Metasomatism as a Self-controlled Process

Wall-rock alteration by a reaction mineral (Korzhinskii, 1970) has been reinvestigated considering the effect of a varying porosity on the process itself. This is because a limit value of porosity at the replacement front has made it possible to analyze the alteration. In diffusion metasomatism, the porosity decreases toward a fissure due to the "salting out" effect. Strongly dependent upon the porosity, the effective diffusion coefficient decreases toward the fissure. Consequently, a steady state of "constant" concentrations of both replacing and replaced components (∂ci/∂x=0) is almost achieved near the replacement front. The "salting-out" also occurs even in combined diffusion and reverse-infiltration metasomatism. This process may occur in nature. In both cases, the alteration by a reaction mineral causes a porosity decrease in the replaced zone, which in turn hinders the process. In other words, this type of metasomatism is a "self-controlled" process. The formation process of vein-type wollastonite skarn around fissures in limestone, a typical wall-rock alteration, as observed at the Fujigatani mine, SW Japan, has been numerically analyzed based on the thermodynamic assumptions. These consist mainly of constant volume and local equilibrium assumptions, essential in analyzing metasomatic processes. As a result, I have concluded that the porosity is reduced to almost zero near the fissure even when the porosity at a replacement front is extremely large. Hence, the composition of a pore solution of wollastonite zone becomes almost the same as that of the replacement front. This means that the front cannot progress. It should be emphasized that the porosity change acts as an obstacle to the development of the skarn. Therefore, to analyze naturally-occurring metasomatism, we must reexamine the assumptions used since Korzhinskii (1970). The effect of changing porosity on the metasomatism in a solid solution mineral has also been evaluated. I have proved that only a small difference in the intrinsic diffusion coefficients of both replacing and replaced components brings about a large variation of porosity, resulting in quite different concentration profiles compared to those calculated under the constant porosity assumption

"Microscopic" Cleavages in Bornite from the Jinmu Mine, SW Japan and their Implications

During microscopic and electron probe investigation of the copper ores from the Jinmu mine, Hiroshima Prefecture, SW Japan, we have found well-developed "microscopic" cleavages oriented in two or three directions in the bornite matrix. They are represented by the regularly arranged intergrowths, lattice or lamellar. According to their distribution density and size (width), the cleavages are divided into three types. (1) Type 1, densely developed and very fine (less than about 0.1 micron in width), visible only under higher magnifications (x 400 or greater); (2) Type 2, less densely developed and fine (about 1micron in width); and (3) Type 3, sparsely developed and coarse (up to about 10 microns in width). The Type 1 cleavages are less common in the Jinmu ores, while they are very rare in natural sulfides. The very fine and coarse lamellae are always chalcopyrite, while the fine ones are mainly wittichenite and/or some chalcopyrite. Under the electron beam only the image of chalcopyrite forms a dark set of lines (backscat-tered image) and appears as dented (topographic image). It is important to note that their abundances of the cleavage types differ significantly from one place to another, even within a polished section. This fact suggests that there might be a compositional heterogeneity in the original solid solution, that is, a difference in the degree of supersaturation, with the higher degree for the Type 1 and Type 2 assemblages than for the Type 3 assemblages. As experimentally confirmed by SUGAKI (1955), the crystallographic intergrowths described are concluded to have been formed by exsolution from the solid solution during cooling. In spite of the difference of the degree of supersaturation, the exsolution reactions under discussion are assumed to be of stepwise in such that the lamellae exsolved in the order of the Type 3→Type 2→Type 1 with decreasing temperatures

3D Plotting of Gold Solubility and Gold Fineness: Quantitative Analysis of Ore-Forming Conditions in Hydrothermal Gold Deposits

The 3D plotting of gold solubility and gold fineness aims to illustrate how to quantify their correlations with ore-forming conditions in hydrothermal gold deposits. The thermodynamic calculation of the Au-Ag solid solutions in Mathematica and the 3D plotting in MATLAB are used to build isopleths of gold solubility and gold fineness at different temperatures (200℃, 400℃), pressures (0.1, 5 kbar), salinities (1, 40 wt% NaCl eq.), and sulfur concentrations (0.01, 0.5 mol/kg). The plot indicates that the ore-forming conditions have different correlations with gold solubility and gold fineness. Average rates of change for the correlations are quantified, showing distinct values in the four pH-logfO2 fields of (I) HSO4−, (II) SO42−, (III) H2S, and (IV) HS−, where dominant gold and silver complexes have different dependencies on the conditions. The quantification of the plots illustrates that a decrease in gold solubility by one order of magnitude is possibly caused by a decrease in temperature of ≥40℃, the salinity of ≥9.6 wt% NaCl eq. or sulfur concentration of ≥0.14 mol/kg, or an increase in pressure of ≥3 kbar, while a decrease in gold fineness by 100 units is possibly caused by a decrease in temperature of ≥14 ℃, pressure of ≥1.4 kbar, or salinity of ≥4 wt% NaCl eq., or an increase in sulfur concentration of ≥0.07 mol/kg. Quantification results suggest that a sharp decrease in temperature may result in large-scale gold mineralization and a great variation in gold fineness. In addition, the quantification reveals that the correlation between gold solubility and gold fineness can be expressed by a function, providing a rapid method for 3D plotting

Integrated genetic and epigenetic analysis defines novel molecular subgroups in rhabdomyosarcoma.

