| Records |
| Author |
Boivin, D.B.; Boudreau, P.; James, F.O.; Kin, N.M.K.N.Y. |
| Title |
Photic resetting in night-shift work: impact on nurses' sleep |
Type |
Journal Article |
| Year |
2012 |
Publication |
Chronobiology International |
Abbreviated Journal |
Chronobiol Int |
| Volume |
29 |
Issue |
5 |
Pages |
619-628 |
| Keywords |
Adaptation, Physiological; Adult; *Circadian Rhythm; *Darkness; Female; Humans; *Light; Male; Melatonin/metabolism; Middle Aged; *Nurses; Sleep/*physiology; Work Schedule Tolerance/*physiology |
| Abstract |
The objective of this study was to quantify daytime sleep in night-shift workers with and without an intervention designed to recover the normal relationship between the endogenous circadian pacemaker and the sleep/wake cycle. Workers of the treatment group received intermittent exposure to full-spectrum bright light during night shifts and wore dark goggles during the morning commute home. All workers maintained stable 8-h daytime sleep/darkness schedules. The authors found that workers of the treatment group had daytime sleep episodes that lasted 7.1 +/- .1 h (mean +/- SEM) versus 6.6 +/- .2 h for workers in the control group (p = .04). The increase in total sleep time co-occurred with a larger proportion of the melatonin secretory episode during daytime sleep in workers of the treatment group. The results of this study showed reestablishment of a phase angle that is comparable to that observed on a day-oriented schedule favors longer daytime sleep episodes in night-shift workers. (Author correspondence: diane.boivin@douglas.mcgill.ca ). |
| Address |
Centre for Study and Treatment of Circadian Rhythms, Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, Quebec, Canada. diane.boivin@douglas.mcgill.ca |
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English |
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| ISSN |
0742-0528 |
ISBN |
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| Notes |
PMID:22621359 |
Approved |
no |
| Call Number |
IDA @ john @ |
Serial |
144 |
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| Author |
Lowden, A.; Akerstedt, T. |
| Title |
Assessment of a new dynamic light regimen in a nuclear power control room without windows on quickly rotating shiftworkers--effects on health, wakefulness, and circadian alignment: a pilot study |
Type |
Journal Article |
| Year |
2012 |
Publication |
Chronobiology International |
Abbreviated Journal |
Chronobiol Int |
| Volume |
29 |
Issue |
5 |
Pages |
641-649 |
| Keywords |
Adaptation, Physiological; Adult; *Circadian Rhythm; Darkness/adverse effects; *Environment, Controlled; Female; Humans; *Light; Male; Melatonin/metabolism; Middle Aged; Photic Stimulation; Pilot Projects; Saliva/chemistry; Sleep/*physiology; *Wakefulness; *Work Schedule Tolerance |
| Abstract |
The aim of the study was to test whether a new dynamic light regime would improve alertness, sleep, and adaptation to rotating shiftwork. The illumination level in a control room without windows at a nuclear power station was ~200 lux (straight-forward horizontal gaze) using a weak yellow light of 200 lux, 3000 K (Philips Master TLD 36 W 830). New lighting equipment was installed in one area of the control room above the positions of the reactor operators. The new lights were shielded from the control group by a distance of >6 m, and the other operators worked at desks turned away from the new light. The new lights were designed to give three different light exposures: (i) white/blue strong light of 745 lux, 6000 K; (ii) weak yellow light of 650 lux, 4000 K; and (iii) yellow moderate light of 700 lux, 4000 K. In a crossover design, the normal and new light exposures were given during a sequence of three night shifts, two free days, two morning shifts, and one afternoon shift (NNN + MMA), with 7 wks between sessions. The operators consisted of two groups; seven reactor operators from seven work teams were at one time exposed to the new equipment and 16 other operators were used as controls. The study was conducted during winter with reduced opportunities of daylight exposure during work, after night work, or before morning work. Operators wore actigraphs, filled in a sleep/wake diary, including ratings of sleepiness on the Karolinska Sleepiness Scale (KSS) every 2 h, and provided saliva samples for analysis of melatonin at work (every 2nd h during one night shift and first 3 h during one morning shift). Results from the wake/sleep diary showed the new light treatment increased alertness during the 2nd night shift (interaction group x light x time, p < .01). Time of waking was delayed in the light condition after the 3rd night shift (group x light, p < .05), but the amount of wake time during the sleep span increased after the 2nd night shift (p < .05), also showing a tendency to affect sleep efficiency (p < .10). Effects on circadian phase were difficult to establish given the small sample size and infrequent sampling of saliva melatonin. Nonetheless, it seems that appropriate dynamic light in rooms without windows during the dark Nordic season may promote alertness, sleep, and better adaptation to quickly rotating shiftwork. |
| Address |
Stress Research Institute, Stockholm University, Stockholm, Sweden. arne.lowden@stress.su.se |
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English |
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| ISSN |
0742-0528 |
ISBN |
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| Notes |
PMID:22621361 |
Approved |
no |
| Call Number |
IDA @ john @ |
Serial |
148 |
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| Author |
Evans, J.A.; Elliott, J.A.; Gorman, M.R. |
| Title |
Dim nighttime illumination accelerates adjustment to timezone travel in an animal model |
Type |
Journal Article |
| Year |
2009 |
Publication |
Current Biology : CB |
Abbreviated Journal |
Curr Biol |
| Volume |
19 |
Issue |
4 |
Pages |
R156-7 |
| Keywords |
*Adaptation, Physiological; Animals; Behavior, Animal/physiology; Biological Clocks/*physiology; Circadian Rhythm/*physiology; Cricetinae; Humans; *Lighting; Mesocricetus; Mice; Motor Activity/physiology; Phodopus; *Photoperiod; Time Factors |
