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Core IdeasConcentration and speciation of Br and I in volcanic ash soils are determined.Br and I were enriched in soils with andic properties, mainly as organic form.Br and I accumulated in surface soils during Andosol formation process. Bromine and iodine are halogens with similar chemical properties. Distributions of Br and I in the soil profile provide insights for understanding of their biogeochemical cycles and fate of these elements derived from artificial origin. Although generally not abundant in parent rock materials, they are often found in higher concentrations in soils, particularly volcanic ash soils in Japan. However, the process of Br and I accumulation in soils during soil formation remains unclear. We investigated the vertical distribution of Br and I to characterize the processes of Br and I accumulation in volcanic ash soils. Soils were collected from three pedons in the southern Shimokita Peninsula, Japan. Bromine (1.4 to 253 mg kg–1) and iodine concentrations (1.2 to 90 mg kg–1) in the soils were significantly correlated. Nondestructive speciation analysis by X‐ray absorption near edge structure spectroscopy showed that both Br and I mainly exist in their organic forms in soils enriched in those elements. Indices of the degree of Andosol formation (oxalate‐extractable Al and Fe, pyrophosphate‐extractable Al and Fe, phosphate absorption coefficient, and soil pH [NaF]) were significantly correlated with both Br and I concentrations in the soils. These results suggest that Br and I, derived from atmospheric deposition, were retained in surface soils after transformation to organic form and accumulated during Andosol formation from their parent tephra deposits.

We used two‐dimensional simulations to investigate the effects of a hydrous lithospheric mantle (HLM) on subduction dynamics. It was demonstrated that the thickness of a subducting HLM strongly controls the motion and deformation of converging plates. When the HLM thickness is lower than a critical value, for example, ∼5 km for a 100‐Ma slab, all serpentine in the HLM decomposes, and the liberated fluid enters the mantle wedge. The fluid weakens the overlying plate, causing trench retreat, rapid plate convergence, and slab stagnation. In contrast, when the HLM thickness exceeds the critical value, dense hydrous magnesium silicates appear in cold parts of the HLM at high pressures. The buoyant dense hydrous magnesium silicates reduce the slab pull force, weakening trench retreat, rapid convergence, and slab stagnation. A low HLM thickness may account for tectonics in some actual subduction zones characterized by trench retreat, rapid convergence, and stagnant slabs, for example, in Northeast Japan. Rocks on the Earth's surface are cooled, hardened, eventually forming rigid plates that move around relative to one another. When two plates converge, one plate overrides the other, which sinks into the Earth's deep mantle. The sinking plate carries water, which softens rocks and also affects the behavior of the sinking/overriding plates and surrounding mantle flows (“subduction dynamics”). To investigate the role of water in subduction dynamics, 2‐D fluid dynamical simulations were performed. The simulations suggest that subduction dynamics change significantly with the level of hydration of the sinking plate, which is represented by the thickness of a hydrous layer. When the hydrous layer is thin, the plate sinks rapidly with a shifting boundary and stagnates above the lower mantle. In contrast, when the hydrous layer is thick, plate convergence is sluggish, the plate boundary remains stationary, and the sinking plate penetrates into the lower mantle. These results indicate that a small amount of water is expected for the northwest part of the Pacific Plate, characterized by the rapid convergence, plate boundary shifting, and stagnation of the sinking plate. Numerical simulation shows how a subducting hydrous lithospheric mantle affects plate velocity and slab geometryA thin (thick) hydrous layer within the lithospheric mantle enhances (weakens) subduction, trench retreat, and slab stagnationA thin hydrous layer within the lithospheric mantle may explain the behavior of converging plates in Northeast Japan

Core IdeasA unified interpretation of clay mineral distributions in Kalimantan was achieved.The conditions under which soil clay minerals formed in Kalimantan were clarified.Systematic sampling, considering parent material and climate, allowed clear analysis.Thermodynamic analysis of clay mineral stability was performed.The clarified mineralogy will allow better ecological and agricultural understanding. It is important to clarify which factors control the distribution of secondary minerals because secondary minerals affect soil physicochemical properties. This study investigated the effects of parent materials and climate at different elevations on secondary mineral distributions in soils under a humid tropical climate with a hilly landscape and without recent volcanic activity. Soil material from B horizons was sampled at 60 sites on gentle slopes at different elevations (20–1700 m altitude). Each major parent material (sedimentary, felsic, and intermediate to mafic) was represented at different elevations. The soil samples were classified based on their total elemental compositions using cluster analysis. Secondary minerals were measured by X‐ray diffraction and selective extractions. The samples were divided into ferric (high Fe contents), K&Mg (high K, Mg, and Si), and silicic (high Si) groups. The ferric soils were derived from mafic parent materials and characterized by high Fe oxides and gibbsite contents. The K&Mg and silicic soils were derived from felsic or sedimentary parent materials and had similar secondary mineral (kaolinite and vermiculite) contents, although more mica was found in the former group. Climate affected secondary mineral distributions only in the silicic group soils; higher temperatures at lower elevations may enhance weathering and increase kaolinite and crystalline Al and Fe contents. The hilly landscape of this study is different from those of shields in tropical humid regions in Africa or South America. Here, secondary mineral distributions were primarily determined by parent material (mafic vs. felsic or sedimentary) and secondarily by climate, which varied with elevation.

