Expression of circadian rhythmicity in Djungarian hamsters under constant light: Effects of light intensity and the circadian system's state

Sperm transfer and fertility of the gypsy moth, Lymantria dispar (L.), held as pupae under constant temperature and 24-h light, 24-h darkness, or a photoperiod of 16:8 (L:D) h were compared with males held in cyclic temperature and 24-h light, 24-h darkness, or a photoperiod of 16:8 (L:D) h. Constant temperature and constant light or darkness severely reduced its ability to transfer sperm. Males held under constant light were more severely affected than males held in darkness, but sperm transfer was not correlated with light intensity (between 80 and 3960 lux). Nearly all males held under constant light and most held under constant darkness were sterile or partially sterile. In either case, sterility was caused by poor sperm transfer. Females with a full complement of sperm were fertile regardless of holding condition of male pupae. The sterilizing effect of constant light or darkness was overridden by cyclic temperature of 28°C for 16 h and 22°C for 8 h. At a photoperiod of 16:8 h, pupae held in constant 28°C transferred less sperm than those held at 25°C. Pupae held at constant 30°C were sterile, but those held at 30°C for 16 h and 25°C for 8 h transferred similar quantities of sperm as males held at constant 28°C.

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Photosynthesis and Respiration by the Flag Leaf and Components of the Ear During Grain Development In Wheat

Australian Journal of Biological Sciences ◽

10.1071/bi9700245 ◽

1970 ◽

Vol 23 (2) ◽

pp. 245 ◽

Cited By ~ 105

Author(s):

LT Evans ◽

HM Rawson

Keyword(s):

Light Intensity ◽

Dark Respiration ◽

Flag Leaf ◽

Gas Analysis ◽

Constant Light ◽

Grain Development ◽

Flag Leaves ◽

Photosynthesis And Respiration

Rates of photosynthesis and dark respiration of the ears and flag leaves of three varieties of wheat grown at 21 DC under a constant light intensity of 3200 f.c. were measured by infrared gas analysis twice weekly throughout the period of grain development. Measurements were made on both the intact ears and the separated grains and ear structures, in air and in a mixture of nitrogen plus 320 p.p.m. C02. Dry weights of the grains, ears, and main stems were also determined.

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The influence of temperature and photoinitiator concentration on photoinitiated polymerization of diacrylate monomer

Open Chemistry ◽

10.2478/bf02475199 ◽

2005 ◽

Vol 3 (4) ◽

pp. 721-730 ◽

Cited By ~ 4

Author(s):

Lavinia Macarie ◽

Gheorghe Ilia

Keyword(s):

Light Intensity ◽

Tertiary Amine ◽

Thermal Polymerization ◽

Optimal Concentration ◽

Constant Light ◽

Influence Of Temperature ◽

Photoinitiated Polymerization ◽

Maximum Conversion ◽

Triethyl Amine ◽

Higher Temperature

AbstractThe behavior of p-methoxybenzoyldiphenylphosphine oxide, previously synthesized, as a photoinitiator for the polymerization of diacrylate monomer, in the presence of 3% (w/w) tertiary amine (triethyl amine) as synergist additive, was studied. The influence of temperature in the range 30–90°C at 3% (w/w) photoinitiator concentration and the influence of the photoinitiator concentration in the range 0.5–3.5% (w/w) at 30°C was investigated by differential scanning photocalorimetry (photo-DSC). In all experiments the photopolymerization was performed at constant light intensity (3 mW cm−2). The maximum conversion was obtained at temperature of 90°C at 3% (w/w) photoinitiator concentration and 3% (w/w) triethyl amine. The optimal concentration of photoinitiator to obtain maximum conversion was 3% (w/w), at 30°C. No thermal polymerization occurred at higher temperature.

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Regulation of melatonin-sensitivity and firing-rate rhythms of hamster suprachiasmatic nucleus neurons: constant light effects

Brain Research ◽

10.1016/0006-8993(93)90682-d ◽

1993 ◽

Vol 602 (2) ◽

pp. 191-199 ◽

Cited By ~ 26

Author(s):

Guang-Di Yu ◽

Benjamin Rusak ◽

Hugh D. Piggins

Keyword(s):

Firing Rate ◽

Suprachiasmatic Nucleus ◽

Constant Light ◽

Light Effects

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Mosquito circadian flight rhythms: differential effects of constant light

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1984.247.6.r960 ◽

1984 ◽

Vol 247 (6) ◽

pp. R960-R967 ◽

Cited By ~ 1

Author(s):

J. R. Clopton

Keyword(s):

Light Intensity ◽

Active Phase ◽

Flight Activity ◽

Constant Light ◽

Constant Darkness ◽

Circadian Pacemaker ◽

Differential Effects ◽

Activity Onset ◽

Culiseta Incidens ◽

Additional Assumptions

The flight activity of Culiseta incidens was automatically recorded in constant darkness and constant light after entrainment to light:dark 12:12 to determine the usefulness of a formal circadian pacemaker model in which the periods of two oscillators respond reciprocally to light intensity. Period at activity onset lengthened approximately 0.4 h from darkness to 0.1 lx, whereas period at offset shortened approximately 0.4 h. Thus within this range, the onset of the nocturnal active phase obeyed Aschoff's rule for nocturnal animals, and the offset (or onset of diurnal rest phase) obeyed the rule for diurnal animals. These data supported a model in which, as light intensity increases, the period of one oscillator (evening) increases while that of another (morning) decreases. This model, with additional assumptions, also provided a framework for mutually consistent explanations of other features among the data. These included long periods at 3.5 lx, short periods at 35 lx, a progressively earlier occurrence of inactivity with increasing light intensity, and a clear example of circa-bi-dian (approximately 2 days) rhythmicity.

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