Abstract：
:The frequency demultiplication hypothesis (FDH) posits that circannual rhythms are generated from circadian cycles by frequency transformation to the lower-frequency rhythm. To test the FDH, we determined the periods of the circannual body mass and estrous cycles of golden-mantled ground squirrels with circadian locomotor activity rhythms entrained to 23-, 24-, or 25-hr days (T-cycles). Circannual period length did not differ among squirrels entrained to the different T-cycles; intergroup ranges were 298-314 days and 303-312 days, respectively, for body mass and estrus. These results are not consistent with the FDH and suggest instead that separate mechanisms generate circadian and circannual rhythms. In ground squirrels the circannual system influences circadian organization, but a reciprocal influence of circadian on circannual rhythms has yet to be demonstrated.
journal_name
J Biol Rhythmsjournal_title
Journal of biological rhythmsauthors
Carmichael MS,Zucker Idoi
10.1177/074873048600100402subject
Has Abstractpub_date
1986-01-01 00:00:00pages
277-84issue
4eissn
0748-7304issn
1552-4531journal_volume
1pub_type
杂志文章abstract：:The hematologic system performs a number of essential functions, including oxygen transport, the execution of the immune response against tumor cells and invading pathogens, and hemostasis (blood clotting). These roles are performed by erythrocytes (red blood cells), leukocytes (white blood cells), and thrombocytes (p...
journal_title：Journal of biological rhythms
pub_type： 杂志文章,评审
doi：10.1177/0748730415592729
更新日期：2015-10-01 00:00:00
abstract：:The light preferences of fruit flies were tested by 2 different means. First, flies were allowed to choose between different illuminations, and their favorite resting, grooming, and feeding places were determined with an infrared-sensitive camera. Second, the activity levels of the animals during their main daily acti...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730407306198
更新日期：2007-10-01 00:00:00
abstract：:The large repertoire of circadian rhythms in diverse organisms depends on oscillating central clock genes, input pathways for entrainment, and output pathways for controlling rhythmic behaviors. Stress-activated p38 MAP Kinases (p38K), although sparsely investigated in this context, show circadian rhythmicity in mamma...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730414555183
更新日期：2014-12-01 00:00:00
abstract：:The Drosophila clock relies on transcriptional feedback loops that generate daily oscillations of the clock gene expression at mRNA and protein levels. In the evening, the CLOCK (CLK) and CYCLE (CYC) basic helix-loop-helix (bHLH) PAS-domain transcription factors activate the expression of the period (per) and timeless...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730407313817
更新日期：2008-04-01 00:00:00
abstract：:The safety and efficacy of chemotherapeutics can vary as a function of the time of their delivery during the day. This study aimed to improve the treatment of glioblastoma (GBM), the most common brain cancer, by testing whether the efficacy of the DNA alkylator temozolomide (TMZ) varies with the time of its administra...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730417696788
更新日期：2017-04-01 00:00:00
abstract：:The purpose of this study was to determine whether decreased day lengths affect reproduction or the immune system in inbred mice. Irrespective of a nocturnal pineal melatonin rise, the signal for day length information, body and testis weights were the same in various strains 8 weeks after transfer from long to short ...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873002129002348
更新日期：2002-02-01 00:00:00
abstract：:The synchronizing stimulus, its transduction site, and the afferent pathways responsible for feeding entrainment remain unknown. In fish, the role of the diet in the development of feeding anticipatory activity (FAA) is not well understood and fundamental questions on the mechanisms of feeding entrainment, such as the...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873040101600107
更新日期：2001-02-01 00:00:00
abstract：:A rhythm mutant of Drosophila melanogaster was induced by chemical mutagenesis and isolated by testing for locomotor activity rhythms, which in the new variant had periods of approximately 16 hr. The sex-linked mutation responsible for this ultrashort period causes 20-hr rhythms when heterozygous with a normal X. This...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873049400900303
更新日期：1994-01-01 00:00:00
abstract：:A role for nitric oxide in circadian responses to light has been indicated in previous studies. To determine the specific function of NO-, the authors manipulated NO- and nitric oxide synthase (NOS) activity prior to light pulses that would normally induce phase shifts. The NOS inhibitor, L-NAME, selectively attenuate...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873049701200404
更新日期：1997-08-01 00:00:00
abstract：:The aim of this study was to replicate and extend previous work in which the authors observed lower, shorter, and advanced nocturnal melatonin secretion patterns in premenstrually depressed patients compared to those in healthy control women. The authors also sought to test the hypothesis that the therapeutic effect o...