横紋筋肉腫におけるゲノム・エピゲノム異常の全体図を解明 -横紋筋肉腫を4群に分類-. 京都大学プレスリリース. 2015-07-03.Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma in childhood. Here we studied 60 RMSs using whole-exome/-transcriptome sequencing, copy number (CN) and DNA methylome analyses to unravel the genetic/epigenetic basis of RMS. On the basis of methylation patterns, RMS is clustered into four distinct subtypes, which exhibits remarkable correlation with mutation/CN profiles, histological phenotypes and clinical behaviours. A1 and A2 subtypes, especially A1, largely correspond to alveolar histology with frequent PAX3/7 fusions and alterations in cell cycle regulators. In contrast, mostly showing embryonal histology, both E1 and E2 subtypes are characterized by high frequency of CN alterations and/or allelic imbalances, FGFR4/RAS/AKT pathway mutations and PTEN mutations/methylation and in E2, also by p53 inactivation. Despite the better prognosis of embryonal RMS, patients in the E2 are likely to have a poor prognosis. Our results highlight the close relationships of the methylation status and gene mutations with the biological behaviour in RMS

Gain-of-function IKBKB mutation causes human combined immune deficiency

Genetic mutations account for many devastating early onset immune deficiencies. In contrast, less severe and later onset immune diseases, including in patients with no prior family history, remain poorly understood. Whole exome sequencing in two cohorts of such patients identified a novel heterozygous de novo IKBKB missense mutation (c.607G>A) in two separate kindreds in whom probands presented with immune dysregulation, combined T and B cell deficiency, inflammation, and epithelial defects. IKBKB encodes IKK2, which activates NF-κB signaling. IKK2V203I results in enhanced NF-κB signaling, as well as T and B cell functional defects. IKK2V203 is a highly conserved residue, and to prove causation, we generated an accurate mouse model by introducing the precise orthologous codon change in Ikbkb using CRISPR/Cas9. Mice and humans carrying this missense mutation exhibit remarkably similar cellular and biochemical phenotypes. Accurate mouse models engineered by CRISPR/Cas9 can help characterize novel syndromes arising from de novo germline mutations and yield insight into pathogenesis

Population changes in Pythium spp. infecting sanionia moss at the Japanese Ny-Ålesund Observatory, Spitsbergen Island, Norway from 2003 to 2010

第2回極域科学シンポジウム/第33回極域生物シンポジウム 11月18日（金） 統計数理研究所 3階リフレッシュフロ

Value of adding the renal pathological score to the kidney failure risk equation in advanced diabetic nephropathy

金沢大学医薬保健研究域医学系Background There have been a limited number of biopsy-based studies on diabetic nephropathy, and therefore the clinical importance of renal biopsy in patients with diabetes in late-stage chronic kidney disease (CKD) is still debated. We aimed to clarify the renal prognostic value of pathological information to clinical information in patients with diabetes and advanced CKD. Methods We retrospectively assessed 493 type 2 diabetics with biopsy-proven diabetic nephropathy in four centers in Japan. 296 patients with stage 3–5 CKD at the time of biopsy were identified and assigned two risk prediction scores for end-stage renal disease (ESRD): the Kidney Failure Risk Equation (KFRE, a score composed of clinical parameters) and the Diabetic Nephropathy Score (D-score, a score integrated pathological parameters of the Diabetic Nephropathy Classification by the Renal Pathology Society (RPS DN Classification)). They were randomized 2:1 to development and validation cohort. Hazard Ratios (HR) of incident ESRD were reported with 95% confidence interval (CI) of the KFRE, D-score and KFRE+D-score in Cox regression model. Improvement of risk prediction with the addition of D-score to the KFRE was assessed using c-statistics, continuous net reclassification improvement (NRI), and integrated discrimination improvement (IDI). Results During median follow-up of 1.9 years, 194 patients developed ESRD. The cox regression analysis showed that the KFRE,D-score and KFRE+D-score were significant predictors of ESRD both in the development cohort and in the validation cohort. The c-statistics of the D-score was 0.67. The c-statistics of the KFRE was good, but its predictive value was weaker than that in the miscellaneous CKD cohort originally reported (c-statistics, 0.78 vs. 0.90) and was not significantly improved by adding the D-score (0.78 vs. 0.79, p = 0.83). Only continuous NRI was positive after adding the D-score to the KFRE (0.4%; CI: 0.0–0.8%). Conclusions We found that the predict values of the KFRE and the D-score were not as good as reported, and combining the D-score with the KFRE did not significantly improve prediction of the risk of ESRD in advanced diabetic nephropathy. To improve prediction of renal prognosis for advanced diabetic nephropathy may require different approaches with combining clinical and pathological parameters that were not measured in the KFRE and the RPS DN Classification. © 2018 Yamanouchi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Recent Results from LHD Experiment with Emphasis on Relation to Theory from Experimentalist’s View

he Large Helical Device (LHD) has been extending an operational regime of net-current free plasmas towardsthe fusion relevant condition with taking advantage of a net current-free heliotron concept and employing a superconducting coil system. Heating capability has exceeded 10 MW and the central ion and electron temperatureshave reached 7 and 10 keV, respectively. The maximum value of β and pulse length have been extended to 3.2% and 150 s, respectively. Many encouraging physical findings have been obtained. Topics from recent experiments, which should be emphasized from the aspect of theoretical approaches, are reviewed. Those are (1) Prominent features in the inward shifted configuration, i.e., mitigation of an ideal interchange mode in the configuration with magnetic hill, and confinement improvement due to suppression of both anomalous and neoclassical transport, (2) Demonstration ofbifurcation of radial electric field and associated formation of an internal transport barrier, and (3) Dynamics of magnetic islands and clarification of the role of separatrix