Factors controlling the abilities of Allophanic Andosols (representative of Japanese volcanic ash soils) to retain radiocesium (RCs) were assessed. The hypothesis was that retention is largely controlled by traces of micaceous minerals deposited as components of aeolian dust. The radiocesium interception potentials (RIPs), mica K contents were determined in the 2‐ to 20‐ and <2.0‐μm particle fractions of 23 soil samples from agricultural fields in areas representative of Japanese Allophanic Andosols. Quartz contents were determined in the 2‐ to 20‐μm particle fractions of the same soil samples. The oxygen isotope ratio (δ18O) in the quartz isolated from each 2‐ to 20‐μm particle fraction was determined to identify the origin of the quartz in each soil sample. The mean RIP for the 2‐ to 20‐ and <2‐μm particles was 1.7 ± 0.8 and 2.6 ± 1.3 mol kg‐1, respectively, and the mica K contents were 3.2 ± 1.3 and 3.4 ± 1.7 g kg‐1, respectively, corresponding to micaceous mineral contents of <5% by mass in each size fraction. In spite of their rather low values, the RIPs and mica K contents in each fraction positively correlated (p< 0.01), indicating that the abilities of the soils to retain RCs were mainly controlled by the micaceous mineral contents. The mica K content was proportional to the quartz content in the <20‐μm particles, and the mean δ18O in the quartz was +14.8‰, similar to those in fine quartz in Chinese loess. These results strongly indicate that the abilities of Allophanic Andosols to retain RCs are largely controlled by micaceous minerals probably originating in aeolian dust.

The radiocesium interception potential (RIP) of bulk soil (RIPsoil) can reliably be used to predict the magnitude of soil‐to‐plant radiocesium transfer. There has been some controversy about which soil properties control the RIPsoil, although the RIP is theoretically proportional to the amount of frayed edge sites in micaceous clay minerals. The RIPsoilwas determined for 97 paddy soils in three regions (Hama‐dori, Naka‐dori, and Aizu) in Fukushima Prefecture, Japan, and the relationships between selected physicochemical properties and the RIP were analyzed. The mean (± standard deviation) of the RIPsoilfor the 97 soils was 1.67 (±0.87) mol kg−1, and the range was 0.34 to 5.36 mol kg−1. Pearson correlation analysis revealed that the RIPsoilpositively correlated best (P< 0.01) with the clay fraction K content as a mass fraction of the bulk soil (clay‐Ksoil) and negatively correlated with the total C content and the phosphate absorption coefficient (P< 0.05). Therefore, clay‐Ksoil, an indicator of the amount of micaceous clay minerals in a soil, was confirmed as being useful for estimating the magnitude of the RIPsoilfor paddy soils in Fukushima. The RIPsoilwas invariably low if either the total C content exceeded 6.0% or the phosphate absorption coefficient exceeded 1500 mg kg−1, suggesting that these parameters could be useful for screening soils with particularly low RIPsoilvalues.

This study presents a forward model to quantify the P‐wave velocity (VP), S‐wave velocity (VS), and electrical conductivity (σ) of the solid‐liquid mixtures for a given set of pressure, temperature, lithology, liquid phase (aqueous fluid or melt), liquid fraction, and geometrical parameters in relation to the aspect ratio and connectivity of the liquid phase. This is based on previous experimental and theoretical studies on seismic velocity and electrical conductivity of solid rocks and liquid phases. A total of 78 lithologies, an aqueous fluid with NaCl (∼0–10 wt.%), and mafic to felsic melt appropriate for the crust and the uppermost mantle conditions were described in terms of VP, VS, and σ, as per previous experimental measurements and molecular dynamics simulation. This forward model is provided as a Windows executable program, and generates synthetic VP, VS, and σ, referring to the seismic velocities and electrical conductivity observed in the northeast Japan arc. After generation of the synthetic VP, VS, and σ, the original lithology and liquid parameters (phase, fraction, aspect ratio, and connectivity) were searched by implementing the grid search algorithm to map the misfit over the broad parameter space. The mapping shows the presence of a global misfit minimum around the optimized solution and the possibility of resolving the lithology and the liquid phase parameters based on the observed VP, VS, and σby using the forward model presented in this study. Liquid phases such as aqueous fluid and magma present within the solid Earth play crucial roles in various geodynamic processes including earthquake and volcanic eruption, as well as in the evolution of our planet. This study aims to improve the subsurface imaging of the potentially variable types of liquid phase and solid rock, based on the near‐surface observations concerning seismic velocity and electrical conductivity of the Earth's interior. We constructed a quantitative model to predict the physical properties of liquids and rocks. Then we used the model to perform “inversion,” which estimates the physical properties of liquid and rock based on the observed seismic velocity and electrical conductivity. The inversion test using synthetic data shows the utility of our model. A forward model is presented to quantify seismic velocity and electrical conductivity of solid‐liquid mixtures in crust‐uppermost mantleThe input parameters include pressure, temperature, lithology, liquid phase composition and fraction, and solid‐liquid geometryFor a given set of seismic velocity and electrical conductivity, the optimal parameter values can be found by inversion A forward model is presented to quantify seismic velocity and electrical conductivity of solid‐liquid mixtures in crust‐uppermost mantle The input parameters include pressure, temperature, lithology, liquid phase composition and fraction, and solid‐liquid geometry For a given set of seismic velocity and electrical conductivity, the optimal parameter values can be found by inversion