journal_title：Journal of biological rhythms
pub_type： 临床试验,杂志文章,随机对照试验
doi：10.1177/074873049701200107
更新日期：1997-02-01 00:00:00
abstract：:A 24-h treatment with the cytokine tumor necrosis factor-alpha (TNF-alpha) suppresses transcription of E-box-driven clock genes (D-site albumin promoter binding protein, Dbp; Tyrotroph embryonic factor, Tef ; Hepatic leukemia factor, Hlf; Period homolog to Drosophila 1/2/3, Per1, Per2, and Per3) by yet unknown molecul...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730409336579
更新日期：2009-08-01 00:00:00
abstract：:Photoperiod influences the distribution of sleep and waking and electroencephalogram (EEG) power density in the Djungarian hamster. In an experimental procedure combining short photoperiod (SP) and low ambient temperature, the light-dark difference in the amount of sleep was decreased, and the changes in slow-wave act...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873040001500508
更新日期：2000-10-01 00:00:00
abstract：:Drosophila littoralis is a latitudinally widespread European species of the Drosophila virilis group. The species has ample genetic variation in photoperiodism (adult diapause) and circadian rhythmicity (pupal eclosion rhythm), with adaptive latitudinal clines in both of them. The possible common genetic basis between...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730405283418
更新日期：2006-02-01 00:00:00
abstract：:Various aspects of mammalian endocrine physiology show a time-of-day variation with a period of 24 h, which represents an adaptation to the daily environmental fluctuations resulting from the rotation of the earth. These 24-h rhythms in hormone abundance and consequently hormone function may rely on rhythmic signals p...
journal_title：Journal of biological rhythms
pub_type： 杂志文章,评审
doi：10.1177/0748730415580881
更新日期：2015-08-01 00:00:00
abstract：:Perhaps the most observable of the many circadian oscillations that have been described in both vertebrate and invertebrate animals is the daily alterations in periods of rest and activity. Recent studies in the fruit fly Drosophila melanogaster suggest that these periods of inactivity are not simply rest but share ma...
journal_title：Journal of biological rhythms
pub_type： 杂志文章,评审
doi：10.1177/0748730402239672
更新日期：2003-02-01 00:00:00
abstract：:In vertebrates, reproductive output often increases with age. Unlike older birds, first-year photoperiodic birds lack experience with the reproductively stimulatory effects of long day lengths (photostimulation). We examined whether age-related differences in annual reproductive development could be partially attribut...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730412468087
更新日期：2013-02-01 00:00:00
abstract：:Most visual system functions, such as opsin gene expression, retinal neural transmission, light perception, and visual sensitivity, display robust day-night rhythms. The rhythms persist in constant lighting conditions, suggesting the involvement of endogenous circadian clocks. While the circadian pacemakers that contr...
