Influence of Daily Variations of Light and Temperature on the Emergence Rhythm of Grayling Fry (Thymallus thymallus)

1991 ◽  
Vol 48 (7) ◽  
pp. 1176-1180 ◽  
Author(s):  
Agnès Bardonnet ◽  
Philippe Gaudin
Keyword(s):  
Constant Temperature ◽  
Early Morning ◽  
Thymallus Thymallus ◽  
Temperature Variations ◽  
Emergence Pattern ◽  
Daily Variations ◽  
Emergence Rhythm ◽  
Dim Light

The emergence rhythm of grayling fry (Thymallus thymallus) was studied in four aquaria fitted with traps under four different conditions of light and temperature. Both light and temperature induced an emergence rhythm characterized by a 24-h period. Under ambient Sight and constant temperature, emergence peaked at the end of the night before the onset of dawn. Under constant dim light and varying temperature, emergence peaked in early morning during the coldest hours. When both light and temperature fluctuated daily the emergence pattern was equivalent to the "sum" of these previous two regimes and was similar to that described in the field in a previous report. In the absence of light and temperature variations, no emergence rhythm was observed.

Diel pattern of emergence in grayling (Thymallus thymallus Linnaeus, 1758)

1990 ◽  
Vol 68 (3) ◽  
pp. 465-469 ◽  
Author(s):  
Agnès Bardonnet ◽  
Philippe Gaudin
Keyword(s):  
Light Conditions ◽  
Diel Pattern ◽  
Thymallus Thymallus ◽  
Daily Pattern ◽  
Rearing Conditions ◽  
Emergence Rhythm

The emergence rhythm of grayling fry (Thymallus thymallus) was studied under semi-natural rearing conditions, using special traps buried in the gravel. The diel pattern of emergence proved to be mainly diurnal, with a maximum just after sunrise. The discussion emphasizes the fact that this distinguishes the grayling from other salmonids, and since eggs are buried at a reduced depth, proposes the hypothesis that light conditions during development influence the daily pattern of emergence.

scholarly journals Simplified Calibration Method for Constant-Temperature Hot-Wire Anemometry

2020 ◽  
Vol 10 (24) ◽  
pp. 9058
Author(s):  
Hidemi Takahashi ◽  
Mitsuru Kurita ◽  
Hidetoshi Iijima ◽  
Seigo Koga
Keyword(s):  
Boundary Layer ◽  
Flow Velocity ◽  
Constant Temperature ◽  
Calibration Method ◽  
Large Temperature ◽  
Velocity Data ◽  
Hot Wire ◽  
Temperature Variations ◽  
Wire Temperature ◽  
Hot Wire Anemometry

This study proposes a unique approach to convert a voltage signal obtained from a hot-wire anemometry to flow velocity data by making a slight modification to existing temperature-correction methods. The approach was a simplified calibration method for the constant-temperature mode of hot-wire anemometry without knowing exact wire temperature. The necessary data are the freestream temperature and a set of known velocity data which gives reference velocities in addition to the hot-wire signal. The proposed method was applied to various boundary layer velocity profiles with large temperature variations while the wire temperature was unknown. The target flow velocity was ranged between 20 and 80 m/s. By using a best-fit approach between the velocities in the boundary layer obtained by hot-wire anemometry and by the pitot-tube measurement, which provides reference data, the unknown wire temperature was sought. Results showed that the proposed simplified calibration approach was applicable to a velocity range between 20 and 80 m/s and with temperature variations up to 15 °C with an uncertainty level of 2.6% at most for the current datasets.

Treatment of Seasonal Affective Disorder with Light in the Evening

1985 ◽  
Vol 147 (4) ◽  
pp. 424-428 ◽  
Author(s):  
Steven P. James ◽  
Thomas A. Wehr ◽  
David A. Sack ◽  
Barbara L. Parry ◽  
Norman E. Rosenthal
Keyword(s):  
Sleep Deprivation ◽  
Affective Disorder ◽  
Seasonal Affective Disorder ◽  
Bright Light ◽  
Early Morning ◽  
Antidepressant Effect ◽  
Comparison Study ◽  
Female Patients ◽  
Dim Light ◽  
Effect Of Light

A cross-over comparison study of exposure, in the evenings only, to bright versus dim light was carried out on nine female patients with seasonal affective disorder. A significant antidepressant effect of the bright lights was shown. No consistent observable effects were produced by the dim lights. These results support earlier studies demonstrating the efficacy of bright light given morning and evening. The antidepressant effect of light is not mediated by sleep deprivation, and the early morning hours are not crucial for a response.

