Effect of Rumen Insufflation on Ruminal Contraction Rate in Sheep

1979 ◽  
Vol 48 (4) ◽  
pp. 934-940 ◽  
Author(s):  
J. A. Louvier ◽  
H. W. Colvin ◽  
G. Ishizaki ◽  
G. A. Iwamoto ◽  
H. R. Parker
Keyword(s):  
Contraction Rate

Vasodilation contributes to the rapid hyperemia with rhythmic contractions in humans

1998 ◽  
Vol 76 (4) ◽  
pp. 418-427 ◽  
Author(s):  
J K Shoemaker ◽  
M E Tschakovsky ◽  
R L Hughson
Keyword(s):  
Blood Flow ◽  
Forearm Blood Flow ◽  
Perfusion Pressure ◽  
Blood Velocity ◽  
Pulsed Doppler ◽  
Contraction Rate ◽  
Handgrip Exercise ◽  
Arterial Diameter ◽  
Exercise Tests ◽  
Rhythmic Contractions

The hypothesis that the rapid increases in blood flow at the exercise onsetare exclusively due to the mechanical effects of the muscle pump was tested in six volunteersduring dynamic handgrip exercise. While supine, each subject completed a series of eightdifferent exercise tests in which brachial artery blood pressure (BP) was altered by25–30 mmHg (1 mmHg = 133.3 Pa) by positioning the arm above or below the heart.Two different weights, corresponding to 4.9 and 9.7% of maximal voluntary isometriccontraction, were raised and lowered at two different contraction rate schedules (1s:1s and 2s:2swork–rest) each with a 50% duty cycle. Beat-by-beat measures of mean blood velocity (MBV)(pulsed Doppler) were obtained at rest and for 5 min following step increases in work ratewith emphasis on the first 24 s. MBV was increased 50–100% above rest following the firstcontraction in both arm positions (p < 0.05). The increase in MBV from rest was greaterin the below position compared with above, and this effect was observed following the first andsubsequent contractions (p < 0.05). However, the positional effect on the increase inMBV could not be explained entirely by the ~40% greater BP in this position. Also, the greaterworkload resulted in greater increases in MBV as early as the first contraction, compared withthe light workload (p < 0.05) despite similar reductions in forearm volume followingsingle contractions. MBV was greater with faster contraction rate tests by 8 s of exercise. Itwas concluded that microvascular vasodilation must act in concert with a reduction in venouspressure to increase forearm blood flow within the initial 2–4 s of exercise.Key words: Doppler, mean blood velocity, arterial diameter,handgrip exercise, perfusion pressure.

Study of the functional state of the only uterine tube in women after the tubal pregnancy operation

1997 ◽  
Vol 78 (5) ◽  
pp. 367-368
Author(s):  
M. I. Mazitova ◽  
I. M. Bogolyubova ◽  
I. M. Mazitov
Keyword(s):  
Functional State ◽  
Contractile Activity ◽  
The State ◽  
Tubal Pregnancy ◽  
The Other ◽  
Contraction Rate ◽  
Uterine Tube ◽  
Investigation Method ◽  
Rate Decrease

The state of the second remained tube after the- tubal pregnancy operation in 16 patients is studied by kymographic tubal insufflation. Salpingectomy is performed in 14 patients and linear salpingotomy of the only uterine tube is performed in 2 patients. The other tube is removed during the first tubal pregnancy operation. It is found that in all patients the remained tubes are permeable as this takes place permeability, contractile activity and contraction rate decrease in 7 patients (in 5 patients after salpingectomy, in 2 patients after salpingotomy). Kymographic tubal insufflation is the information investigation method of the state of the remained uterine tube after the tubal pregnancy operation.

scholarly journals Theoretical Comparison of McKibben-Type Artificial Muscle and Novel Straight-Fiber-Type Artificial Muscle

2011 ◽  
Vol 5 (4) ◽  
pp. 544-550 ◽  
Author(s):  
Hiroki Tomori ◽  
◽  
Taro Nakamura
Keyword(s):  
Steady State ◽  
Dynamic Characteristic ◽  
Fiber Type ◽  
Human Life ◽  
Artificial Muscle ◽  
Artificial Muscles ◽  
Contraction Rate ◽  
Theoretical Comparison ◽  
Straight Fiber ◽  
Force Characteristics

Robots have entered human life, and closer relationships are being formed between humans and robots. It is desirable that these robots be flexible and lightweight. With this as our goal, we have developed an artificial muscle actuator using straight-fiber-type artificial muscles derived from the McKibben-type muscles, which have excellent contraction rate and force characteristics. In this study, we compared the steady state and dynamic characteristic of straightfiber-type and McKibben-type muscles and verified the usefulness of straight-fiber-type muscles.

scholarly journals Effects of training and detraining on muscle strength in rowers

2019 ◽  
Vol 72 (7-8) ◽  
pp. 223-227
Author(s):  
Nebojsa Janjic ◽  
Mina Maricic ◽  
Andrea Zubnar ◽  
Vedrana Karan ◽  
Miodrag Drapsin ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Muscle Adaptation ◽  
Contraction Rate ◽  
Lower Limb Muscles ◽  
Muscle Groups ◽  
Leg Extensor Power ◽  
Novi Sad ◽  
Periodized Training ◽  
Leg Extensors ◽  
Training And Detraining

