Quaternary period. In the Abukuma Mountains on the forearc side of northeast Japan, a low-relief peneplain that was uplifted in the Pliocene period is widely developed. Degradational fluvial terraces that are discontinuously distributed along draining rivers are scattered in the study area. The fluvial sediments were mainly transported from the summit regions as debris flows or hyperconcentrated flows. The terrace deposits are capped by a series of eolian veneers containing key tephra beds. From the oldest to the youngest, these tephra beds are the 150–125 ka Iizuna–Kamitaru tephra, the 135–125 ka Hiuchigatake–Tagashira tephra, the 120 ka Adatara–Dake tephra, the 70–80 ka Bandai–Hayama-2 tephra, the 45 ka Numazawa–Mizunuma tephra and the 42 ka Bandai–Hayama-1 tephra. Using tephrochronological data, the terraces are divided into three groups: higher, middle and lower. The ages of formation of the higher, middle and lower terraces are estimated to be within marine isotope stage (MIS) 6, MIS 5.4–5.2 and MIS 3 to MIS 2, respectively. The incision rate, calculated from the relative height between the terrace surface and present-day valley floor fill, is 1.5–0.8 m/10 000 years in the elevations from 350 to 700 m. The calculated rate does not show significant differences between the higher, middle and lower terraces. All the relative heights decrease with increasing elevation, because the erosional rates of streams in the upper reaches are lower than those in downstream reaches where the discharge rates are higher. This value can be regarded as an estimate of the rate of incision in granitic mountains where there is no volcanic or distinct tectonic activity. [ABSTRACT FROM AUTHOR]

We estimate the total mass of ash fall deposits for individual eruptions of Sakurajima Volcano, southwest Japan based on distribution maps of the tephra fallout. Five ash-sampling campaigns were performed between 2011 and 2015, during which time Sakurajima continued to emit ash from frequent Vulcanian explosions. During each survey, between 29 and 53 ash samplers were installed in a zone 2.2-43 km downwind of the source crater. Total masses of erupted tephra were estimated using several empirical methods based on the relationship between the area surrounded by a given isopleth and the thickness of ash fall within each isopleth. We obtained 70-40,520 t (4.7 × 10−8-2.7 × 10−5-km3 DRE) as the minimum estimated mass of erupted materials for each eruption period. The minimum erupted mass of tephra produced during the recorded events was calculated as being 890-5140 t (5.9 × 10−7-3.6 × 10−6-km3 DRE). This calculation was based on the total mass of tephra collected during any one eruptive period and the number of eruptions during that period. These values may thus also include the contribution of continuous weak ash emissions before and after prominent eruptions. We analyzed the meteorological effects on ash fall distribution patterns and concluded that the width of distribution area of an ash fall is strongly controlled by the near-ground wind speed. The direction of the isopleth axis for larger masses is affected by the local wind direction at ground level. Furthermore, the wind direction influences the direction of the isopleth axes more at higher altitude. While a second maximum of ash fall can appear, the influence of rain might only affect the finer particles in distal areas. [ABSTRACT FROM AUTHOR]

Abstract: Microalgal-based indicators were used to assess terrestrial influence on Shiraho coral reef of Ishigaki Island (Okinawa, Japan). A typhoon occurred on 4–5 August 2005 and sampling were made on three occasions thereafter (6, 8, and 11 August). Pre-typhoon sampling was conducted on 26 July. The typhoon-enhanced terrestrial discharges increased reef nutrient levels (e.g. average -N: 0.088mg/L pre-typhoon to 0.817mg/L post-typhoon). This elevated chlorophyll-a concentrations by four times and shifted phytoplankton composition (spectral class-based) from an initial dominance of diatoms and green microalgae to the dominance of bluegreen microalgae (cyanobacteria) and cryptophytes. Cyanobacteria later increased by more than 200% and accounted for as much as 80% of total chl-a (∼0.29μg/L), possibly assisted by favorable nutrient availability. In outer reef waters, diatoms and green microalgae predominated whereas cyanobacteria and cryptophytes were nearly undetectable. Due to detrital decomposition and river discharge, the CDOM was much higher in the inner reef than in the outer reef. Benthic bluegreen microalgae were relatively more abundant in areas close to the river mouth and coastal agricultural fields. At these locations, nutrient concentrations were much higher due to river discharge and potentially significant groundwater discharge. Thus, phytoplankton and benthic microalgae can serve as indicators of terrestrial influence on coral reefs. [Copyright &y& Elsevier]

