On sections of hyperelliptic Lefschetz fibrations

We construct a relation among right-handed Dehn twists in the mapping class group of a compact oriented surface of genus g with 4g+4 boundary components. This relation gives an explicit topological description of 4g+4 disjoint (-1)-sections of a hyperelliptic Lefschetz fibration of genus g on the manifold {CP}^2#(4g+5){-CP}^2.Comment: 19 pages, 21 figure

The Potential of Alternative Fuel Vehicles: A Cost-Benefit Analysis

This study investigates the economic validity of the diffusion of fuel cell vehicles (FCVs) and all-electric vehicles (EVs), employing a cost-benefit analysis from the social point of view. This research assumes the amount of NOx and tank-to-wheel CO2 emissions and gasoline use reduction as the benefits and the purchase costs, infrastructure expenses, and maintenance costs of alternative vehicles as the costs of switching internal combustion engine (ICE) vehicles to alternative energy vehicles. In addition, this study conducts a sensitivity analysis considering cost reductions in FCV and EV production and increasing costs for CO2 abatement as well as increasing gasoline prices. In summary, the results show that the diffusion of FCVs is not economically beneficial until 2110, even if the FCV purchase cost decreases to that of an ICE vehicle. EV diffusion might be beneficial by 2060 depending on increases in gasoline prices and CO2 abatement costs

Effects of heat treatment on human hair keratin film

5ArticleJOURNAL OF JAPANESE COSMETIC SCIENCE SOCIETY. 37(3):165-170 (2013)journal articl

C‐Glycosyltransferases catalyzing the formation of di‐C‐glucosyl flavonoids in citrus plants

Citrus plants accumulate many kinds of flavonoids, including di‐C‐glucosyl flavonoids, which have attracted considerable attention due to their health benefits. However, the biosynthesis of di‐C‐glucosyl flavonoids has not been elucidated at the molecular level. Here, we identified the C‐glycosyltransferases (CGTs) FcCGT (UGT708G1) and CuCGT (UGT708G2) as the primary enzymes involved in the biosynthesis of di‐C‐glucosyl flavonoids in the citrus plants kumquat (Fortunella crassifolia) and satsuma mandarin (Citrus unshiu), respectively. The amino acid sequences of these CGTs were 98% identical, indicating that CGT genes are highly conserved in the citrus family. The recombinant enzymes FcCGT and CuCGT utilized 2‐hydroxyflavanones, dihydrochalcone, and their mono‐C‐glucosides as sugar acceptors and produced corresponding di‐C‐glucosides. The Km and kcat values of FcCGT toward phloretin were <0.5 μm and 12.0 sec−1, and those toward nothofagin (3ʹ‐C‐glucosylphloretin) were 14.4 μm and 5.3 sec−1, respectively; these values are comparable with those of other glycosyltransferases reported to date. Transcripts of both CGT genes were found to concentrate in various plant organs, and particularly in leaves. Our results suggest that di‐C‐glucosyl flavonoid biosynthesis proceeds via a single enzyme using either 2‐hydroxyflavanones or phloretin as a substrate in citrus plants. In addition, Escherichia coli cells expressing CGT genes were found to be capable of producing di‐C‐glucosyl flavonoids, which is promising for commercial production of these valuable compounds.ArticlePlant Journal.91(2):187-198(2017)journal articl

Human movement decisions during Coronavirus Disease 2019

To predict epidemics' future course in changing situations, understanding human mobility patterns is important, notwithstanding decision-making process uncertainties owing to difficulties in quantifying people's mobility change decision timings, which make the mobility-epidemic causal relationship unclear. We used the 'mobility avoidance index' to investigate time-series changes during Japan's Coronavirus Disease 2019 (eight waves until February 2023) as a previous study, which measured this index using accommodation reservation data-booking/cancellation timings-was able to quantify the timing of decision-making for mobility changes. Our analyses revealed two general patterns: 1) the index increased/decreased proportional to logarithms of reported cases during the first wave, conforming with Weber-Fechner's psychophysics law; 2) its slope against the change in the number of reported cases had similar values among the waves, but its intercepts changed as the waves passed, suggesting that people neglected reported cases lower than a certain threshold for behavioural decision-making. We shifted the threshold level as the waves passed, and named this pattern 'shift of negligible epidemic' rule. It is the first pattern quantitatively observed, that possesses decision making tendencies for future mobility avoidance. Our findings contribute to constructing a mathematical model, which simultaneously considers epidemics and human mobility dynamics

Anti-invasive activity of α-tocopherol against hepatoma cells in culture via protein kinase C inhibition

