• 제목/요약/키워드: muscle performance

검색결과 1,030건 처리시간 0.03초

Analyses of physiological wrist tremor with increased muscle activity during bench press exercise

  • Son, Hyewon;Kim, Jisu;Hong, Gyuseog;Park, Wonil;Yoon, Sungjin;Lim, Kiwon;Park, Jonghoon
    • 운동영양학회지
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    • 제23권1호
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    • pp.1-6
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    • 2019
  • [Purpose] To date, there have been no studies on the response of wrist tremor to increased muscle activity during exercise. This study aimed to evaluate the wrist tremor response with increasing muscle activity during bench press exercise. [Methods] Triceps muscle activity and wrist tremor response were measured by electromyography and an accelerometer, respectively, during bench press exercise in 11 healthy men without weight-training experience. Subjects performed bench press at 30% repetition maximum (RM), and the rating of perceived exertion (RPE) and lactate concentration were measured before and after exercise. One week later, an equivalent number of bench presses at 30% RM was performed without weight load as a control trial (CT). [Results] RPEs and lactate concentrations significantly increased after resistance exercise (30% RM) from 7.4 to 14.3 and 1.7 to 4.9, respectively (P<.01), but no such difference was observed in the CT. Muscle activity linearly increased during the 30% RM exercise, and wrist tremors were shown to linearly decrease. A strong negative correlation was observed between the two variables (r=-0.88, P<.001). [Conclusion] We found that wrist tremors during resistance exercise, as measured using an accelerometer, can be used to predict muscle activity.

Effects of a β-Adrenergic Agonist on Growth Performance and Protein Metabolism in Broilers Treated with or without an Antithyroid Substance

  • Hamano, Y.;Yamazaki, S.;Miyahara, M.;Hamada, Y.;Kobayashi, S.;Terashima, Y.
    • Asian-Australasian Journal of Animal Sciences
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    • 제12권5호
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    • pp.788-793
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    • 1999
  • To determine the interrelationship between thyroid status and the reparitioning action of clenbuterol (CLE) in broilers, two-week-old female chickens were fed diets containing an antithyroid substance, propylthiouracil (PTU, 0 or 0.3%), CLE (0 to 1 mg/kg), or both for 18 days in a $2{\times}2$ factorial design experiment. Muscle weights (breast muscle, gastrocnemius and peroneus longus) increased only in the normal chickens fed CLE. As absolute mass, protein of leg muscle quantitatively increased in the CLE-fed normal birds. In contrast, inhibition of the CLE-induced protein accretion, especially of peroneus longus, occurred in the PTU group. A quantitative increase in DNA was observed in leg muscles of the normal chickens, but no DNA response to CLE was shown in the PTU-treated chickens. The decreased RNA in leg muscles of the PTU group was more reduced by CLE feeding. Although not statistically significant, the reduced degradation rate of whole muscle protein in normal chickens fed CLE was not confirmed in the PTU-fed group. The present study, therefore, concluded that metabolic action of thyroid hormones was a prerequisite for the hypertrophic effect of ${\beta}$-agonist in broilers.

공압인공근육을 이용한 조작기 위치의 강인제어 (Robust Control of the Position of a Manipulator Using Pneumatic Artificial Muscle)

  • 박노철;양현석;박영필
    • 대한기계학회논문집A
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    • 제20권6호
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    • pp.1882-1892
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    • 1996
  • This paper is concerned with the position control of the ond degree-of freedom manipulator using pneumatic artificial muscle actuator which is built to have a proper compliance. For t his pneumatic artificial muscle actuator though, it is difficult to make an effective control scheme due to the nonlinearity and uncertainties on the dynamics of the actuator. In this paper, a third-order equation of motion is derived for the actuator including the dynamics of the pneumatic servovalve. Later, various modeling uncertainties due to the nonlinearity and unmodeled dynamics of the servo vlave and the actuator are taken care of, as a trade-off between the closed-loop performance of the controlled system and its robustness to uncertainties. A controller using .mu. synthesis thchnique is designed, and robust performance against measurement noise, various modeling uncertainties due to the dynamics of the servo valve and actuator is achieved. The effectiveness of the proposed control methods is illustrated through simulations and experiments.

