319 research outputs found
Wood traceability system using blockchain and zero-knowledge proof
The system proposed in this study uses zero-knowledge proof (ZKP) to verify
the traceability of wood recorded in a public blockchain. Wood is a byproduct
of several states, ranging from standing trees to logs, lumber, and wood
products (hereinafter ``wood objects''). The advantage of using the blockchain
for record keeping is that participants can freely record the information at
their discretion, without any restrictions. However, the openness of the
blockchain may allow a malicious third party to introduce disinformation. In
this study, we employ ZKP and near-field communication (NFC) chips to eliminate
the possibility of disinformation introduction. ZKP is used to prove/validate
changes in the state of wood objects, and the unique nonce associated with that
state is encrypted and recorded on an NFC chip. The nonce is concealed and id
of the wood object is defined as hash value of this nonce. We developed a
prototype system based on an Android application and an Ethereum smart
contract. We confirm that wood traceability and verification can be performed
using the prototype system.Comment: 4 pages, 3 figures, accepted for Blockchain and Cryptocurrency
Congress (B2C' 2022
Activation of G protein-coupled inward rectifier K+ channels in brain neurons requires association of G protein βγ subunits with cell membrane
AbstractIn cultured noradrenergic neurons from the rat locus coeruleus, application of recombinant G protein β1γ2 subunits (30 nM) to the cytoplasmic side induced single channel activity similar to the somatostatin-induced single channel activity of G protein-coupled inward rectifier potassium channels (Kir (G)). In contrast, recombinant GTPγS-activated, myristoylated αi2 (100 nM) did not activate this brain Kir (G). Application of β1γ2C68S (30 nM or 150 nM), in which the cysteine residue fourth from the carboxyl terminus of γ2 was replaced by serine, failed to activate the brain Kir(G). This mutant lacks prenylation which is required for the association of βγ subunit with the cell membrane. Thus, our results suggest that the association of βγ subunit with the cell membrane is a prerequisite for activating Kir(G) channels
Clustering Properties of Low-Luminosity Star-Forming galaxies at z = 0.24 and 0.40 in the Subaru Deep Field
We present our analysis on the clustering properties of star-forming galaxies
selected by narrow-band excesses in the Subaru Deep Field. Specifically we
focus on Halpha emitting galaxies at z = 0.24 and z = 0.40 in the same field,
to investigate possible evolutionary signatures of clustering properties of
star-forming galaxies. Based on the analysis on 228 Halpha emitting galaxies
with 39.8 < log L(Halpha) < 40.8 at z = 0.40, we find that their two-point
correlation function is estimated as xi = (r/1.62^{+0.64}_{-0.50} Mpc)^{-1.84
+/- 0.08}. This is similar to that of Halpha emitting galaxies in the same
Halpha luminosity range at z = 0.24, xi = (r/1.88^{+0.60}_{-0.49} Mpc)^{-1.89
+/- 0.07}. These correlation lengths are smaller than those for the brighter
galaxy sample studied by Meneux et al. (2006) in the same redshift range. The
evolution of correlation length between z = 0.24 and z = 0.40 is interpreted by
the gravitational growth of the dark matter halos.Comment: 16 pages, 7 figures, PASJ, Vol.60, No.6, in pres
Denudation Process of Crystalline Nappes in a Continental Collision Zone Constrained by Inversion of Fission‐Track Data and Thermokinematic Forward Modeling: An Example From Eastern Nepalese Himalaya
Thermochronological methods were applied to the Higher Himalayan Crystalline (HHC) nappe and the underlying Lesser Himalayan Sequences (LHS) to elucidate the denudation process for the middle- and upper-crust of eastern Nepal over millions of years. Thermochronological inverse modeling was undertaken for new results of fission-track (FT) age and FT length data of zircon and apatite in order to reconstruct the time-temperature (t-T) paths in the temperature range of 60–350°C. Eight t-T paths calculated along the across-strike section show that the cooling process of the HHC nappe in this study area is characterized by the following three aspects: (a) gradual cooling followed by rapid cooling and subsequent gradual cooling, (b) northward-younging of the timing of the rapid cooling, and (c) gradual cooling followed by <2 Myr rapid cooling in the frontmost part of the HHC nappe. The observed FT ages and t-T paths were then compared with those predicted by forwarding thermokinematic modeling. The results of the thermokinematic modeling for the “Flat-Ramp-Flat MHT model”, in which the HHC and the underlying LHS are denudated in direct proportion to the uplift of rocks transported along the Main Himalayan Thrust (MHT), reproduced the observed t-T paths and FT ages in eastern Nepal. This indicates that the observed FT ages and t-T paths reflect a denudation process driven by the movement of the MHT with a flat-ramp-flat geometry and that the denudation rate and its spatial distribution have roughly been constant in eastern Nepal since ca. 9 Ma
