An Estimation Method for Environmental Friction Based on Body Dynamic Model of Caenorhabditis elegans

Caenorhabditis elegans is a small worm which is approximately 1 mm in length. The present study proposes an estimation method for frictional force using locomotion information obtained from video analysis of actual worms. The results indicate that the body model driven by the estimated frictional force can trace the locomotion of the worm within a low error level of 4% of the body length. The proposed method can be applied to analyze the relationship between friction and gait control.This work was supported by JSPS KAKENHI Grant Numbers 15H03950 and 20115010

Reaction of 3′,5′-di-O-acetyl-2′-deoxyguansoine with hypobromous acid

AbstractHypobromous acid (HOBr) is formed by eosinophil peroxidase and myeloperoxidase in the presence of H2O2, Cl−, and Br− in the host defense system of humans, protecting against invading bacteria. However, the formed HOBr may cause damage to DNA and its components in the host. When a guanine nucleoside (3′,5′-di-O-acetyl-2′-deoxyguansoine) was treated with HOBr at pH 7.4, spiroiminodihydantoin, guanidinohydantoin/iminoallantoin, dehydro-iminoallantoin, diimino-imidazole, amino-imidazolone, and diamino-oxazolone nucleosides were generated in addition to an 8-bromoguanine nucleoside. The major products were spiroiminodihydantoin under neutral conditions and guanidinohydantoin/iminoallantoin under mildly acidic conditions. All the products were formed in the reaction with HOCl in the presence of Br−. These products were also produced by eosinophil peroxidase or myeloperoxidase in the presence of H2O2, Cl−, and Br−. The results suggest that the products other than 8-bromoguanine may also have importance for mutagenesis by the reaction of HOBr with guanine residues in nucleotides and DNA

Diarrhea and related personal characteristics among Japanese university students studying abroad in intermediate- and low-risk countries

Despite an increasing number of students studying abroad worldwide, evidence about health risks while they are abroad is limited. Diarrhea is considered the most common travelers' illness, which would also apply to students studying abroad. We examined diarrhea and related personal characteristics among Japanese students studying abroad. Japanese university students who participated in short-term study abroad programs between summer 2016 and spring 2018 were targeted (n = 825, 6-38 travel days). Based on a 2-week-risk of diarrhea (passing three or more loose or liquid stools per day) among travelers by country, the destination was separated into intermediate- and low-risk countries. After this stratification, the associations between personal characteristics and diarrhea during the first two weeks of their stay were evaluated using logistic regression models. Among participants in intermediate-risk countries, teenagers, males and those with overseas travel experience were associated with an elevated risk of diarrhea; the odds ratios (95% confidence intervals) were 2.42 (1.08-5.43) for teenagers (vs. twenties), 1.93 (1.08-3.45) for males (vs. females) and 2.37 (1.29-4.33) for those with overseas experience (vs. none). Even restricting an outcome to diarrhea during the first week did not change the results substantially. The same tendency was not observed for those in the low-risk countries. Teenage students, males and those with overseas travel experience should be cautious about diarrhea while studying abroad, specifically in intermediate-risk countries

A computational model of internal representations of chemical gradients in environments for chemotaxis of Caenorhabditis elegans

The small roundworm Caenorhabditis elegans employs two strategies, termed pirouette and weathervane, which are closely related to the internal representation of chemical gradients parallel and perpendicular to the travelling direction, respectively, to perform chemotaxis. These gradients must be calculated from the chemical information obtained at a single point, because the sensory neurons are located close to each other at the nose tip. To formulate the relationship between this sensory input and internal representations of the chemical gradient, this study proposes a simple computational model derived from the directional decomposition of the chemical concentration at the nose tip that can generate internal representations of the chemical gradient. The ability of the computational model was verified by using a chemotaxis simulator that can simulate the body motions of pirouette and weathervane, which confirmed that the computational model enables the conversion of the sensory input and head-bending angles into both types of gradients with high correlations of approximately r > 0.90 (p < 0.01) with the true gradients. In addition, the chemotaxis index of the model was 0.64, which is slightly higher than that in the actual animal (0.57). In addition, simulation using a connectome-based neural network model confirmed that the proposed computational model is implementable in the actual network structure.This work was supported by JSPS KAKENHI Grant Number 15H03950 to T.T and MEXT KAKENHI Grant Numbers 20115010 to T.T. and 20115002 to Y.I

