International Pacific University
Okayama-shi, Japan

International Pacific University is a private university in Higashi-ku, Okayama, Japan, established in 2007. Wikipedia.

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Zhao H.,International Pacific University | Hsu P.-C.,International Pacific University | Murakami H.,Princeton UniversityPrinceton
Journal of Advances in Modeling Earth Systems | Year: 2014

This study attempts to understand why the tropical cyclone (TC) frequency over the western North Pacific and the South China Sea was so low in 2010 and 1998 even though a strong La Niña signal occurred in both years. We found that the TC frequency during the late-season (October to December), not in the peak season (July to September), makes 2010 a record low year; the next lowest year is 1998. Specifically, four TCs were observed over the South China Sea (SCS) in the late-season of 1998, but no TCs occurred over the SCS in the same season during 2010. The genesis potential index is used to help diagnose changes in environmental conditions for TC genesis frequency. Results indicate that the decreased low-level vorticity makes the largest contribution to the decreased TC formation over the SCS. The second largest contribution comes from the enhanced vertical wind shear, with relatively small contributions from the negative anomaly in potential intensity and reduction in midlevel relative humidity. These observational results are consistent with numerical simulations using a state of the art model from the Meteorological Research Institute (MRI-AGCM 3.2 Model). Numerical experiments show that the unfavorable conditions for sharply decreased TC formation during the late-season over the SCS in 2010 mainly results from the sea surface temperature anomaly over the western North Pacific basin. This effect is partly offset by the sea surface temperature anomaly in the South Indian Ocean and Northern Indian Ocean basins. © 2014. The Authors.

Murakami H.,International Pacific University | Murakami H.,Meteorological Research Institute | Li T.,International Pacific University | Hsu P.-C.,International Pacific University | Hsu P.-C.,Nanjing University of Information Science and Technology
Journal of Climate | Year: 2014

In recent decades, tropical cyclone (TC) activity in the North Atlantic has shown a marked positive anomaly in genesis number, mean lifespan, number of intense hurricanes, and mean maximum intensity. The accumulated cyclone energy (ACE), which is defined as the sum of the square of the maximum surface wind velocity throughout the lifetime of a TC, is one of the measures that can be used to synthesize these factors. Similar to the ACE, the power dissipation index (PDI), which is defined as the integrated third power of maximum surface wind velocity, has also been used to describe TC activity. The basin-total ACE and PDI for the North Atlantic have also followed a large positive anomaly during the period 1995-2012; however, the relative importance of factors such as TC genesis number, TC track property (e.g., duration and lifespan), and TC intensity remains unclear in terms of their contribution to the positive anomalies in ACE and PDI. This study uses a new empirical statistical approach to analyze the TC data and finds that the increase in the TC genesis number is primarily responsible for the positive anomalies in ACEand PDI. Other factors, such as TC track property and TC intensity, appear to be minor influences. © 2014 American Meteorological Society.

Imamura H.,Nagasaki International University | Nagata A.,Nagasaki International University | Oshikata R.,Seika Womens Junior College | Yoshimura Y.,Beppu University | And 4 more authors.
International Journal of Sports Medicine | Year: 2013

Many of the published data on the lipid profile of athletes is based on studies of endurance athletes. The data on soccer players are rare. The purpose of this study was to examine serum high-density lipoprotein cholesterol subfractions and lecithin:cholesterol acyltransferase activity in collegiate soccer players. 31 well-trained male collegiate soccer players were divided into 2 groups: 16 defenders and 15 offenders. They were compared with 16 sedentary controls. Dietary information was obtained with a food frequency questionnaire. The subjects were all non-smokers and were not taking any drug known to affect the lipid and lipoprotein metabolism. The offenders had significantly higher high-density lipoprotein cholesterol, high-density lipoprotein2 cholesterol, and apolipoprotein A-I than the defenders and controls, whereas the defenders had the significantly higher high-density lipoprotein2 cholesterol than the controls. Both groups of athletes had significantly higher lecithin:cholesterol acyltransferase activity than the controls. The results indicate that favorable lipid and lipoprotein profile could be obtained by vigorous soccer training.© Georg Thieme Verlag KG . Stuttgart . New York.

