共查询到20条相似文献，搜索用时 15 毫秒
1.
Background
Very little is known about the perinatal genesis of circadian rhythmicity in the human fetus. Some researchers have found evidence of rhythmicity early on in fetal development, whereas others have observed a slow development of rhythmicity during several years after birth. 相似文献2.
Megan L Fritz Juan Huang Edward D Walker M Nabie Bayoh John Vulule James R Miller 《Journal of circadian rhythms》2008,6(1):2
Background
Anopheles gambiae s.s. Giles is a major malaria vector in Sub-Saharan Africa. Studies of the basic biology of this mosquito, including oviposition, provide a background for assessing which attributes might be exploited for suppressing A. gambiae populations. Here, we report on when during the diel cycle A. gambiae individuals deposit eggs as compared to the ovipositional patterns of groups. 相似文献3.
Harada T 《Journal of circadian rhythms》2004,2(1):4
Background
In a previous study, when adult subjects were exposed to a level of 400 lux light for more than 30 min or a level of 300 lux light for more than 2 hours, salivary melatonin concentration during the night dropped lower than when the subjects were exposed to dim illumination. It was suggested that such light exposure in adolescents or children during the first half of subjective night in normal life might decrease the melatonin level and prevent the falling into sleep. However, there has been no actual study on the effects of light exposure in adolescents. 相似文献4.
Esmot ara Begum Motoki Bonno Makoto Obata Hatsumi Yamamoto Masatoshi Kawai Yoshihiro Komada 《Journal of circadian rhythms》2006,4(1):11-7
Background
Biological rhythmicity, particularly circadian rhythmicity, is considered to be a key mechanism in the maintenance of physiological function. Very little is known, however, about biological rhythmicity pattern in preterm and term neonates in neonatal intensive care units (NICU). In this study, we investigated whether term and preterm neonates admitted to NICU exhibit biological rhythmicity during the neonatal period. 相似文献5.
Background
Changes in the survival-rate during the larval phase may strongly influence the recruitment level in marine fish species. During the larval phase different 'critical periods' are discussed, e.g. the hatching period and the first-feeding period. No such information was available for the Baltic cod stock, a commercially important stock showing reproduction failure during the last years. We calculated field-based mortality rates for larval Baltic cod during these phases using basin-wide abundance estimates from two consecutive surveys. Survey information was corrected by three dimensional hydrodynamic model runs. 相似文献6.
Background
There is accumulated evidence that plasma concentration of the sulfur-containing amino-acid homocysteine (Hcy) is a prognostic marker for cardiovascular morbidity and mortality. Both fasting levels of Hcy and post methionine loading levels are used as prognostic markers. The aim of the present study was to investigate the existence of a daily rhythm in plasma Hcy under strictly controlled nutritional and sleep-wake conditions. We also investigated if the time during which methionine loading is performed, i.e., morning or evening, had a different effect on the resultant plasma Hcy concentration. 相似文献7.
Background
This work describes the effect of a 48-h litter separation on 24-h patterns of plasma prolactin, FSH and LH concentration in female lactating rabbits kept under a 16:8 light-dark photoperiod (lights on at 0800 h). 相似文献8.
Background
We investigated the effects of energetic constraints on the breeding behaviour of male European treefrogs Hyla arborea and how calling males allocated additional energy supplied by feeding experiments. 相似文献9.
Background
Daylight saving time is widely adopted. Little is known about its influence on the daily rest-activity cycles. We decided to explore the effects of transition into daylight saving time on the circadian rhythm of activity. 相似文献10.
Background
The effects of lighting on the human circadian system are well-established. The recent discovery of 'non-visual' retinal receptors has confirmed an anatomical basis for the non-image forming, biological effects of light and has stimulated interest in the use of light to enhance wellbeing in the corporate setting. 相似文献11.
Hamdan H Al-Jahdali Haithm A Khogeer Waleed A Al-Qadhi Salim Baharoon Hani Tamim Fayez F Al-Hejaili Saeed M Al-Ghamdi Abdullah A Al-Sayyari 《Journal of circadian rhythms》2010,8(1):7
Background
Studies have shown that insomnia is a common sleep disorder among patients with end-stage renal disease (ESRD). This study aimed to assess the prevalence of insomnia in Saudi patients with ESRD who are on maintenance dialysis. 相似文献12.
Tatsushi Kimura Tsutomu Inamizu Kiyokazu Sekikawa Masayuki Kakehashi Kiyoshi Onari 《Journal of circadian rhythms》2009,7(1):7-6
Background
Numerous processes in the living body exhibit daily rhythmicity. In this study, we characterized a daily rhythm of blood fluidity and identified its determinants. 相似文献13.
Keny Vanlalhriatpuia Vanlalnghaka Chhakchhuak Satralkar K Moses SB Iyyer MS Kasture AJ Shivagaje Barnabas J Rajneesh Dilip S Joshi 《Journal of circadian rhythms》2007,5(1):1-11
Background
We recently reported that the altitude of origin altered the photic and thermal sensitivity of the circadian pacemaker controlling eclosion and oviposition rhythms of high altitude Himalayan strains of Drosophila ananassae. The present study was aimed at investigating the effects of altitude of origin on the pacemaker controlling the adult locomotor activity rhythm of D. helvetica. 相似文献14.
Katsutaka Oishi Naoki Ohkura Koji Kadota Manami Kasamatsu Kentaro Shibusawa Juzo Matsuda Kazuhiko Machida Shuichi Horie Norio Ishida 《Journal of circadian rhythms》2006,4(1):13-7
Background
Although the number of circulating immune cells is subject to high-amplitude circadian rhythms, the underlying mechanisms are not fully understood. 相似文献15.
Background
Changes in land surface phenology are of major importance to the understanding of the impact of recent and future climate changes in the Arctic. This paper presents an extensive study from Zackenberg Ecological Research Operations (ZERO) where snow melt, climate and growing season characteristics of six major high arctic vegetation types has been monitored during 1999 to 2005. We investigate the growth dynamics for dry, mesic and wet types using hand held measurements of far red normalised difference vegetation index (NDVI-FR) and generalized additive mixed models (GAMM). 相似文献16.
Ana I Esquifino Fernando Chacón Vanessa Jimenez Carlos F Reyes Toso Daniel P Cardinali 《Journal of circadian rhythms》2004,2(1):1
Background
This work analyzes the effect of social isolation (a mild stressor) on the 24-h variation of pituitary-testicular function in young Wistar rats, assessed by measuring circulating levels of prolactin, FSH, LH and testosterone. 相似文献17.
Giuseppe Piccione Augusto Foà Cristiano Bertolucci Giovanni Caola 《Journal of circadian rhythms》2006,4(1):16-4
Background
In domestic animals many biochemical and physiological processes exhibit daily rhythmicity. The aim of the present study was to investigate the rhythmic pattern of salivary and serum urea concentrations in sheep. 相似文献18.
Armin M Stroebel Matthias Bergner Udo Reulbach Teresa Biermann Teja W Groemer Ingo Klein Johannes Kornhuber 《Journal of circadian rhythms》2010,8(1):10
Background
Animals, including humans, exhibit a variety of biological rhythms. This article describes a method for the detection and simultaneous comparison of multiple nycthemeral rhythms. 相似文献19.
Background
The rapid expansion in the availability of genome and DNA sequence information has opened up new possibilities for the development of methods for detecting free-living protozoa in environmental samples. The protozoan Blepharisma japonicum was used to investigate a rapid and simple detection system based on polymerase chain reaction amplification (PCR) from organisms immobilised on FTA paper. 相似文献20.