Collection of Toyama City Library Written byYoshio Yamada Transcription of “Man’yo¯-shu¯ kenkyu¯ no igi to junjo” (first half)

本稿は、富山市立図書館山田孝雄文庫蔵、山田孝雄による『萬葉集研究の意義と順序』と題された未発表自筆原稿の翻刻である。本原稿の執筆年代は不明であるが、『校本萬葉集』一（岩波書店、一九三一年刊行）の引用があることにより、一九三一年以降執筆されたことが明らかとなっている（富山市立図書館『山田孝雄文庫　原稿書誌詳細』）。山田の万葉集研究に関する業績は、注釈書や文法書など幅広いが、その中でも本稿は、特に万葉集研究の意義と万葉仮名の訓義について論じたものである。departmental bulletin pape

Biomimetic Control Based on a Model of Chemotaxis in Escherichia coli

Abstract In the field of molecular biology, extending now to the more comprehensive area of systems biology, the development of computer models for synthetic cell simulation has accelerated extensively and has begun to be used for various purposes, such as biochemical analysis. These models, describing the highly efficient environmental searching mechanisms and adaptability of living organisms, can be used as machine-control algorithms in the field of systems engineering. To realize this biomimetic intelligent control, we require a stripped-down model that expresses a series of information-processing tasks from stimulation input to movement. Here we selected the bacterium Escherichia coli as a target organism because it has a relatively simple molecular and organizational structure, which can be characterized using biochemical and genetic analyses. We particularly focused on a motility response known as chemotaxis and developed a computer model that includes not only intracellular information processing but also motor control. After confirming the effectiveness and validity of the proposed model by a series of computer simulations, we applied it to a mobile robot control problem. This is probably the first study showing that a bacterial model can be used as an autonomous control algorithm. Our results suggest that many excellent models proposed thus far for biochemical purposes can be applied to problems in other fields

Framework for a cooperative program curriculum among elementary, junior, and senior high schools to develop students' qualities and competence in home economics: Proposal for implementing a cooperative program curriculum for encouraging students to develop an understanding of food cultures and deepen their learning

The purpose of this study is to use surveys to clarify students' awareness at the elementary, junior, and senior high school levels of food cultures and their related issues, and to formulate and implement a class program for junior and senior high schools based on the clarified results. The program will develop students' understanding of food cultures and seeks to combine and systematize home economics education among the three levels of schooling. The study found transformations among elementary and junior high school students, in terms of their understanding of the ideas of food cultures and related issues. In addition, class programs were formulated for Grade 9 students, to broaden their views on a range of topics, and for Grade 10 students, to broaden their view of changes over time, both of which ended with successful results

Factors related to employment in childhood cancer survivors in Japan: A preliminary study

PurposePrevious research has revealed vocational and academic difficulties in childhood cancer survivors, and explored impact of survivors' medical history and physical function on vocational and academic status. However, we often encounter survivors with similar diagnoses and late effects but different academic or employment statuses. This raises the question of what affects academic attainment and employment other than treatment or late effects. This study aimed to explore factors associated with childhood cancer survivors' employment status and academic achievement.MethodsComprehensive health check-up and questionnaire survey were conducted for 69 survivors who were over the age of 18 and participated in St. Luke's Lifetime cohort study. We obtained survivors' biological function using comprehensive health check-up, neurocognitive states, quality of life, transition readiness, and family function. We conducted univariate analysis (Mann–Whitney U tests or chi-square tests) to compare the differences between the regular workers/students and non-regular workers/unemployed groups. The variables with p-values &lt;0.1 were used as independent variables multivariate logistic regression to explore predictors of employment status and academic attainment.ResultsResult of the univariate analysis, intelligence quotient, SF-8 PCS, transition readiness, family function were used for multivariate logistic regression as independent variables. The stepwise likelihood method was conducted; intelligence quotient (odds ratio [OR] = 1.100; 95% confidence interval [CI] 1.015–1.193; p = 0.021), transition readiness (OR = 0.612; 95% CI 0.396–0.974; p = 0.038), and family function (OR = 2.337; 95% CI 1.175–4.645; p = 0.015) were found to be associated with survivors' regular workers/students in the final regression model.ConclusionLong-term follow-up of pediatric cancer survivors requires the provision of total care, which supports physical, psychological, and social functions to improve health, readiness for transition to self-management, and family functioning