Postcontraction Influences on Reaction Time

Abstract

The purpose of this study was to compare reaction time (RT) and fractionated RT components (premotor and motor times) between normal and postcontraction conditions. Twelve participants performed 20 trials each of control and postcontraction RT conditions. For the control condition, participants executed a learned, rapid, knee-extension contraction response to an auditory stimulus. The postcontraction condition was identical to the control condition except that the participants performed a 3-s isometric contraction of the knee extensor muscles prior to an auditory stimulus. Muscle activity was recorded from the quadriceps muscle group. Results indicated that the postcontraction condition was significantly faster than the control condition for the average RT, premotor time, and motor time. It was concluded that reaction time, processing time, and muscle contraction time for a learned task could be significantly reduced following an isometric contraction.     

Physical activity levels in American and Japanese men from the ERA-JUMP Study and associations with metabolic syndrome

Background:Metabolic syndrome(MetS) is a global health problem.Physical activity(PA) is a known modifiable risk factor for MetS and individual MetS components.However,the role of PA could differ between sub-populations due to differences in the variability of PA and other MetS risk factors.To examine these differences,multi-country studies with standardized outcome measurement methods across cohorts are needed.Methods:Cross-sectional PA levels(total and domain specific) in healthy middle-aged(44-56 years) men in the Risk Factor Assessment among Japanese and U.S.Men in the Post-World War Ⅱ Birth Cohort(ERA-JUMP) Study(n=730;American:n=417;Japanese:n=313;from population-representative samples in Pittsburgh,Pennsylvania,USA,and Kusatsu,Shiga,Japan) were compared.The relationships between PA levels and MetS(overall and specific components) in/across the American and Japanese sub-cohorts(adjusting for age,smoking,and alcohol consumption)were also assessed using the same instruments(pedometer and validated questionnaire) to measure PA in both cohorts.Results:A total of 510 individuals provided complete data on PA(American:n=265;Japanese:n=245).The American cohort had significantly lower mean±SD steps/day(7878±3399 steps/day) vs.the Japanese cohort(9055±3797 steps/day)(p <0.001) but had significantly higher self-reported moderate-vigorous leisure PA(American:15.9(7.4-30.3) metabolic task equivalent hours per week(MET-b/week) vs.Japanese:4.0(0-11.3) METh/week,p <0.0001).In both sub-cohorts,each 1000 steps/day increase was associated with lower odds of having MetS(American:OR=0.90,95%CI:0.83-0.98;Japanese:OR=0.87,95%CI:0.79-0.95) and the individual MetS component of high waist circumference(American:OR=0.86,95%CI:0.79-0.94;Japanese:OR=0.87,95%CI:0.80-0.95).In the American cohort only,higher self-reported leisure PA(Met-b/week) was associated with lower odds of MetS and high waist circumference(OR=0.98,95%CI:0.97-0.99 for MetS and waist circumference,respectively).Conclusion:Higher total step counts/day had an important protective effect on MetS prevalence in both the Japanese and American cohorts,despite differences in PA levels and other MetS risk factors.The effect of steps/day(across all intensity levels) was much greater than domainspecific moderate-vigorous PA captured by questionnaire,suggesting the need for measurement tools that can best capture total movement when examining the effects of PA on MetS development.     

Effects of intense exercise on the physiological and mental condition of female university judoists during a training camp

To clarify the physical and mental fatigue caused by intense exercise and the relationship between the two types of fatigue, we examined changes in anthropometric and biochemical variables, neutrophil function, and the Profile of Mood States (POMS) questionnaire in 13 female university judoists attending a one-week training camp. Blood glucose, total cholesterol, haemoglobin, leukocyte count, IgG, and phagocytic activity all decreased after the training camp compared with baseline (P < or = 0.046). Aspartate aminotransferase, lactate dehydrogenase, creatine kinase, and neutrophil oxidative burst activity increased after the training camp (P < or = 0.007). Of the POMS scores, that for Fatigue increased after the training camp (P = 0.041) and that for Vigour decreased (P = 0.042). The changes in several POMS scores correlated with the changes in blood biochemical variables. In particular, the change in Total mood disturbance was negatively associated with changes in myogenic enzymes (P < or = 0.032). Our results suggest that intense exercise during training camps for female judoists leads to the appearance and accumulation of mental and physical fatigue, which are related to each other.     

Early effects of oral administration of omeprazole and roxatidine on intragastric pH

Objective

The ideal medication for the treatment of acid-related diseases, e.g., peptic ulcers, stress-related gastric bleeding, functional dyspepsia, and gastroesophageal reflux disease, should have a rapid onset of action to promote hemostasis and relieve the symptoms. The aim of our study was to investigate the inhibitory effects on gastric acid secretion of a single oral administration of a proton pump inhibitor, omeprazole 20 mg, and an H₂-receptor antagonist, roxatidine 75 mg.

Methods

Ten Helicobacter pylori-negative male subjects participated in this randomized, two-way crossover study. Intragastric pH was monitored continuously for 6 h after single oral administration of omeprazole 20 mg and roxatidine 75 mg. Each administration was separated by a 7-d washout period.

