CIRCADIAN RHYTHM OF FREE OESTRADIOL IN RELATION TO PLASMA CORTISOL IN LATE HUMAN PREGNANCY

1979 ◽  
Vol 90 (3) ◽  
pp. 519-524 ◽  
Author(s):  
G. Reck ◽  
U. Noss ◽  
M. Breckwoldt
Keyword(s):  
Circadian Rhythm ◽  
Plasma Cortisol ◽  
Life Time ◽  
Early Morning ◽  
Diurnal Variations ◽  
Time Intervals ◽  
Human Pregnancy ◽  
Short Time ◽  
Plasma Oestradiol ◽  
Free Plasma

ABSTRACT The present study investigates the diurnal variations of free plasma oestradiol levels in late human pregnancy. The oestradiol levels are correlated to the maternal adrenal function as reflected by the plasma levels of cortisol. According to the half life time of oestradiol, blood samples were collected at short time intervals of 30 and 60 min, respectively. Three pregnant women volunteered in the study. Free oestradiol was measured by radioimmunoassay and cortisol was quantitated by a protein binding method. All patients exhibited a circadian rhythm for free oestradiol with significantly higher values in the early morning (28.3 ± 7.2 ng/ml) than in the afternoon and early night (21.2 ± 3.6 ng/ml, P < 0.001). The course of oestradiol followed in a moderate but significant correlation plasma cortisol (r = 0.34, P < 0.001). During the period of increasing cortisol the oestradiol levels demonstrated the phenomenon of episodic secretion. The results obtained suggest that the maternal adrenals predominantly regulate the diurnal rhythm of free oestradiol in late human pregnancy.

CORRELATION OF PLASMA NON-CONJUGATED OESTRIOL AND PLASMA CORTISOL IN LATE HUMAN PREGNANCY

1979 ◽  
Vol 92 (3) ◽  
pp. 553-559 ◽  
Author(s):  
G. Reck ◽  
A. Renner ◽  
G. Sinns ◽  
M. Breckwoldt
Keyword(s):  
Plasma Cortisol ◽  
Life Time ◽  
Significant Negative Correlation ◽  
Maternal Plasma ◽  
Cortisol Concentration ◽  
Diurnal Variations ◽  
Human Pregnancy ◽  
Back Action ◽  
Low Cortisol ◽  
Free Plasma

ABSTRACT The present study concerns the diurnal variations of free plasma oestriol and their relationship to maternal plasma cortisol in late human pregnancy. Four pregnant women volunteered for the study. According to the half-life time of oestriol blood was drawn at intervals of 30 and 60 minutes, respectively, over a period of 24 hours. Free oestriol was measured by radioimmunoassay and cortisol was quantitated by a protein binding method. All patients exhibited a circadian rhytm for free oestriol with higher values in the evening and early night (14.4 ± 3.7 ng/ml) than in the morning (11.3 ± 2.3 ng/ml, P < 0.001). The course of oestriol followed plasma cortisol in a significant negative correlation (r = −0.566, P < 0.001). During the period of low cortisol concentration oestriol levels demonstrated the phenomenon of episodic secretion. The results suggest that the maternal adrenals predominantly regulate the circadian rhythm of free oestriol by a negative feed-back action on the foetal hypothalamus.

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.

Reduced Testosterone Levels in Cluster Headache: A Stress-Related Phenomenon?

Cephalalgia ◽  
1986 ◽  
Vol 6 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Fabio Facchinetti ◽  
Giuseppe Nappi ◽  
Claudio Cicoli ◽  
Giuseppe Micieli ◽  
Michela Ruspa ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Cluster Headache ◽  
Plasma Cortisol ◽  
Active Phase ◽  
Early Morning ◽  
Related Phenomenon ◽  
Cortisol Secretion ◽  
Plasma Cortisol Concentration ◽  
Episodic Cluster Headache ◽  
Cortisol Levels

The circadian changes in testosterone (T) and cortisol secretion and morning luteinizing hormone (LH) levels were evaluated in nine episodic cluster headache (CH) patients in active phase and in seven healthy volunteers, with collection of blood samples every 2 h for 24 h. CH showed a significant reduction of the 24-h integrated mean T value (mesor) (4.4 + 1.1 ng/ml; x ± SD) in comparison with controls (6.6 ± 0.8 ng/ml) ( P < 0.0l). Both groups had plasma T circadian rhythm with peak values in early morning, but in CH single cosinor analysis showed its absence in three out of nine CH patients. The rhythm showed an acrophase delay of 101 min in CH. Both patients and controls had a significant circadian rhythm of plasma cortisol concentration. CH patients, however, showed an acrophase delay of 106 min and significantly increased concentrations from 1200 h to 2000 h. Morning LH values were similar in the two groups. The reduced secretion of plasma T in CH patients in the active phase coexisted with an acrophase delay of its circadian rhythm. A similar delay was found in 24-h plasma cortisol levels. We suggest that stress accompanying attack expectancy in the active phase is the mechanism behind the elevated plasma cortisol levels. This in turn could reduce T concentrations, acting at the testicular level. These disturbances in internal chronoorganization support the hypothesis that cluster headache is basically a dyschronic disorder.

