Deglutitive inhibition affects both esophageal peristaltic amplitude and shortening

2003 ◽  
Vol 284 (4) ◽  
pp. G575-G582 ◽  
Author(s):  
Guoxiang Shi ◽  
John E. Pandolfino ◽  
Qing Zhang ◽  
Ikuo Hirano ◽  
Raymond J. Joehl ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Longitudinal Muscle ◽  
Short Interval ◽  
Circular Muscle ◽  
Distal Segment ◽  
Esophageal Wall ◽  
Strongly Correlated ◽  
Time Intervals ◽  
Rapid Sequence ◽  
Short Time

Deglutitive inhibition attenuates ongoing esophageal contractions if swallows are separated by short time intervals. This study aimed to determine whether esophageal shortening, mediated by longitudinal muscle, was similarly affected. Eight healthy subjects with two distal esophageal segments demarcated by mucosal clips and manometric recording sites positioned within those segments underwent concurrent manometry and fluoroscopy. Peristaltic amplitude and change in distal segment lengths were quantified during single swallows, paired swallows separated by progressively prolonged intervals, and a series of rapid repetitive swallows. During grouped swallows, deglutitive inhibition with complete attenuation of both the manometric contraction and segment shortening was evident with short-interval swallows and rapid-sequence swallows. No inhibition of either was evident with long-interval pairs. With intermediate interswallow intervals, the occurrence and degree of deglutitive inhibition between peristaltic amplitude and segment shortening were closely correlated. Deglutitive inhibition affects both the longitudinal and circular muscle layers of the esophageal wall, and the occurrence of inhibition evident in one layer is strongly correlated with the other.

Image intersification applied to biological problems

1972 ◽  
Vol 5 (3) ◽  
pp. 295-347 ◽  
Author(s):  
George T. Reynolds
Keyword(s):  
Specific Activity ◽  
Biological Research ◽  
Biological Processes ◽  
X Rays ◽  
Radioactive Tracers ◽  
X Ray Diffraction ◽  
Time Intervals ◽  
X Ray ◽  
Rapid Sequence ◽  
Short Time

In many important types of observations in biological research, the information provided by the specimens is in the form of photons-quanta of visible light, u.v., or X-rays. The process of observation becomes one of recording this information in useful form, with as high an efficiency as possible. The problem becomes particularly important when for some reason or other the total number or rate of quanta provided by the specimen is small. Examples of such limitations are included in the following: (i) Processes permitting only low-intensity illumination in order not to interfere with the biological processes under observation. (ii) Processes changing very rapidly and requiring rapid sequence recording. (iii) Processes providing only a limited number of photons per event, such as bioluminescence. (iv) Processes in which radioactive tracers are utilized, and observation of radioactivity is desirable at low specific activity or within short time intervals. (v) X-ray diffraction processes where the specimen is weakly diffracting or where the X-ray intensity must be kept low in order not to damage the specimen. (vi) Processes involving the observation of fluorescence, where the intensity is low because of limitations on the amount of tagging material.

Estimation of Time and the Subclassification of Schizophrenic Disorders

1983 ◽  
Vol 57 (3) ◽  
pp. 911-918 ◽  
Author(s):  
Lennart Tysk
Keyword(s):  
Personality Disorders ◽  
Healthy Subjects ◽  
Chronic Patients ◽  
Time Intervals ◽  
Schizotypal Personality ◽  
Different Types ◽  
Verbal Estimation ◽  
Schizophrenic Patients ◽  
Short Time ◽  
Estimation Of Time

Estimation of short time intervals by 60 healthy subjects, 50 patients with schizophrenic disorders, and 8 with schizotypal personality disorders, was investigated using the three different methods, adjusting a metronome, verbal estimation, and operative estimation (production). The schizophrenic patients tended to over-estimate time with all three methods. Over-estimation was also found when longer intervals were studied. Patients with different types of schizophrenic disorders, classified according to DSM-III criteria, over-estimated time about the same; no significant differences were found. Different courses of schizophrenia were also studied. Patients in remission over-estimated time to the same extent as chronic patients; the subchronic patients probably over-estimated less. Schizotypal personality disorders did not seem to be associated with a tendency to over-estimate short time intervals. The results were discussed in the context of perceptual disturbances in schizophrenic disorders.