Calibration of Constant-Temperature Hot-Wire Anemometers at Low Velocities in Water with Variable Fluid Temperature

1972 ◽  
Vol 94 (1) ◽  
pp. 17-22 ◽  
Author(s):  
K. Hollasch ◽  
B. Gebhart
Keyword(s):  
Experimental Study ◽  
Natural Convection ◽  
Constant Temperature ◽  
Fluid Temperature ◽  
Hot Wire ◽  
Temperature Variations ◽  
Wire Probe ◽  
Temperature Mode

Calibration of hot-wire probes operated in a constant-temperature mode in water at low velocities is discussed. Operation under circumstances where natural convection effects are important is considered. A method of calibrating a constant-temperature hot-wire probe for variations in fluid temperature is presented. The method consists of varying wire overheat during calibration at a constant fluid temperature. A relation is derived analytically relating anemometer output with a variable overheat resistance to anemometer output with fluid temperature variations. An experimental study to verify the analysis is presented.

scholarly journals Daytime Colour Preference in Drosophila Depends on the Circadian Clock and TRP Channels

2019 ◽  
Author(s):  
Stanislav Lazopulo ◽  
Andrey Lazopulo ◽  
James Baker ◽  
Sheyum Syed
Keyword(s):  
Circadian Clock ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Receptor Potential ◽  
Early Morning ◽  
Time Of Day ◽  
Colour Preference ◽  
Genetic Manipulations ◽  
Dim Light ◽  
Transient Receptor

By guiding animals towards food and shelter and repelling them from potentially harmful situations, light discrimination according to colour can confer survival advantages1,2. Such colour-dependent behaviour may be experiential or innate. Data on innate colour preference remain controversial in mammals3 and limited in simpler organisms4–7. Here we show that when given a choice among blue, green and dim light, fruit flies exhibit an unexpectedly complex pattern of colour preference that changes with the time of day. Flies show a strong preference for green in the early morning and late afternoon, a reduced green preference at midday and a robust avoidance of blue throughout the day. Genetic manipulations reveal that the peaks in green preference require rhodopsin-based photoreceptors, and are controlled by the circadian clock. The midday reduction in green preference in favour of dim light depends on the Transient Receptor Potential (TRP) channels dTRPA1 and Pyrexia (Pyx), and is also timed by the clock. In contrast, blue avoidance is primarily mediated by class IV multidendritic neurons, requires the TRP channel Painless (Pain) and is independent of the clock. With unexpected roles for several TRP channels in Drosophila colour-specific phototransduction, our results reveal distinct pathways of innate colour preference that coordinate the fly’s behavioural dynamics in ambient light.

The Microstructure of Pure Copper after Stepwise Change of Irradiation Temperature

2005 ◽  
Vol 475-479 ◽  
pp. 1479-1482 ◽  
Author(s):  
Y. Sumino ◽  
H. Watanabe ◽  
Naoaki Yoshida
Keyword(s):  
Temperature Variation ◽  
Constant Temperature ◽  
Temperature Region ◽  
Pure Copper ◽  
Heavy Ion ◽  
Irradiation Temperature ◽  
Temperature Variations ◽  
Stepwise Change ◽  
One Step ◽  
Periodic Temperature

In order to investigate the effect of stepwise change of irradiation temperature on pure copper, heavy ion irradiations under constant temperature and varying temperature conditions were performed. Specimens were irradiated up to 10dpa. In the temperature region of 473K ~ 673K, one-step temperature variation and periodic temperature variations were performed during irradiation. The resulting microstructures were compared with those induced by the irradiation at the constant temperature of 673K.

Use of Constant Temperature and Sodium Borohydride in the Trihydroxyindole Method for Catecholamines

1966 ◽  
Vol 12 (10) ◽  
pp. 659-669 ◽  
Author(s):  
Elizabeth Carlsen Gerst ◽  
Odd S Steinsland ◽  
William W Walcott
Keyword(s):  
Ascorbic Acid ◽  
Constant Temperature ◽  
Sodium Borohydride ◽  
Small Temperature ◽  
Temperature Variations ◽  
Stabilizing Agent ◽  
Fluorescent Analysis

Abstract Small temperature variations during fluorescent analysis with the trihydroxyindole method can introduce significant errors in the measurement of 15µg./L. or less of epinephrine or norepinephrine. To minimize temperature differences, we have devised a simple, constant-temperature system for the Farrand fluorometer. Decomposition of ascorbic acid prior to and during analysis also must be prevented. Sodium borchydride was found to be an effective stabilizing agent that contributes negligible fluorescence.These modifications minimize or eliminate much of the difficulty previously encountered in the use of the trihydroxyindole method.