Effect of Fish Oil Supplement on Growth Performance, Ruminal Metabolism and Fatty Acid Composition of Longissimus Muscle in Korean Cattle

  • Kook, K.;Choi, B.H.;Sun, S.S.;Garcia, Fernando;Myung, K.H.
    • Asian-Australasian Journal of Animal Sciences
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    • 제15권1호
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    • pp.66-71
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    • 2002
  • We investigated the effect of fish oil (FOS) on growth performance, ruminal metabolism and fatty acid composition and physical characteristics of longissimus muscle in 10 steers and 10 bulls of Korean cattle. Concentrates diet was supplemented with FOS at 5% of the diet. FOS contained 3.34% eicosapentaenoic acid (EPA) and 24.87% docosahexaenoic acid (DHA) of total fatty acids by weight. Average daily weight gain and feed efficiency were not affected (p>0.871) by FOS, but feed intake was decreased. FOS had lower (p<0.003) pH and higher (p<0.001) $NH_3$-N than that of control. There was a treatment effect (p<0.001) for serum cholesterol concentrations. FOS increased (p<0.009) concentrations of n-3 fatty acids, including linolenic, EPA and DHA in longissimus muscle. Physical traits were significantly (p<0.015) changed by feeding FOS except for pH and lightness (L). We concluded that the fatty acid composition and physical properties of the muscle in fattening Korean cattle can be altered by feeding 5% FOS.

HPLC를 이용한 식육내 타이로신의 잔류분석법 (Determination of tylosin in edible meats by high-performance liquid chromatography)

  • 김곤섭;신선혜;김종수;라도경
    • 대한수의학회지
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    • 제41권1호
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    • pp.13-19
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    • 2001
  • A simple and rapid analytical method for the determination of tylosin in chicken, pork and muscle was established by High-Performance Liquid Chromatography(HPLC). Chicken, pork and beef muscle(5 g) were fortified by adding the $0.2{\mu}g/ml$ of standard tylosin and the drug was extracted from meats with 70% acetonitrile(ACN) and followed by liquid-liquid partition for clean-up procedure. Then $20{\mu}l$ portion of ACN elution was directly analyzed by HPLC with spectra 100 variable wavelength detector, and unfortified blank control were treated similarly. The average recovery rate of tylosin added to chicken, pork and beef muscle were $83{\pm}2.3$, $96{\pm}3.3$ and $92{\pm}1.6$(%) at the level 0.2 ppm, respectively. No tylosin residues in marketing meats. These results suggested that HPLC methodology could be acceptable for the extraction, determination and screening of tylosin residues in edible meats.

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Strength Training-Induced Changes in Muscle Size and Motor Improvement in Bilateral Schizencephaly: An Experimenter-Blind Case Report With 3-Month Follow-Up

  • Lee, Dong-Ryul;You, Sung-Hyun;Lee, Nam-Gi;Yoo, In-Gyu;Jung, Min-Ye;Han, Bong-Soo
    • 한국전문물리치료학회지
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    • 제17권4호
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    • pp.77-87
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    • 2010
  • The present case study highlights the effects of a novel Comprehensive Hand Repetitive Intensive Strengthening Training (CHRIST) on morphological changes and associated upper extremity (UE) muscle strength and motor performance in a child with spastic quadriplegic cerebral palsy (CP). The Child, a 10-year-old girl with spastic quadriplegic CP, was treated with CHRIST for 60 minutes a day, five times a week, for 5 weeks. The CHRIST was designed to improve motor function and strength. Clinical tests including the modified Wolf Test, Jebsen-Taylor Hand Function Test, and Pediatric Motor Activity Log questionnaire were used to determine motor function. Ultrasound imaging was performed to determine the changes in the cross-section area (CSA) of the extensor carpi radialis (ECR) and triceps brachii (TRI). Muscle strength was measured with a dynamometer at pretest, and post-test, and 3-month follow-up. Ultrasound imaging data showed that the CSAs of both ECR and TRI muscles were enhanced as a function of the intervention. These changes were associated with muscle strength and motor performance and their effects remained even at a 3-month follow-up test. Our results suggest that the CHRIST was effective at treating muscle atrophy, weakness and motor dysfunction in a child with spastic quadriplegic CP.