Gastrointestinal longitudinal muscle contractions

1993 ◽  
Vol 265 (1) ◽  
pp. G156-G164 ◽  
Author(s):  
S. K. Sarna
Keyword(s):  
Small Intestine ◽  
Longitudinal Muscle ◽  
Circular Muscle ◽  
Muscle Contractions ◽  
Strongly Correlated ◽  
Elongation Complex ◽  
Fed State ◽  
Significant Difference ◽  
Enteric Nerves ◽  
Small Intestinal

The patterns of longitudinal muscle contractions of the stomach and the small intestine and their relationship with circular muscle contractions during the fasting and the fed state were investigated in conscious dogs. In the stomach, the longitudinal muscle contracted in a 1:1 relationship with the circular muscle contractions. There was no significant difference between the frequency, duration, and time of onset of gastric longitudinal and circular muscle contractions, and their amplitudes were significantly correlated with each other. In the small intestine when the circular muscle contracted, the longitudinal muscle exhibited passive elongation during the fasting and the fed state. There was no significant difference between the onset, duration, and frequency of small intestinal circular muscle contractions and the passive longitudinal muscle elongations; their amplitudes were strongly correlated with each other. During a circular muscle giant migrating contraction, the longitudinal muscle exhibited a monophasic contraction, initially a contraction followed by passive elongation or a pure passive elongation. During a retrograde giant contraction, the longitudinal muscle exhibited only a pure monophasic contraction or a contraction-elongation complex. These data suggest that the enteric nerves in the small intestine innervate the two muscle layers in a reciprocal fashion and those in the stomach in a complementary fashion.

scholarly journals Local longitudinal muscle shortening of the human esophagus from high-frequency ultrasonography

2001 ◽  
Vol 281 (4) ◽  
pp. G1022-G1033 ◽  
Author(s):  
Mark A. Nicosia ◽  
James G. Brasseur ◽  
Ji-Bin Liu ◽  
Larry S. Miller
Keyword(s):  
Muscle Contraction ◽  
Muscle Fiber ◽  
Longitudinal Muscle ◽  
Circular Muscle ◽  
Intraluminal Pressure ◽  
Esophageal Wall ◽  
Pressure Amplitude ◽  
Longitudinal Contraction ◽  
Local Contraction ◽  
Muscle Shortening

We analyzed local longitudinal shortening by combining concurrent ultrasonography and manometry with basic principles of mechanics. We applied the law of mass conservation to quantify local axial shortening of the esophageal wall from ultrasonically measured cross-sectional area concurrently with measured intraluminal pressure, from which correlations between local contraction of longitudinal and circular muscle are inferred. Two clear phases of local longitudinal shortening were observed during bolus transport. During luminal filling by bolus fluid, the muscle layer distends and the muscle thickness decreases in the absence of circular or longitudinal muscle contraction. This is followed by local contraction, first in longitudinal muscle, then in circular muscle. Maximal longitudinal shortening occurs nearly coincidently with peak intraluminal pressure. Longitudinal muscle contraction begins before and ends after circular muscle contraction. Larger longitudinal shortening is correlated with higher pressure amplitude, suggesting that circumferential contractile forces are enhanced by longitudinal muscle shortening. We conclude that a peristaltic wave of longitudinal muscle contraction envelops the wave of circular muscle contraction as it passes through the middle esophagus, with peak longitudinal contraction aligned with peak circular muscular contraction. Our results suggest that the coordination of the two waves may be a physiological response to the mechanical influence of longitudinal shortening, which increases contractile force while reducing average muscle fiber tension by increasing circular muscle fiber density locally near the bolus tail.

RESPONSE OF PLASMA NON-CONJUGATED OESTRADIOL TO MANIPULATED ADRENAL FUNCTION BY ACTH AND DEXAMETHASONE

1979 ◽  
Vol 90 (3) ◽  
pp. 525-533
Author(s):  
G. Reck ◽  
U. Noss ◽  
M. Breckwoldt
Keyword(s):  
Plasma Cortisol ◽  
Maximum Level ◽  
Adrenal Function ◽  
Strongly Correlated ◽  
Acth Secretion ◽  
Time Intervals ◽  
Short Time ◽  
Plasma Oestradiol ◽  
Free Plasma ◽  
Stimulation Of

ABSTRACT The present study is concerned with the regulation of free plasma oestradiol in relation to maternal adrenal function during late human pregnancy. Blood was collected in 9 patients at short time intervals of 30 min from 17 h to 3 h. In order to exclude endogenous ACTH-secretion 5 patients received 12 mg dexamethasone over 48 h. Between 20 h and 2 h 0.25 mg ACTH1-24 (Synacthen°) was infused into the subjects. Nonconjugated oestradiol was determined by radioimmunoassay and total plasma cortisol by protein binding method. During the application of ACTH free oestradiol increased from 21.3 ± 5.7 to 25.5 ± 7.1 ng/ml (P < 0.025) in the patients without dexamethasone. The increase was moderately correlated to rising cortisol (r = 0.58, P < 0.001). Plasma oestradiol reached its maximum level after 90 min, followed by a tendency to decline despite persisting stimulation of maternal adrenals. The patients receiving dexamethasone exhibited during ACTH-infusion a rise of oestradiol from 3.8 ± 1.9 to 7.8 ± 3.1 ng/ml (P < 0.001). Increasing oestradiol was strongly correlated to plasma cortisol (r = 0.67, P < 0.001). The phenomenon of earlier declining oestradiol levels did not occur. These results suggest that maternal adrenals predominantly regulate the formation of free oestradiol. Plasma cortisol indicating maternal precursor production balances the increase of oestradiol by suppressing foetal precursor supply.