Brief Morning Light Exposure, Visuomotor Performance, and Biochemistry in Sport Shooters

2016 ◽  
Vol 11 (6) ◽  
pp. 756-762
Author(s):  
Veronika Leichtfried ◽  
Friedrich Hanser ◽  
Andrea Griesmacher ◽  
Markus Canazei ◽  
Wolfgang Schobersberger
Keyword(s):  
Cognitive Performance ◽  
Physical Performance ◽  
Light Exposure ◽  
Bright Light ◽  
Early Morning ◽  
Dim Light ◽  
External Stimuli ◽  
The Impact ◽  
Related Measure ◽  
Visuomotor Performance

Context:Demands on concentrative and cognitive performance are high in sport shooting and vary in a circadian pattern, aroused by internal and external stimuli. The most prominent external stimulus is light. Bright light (BL) has been shown to have a certain impact on cognitive and physical performance.Purpose:To evaluate the impact of a single half hour of BL exposure in the morning hours on physical and cognitive performance in 15 sport shooters. In addition, courses of sulfateoxymelatonin (aMT6s), tryptophan (TRP), and kynurenine (KYN) were monitored.Methods:In a crossover design, 15 sport shooters were exposed to 30 min of BL and dim light (DL) in the early-morning hours. Shooting performance, balance, visuomotor performance, and courses of aMT6s, TRP, and KYN were evaluated.Results:Shooting performance was 365.4 (349.7–381.0) and 368.5 (353.9–383.1), identical in both light setups. Numbers of right reactions (sustained attention) and deviations from the horizontal plane (balance-related measure) were higher after BL. TRP concentrations decreased from 77.5 (73.5–81.4) to 66.9 (60.7–67.0) in the DL setup only.Conclusions:The 2 light conditions generated heterogeneous visuomotor and physiological effects in sport shooters. The authors therefore suggest that a single half hour of BL exposure is effective in improving cognitive aspects of performance, but not physical performance. Further research is needed to evaluate BL’s impact on biochemical parameters.

Near-Infrared Diffuse Reflectance Measurement Method Based on Temperature-Insensitive Radial Distance

2018 ◽  
Vol 72 (7) ◽  
pp. 1021-1028
Author(s):  
Minglei Wu ◽  
Rong Liu ◽  
Kexin Xu
Keyword(s):  
Constant Temperature ◽  
Glucose Concentration ◽  
Measurement Method ◽  
Diffuse Reflectance ◽  
Near Infrared ◽  
Radial Distance ◽  
Field Analysis ◽  
Detection Accuracy ◽  
Reflectance Measurement ◽  
Temperature Variations

The variation of temperature is one of the main interference factors that affect the detection accuracy of near-infrared (NIR) diffuse reflectance. In this paper, a measurement method based on temperature-insensitive radial distance was proposed, and its feasibility and effectiveness were verified in Intralipid solutions. First, the possibility of temperature-insensitive radial distance was deduced based on the analytic solution of the steady-state diffusion equation in an infinite media, and the temperature-insensitive radial distances of 3% Intralipid solution in the wavelength range of 1000–1600 nm was calculated. Second, a detection system was designed to measure the diffuse reflectance of 3% Intralipid solutions at multiple radial distances with different glucose concentration (0–100 mM) and different temperatures (35–40 ℃). Both theoretical calculations and experimental results demonstrated the existence of temperature-insensitive radial distances in the range of 1000–1340 nm and 1440–1600 nm, and the distances were hardly affected by glucose variations. Finally, the glucose information extracted from the diffuse reflectance of Intralipid solutions at different radial distances under random temperature variations and constant temperature were compared. The result showed that the correlation between the glucose concentration and the diffuse reflectance obtained at the temperature-insensitive radial distance was significantly better than that of other radial distances, which was almost close to the situation of constant temperature. Therefore, the measurement method based on temperature-insensitive radial distance can effectively reduce the influence of temperature variations on NIR diffuse reflectance, and it is expected to improve the accuracy of diffuse reflectance in human body components detection and industrial field analysis.

Elevated rectal temperature produced by all-night bright light is reversed by melatonin infusion in men

1991 ◽  
Vol 71 (6) ◽  
pp. 2178-2182 ◽  
Author(s):  
R. J. Strassman ◽  
C. R. Qualls ◽  
E. J. Lisansky ◽  
G. T. Peake
Keyword(s):  
Body Temperature ◽  
Sleep Deprivation ◽  
Rectal Temperature ◽  
Minimum Temperature ◽  
Core Body Temperature ◽  
Bright Light ◽  
Early Morning ◽  
Exogenous Melatonin ◽  
Dim Light ◽  
Light Sleep

Early morning rectal body temperature is lowest when melatonin levels are highest in humans. Although pharmacological doses of melatonin are hypothermic in humans, the relationship between endogenous melatonin and temperature level has not been investigated. We measured rectal body temperature in nine normal men whose melatonin levels were suppressed by all-night sleep deprivation in bright light and compared values with those seen in sleep in the dark, sleep deprivation in dim light (to control for the stimulatory effect of wakefulness on temperature), and sleep deprivation in bright light with an infusion of exogenous melatonin that replicated endogenous levels. Minimum rectal temperature, calculated from smoothed temperature data from 2300 to 0515 h, was greater in bright-light sleep deprivation, resulting in suppression of melatonin, than in conditions of sleep deprivation in dim light or sleep in the dark. An exogenous melatonin infusion in bright light returned the minimum temperature to that seen in dim-light sleep deprivation. A nonsignificant elevation in mean and minimum temperature was noted in all conditions of sleep deprivation relative to sleep. We conclude that melatonin secretion contributes to the lowering of core body temperature seen in the early morning in humans.

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