EFFECTS OF LYSINE AND ENERGY LEVELS ON GROWTH PERFORMANCE THIGH MUSCLE COMPOSITION AND UTILIZATION OF NUTRIENTS IN BROILER CHICKS

  • Park, B.C.;Han, I.K.;Choi, Y.J.;Yun, C.H.
    • Asian-Australasian Journal of Animal Sciences
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    • 제5권1호
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    • pp.129-138
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    • 1992
  • The effects of dietary levels of lysine and energy on growth performance, the content of DNA, RNA and protein in liver, thigh muscle composition and nutrient utilization in broiler chicks were investigated in an experiment involvies with 2 levels of dietary energy : 3,200 (2900) 2,900 (2700) kcal ME/kg) and 6 levels of lysine : 0.6(0.5), 0.8(0.7), 1.0(0.9), 1.2(1.1), 1.4(1.3), and 1.6(1.5)% was carried out. A total number of 384 male broiler chicks was used for a period of 7 weeks. Body weight gain of 1.0(0.9)% lysine level group was significantly (p < 0.01) higher than that of any other groups. Interaction between lysine and energy in the feed intake was observed (p < 0.05). Present data indicate that the content of DNA in liver tissues was significantly (p < 0.05) different by the levels of lysine, namely, 1.0(0.9)% or 1.2(1.1)% lysine level groups showed higher content than other groups (p < 0.01). Dietary levels of 1.2(1.1)% or 1.6(1.5)% lysine groups showed the highest protein content in thigh muscle tissues than that of any other groups (p < 0.05). Interaction between energy and lysine in the content of protein of thigh muscle tissues was shown (p < 0.01). The level of 0.6% lysine group showed the highest fat content in thigh muscle tissues than any other groups. Interaction between lysine and energy in the content of crude ash and crude fat of thigh muscle tissues was observed (p < 0.01). Apparent amino acid availability of arginine, glycine and threonine (p < 0.01), phenylalanine (p < 0.05) were significantly affected by the levels of lysine and interaction between lysine and energy was found only in arginine (p < 0.01).

Effects of Dietary Inclusion of Astaxanthin on Growth, Muscle Pigmentation and Antioxidant Capacity of Juvenile Rainbow Trout (Oncorhynchus mykiss)

  • Rahman, Md Mostafizur;Khosravi, Sanaz;Chang, Kyung Hoon;Lee, Sang-Min
    • Preventive Nutrition and Food Science
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    • 제21권3호
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    • pp.281-288
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    • 2016
  • This study was designed to investigate the effects of dietary astaxanthin levels on growth performance, feed utilization, muscle pigmentation, and antioxidant capacity in juvenile rainbow trout. Four experimental diets were formulated to contain 0, 50, 75, and 100 mg/kg astaxanthin (designed as AX0, AX50, AX75, and AX100). Each diet was fed to triplicate groups of fish (18.5 g/fish) for 10 weeks. Growth performance and muscle composition of fish were not affected by dietary astaxanthin levels. Total carotenoid concentration in the muscle of fish fed the AX50 diet was higher than that of fish fed the AX0 diet, but no significant differences were observed between these fish and those fed the AX75 and AX100 diets. Muscle astaxanthin content increased with increased astaxanthin in the diet. Deposition of astaxanthin in the flesh resulted in a decrease in lightness and an increase in redness and yellowness. The fillets from trout fed the AX75 diet had significantly lower lightness than trout fed the AX50 and AX100 diets. Fish fed the AX50 and AX75 diets showed significantly lower catalase activity than those fed the control diet. Total antioxidant status increased significantly in all astaxanthin supplemented groups when compared to the control group. Superoxide dismutase activity was significantly decreased in fish fed the AX50 diet compared to fish fed the AX0 diet. These findings suggest that while fillet pigmentation increased with increasing dietary astaxanthin concentration, indices of fish antioxidant capacity may not be affected in a dose dependent manner.

