miR-125bの骨芽細胞特異的過剰発現は骨格成長への影響なく骨吸収を阻害し、加齢性の骨量や骨質への変化を改善する

内容の要約広島大学(Hiroshima University)博士(歯学)Doctor of Philosophy in Dental Sciencedoctora

Competition model explains trends of long‐term fertilization in plant communities

Over 40 years ago, Kempton (Biometrics, 35, 1979, 307) reported significant modification to plant community structure following a long-term fertilization experiment. Many researchers have investigated this phenomenon in the years since. Collectively, these studies have shown consistent shifts in rank abundance relationships among species in communities following fertilization. The previous studies indicated that fertilization affects community structure through several critical processes, including trait-based functional response, reordering of species in rank abundance diagram (RAD), and niche dimensionality, although some questions have remained. How does the species reordering driven by the plant responses cause characteristic trends in temporal changes of RAD? Why are those trends ubiquitous in various systems? To answer those questions, we theoretically investigated the effects of fertilization on community structure based on a colonization model (or Levins model) with competition–fecundity trade-offs, which can result in the coexistence of multiple species under competition. The model represents characteristic RAD, which can be an adequate tool to study community composition. Our theoretical model comprehensively represents observed trends in rank abundance relationships following long-term fertilization and suggests that competitive interactions among species are a critical factor in structuring species diversity in plant communities

An Agent that Facilitates Crowd Discussion

Online discussion platforms are perceived as the next-generation method of citizen involvement. Such platforms can collect, integrate, and synthesize opinions to achieve social good. Crowd-scale platforms are being developed and deployed in social experiments that involve citizens and local governments. In such platforms, human facilitation is often used to preserve the quality of the discussions. Human facilitators often face difficulties when the discussions grow in size. In this paper, we present “D-agree, ” a crowd-scale discussion support system based on an automated facilitation agent. The agent extracts discussion structures from online discussions, analyzes them, and posts facilitation messages. We conducted small- and large-scale social experiments in Japan to assess the social impact of the platform. The results showcase the success of our automated facilitation agents in gathering valuable opinions from citizens. In addition, our experiments highlight the effect of an automated facilitation agent on online discussions. In particular, we find that combining the agent facilitator with human facilitators leads to higher user satisfaction

No-Transaction Band Network: A Neural Network Architecture for Efficient Deep Hedging

Deep hedging (Buehler et al. 2019) is a versatile framework to compute the optimal hedging strategy of derivatives in incomplete markets. However, this optimal strategy is hard to train due to action dependence, that is, the appropriate hedging action at the next step depends on the current action. To overcome this issue, we leverage the idea of a no-transaction band strategy, which is an existing technique that gives optimal hedging strategies for European options and the exponential utility. We theoretically prove that this strategy is also optimal for a wider class of utilities and derivatives including exotics. Based on this result, we propose a no-transaction band network, a neural network architecture that facilitates fast training and precise evaluation of the optimal hedging strategy. We experimentally demonstrate that for European and lookback options, our architecture quickly attains a better hedging strategy in comparison to a standard feed-forward network

Involvement of the leaf-specific multidrug and toxic compound extrusion (MATE) transporter Nt-JAT2 in vacuolar sequestration of nicotine in Nicotiana tabacum

Alkaloids play a key role in higher plant defense against pathogens and herbivores. Following its biosynthesis in root tissues, nicotine, the major alkaloid of Nicotiana species, is translocated via xylem transport toward the accumulation sites, leaf vacuoles. Our transcriptome analysis of methyl jasmonate-treated tobacco BY-2 cells identified several multidrug and toxic compound extrusion (MATE) transporter genes. In this study, we characterized a MATE gene, Nicotiana tabacum jasmonate-inducible alkaloid transporter 2 (Nt-JAT2), which encodes a protein that has 32% amino acid identity with Nt-JAT1. Nt-JAT2 mRNA is expressed at a very low steady state level in whole plants, but is rapidly upregulated by methyl jasmonate treatment in a leaf-specific manner. To characterize the function of Nt-JAT2, yeast cells were used as the host organism in a cellular transport assay. Nt-JAT2 was localized at the plasma membrane in yeast cells. When incubated in nicotine-containing medium, the nicotine content in Nt-JAT2-expressing cells was significantly lower than in control yeast. Nt-JAT2-expressing cells also showed lower content of other alkaloids like anabasine and anatabine, but not of flavonoids, suggesting that Nt-JAT2 transports various alkaloids including nicotine. Fluorescence assays in BY-2 cells showed that Nt-JAT2-GFP was localized to the tonoplast. These findings indicate that Nt-JAT2 is involved in nicotine sequestration in leaf vacuoles following the translocation of nicotine from root tissues