Changes in circadian rhythm and suppression of the plasma cortisol level after prolonged stress in the sheep

1985 ◽  
Vol 110 (4) ◽  
pp. 540-545 ◽  
Author(s):  
F. Przekop ◽  
E. Stupnicka ◽  
E. Wolińska-Witort ◽  
K. Mateusiak ◽  
B. Sadowski ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Cortisol Level ◽  
Plasma Cortisol ◽  
Plasma Cortisol Level ◽  
Diurnal Variations ◽  
Cortisol Response ◽  
Time Of Application ◽  
Prolonged Stress ◽  
Similar Decrease ◽  
Stimulation Of

Abstract. Diurnal variations in the plasma cortisol level were studied in anoestrous, pro-oestrous and pregnant ewes subjected to weak electric stimulation of the forelimbs 9 h daily for 3 consecutive days. In non-pregnant ewes the cortisol level rose on each of the 3 days when the stimulation was applied and then decreased on the day following the stimulation. A similar decrease in plasma cortisol concentrations in pregnant ewes appeared on the second day of footshocking. The acrophase of the circadian rhythm on electrostimulation days was synchronous with the time of application of footshocks; therefore, in stimulated ewes it was significantly accelerated compared to the prestimulatory day. A decrease in the plasma cortisol level in pro-oestrous and pregnant ewes was accompanied by disappearance of its normal rhythmicity. Since a normal plasma cortisol response to exogenous corticotrophin was noted after 3 days of foot-shocking it seems unlikely that the decrease in the cortisol level after prolonged stress was caused by exhaustion of the adrenal cortex. Some central mechanisms which could account for the biphasic changes in the plasma cortisol level and for disturbances of the hormone diurnal rhythmicity under conditions of prolonged stress are discussed.

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.

scholarly journals Optimal Perturbations of an Oceanic Vortex Lens

Fluids ◽  
2018 ◽  
Vol 3 (3) ◽  
pp. 63 ◽  
Author(s):  
Thomas Meunier ◽  
Claire Ménesguen ◽  
Xavier Carton ◽  
Sylvie Le Gentil ◽  
Richard Schopp
Keyword(s):  
Normal Mode ◽  
Growth Rates ◽  
Time Interval ◽  
Time Intervals ◽  
Horizontal Structure ◽  
Azimuthal Wave ◽  
Wave Numbers ◽  
Non Linear ◽  
Long Time ◽  
Short Time

The stability properties of a vortex lens are studied in the quasi geostrophic (QG) framework using the generalized stability theory. Optimal perturbations are obtained using a tangent linear QG model and its adjoint. Their fine-scale spatial structures are studied in details. Growth rates of optimal perturbations are shown to be extremely sensitive to the time interval of optimization: The most unstable perturbations are found for time intervals of about 3 days, while the growth rates continuously decrease towards the most unstable normal mode, which is reached after about 170 days. The horizontal structure of the optimal perturbations consists of an intense counter-shear spiralling. It is also extremely sensitive to time interval: for short time intervals, the optimal perturbations are made of a broad spectrum of high azimuthal wave numbers. As the time interval increases, only low azimuthal wave numbers are found. The vertical structures of optimal perturbations exhibit strong layering associated with high vertical wave numbers whatever the time interval. However, the latter parameter plays an important role in the width of the vertical spectrum of the perturbation: short time interval perturbations have a narrow vertical spectrum while long time interval perturbations show a broad range of vertical scales. Optimal perturbations were set as initial perturbations of the vortex lens in a fully non linear QG model. It appears that for short time intervals, the perturbations decay after an initial transient growth, while for longer time intervals, the optimal perturbation keeps on growing, quickly leading to a non-linear regime or exciting lower azimuthal modes, consistent with normal mode instability. Very long time intervals simply behave like the most unstable normal mode. The possible impact of optimal perturbations on layering is also discussed.

An Automatic Paperless Velocity Measuring and Recording System

2014 ◽  
Vol 889-890 ◽  
pp. 745-748
Author(s):  
Jian Sheng Cao ◽  
Wan Jun Zhang ◽  
Xin Hua Zeng
Keyword(s):  
Flow Velocity ◽  
Optical Pulse ◽  
Electric Pulse ◽  
Automatic Monitoring ◽  
Time Intervals ◽  
Stream Flows ◽  
Fluid Flow Velocity ◽  
Photoelectric Sensor ◽  
Velocity Measuring ◽  
Short Time

Automatic monitoring of hydrologic properties such as water velocity at short-time intervals is critical for understanding watershed eco-hydrological processes. This can also be used to study the laws of stream flows and interactions ecological process. The advent of modern electronic technology (and the near-perfection of especially sensor and data collection technologies), has made it possible to use automatic monitoring systems to continuously measure hydrologic properties at short-time intervals. This paper introduces one such paperless flow velocity measuring/recoding system. The system uses a photoelectric sensor that is mainly comprised of photoelectric velocity sensor and pulse recorder. The system uses propellers (with reflective panels and photoemission cells) to transform flow velocities into optical pulse signals. It also uses photosensitive tubes to transform optical pulse signals into electric pulse signals. The electric pulse counts (generated in unit time) are recorded via pulse recorders. This therefore accomplishes automatic monitoring and continuous recording of fluid flow velocity.

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