Imamura H.,Nagasaki International University | Iide K.,International Pacific University | Yoshimura Y.,Beppu University | Kumagai K.,Nagasaki International University | And 5 more authors.
Journal of the International Society of Sports Nutrition | Year: 2013

Background: There are two main playing positions in rugby (backs and forwards), which demonstrate different exercise patterns, roles, and physical characteristics. The purpose of this study was: 1) to collect baseline data on nutrient intake in order to advise the athletes about nutrition practices that might enhance performance, and 2) to compare serum lipids, lipoproteins, apolipoproteins (apo), lecithin:cholesterol acyltransferase (LCAT) activity, and iron status of forwards and backs.Methods: The sporting group was divided into 18 forwards and 16 backs and were compared with 26 sedentary controls. Dietary information was obtained with a food frequency questionnaire. Results: There were significant differences among the three groups. The forwards had the highest body weight, body mass index, percentage of body fat (calculated by sum of four skinfold thicknesses), as well as the highest lean body mass, followed by the backs and the control group. The mean carbohydrate intake was marginal and protein intake was lower than the respective recommended targets in all three groups. The mean intakes of calcium, magnesium, and vitamins A, B1, B2, and C were lower than the respective Japanese recommended dietary allowances or adequate dietary intakes for the rugby players. The forwards had significantly lower high-density lipoprotein cholesterol (HDL-C) and HDL2-C than the backs and had significantly higher apo B and LCAT activity than the controls. The backs showed significantly higher HDL-C, HDL3-C, low-density lipoprotein cholesterol, and apo A-I, and LCAT activity than the controls. Four forwards (22%), five backs (31%), and three controls (12%) had hemolysis. None of the rugby players had anemia or iron depletion. Conclusion: The findings of our study indicate that as the athletes increased their carbohydrate and protein intake, their performance and lean body mass increased. Further, to increase mineral and vitamin intakes, we recommended athletes increase their consumption of green and other vegetables, milk and dairy products, and fruits. The forwards showed more atherogenic lipid profiles than the backs, whereas the backs showed not only anti-atherogenic lipid profile, but also showed more atherogenic lipid profile relative to the control group. Additionally, our study showed none of the rugby players experienced anemia and/or iron depletion. © 2013 Imamura et al.; licensee BioMed Central Ltd.

Aizawa K.,Center for Disease Biology and Integrative Medicine | Iemitsu M.,International Pacific University | Maeda S.,University of Tsukuba | Otsuki T.,St. Catherine University of Japan | And 5 more authors.
Steroids | Year: 2010

Androgens, such as testosterone, play important roles in regulation of diverse physiological process of target tissues. Recently, we reported that steroidogenic enzymes exist in skeletal muscle and regulate local production of testosterone in response to exercise. Testosterone is transformed into a bioactive androgen metabolite, dihydrotestosterone (DHT) by 5α-reductase. However, it is unclear whether exercise stimulates local bioactive androgen metabolism in the skeletal muscle in both sexes. In the present study, we examined sex differences in the levels of dehydroepiandrosterone (DHEA), free testosterone, DHT, and steroidogenesis-related enzymes 5α-reductase and androgen receptor (AR) in rat's skeletal muscle before and after a single bout of exercise. Basal muscular free testosterone and DHT levels were higher in males than females, whereas the levels of DHEA did not differ between the sexes. Muscular DHEA, free testosterone, and DHT levels were increased in both sexes after the exercise. There were no differences of 5α-reductase and AR transcripts and proteins between the sexes, and the expression of 5α-reductase was significantly increased in both sexes after the exercise. Finally, the expression of AR was significantly higher in female rats, but not in males after the exercise. These data suggest that acute exercise enhances the local bioactive androgen metabolism in the skeletal muscle of both sexes. © 2009 Elsevier Inc. All rights reserved.

Koga T.,Hirosaki University | Koga T.,International Pacific University | Umeda T.,Hirosaki University | Kojima A.,Nippon Sport Science University | And 8 more authors.
Luminescence | Year: 2013

We studied the effects of a high intensity and high frequency 3-month training program on muscle damage and neutrophil function in male judoists. The study included 15 male judoists who started intensive judo training program after a 6-month break. Creatine kinase (CK), neutrophil counts and reactive oxygen species (ROS) production capability as well as phagocytic activity (PA) of neutrophils were measured at 2 stages; entering university (pre-training) and after 3-month training (post-training). At both points, we investigated parameters three times: just before, immediately after and 24 h after a 2-h practice session. Practice-mediated change in CK was lower at post-training than at pre-training. Neutrophil count significantly increased after 2-h practice but recovered 24 h later whereas it showed no subsequent and further increased at 24 h post-practice. Although neutrophil ROS production capability and PA both decreased (breakdown) after practice session, ROS production capability increased and PA decreased (well-adapted) at the post-training. Long-term training strengthened muscular function and improved neutrophil reaction against practice-mediated stress. Copyright © 2012 John Wiley & Sons, Ltd.