Results

During the 6-h study period, the average pH after administration of roxatidine was higher than that after administration of omeprazole (median: 4.45 vs. 2.65; P=0.0367). Also during the 6-h study period, a longer duration of maintenance at pH above 2, 5, and 6 was observed after administration of roxatidine 75 mg than after administration of omeprazole 20 mg (median: 90.6% vs. 55.2%, P=0.0284; 43.7% vs. 10.6%, P=0.0125; 40.3% vs. 3.3%, P=0.0125; respectively).

Conclusions

In Helicobacter pylori-negative healthy male subjects, oral administration of roxatidine 75 mg increased the intragastric pH more rapidly than that of omeprazole 20 mg.     

Age-Related Changes of Serum Soluble Interleukin 9 Receptor (sIL-9Rα) in Healthy Subjects

Most cytokine receptors including interleukin (IL)-9 have soluble counterparts in body fluids. We planned to investigate the pathophysiological significance of the serum soluble IL-9 receptor (sIL-9R) level. We determined the serum sIL-9Rα chain (sIL-9Rα) levels in 96 healthy Japanese individuals to establish a control value by means of specific human sIL-9Rα ELISA, followed by a preliminary application in a patient with diarrhea positive hemolytic uremic syndrome. Age was negatively correlated with the sIL-9Rα level (Spearman r = −0.241, n = 96, p = 0.0180). The serum sIL-9Rα level showed a progressive decline to the normal adult level by the age of 30. The serum sIL-9Rα level of the patient with HUS was markedly higher than those of the age-matched control from the onset of the disease. Because of the remarkable age-dependent variability of sIL-9Rα in healthy subjects, disease-related changes, as well as therapy-dependent alterations, should be considered with caution. Thus, it is recommended that when the serum sIL-9Rα levels of patients are evaluated, the values should be compared with those of age-matched controls. The established control value will be used to discriminate between normal and the pathological conditions in our future studies.     

Cross‐cultural Similarities in Attitudes toward Computers and the Implications for Teacher Education

ABSTRACT

Results of a three year longitudinal study of elementary school children's attitudes toward computers in Japan, Mexico, and the United States of America are presented, along with implications of the findings for teacher education. Two types of attitudes toward computers (importance and enjoyment) were found to be positively influenced by the introduction of computer activities in primary school. No novelty effect was found regarding enjoyment of computers, and perceived computer importance declined less from Grades 1–3 than several other dispositions measured. No consistent gender differences were found for attitudes toward computers among the three nations. These findings imply that students begin school eager to learn about computers and lacking the gender biases often found in older age groups, and that teachers should be educated to help preserve interest in and access to information technology for all students. Reflections for teacher education conclude the article.     

Evolution From Collaborative Learning to Symbiotic E-learning： Creation of New E-learning Environment for Knowledge Society

For people who live in the knowledge society which have rapidly been changing, learning in the widest sense becomes indispensable in all phases of working, living and playing. The construction of an environment, to meet the demands of people who need to acquire new knowledge and skills as the need arises, and enlighten each other regularly, is becoming very important. Thus, we hope to make the best use of the advantages of a rich e-learning environment which aims at ＂anytime, anywhere and anybody＂ learning, because participants in lifelong learning for the knowledge society demand to learn at the right place and right time, and with learning content, they can select themselves. However, in a general e-learning environment so far, because the situation is usual in which the instructor is absent and has the asynchronous access without an immediate communication with others, the participants tend to be solitude and it is difficult to maintain the learning motivation. Therefore, the creation of a new e-learning environment becomes extremely important in which various participants can learn and enlighten each other through an occasional and helpful interaction among them in appropriate learning communities in the network environment. In this paper, we present 5 points as basic requirements for the construction of an e-learning environment which can satisfy the various learning demands of the knowledge society, and discuss how to realize them. The key point here is the extension of the usual ＂strong＂ collaborative learning to effective ＂weak collaborative learning＂. In addition, the evolution of ＂symbiotic learning＂ for the knowledge society, that is, the necessity of ＂symbiotic e-learning environment based on occasional collaborative relationship＂ and its effective realization are discussed.     

亚洲本土学者对亚洲史重构研究的探索——以滨下武志、王正毅为例

全球化进程的深入发展要求对为西方中心论所遮蔽的亚洲历史进行重构，王正毅、滨下武志的探索表明，亚洲本土学的重构亚洲史的工作正处于逐步深入的阶段；在理论取向上，他们试图跳出本土论与照搬西方理论的范畴；在做法上，目前多是侧重于对中观层面的关注或对具体问题的深度挖掘。     

CAMELOT: collaborative and multimedia environment for learners on teams

In the business-systems-design learning environment, there may be more than one solution to any given problem. For instance, the data model will be different depending on each learner’s perspective. Accordingly, group learning systems are very effective in this domain. We have developed a collaborative and multimedia environment for learners on teams (CAMELOT) using the ‘nominal group technique’ for group problem solving. In this paper, the basic framework of the collaborative learning system and the effectiveness of collaborative learning in designing the data model are described. By using CAMELOT, each learner learns how to analyse through case studies and how to collaborate with his or her group in problem solving. Learners come to a deeper understanding from using CAMELOT than from studying independently because they can reach better solutions through discussion, tips from other learners and examination of one another’s individual works.