| Abstract |
Jetlag reflects a mismatch between local and circadian time following rapid timezone travel [1]. Appropriately timed bright light can shift human circadian rhythms but recovery is slow (e.g., 1-2 days per timezone). Most symptoms subside after resynchronization, but chronic jetlag may have enduring negative effects [2], including even accelerated mortality in mice [3]. Melatonin, prescription drugs, and/or exercise may help shift the clock but, like bright light, require complex schedules of application [1]. Thus, there is a need for more efficient and practical treatments for addressing jetlag. In contrast to bright daytime lighting, nighttime conditions have received scant attention. By incorporating more naturalistic nighttime lighting comparable in intensity to dim moonlight, we demonstrate that recovery after simulated jetlag is accelerated when nights are dimly lit rather than completely dark. |
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English |
Summary Language |
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Edition |
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0960-9822 |
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| Notes |
PMID:19243688 |
Approved |
no |
| Call Number |
IDA @ john @ |
Serial |
152 |
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| Author |
Dacke, M.; Nilsson, D.-E.; Scholtz, C.H.; Byrne, M.; Warrant, E.J. |
| Title |
Animal behaviour: insect orientation to polarized moonlight |
Type |
Journal Article |
| Year |
2003 |
Publication |
Nature |
Abbreviated Journal |
Nature |
| Volume |
424 |
Issue |
6944 |
Pages |
33 |
| Keywords |
Adaptation, Physiological/physiology; Animals; Beetles/*physiology; Feces; Feeding Behavior/physiology; *Light; Locomotion/*physiology; *Moon; Orientation/*physiology; Scarabaeus zambesianus |
| Abstract |
Moonlight, like sunlight, scatters when it strikes tiny particles in the atmosphere, giving rise to celestial polarization patterns. Here we show that an African dung beetle, Scarabaeus zambesianus, uses the polarization of a moonlit sky to orientate itself so that it can move along a straight line. Many creatures use the Sun's light-polarization pattern to orientate themselves, but S. zambesianus is the first animal known to use the million-times dimmer polarization of moonlight for this purpose. |
| Address |
Department of Cell and Organism Biology, University of Lund, 223 62 Lund, Sweden. marie.dacke@cob.lu.se |
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English |
Summary Language |
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Edition |
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| ISSN |
0028-0836 |
ISBN |
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Conference |
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| Notes |
PMID:12840748 |
Approved |
no |
| Call Number |
IDA @ john @ |
Serial |
242 |
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| Author |
Sasseville, A.; Benhaberou-Brun, D.; Fontaine, C.; Charon, M.-C.; Hebert, M. |
| Title |
Wearing blue-blockers in the morning could improve sleep of workers on a permanent night schedule: a pilot study |
Type |
Journal Article |
| Year |
2009 |
Publication |
Chronobiology International |
Abbreviated Journal |
Chronobiol Int |
| Volume |
26 |
Issue |
5 |
Pages |
913-925 |
| Keywords |
Adaptation, Physiological; Adult; Biological Clocks; Circadian Rhythm; Female; Humans; *Light; Male; Middle Aged; Photoperiod; Pilot Projects; Seasons; *Sleep; Wakefulness; *Work Schedule Tolerance; shift work; blue light; blue blocker; light therapy |
| Abstract |
Night shiftworkers often complain of disturbed sleep during the day. This could be partly caused by morning sunlight exposure during the commute home, which tends to maintain the circadian clock on a daytime rhythm. The circadian clock is most sensitive to the blue portion of the visible spectrum, so our aim was to determine if blocking short wavelengths of light below 540 nm could improve daytime sleep quality and nighttime vigilance of night shiftworkers. Eight permanent night shiftworkers (32-56 yrs of age) of Quebec City's Canada Post distribution center were evaluated during summertime, and twenty others (24-55 yrs of age) during fall and winter. Timing, efficacy, and fragmentation of daytime sleep were analyzed over four weeks by a wrist activity monitor, and subjective vigilance was additionally assessed at the end of the night shift in the fall-winter group. The first two weeks served as baseline and the remaining two as experimental weeks when workers had to wear blue-blockers glasses, either just before leaving the workplace at the end of their shift (summer group) or 2 h before the end of the night shift (fall-winter group). They all had to wear the glasses when outside during the day until 16:00 h. When wearing the glasses, workers slept, on average +/-SD, 32+/-29 and 34+/-60 more min/day, increased their sleep efficacy by 1.95+/-2.17% and 4.56+/-6.1%, and lowered their sleep fragmentation by 1.74+/-1.36% and 4.22+/-9.16% in the summer and fall-winter group, respectively. Subjective vigilance also generally improved on Fridays in the fall-winter group. Blue-blockers seem to improve daytime sleep of permanent night-shift workers. |
| Address |
Centre de Recherche Universite Laval Robert-Giffard/Department of Oto Rhino Laryngology and Ophtalmology, Universite Laval, Quebec, Canada |
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English |
Summary Language |
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Series Title |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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| ISSN |
0742-0528 |
ISBN |
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Medium |
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Expedition |
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Conference |
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| Notes |
PMID:19637050 |
Approved |
no |
| Call Number |
IDA @ john @ |
Serial |
295 |
| Permanent link to this record |