Effects of α-, β-, γ- and δ-tocopherols on the proliferation and invasion of AH109A hepatoma cells and their modes of action were investigated. Four tocopherols inhibited the invasion as well as the proliferation of AH109A cells. Their inhibitory effects were more prominent on the invasion than on the proliferation. At 1 µM, α-tocopherol showed most potent anti-invasive activity without any influence on the proliferation. We have previously demonstrated that reactive oxygen species increase the invasion of AH109A cells. α-Tocopherol suppressed the reactive oxygen species-induced invasion but failed to suppress the reactive oxygen species-induced rises in intracellular peroxide level. GF 109203X, a protein kinase C inhibitor, decreased the invasive activity of AH109A cells. In contrast, phorbol-12-myristate-13-acetate, a protein kinase C activator, increased the invasive capacity of AH109A cells. α-Tocopherol suppressed the phorbol-12-myristate-13-acetate-induced increase in the invasion, and canceled the phorbol-12-myristate-13-acetate-induced rises in protein kinase C activity and phosphorylation of extracellular signal-regulated kinase. These results suggest that tocopherols, especially α-tocopherol, possess inhibitory effect more strongly on the invasion of AH109A cells than on the proliferation. They also suggest that the anti-invasive activity of α-tocopherol is raised through suppression of PKC/ERK signaling

Isolation and Cs+ resistance mechanism of Escherichia coli strain ZX-1

This research aims to elucidate the physiological mechanisms behind the accidental acquisition of high-concentration cesium ions (Cs+) tolerance of Escherichia coli and apply this understanding to develop bioremediation technologies. Bacterial Cs+ resistance has attracted attention, but its physiological mechanism remains largely unknown and poorly understood. In a prior study, we identified the Cs+/H+ antiporter TS_CshA in Microbacterium sp. TS-1, resistant to high Cs+ concentrations, exhibits a low Cs+ affinity with a Km value of 370 mM at pH 8.5. To enhance bioremediation efficacy, we conducted random mutagenesis of TS_cshA using Error-Prone PCR, aiming for higher-affinity mutants. The mutations were inserted downstream of the PBAD promoter in the pBAD24 vector, creating a mutant library. This was then transformed into E. coli-competent cells. As a result, we obtained a Cs+-resistant strain, ZX-1, capable of thriving in 400 mM CsCl—a concentration too high for ordinary E. coli. Unlike the parent strain Mach1™, which struggled in 300 mM CsCl, ZX-1 showed robust growth even in 700 mM CsCl. After 700 mM CsCl treatment, the 70S ribosome of Mach1™ collapsed, whereas ZX-1 and its derivative ΔZX-1/pBR322ΔAp remained stable. This means that the ribosomes of ZX-1 are more stable to high Cs+. The inverted membrane vesicles from strain ZX-1 showed an apparent Km value of 28.7 mM (pH 8.5) for Cs+/H+ antiport activity, indicating an approximately 12.9-fold increase in Cs+ affinity. Remarkably, the entire plasmid isolated from ZX-1, including the TS_cshA region, was mutation-free. Subsequent whole-genome analysis of ZX-1 identified multiple SNPs on the chromosome that differed from those in the parent strain. No mutations in transporter-related genes were identified in ZX-1. However, three mutations emerged as significant: genes encoding the ribosomal bS6 modification enzyme RimK, the phage lysis regulatory protein LysB, and the flagellar base component protein FlgG. These mutations are hypothesized to affect post-translational modifications, influencing the Km value of TS_CshA and accessory protein expression. This study unveils a novel Cs+ resistance mechanism in ZX-1, enhancing our understanding of Cs+ resistance and paving the way for developing technology to recover radioactive Cs+ from water using TS_CshA-expressing inverted membrane vesicles

Explaining Japan's Lack of Green Parties : A Social-Milieu Approach

Although Japan is a highly industrialized country, it still lacks any significant green parties. This apparent Japanese exceptionalism in terms of green parties cannot be clarified by such conventional explanations as its electoral institutions, party competition, and degree of post−materialism. This paper will instead utilize the German−developed framework of social−milieu studies to explain this phenomenon. It focuses on green parties’ potential support bases, paying attention to the characteristics of green milieu parties. German milieu studies have found that alternative or techno milieus with high educational and occupational qualifications and left−libertarian value orientations have supported the German Green Party. Our data show that an ironist milieu can be regarded as a potential basis of support for Japanese green parties, as Japanese ironist are more leftist toward political and economic issues and more liberal in their cultural attitudes. However, German alternatives tend to be active, while Japanese ironists tend to be passive and disinclined to participate in various groups or to associate with others. Such passivity inclines them to retreat into their private lives without expressing their left− libertarian value orientation in the political arena. Our findings therefore suggest that a milieu exists that could potentially support Japanese green parties, but that these parties have been failing to gain support from it because of its members’ passivity and apolitical behavior

Effect of Impeller Agitation on Preparation of Tetra- n

The slurries-containing tetra-n-butyl ammonium bromide (TBAB) solution and its semiclathrate hydrate have attracted a lot of interest as latent heat transport media. These hydrate slurries contain some microparticles of crystal, and the size and shape of these hydrate particles could affect the mobility of slurries. Hence, it is essential to investigate the efficient hydrate-slurry preparation methods and the effect of hydrate particles on the fluid property of slurries for the application to latent heat transport media. In the present study, the effect of agitation on particle size distribution and aggregation of particles was studied to prepare easily flowing TBAB hydrate slurries that were suitable for fluid transport. First of all, the effects of impeller rotational speed and impeller type on the particle size and frequency of aggregation were investigated. The results suggested that the particle size distribution and the frequency of particle aggregation are strongly affected by the intensity of shear rate and its uniformity, which was controllable with impeller type and its rotation speed