Miyaji T.,Tsukuba Center Inc. | Sato M.,Tsukuba Center Inc. | Maemura H.,International Pacific University | Takahata Y.,Tsukuba Center Inc. | Morimatsu F.,Tsukuba Center Inc.
Journal of the International Society of Sports Nutrition | Year: 2012

Background: Carnosine is a dipeptide that improves exercise performance. The carnosine synthesis mechanism through carnosine and ß-alanine ingestion remains unclear. Therefore, we investigated the tissue distribution of carnosine synthase, ATP-grasp domain-containing protein-1 (ATPGD1) mRNA, and ATPGD1 and carnosine specific dipeptidase (CN1) gene expression profiles in mice that were given carnosine or ß-alanine orally.Methods: ddY mice (7-week-old) were randomly divided into three groups (n = 6 to 8 animals per group) and were orally given 2 g/kg body weight of carnosine, ß-alanine, or water. After 15, 30, 60, 120, 180, or 360 min of treatment, the tissues (brain, blood, liver, kidneys, olfactory bulbs, hindleg muscles) were collected. The obtained tissues measured the expression of ATPGD1 and CN1 genes using quantitative PCR methods.Results: The ATPGD1 gene was expressed in muscle and to a lesser extent in brain. The expression of ATPGD1 in the vastus lateralis muscle increased significantly at 180 min (P = 0.023) after carnosine ingestion and 60 (P = 0.023) and 180 min (P = 0.025) after ß-alanine ingestion. Moreover, the carnosine group showed a significantly increased renal expression of the CN1 gene 60 min after ingestion (P = 0.0015).Conclusions: The ATPGD1 gene showed high expression levels in brain and muscle. The ß-alanine or carnosine administration significantly increased ATPGD1 and CN1 expression in mice. © 2012 Miyaji et al; licensee BioMed Central Ltd.

Zempo H.,University of Tsukuba | Tanabe K.,University of Tsukuba | Murakami H.,National Institute of Health and Nutrition | Iemitsu M.,International Pacific University | And 2 more authors.
International Journal of Sports Medicine | Year: 2010

Muscle mass is an important factor influencing the activity of daily living in older adults. We aimed to investigate whether -actinin-3 (ACTN3) gene R577X polymorphism affects muscle mass in older Japanese women. A total of 109 women (mean±SD, 64.1±6.0 years) were genotyped for the R/X variant of ACTN3. Mid-thigh muscle cross-sectional area (CSA) was assessed using MRI and compared using analysis of covariance models adjusted for body weight. In addition, physical activity and protein intake were measured as the living environmental factors affecting muscle mass. The ACTN3 R577X genotype distributions of the subjects were 19, 63 and 27 for the RR, RX, and XX genotypes, respectively. No differences in physical activity and protein intake were observed among the genotypes. The XX genotype showed lower thigh muscle CSA compared with RR&RX genotype (mean±SEM; XX: 69.1±1.8cm 2, RR&RX: 73.6±1.1cm2; p<0.05). The results of the present study suggest that ACTN3 R577X polymorphism influences muscle mass in older Japanese women. © Georg Thieme Verlag KG Stuttgart · New York.

Hayata G.,International Pacific University | Miyakawa T.,Kawasaki University of Medical Welfare
Japanese Journal of Physical Fitness and Sports Medicine | Year: 2014

The purpose of this study is to show the kinetic effect on the stop-jump movement in wearing overlap length change of the knee joint supporter. Ten young health males volunteered as subjects for this study. Three-dimensional videographic and ground reaction force data in a stop-jump task were collected in three conditions. Overlap length of supporter, peak ground reaction force, peak knee flexion angle, peak knee extension torque at landing, peak jump height, peak jump velocity at takeoff were compared among conditions: high pressure condition, middle pressure condition and no supporter. The high pressure condition significantly increased peak knee flexion angle and peak knee extension torque at landing. It is considered that the high pressure condition enlarged the knee joint angle and the knee joint extension torque in stop task because the rigidity of the supporter increased. On the other hand, it was suggested that the pressure change of wearing the knee joint supporter don't affect jump performance.

PubMed | International Pacific University, Tokai University and Ahead Laboratories Inc.
Type: Journal Article | Journal: European journal of plastic surgery | Year: 2015

Recent advances in human-machine interface technology have enabled the development of multifunctional, primarily orthopedic myoelectric prostheses. We developed a noninvasive blinking periorbital prosthesis that can synchronize with blinking of the intact eyelid by using surface electromyographic signals of the orbicularis oculi muscle.Myoelectric potentials of the orbicularis oculi muscle while blinking were measured with surface electrodes on the eyelid in four healthy adults. Possible cross talk introduced via the electrodes was also measured and assessed to determine whether cross talk would affect surface electromyographic measurements while blinking.The amplitude of the surface myoelectric potential of the orbicularis oculi muscle was sufficiently high for the practical use of blinking prostheses. Our blinking model was successfully synchronized with blinks of the subjects eyelids under experimental conditions without cross talk between the orbicularis oculi muscle and other muscles.Although our study revealed several problems, the use of surface electromyographic signals could be a promising and useful technique for synchronizing blinking of the prosthetic eyelid with blinking of the intact eyelid. Level of Evidence: Level V, therapeutic study.

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