journal_title：Journal of biological rhythms
pub_type： 杂志文章,评审
doi：10.1177/0748730419863917
更新日期：2019-10-01 00:00:00
abstract：:Transplantation of the fetal suprachiasmatic nucleus (SCN) in arrhythmic SCN-lesioned rats can reinstate circadian drinking rhythms in 40% to 50% of the cases. In the current article, it was investigated whether the failure in the other rats could be due to the absence of a circadian rhythm in the grafted SCN, using a...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873099129000416
更新日期：1999-02-01 00:00:00
abstract：:In isolated slices of hypothalamus, suprachiasmatic nucleus (SCN) neurons were recorded intracellularly. Blockade of Ca++ channels increased spike duration, eliminating an early component of the afterhyperpolarization (AHP) that followed evoked spikes. The duration and reversal potential of AHPs were, however, unaffec...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873049000500106
更新日期：1990-04-01 00:00:00
abstract：:Using quantitative autoradiography, 2-(125)I-melatonin binding was investigated throughout the light:dark cycle in the suprachiasmatic nuclei (SCN), paraventricular nuclei (PVT), and pars tuberalis (PT) of adult female Siberian hamsters kept for 10 weeks in either long or short photoperiods (LP or SP, respectively). P...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873049601100406
更新日期：1996-12-01 00:00:00
abstract：:Little is known about the differences in the neural substrates of circadian rhythms that are responsible for the maintenance of differences between diurnal and nocturnal patterns of activity in mammals. In both groups of animals, the suprachiasmatic nucleus (SCN) functions as the principal circadian pacemaker, and sur...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873099129000713
更新日期：1999-08-01 00:00:00
abstract：:The authors sought to investigate the role of phytochromes A and B (phyA and phyB) and cryptochromes 1 and 2 (cryl and cry2) in the synchronization of the leaf position rhythm in Arabidopsis thaliana. The seedlings were transferred from white light-dark cycles to free-running conditions with or without exposure to a l...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873001129002213
更新日期：2001-12-01 00:00:00
abstract：:Surgical isolation of the suprachiasmatic nuclei (SCN) within a hypothalamic island is reported to produce loss of circadian rhythmicity. The results have been interpreted to indicate that SCN efferents are necessary for the expression of circadian rhythms. It is not clear, however, whether the loss of circadian rhyth...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873049100600201
更新日期：1991-07-01 00:00:00
abstract：:Despite the omnipresence of artificial and natural light exposure, there exists little guidance in the United States and elsewhere on light exposure in terms of timing, intensity, spectrum, and other light characteristics known to affect human health, performance, and well-being; in parallel, there is little informati...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730418789506
更新日期：2018-10-01 00:00:00
abstract：:The mammalian circadian clock in the suprachiasmatic nucleus (SCN) drives and maintains 24-h physiological rhythms, the phases of which are set by the local environmental light-dark cycle. Gastrin-releasing peptide (GRP) communicates photic phase setting signals in the SCN by increasing neurophysiological activity of ...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730410396678
更新日期：2011-04-01 00:00:00
abstract：:The mammalian SCN contains a biological clock that drives remarkably precise circadian rhythms in vivo and in vitro. Recent advances have revealed molecular and cellular mechanisms required for the generation of these daily rhythms and their synchronization between SCN neurons and to the environmental light cycle. Thi...
journal_title：Journal of biological rhythms
pub_type： 杂志文章,评审
doi：10.1177/0748730404268786
更新日期：2004-10-01 00:00:00
abstract：:Groups of Syrian hamsters were exposed to LD cycles with twilight transitions and photoperiods simulating natural lighting conditions at the summer solstice (SS), equinox, and winter solstice (WS) at 41 degrees N and at the winter solstice at the Arctic Circle (WS 66 degrees N) but with daytime illuminance truncated a...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730404272907
更新日期：2005-04-01 00:00:00
abstract：:During the first 7 weeks of postnatal life, short day lengths inhibit the onset of puberty in many photoperiodic rodents, but not in Syrian hamsters. In this species, timing of puberty and fecundity are independent of the early postnatal photoperiod. Gestational day length affects postnatal reproductive development in...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730408322985
更新日期：2008-10-01 00:00:00
abstract：:The authors analyzed the upstream regulatory region of purF, a gene that is expressed in a minority phase that peaks at dawn (class 2 circadian phasing) in Synechococcus elongatus, to determine whether specific cis elements are responsible for this characteristic expression pattern. Fusions of various promoter-bearing...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730403262056
更新日期：2004-04-01 00:00:00
abstract：:While the rapid development of personal computers and high-throughput recording systems for circadian rhythms allow chronobiologists to produce huge amounts of data, the software to analyze them often lags behind. Here, we announce newly developed chronobiology software that is easy to use, compatible with many differ...
journal_title：Journal of biological rhythms
pub_type： 信件
doi：10.1177/0748730411414264
更新日期：2011-10-01 00:00:00