Introduction. Annual and periodized training protocols significantly affect the muscle adaptation in rowers. Considering that the main goal of the training period is increasing specific muscle strength and of detraining period increasing general strength and active rest, the aim of this study was to compare the strength of different muscle groups between training and detraining periods. Material and Methods. The study was conducted at the Department of Physiology, Faculty of Medicine Novi Sad, and it included 34 male and female rowers, 15 to 18 years of age. The muscle strength was measured using a Concept 2 DYNO dynamometer. The strength of the arm extensors and flexors, as well as the leg extensors was measured twice, at the end of the competition season (peak of performance) and before the beginning of the preparation season (after detraining). Results. A statistically significant decrease was found in absolute and relative muscle strength, flexor and arm extensor contraction rate, as well as relative leg extensor strength and contraction rate during the training and detraining periods (p < 0.05). No difference was found in the absolute leg extensor power between the two measurements (p > 0.05). Conclusion. Periodization of the annual training program in rowers has a higher impact on differences in the upper limb muscle adaptation, compared to lower limb muscles in terms of absolute strength.

Antral contraction rate estimation from dynamic antral scintigraphy using Hilbert-Huang transform

2020 ◽  
Vol 117 ◽  
pp. 103560
Author(s):  
Panasun Ngamsirijit ◽  
Tongchatra Watcharawittayakul ◽  
Pisit Jarumaneeroj ◽  
Tawatchai Chaiwatanarat ◽  
Yothin Rakvongthai
Keyword(s):  
Contraction Rate ◽  
Hilbert Huang Transform ◽  
Rate Estimation

Numerical analysis of the effect of the contraction rate of the curved hopper on flow characteristics of the silo discharge

2019 ◽  
Vol 356 ◽  
pp. 858-870 ◽  
Author(s):  
Hanru Liu ◽  
Fuguo Jia ◽  
Yawen Xiao ◽  
Yanlong Han ◽  
Gengrun Li ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Flow Characteristics ◽  
Contraction Rate ◽  
Silo Discharge

scholarly journals Close-up observations on the spawning behavior of a captive Japanese flying squid (Todarodes pacificus)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jun Yamamoto ◽  
Kohsuke Adachi ◽  
John R. Bower ◽  
Hajime Matsui ◽  
Mitsuhiro Nakaya ◽  
...  
Keyword(s):  
The Body ◽  
Egg Mass ◽  
Spawning Behavior ◽  
Contraction Rate ◽  
Todarodes Pacificus ◽  
Close Observation

AbstractThe spawning behavior of a Japanese flying squid (Todarodes pacificus) is described based on up-close observation of a captive female. The squid was first transferred from a 10-ton tank to a polystyrene plastic box containing 45 liters of seawater. About one hour later, the mantle-contraction rate increased rapidly, followed by a brief convulsion of the mantle and arms and a whitening of the body. The mantle contractions become shallow and rapid, and several seconds later, semitransparent jelly presumably from the nidamental glands emerged from the funnel and passed between the ventral pair of arms. Approximately 90 seconds after the egg mass first emerged, the female began ejecting oocytes through the funnel into the egg mass using rapid, powerful mantle contractions. Soon after the oocytes were ejected, translucent strands (presumably sperm) emanated from the buccal membrane. The female continued to eject oocytes for approximately two minutes, after which the mantle convulsed, and the mantle-contraction rate decreased slowly for about one minute until the contractions stopped. The squid died soon afterwards.

Diaphragmatic responses to graded stimulation of pulmonary C-fibers with capsaicin

1985 ◽  
Vol 59 (5) ◽  
pp. 1487-1494 ◽  
Author(s):  
J. R. Coast ◽  
S. S. Cassidy
Keyword(s):  
Dose Response ◽  
Strain Gauge ◽  
Contraction Rate ◽  
C Fibers ◽  
C Fiber ◽  
Shallow Breathing ◽  
Fiber Stimulation ◽  
Rapid Shallow Breathing ◽  
Stimulation Of

It has been suggested that pulmonary C-fiber stimulation is responsible for the rapid shallow breathing that accompanies pulmonary edema. However, pulmonary C-fiber stimulation also causes apnea. To determine whether it was possible for both responses to occur from one stimulus, we infused varying concentrations of capsaicin (a compound that selectively stimulates C-fiber receptors in the dog) into an in situ vascularly isolated dog lung and measured rates and strengths of diaphragmatic contractions with a strain gauge sutured to the diaphragm and electromyogram electrodes implanted in the diaphragm. There was a dose response to capsaicin in that increased doses were related directly with the duration of cessation of diaphragmatic contractions (2–100 s) and inversely with the latency from the start of stimulation to the beginning of the cessation of diaphragmatic contractions (100–5 s). There was no evidence, however, of rapid shallow breathing in this set of experiments. Either a gradual return to normal rate from prolonged contraction intervals or no change in contraction rate was seen, depending on capsaicin concentration. We conclude that the primary diaphragmatic response to pulmonary C-fiber stimulation is a cessation of diaphragmatic contractions rather than rapid shallow contractions.

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