Time Estimation by Healthy Subjects and Schizophrenic Patients: A Methodological Study

1983 ◽  
Vol 56 (3) ◽  
pp. 983-988 ◽  
Author(s):  
Lennart Tysk
Keyword(s):  
Pulse Rate ◽  
Healthy Subjects ◽  
Time Estimation ◽  
Time Interval ◽  
Oral Temperature ◽  
Methodological Study ◽  
Time Intervals ◽  
Verbal Estimation ◽  
Schizophrenic Patients ◽  
Short Time

Three different methods were used to investigate the perception of short time intervals by 60 healthy subjects and a pilot group of 15 schizophrenic patients. The usefulness of metronome adjustment, verbal estimation, and operative estimation was evaluated. Estimation of longer time intervals was also studied. The influence of age, sex, oral temperature, and pulse rate was assessed. Earlier findings that schizophrenic subjects tend to overestimate short time intervals were supported by data from all three methods. Operative estimation—the subject's production of a requested time interval—could possibly best discriminate between the two groups. Estimation of longer time intervals did not differ significantly for the two groups.

Proposal of PV Output Estimate Method in Short Time Intervals

2016 ◽  
Vol 136 (12) ◽  
pp. 891-897 ◽  
Author(s):  
Katsuhiro Matsuda ◽  
Kazuhiro Misawa ◽  
Hirotaka Takahashi ◽  
Kenta Furukawa ◽  
Satoshi Uemura
Keyword(s):  
Time Intervals ◽  
Estimate Method ◽  
Short Time

EVALUATION OF SHORT TIME INTERVALS IN NORMAL AGING AND LATE-LIFE DEPRESSIONS

2020 ◽  
pp. 54-69
Author(s):  
Elena Yu. Balashova ◽  
◽  
Lika I. Mikeladze ◽  
Elena K. Kozlova ◽  
◽  
...  
Keyword(s):  
Late Life ◽  
Normal Aging ◽  
Time Intervals ◽  
Short Time

scholarly journals Neural Network Approach for Global Solar Irradiance Prediction at Extremely Short-Time-Intervals Using Particle Swarm Optimization Algorithm

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1213
Author(s):  
Ahmed Aljanad ◽  
Nadia M. L. Tan ◽  
Vassilios G. Agelidis ◽  
Hussain Shareef
Keyword(s):  
Neural Networks ◽  
Particle Swarm Optimization ◽  
Solar Irradiance ◽  
Particle Swarm ◽  
Time Interval ◽  
Time Intervals ◽  
Swarm Optimization ◽  
Backpropagation Neural Networks ◽  
Proposed Model ◽  
Short Time

Hourly global solar irradiance (GSR) data are required for sizing, planning, and modeling of solar photovoltaic farms. However, operating and controlling such farms exposed to varying environmental conditions, such as fast passing clouds, necessitates GSR data to be available for very short time intervals. Classical backpropagation neural networks do not perform satisfactorily when predicting parameters within short intervals. This paper proposes a hybrid backpropagation neural networks based on particle swarm optimization. The particle swarm algorithm is used as an optimization algorithm within the backpropagation neural networks to optimize the number of hidden layers and neurons used and its learning rate. The proposed model can be used as a reliable model in predicting changes in the solar irradiance during short time interval in tropical regions such as Malaysia and other regions. Actual global solar irradiance data of 5-s and 1-min intervals, recorded by weather stations, are applied to train and test the proposed algorithm. Moreover, to ensure the adaptability and robustness of the proposed technique, two different cases are evaluated using 1-day and 3-days profiles, for two different time intervals of 1-min and 5-s each. A set of statistical error indices have been introduced to evaluate the performance of the proposed algorithm. From the results obtained, the 3-days profile’s performance evaluation of the BPNN-PSO are 1.7078 of RMSE, 0.7537 of MAE, 0.0292 of MSE, and 31.4348 of MAPE (%), at 5-s time interval, where the obtained results of 1-min interval are 0.6566 of RMSE, 0.2754 of MAE, 0.0043 of MSE, and 1.4732 of MAPE (%). The results revealed that proposed model outperformed the standalone backpropagation neural networks method in predicting global solar irradiance values for extremely short-time intervals. In addition to that, the proposed model exhibited high level of predictability compared to other existing models.

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