Cu2ZnSn(SxSe1-x)4 Thin-Film Solar Cells Utilizing Simultaneous Reaction of a Metallic Precursor with Elemental Sulfur and Selenium Vapor Sources

A Cu2ZnSn(SxSe1-x)(4) (CZTSSe) solid alloy was prepared by reacting a metallic precursor with sulfur and selenium in a closed tube simultaneously. It was confirmed that the CZTSSe alloy could be synthesized over the whole compositional range and its lattice transformation was in good agreement with Vegard's law. The crystal grain size and electrical conductivity were enhanced when the selenium content was increased. In a CdS/CZTSSe heterojunction solar cell, the photovoltaic efficiency was improved due to the enhancement of the short-circuit current in accordance with the narrowing of the optical bandgap of the CZTSSe absorber. (c) 2012 The Japan Society of Applied PhysicsArticleAPPLIED PHYSICS EXPRESS. 5(8): 81201 (2012)journal articl

Investigation of biomarkers in a rare case of fulminant necrotizing enterocolitis in a preterm infant

We encountered a very rare case of fulminant necrotizing enterocolitis (F-NEC) in a preterm male baby. The course of NEC and sepsis in this case was clearly different from the usual course. After onset at 14 days of life, catheter-related bloodstream infection was first assumed, and antibiotics and γ-globulin administration were started. However, 12 hours after onset, the baby's abdominal distension increased remarkably, and his entire abdominal wall turned red to purple. Escherichia coli were isolated from the blood culture, but the catheter tip culture was negative. Exchange transfusion was performed 32 hours after onset, but no significant changes were observed in the baby's general condition, and he died 46 hours after onset. The acute phase reactants of CRP and α1-acid glycoprotein increased, but haptoglobin did not. Although IL-1β and TNFα increased as expected with sepsis, IL-6, IL-8, IL-10, and G-CSF however increased to a greater extent than expected. From the above, we diagnosed the development of intestinal necrosis as a result of widespread intestinal ischemia, and that sepsis was associated with this poor condition

Crystal field excitation in the chiral helimagnet YbNi3_3Al9_9

Crystal field level scheme of a uniaxial chiral helimagnet YbNi$_3$Al$_9$, exhibiting a chiral magnetic soliton lattice state by Cu substitution for Ni, has been determined by inelastic neutron scattering. The ground and the first excited doublets are separated by 44 K and are simply expressed as $\alpha|\pm 7/2\rangle + \beta |\mp 5/2\rangle$ with $\alpha$ and $\beta$ nearly equal to $\pm 1/\sqrt{2}$. The easy axis of the crystal field anisotropy is the $c$ axis when the excited levels are populated at high temperatures and high magnetic fields. On the other hand, the magnetism at low temperatures and low magnetic fields, where only the ground doublet is populated, is described by an easy plane anisotropy which may be treated as an $S=1/2$ system with an anisotropic $g$-factor, $g_{xy}=3.02$ and $g_z=1.14$. An orbital dependent exchange interaction is also discussed to explain the temperature dependence of the magnetic susceptibility based on this level scheme.Comment: 9 pages, 7 figures, 2 figures in the supplemental material, accepted for publication in Phys. Rev.

Functional Ingredients Extraction from Garcinia mangostana Pericarp by Liquefied Dimethyl Ether

The mangosteen (Garcinia mangostana Linn.) pericarp contains rich xanthone, a one kind of the polyphenols in the non-edible portion. In recent years, xanthones have been noted as a functionality such as anti-cancer effect and is expected as pharmaceuticals and health supplements. In this work, extraction of xanthones from mangosteen pericarp by using liquefied DME were investigated. Wet powder and cube samples were used as a raw material. Experimental conditions were 35°C, 0.8 MPa with various amounts of sample (1, 3, 6 g). Extracted components were analyzed by using high performance liquid chromatography (HPLC). As a result, it was confirmed that eight kinds of xanthones such as alpha-mangostin, 3-Isomangostin, Mangostanol, 8-Desoxygartanin, Gartanin, Garcinone E, 9-Hydroxycalabaxanthone, beta-Mangostin were extracted. The highest yield of alpha-mangostin (42.9 mg/g_dry sample) was obtained with a powder sample of 6 g loaded. Final alpha-magostin corresponded to about 104% of the ethanol extraction with wet mangosteen pericarp, and 72% of the dried sample. Therefore, it was considered that in the extraction of xanthones from the mangosteen, liquefied DME extraction was valid