Introduction:Trisomy 18 (T18) is a genetic diagnosis often associated with cardiac malformations. Several recent studies have reported that cardiac interventions improve the survival of T18 infants; however, none have described the optimal age for performing pulmonary artery banding (PAB).Purpose:We investigated the cut-off age for performing PAB, as we have empirically observed that T18 infants who undergo PAB beyond 30 days of life have a relatively poor prognosis.Methods:We reviewed the detailed clinical information of T18 patients at our institute between July 2004 and December 2018. The area under the receiver operating characteristic (ROC) curve (AUC) was used to identify the optimal cut-off age for PAB to predict the one- and five-year survival, and the long-term survival was assessed with the Kaplan-Meier method.Results:A total of 110 infants were diagnosed with T18 at our hospital, and 51 of them underwent PAB, not achieving intracardiac repair. The PAB cases included 34 cases of PAB with patent ductus arteriosus closure, 8 with isolated PAB, 7 with bilateral PAB, and 2 with coarctectomy. The median age at PAB was 29 days old (range, 6-190 days). The age at PAB was younger in alive patients than in dead patients at 1 and 5 years old (P=0.093 and 0.107, respectively). The ROC analysis showed that the optimal cut-off age for PAB was 33 days old for the 5-year survival (sensitivity 80% and specificity 80%, AUC: 0.740) and 42 days old for the 1-year survival (sensitivity 75% and specificity 56%, AUC: 0.593). The 5-year survival rates were 19.8% and 66.5% in PAB patients >33 and ?33 days old, respectively (Log-rank, P=0.046).Conclusions:This is the first study to analyze the optimal age of PAB using the ROC method. Our findings suggest that the optimal age of PAB in T18 infants was ?33 days old if possible, or 42 days old at the latest to improve the long-term survival.

Introduction:Trisomy 18 (T18) is a genetic diagnosis that is often associated with cardiac malformations. Limited literature is available on the impact of congenital heart surgery (CHS) on the prognosis of trisomy 18 patients. None have investigated it using a propensity score matched analysis.Purpose:We aimed to investigate the impact of CHS on long-term survival and the home discharge rate.Methods:We reviewed the detailed clinical information of T18 patients treated at our institute between July 2004 and December 2018. The patients were divided into 2 groups depending on whether they underwent CHS or not (non-CHS). CHS included all types of cardiac surgery (e.g., pulmonary artery banding, patent ductus arteriosus closure, coarctectomy, or intracardiac repair). The long-term survival and home discharge rates were compared by propensity score matching (1:1 matching, caliper: 0.2).Results:A total of 110 infants were diagnosed with T18. Among them, the survival of the CHS group (n=73, 66.3%) was longer than that of the non-CHS group (n=37, 33.6%) (hazard ratio [HR]:0.41, 95% confidence interval [CI]: 0.24-0.69; P<0.001). The home discharge rate of the CHS group was better than that of the non-CHS group (79.5%, 46.9%, respectively; P=0.002). After propensity score matching (C-statistic = 0.773), the CHS group (n=19) survived longer than the non-CHS group (n=19) (HR: 0.40, 95% CI: 0.17-0.99, P=0.047). During follow-up, the CHS group had higher rates of 1-, 3-, 5-year survival than the non-CHS group (68.4% vs. 32.6%, 46.3% vs. ?11.5%, 39.7% vs. ?11.5). The home discharge rate in the CHS group tended to be better than that in the non-CHS group (84.2%, 57.1%, respectively; P=0.183).Conclusions:This is the first study to investigate survival and the rate of home discharge according to CHS in T18 patients by a propensity score matched analysis. Our findings suggest that CHS prolongs long-term survival and that CHS may increase the chance of home discharge in T18 patients.