능동형 근육펌프 구조의 수액 주입 펌프 개발에 관한 연구 (A Study on the Development of a Infusion Pump based on an Active Muscle Pump)

  • 이정환;이상엽;이정은;안인석
    • 한국산업융합학회 논문집
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    • 제25권3호
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    • pp.443-449
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    • 2022
  • In this study, in order to improve the disadvantages of the environmental error of the infusion set that performs infusion therapy in the existing clinical practice and to maximize the user's convenience by miniaturizing the existing infusion pump system, the structure of the muscle pump of the human vein was imitated. As a double check valve method, a method for preventing the backflow of fluid and discharging a constant fluid in one direction by external pressure was proposed. The proposed bio-mimic muscle pump uses a check valve that controls the flow of fluid in one direction and a silicone tube with elasticity, and a chamber is constructed. A peristaltic pump for applying intermittent pressure to the tube chamber was constructed using a multi-cam structure roller. In order to verify the performance of the proposed pump, optimization was performed while changing the number of multi-cam rollers and adjusting the speed of the roller driving motor, and the reproducibility of the instantaneous discharge amount and the continuous discharge amount of the pump was compared and tested. The performance of the muscle pump proposed in this study was verified through experiments that it can inject up to 1L of fluid within 12 hours, and that it is possible to inject the fluid with an accuracy of ±0.1ml. Real-time monitoring of the fluid injection volume through the bio-mimic muscle pump proposed in this study not only increases the convenience of the administrator, but also provides a precise fluid administration environment to more patients at a low cost, and additionally applies bubble detection and occlusion detection technology If so, it is believed that a safer medical environment can be provided to patients.

Exploring effects of different male parent crossings on sheep muscles and related regulatory genes using mRNA-Seq

  • Shi, Jinping;Zhang, Quanwei;Song, Yali;Lei, Zhaomin;Fu, Lingjuan;Cheng, Shuru
    • Animal Bioscience
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    • 제35권8호
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    • pp.1129-1140
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    • 2022
  • Objective: With improvements in living standards and increase in global population, the demand for meat products has been increasing; improved meat production from livestock could effectively meet this demand. In this study, we examined the differences in the muscle traits of different male crossbred sheep and attempted to identify key genes that regulate these traits. Methods: Dubo sheep×small-tailed Han sheep (DP×STH) and Suffolk×small-tailed Han sheep (SFK×STH) were selected to determine meat quality and production performance by Masson staining. Transcriptome sequencing and bioinformatic analysis were performed to identify differentially expressed genes (DEGs) related to meat quality. The presence of DEGs was confirmed by real-time polymerase chain reaction. Results: The production performance of SFK×STH sheep was better than that of DP×STH sheep, but the meat quality of DP×STH sheep was better than that of SFK×STH sheep. The muscle fiber diameter of DP×STH sheep was smaller than that of SFK×STH sheep. Twenty-two DEGs were identified. Among them, four gene ontology terms were related to muscle traits, and three DEGs were related to muscle or muscle fibers. There were no significant differences in the number of single nucleotide mutations and mutation sites in the different male parent cross combinations. Conclusion: This study provides genetic resources for future sheep muscle development and cross-breeding research.