Highlights • The coupled SWAT-MODFLOW model is able to effectively predict stream flow, sediment, and nutrients on long term and high resolution configuration. • The groundwater and surface water shows strong interactions in terms of the exchanges of both water quantity and quality between streams and aquifer. • The agricultural best management practices (BMPs), particularly combined BMPs, are effective in reducing NPS pollution loads in a predominately agricultural coastal watershed. Abstract The predominantly agricultural coastal watershed located in tropical–subtropical Island has served as a pathway for nonpoint source (NPS) pollution loading into the downstream coastal ecosystems. The present study aims to assess watershed hydrology and water quality by applying a watershed model to long–term high–resolution monitoring data, and to evaluate the reduction of nonpoint–source pollution by implementing best management practices (BMPs) in a small agricultural watershed located in southwestern Japan. The Soil Water and Assessment Tool (SWAT) was coupled to a groundwater model (MODFLOW) and applied to simulate stream flow, sediment, and nutrients discharges. The results revealed that the model successfully predicted hourly stream flow, sediment, and nutrients concentrations in the study watershed and that the model could be further used to evaluate BMP scenarios. This is the first attempt to quantify the impacts of multiple agricultural mitigation measures on long-term water quality for sediment, nitrate, and phosphate at an hourly resolution. From the model results, the land cover conversion and mulching scenarios achieved a significant reduction in sediment, followed by the cover crop, alternative tillage, and filter strip scenarios. Moreover, conversion of all summer sugarcane to pasture farmland and fertilizer control scenarios gave the superior reduction in nitrate load, while other scenarios were minimally effective. On the other hand, most of the scenarios significantly achieved the reduction of phosphate load. The results further indicated that the BMPs recommended in this study are appropriately combined scenarios, which achieved the significant reduction in all NPS loads. Although this study revealed some effective mitigation measures to improve the water quality in the study watershed, actual implementation of correct ones may be practically challenging unless other environmental and economic risks (e.g. the increase of other pollutants and reduction in agricultural productivity) are also taken into considerations. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To investigate the prevalence and associated factors of delirium in critically ill patients during an intensive care unit (ICU) stay. Methods: We investigated 103 of 172 patients admitted consecutively to a university-based 20-bed ICU in a 3-month period. Six ICU physicians, who were familiar with the Confusion Assessment Method for the ICU (CAM-ICU), assessed patient delirium daily. Patient demographics, diagnosis, Acute Physiology and Chronic Health Evaluation (APACHE) II score, mechanical ventilation and maximum serum C-reactive protein (max-CRP) level during the ICU stay (max-CRP) were compared between patients who developed delirium and those who did not. Results: Twenty-one (20%) of 103 patients and 13 (76%) of 17 mechanically ventilated patients developed delirium. APACHE II scores and max-CRP were significantly higher in patients who experienced delirium than in those who did not (P<.001). Use of a mechanical ventilator (P=.002), max-CRP (P=.032) and length of ICU stay (P=.043) were identified as independent associations for delirium development. Conclusions: The prevalence of delirium was 20% in ICU patients and 80% in ventilated patients in a Japanese ICU. [Copyright &y& Elsevier]

The adsorption layer system has shown great potential as a cost-effective and practical strategy for the recycling and management of excavated rocks containing potentially toxic elements (PTEs). Although this system has been employed in various civil engineering projects throughout Japan, its long-term performance to immobilize PTEs has rarely been investigated. This study aims to evaluate the effectiveness of the adsorption layer system applied in an actual road embankment approximately 11 years after construction. The embankment system is comprised of a layer of excavated arsenic (As)-bearing mudstone built on top of a bottom adsorption layer mixed with an iron (Fe)-based adsorbent. Collection of undisturbed sample was carried out by implementing borehole drilling surveys on the embankment. Batch leaching experiments using deionized water and hydrochloric acid were conducted to evaluate the water-soluble and acid-leachable concentrations of As, Fe, and other coexisting ions. The leaching of As from the mudstone layer was likely induced by As desorption from Fe-oxides/oxyhydroxides naturally present under alkaline conditions, including the oxidation of framboidal pyrite, which was identified as a potential source of As. This was supported by electron probe microanalyzer (EPMA) observations showing the presence of trace amounts of As in framboidal pyrite crystals. Arsenic leached from the mudstone layer was then immobilized by Fe oxyhydroxides found in the adsorption layer. Based on geochemical modeling and X-ray photoelectron spectroscopy (XPS) results, leached As predominantly existed as the negatively charged HAsO 4 2- oxyanion, which is readily sequestered by Fe oxyhydroxides. Moreover, the effectiveness of the adsorption layer was assessed and its lifetime was estimated, and the results revealed it still possessed enough capacity to adsorb As released from mudstone in the foreseeable future. This prediction utilized the maximum potential amount of As that could leach from the excavated rock layer with time., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The Japanese Association for Acute Medicine Committee recently proposed a novel classification system for the severity of heat-related illnesses. The illnesses are simply classified into three stages based on symptoms and management or treatment. Stages I, II, and III broadly correspond to heat cramp and syncope, heat exhaustion, and heat stroke, respectively. Our objective was to examine whether this novel severity classification is useful in the diagnosis by healthcare professionals of patients with severe heat-related illness and organ failure. A nationwide surveillance study of heat-related illnesses was conducted between 1 June and 30 September 2012, at emergency departments in Japan. Among the 2130 patients who attended 102 emergency departments, the severity of their heat-related illness was recorded for 1799 patients, who were included in this study. In the patients with heat cramp and syncope or heat exhaustion (but not heat stroke), the blood test data (alanine aminotransferase, creatinine, blood urea nitrogen, and platelet counts) for those classified as Stage III were significantly higher than those of patients classified as Stage I or II. There were no deaths among the patients classified as Stage I. This novel classification may avoid underestimating the severity of heat-related illness.