Low serum amylase in association with metabolic syndrome and diabetes: A community-based study
<p>Abstract</p> <p>Background</p> <p>Low serum amylase levels may reflect impaired exocrine-endocrine relationship in the pancreas. However, few clinical studies have addressed this issue. Therefore, in this epidemiological study, we investigated whether low serum amylase was associated with the pathogenesis of impaired insulin action: metabolic syndrome (MetS) and diabetes.</p> <p>Research Design and Methods</p> <p>Serum amylase, cardiometabolic risk factors, MetS (Adult Treatment Panel III criteria), and diabetes were examined in 2,425 asymptomatic subjects aged 30-80 years who underwent medical checkups recently (April 2009-March 2010) and 5 years ago.</p> <p>Results</p> <p>Clinical variables, except for age and estimated glomerular filtration rate (eGFR), shifted favorably with increasing serum amylase levels. Plasma glucose levels at 1- and 2-hr during OGTT increased significantly with decreasing serum amylase levels. Multiple logistic analyses showed that, compared with highest quartile of serum amylase, lowest quartile was associated with increased risk for MetS and diabetes after adjustment for confounding factors [odds ratio (95% CI), 2.07 (1.39-3.07) and 2.76 (1.49-5.11), respectively]. In subjects who underwent checkups 5 years ago (n = 571), lower amylase at the previous checkup were associated with larger numbers of metabolic abnormalities at the recent checkup. The fluctuation over time in serum amylase levels in subjects with low serum amylase at the previous checkup was slight and was unaffected by kidney dysfunction.</p> <p>Conclusions</p> <p>Our results indicate that low serum amylase is associated with increased risk of metabolic abnormalities, MetS and diabetes. These results suggest a pancreatic exocrine-endocrine relationship in certain clinical conditions.</p
Phosphatidic acid-dependent localization and basal de-phosphorylation of RA-GEFs regulate lymphocyte trafficking
Background: Lymphocytes circulate between peripheral lymphoid tissues via blood and lymphatic systems, and chemokine-induced migration is important in trafficking lymphocytes to distant sites. The small GTPase Rap1 is important in mediating lymphocyte motility, and Rap1-GEFs are involved in chemokine-mediated Rap1 activation. Here, we describe the roles and mechanisms of Rap1-GEFs in lymphocyte trafficking. Results: In this study, we show that RA-GEF-1 and 2 (also known as Rapgef2 and 6) are key guanine nucleotide exchange factors (GEF) for Rap1 in lymphocyte trafficking. Mice harboring T cell-specific knockouts of Rapgef2/6 demonstrate defective homing and egress of T cells. Sphingosine-1-phosphate (S1P) as well as chemokines activates Rap1 in a RA-GEF-1/2-dependent manner, and their deficiency in T cells impairs Mst1 phosphorylation, cell polarization, and chemotaxis toward S1P gradient. On the other hand, B cell-specific knockouts of Rapgef2/6 impair chemokine-dependent retention of B cells in the bone marrow and passively facilitate egress. Phospholipase D2-dependent production of phosphatidic acid by these chemotactic factors determines spatial distribution of Rap1-GTP subsequent to membrane localization of RA-GEFs and induces the development of front membrane. On the other hand, basal de-phosphorylation of RA-GEFs is necessary for chemotactic factor-dependent increase in GEF activity for Rap1. Conclusions: We demonstrate here that subcellular distribution and activation of RA-GEFs are key factors for a directional movement of lymphocytes and that phosphatidic acid is critical for membrane translocation of RA-GEFs with chemokine stimulation
Estimation of diameter growth parameters for Cryptomeria Plantations in� Taiwan Using the Local Yield Table Construction System
We applied the Local Yield Table Construction System (LYCS), a computer program that estimates stand growth as a function of various density control strategies, to Cryptomeria plantations in Taiwan. Parameters of the growth model were estimated from permanent plot data on Cryptomeria stands stored in a database at the Experimental Forest of National Taiwan University. The diameter at breast height (DBH) and the number of trees measured in permanent plots were used as parameters to estimate the curve of the DBH growth rate, the effects of stand density on diameter growth, growth in terms of DBH, and diameter distribution. The estimated stand growth could be adapted to the observed values in the permanent plots. Based on these results, yield tables for various stand density control strategies can now be constructed for Cryptomeria stands in Taiwan
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